vortech FAQ: read this before asking vortech questions
05-10-2007, 02:06 PM
#1
vortech FAQ: read this thread before asking vortech questions
I'm happy to answer PM's, but try to do your own research and search through past threads first.
Bear in mind I really don't know everything or have all the answers, especially from a mechanic or installation point of view.
I'm just listing out common answers to common questions about the vortech kits. I try to keep this thread updated with current info and findings, but I might not always be on top of every single new thing to come out or the latest thing someone tried on their car, especially the later vortech kits for the VQ35 REVUP engine since I don't have one.
- the vortech kit generally speaking is very reliable. There's been very few damaged engines with it, but some have fatally blown for various reasons. Usually those blown engines were not fatal and were often caused by abuse and/or driving it when it was running lean. Usually when damage occurs with a vortech, the piston rings get damaged or a crankshaft bearing spun. When that happens the engine still runs, but will have less power and possibly blow black smoke out the exhaust. For the 3 or so engines that broke a rod and had a catastrophic failure, there's been some question about the engine being abused before the vortech was installed on those cars. Personally, I wouldn't feel comfortable really pushing a really high whp vortech setup with only 91 octane gas or without water/meth injection.
- install is about as easy as it gets for a FI kit. It takes most people 8-12 hours. A lift is not needed, but of course helps. Usually people think the harness wiring for the engine management is the most difficult part.
- the full kit is fairly complete. It comes with everything you need to get up and running safely. For 400whp or less, it works just fine and is really all you'll need.
- the tuner kit should be considered if you're planning on going for more than 400whp or already have a decent engine management. The full kit will work ok up to 400whp but it's not ideal beyond that since the stock injectors will be near their max and could possibly fail leading to a blown engine. The tuner kit generally seems to sell for about $1700 less than the full kit. It doesn't come with engine management, a fuel system, injectors, or fuel pump.
- to save some money and have a more capable setup, many people buy the tuner kit, a 3rd party engine management, walbro fuel pump, 650 injectors, and leave the fuel system alone. It costs a little more than the full kit, but the setup works well for up to around 400whp and will save money in the long run for going beyond 400whp. Just make sure to use an engine management that can handle large injectors or get an ECU flash for the injectors (which works better than a piggyback)
- a return fuel system and upgraded fuel pump are generally recommended for going beyond 400whp no matter what
- With the full kit, the stock injectors are fine up to maybe 400whp at the most. Past that, 440cc are recommended. 380's will work ok and will be drastically better than the stock ones (which are 290cc), but 440's are generally what you want. If you plan to step up to the 2.87 pulley and make more than 420whp, then look into 550 injectors. 500's probably will be ok, but get 550's if possible. Some people have had trouble scaling 550 injectors with the SS box for whatever reason though, while some haven't. It's better to have injectors too big than too small unless your engine management can't handle it.
- I often recomend an ECU flash to scale your injectors and to raise your idle so the vortech spins fast enough to not rattle at idle. The car will idle and run smoother with an ECU flash than a typical piggyback engine management trying to scale the injectors. Altered Atmosphere, Technosquare, and GT Motorsports have good flashes. Cobb tuning's Access Port programmer is another option. A full standalone is always the best (and most expensive option), but piggybacks have proven to get the job done just fine in most cases
- tapping the oil pan is NOT a big deal and can be later welded back shut if need be. Many people get oil pan spacers and tap them or go with a larger oil pan that already has a tap. It's a good thing to have more oil anyway since the vortech will be sharing that oil. Use quality oil and try to replace it every 2000-3000 miles. Be sure to check the oil level every few weeks and add more if needed.
- IMO tapping the upper oil pan on the engine is probably the better way of tapping into oil with the vortech kit than using an oil pan or spacer with a tap. I don't think it's the hugest deal though if you use synthetic oil and wait for the car to warm up before running it hard. There is less backpressure with vortech's method of tapping into the upper oil pan vs tapping into the lower oil pan, but I haven't had any issues yet with my lower pan tapped.
- the rev up engine has a MUCH better stock belt design than the non-REVUP kit. The REVUP kits come with different pulley diameters than the original VQ35 kit. They actually come with the 3.12 pulley as the stock pulley, but have different sized cog pulleys to reduce its effectiveness since the kit is designed to spin the blower up to 7000 rpms. Bear in mind I'll mainly be referring to the non-revup kits as far as pulley sizes go because that's what I have experience with
- For the non-REVUP kits, the 3.12 pulley adds about 25whp more than the stock 3.33 pulley while the 2.87 pulley adds about 30whp more than the 3.12. There's also another step up you can do with changing the cog pulley that drives the 2nd smaller belt attached to the vortech. Changing it to a 34 tooth pulley can possibly give you more power too, however some people experienced a power loss with the 2.87+34/28 cog setup. IMO the stock 3.33 pulley isn't very impressive. The stock pulley for most people feels like it's doing too little, too late. Upgrading the pulley(s) brings the boost on sooner and gives you more of it, making the car much more exciting to drive. IMO a basic Stillen supercharger is going to be a much more exciting setup to drive compared to the stock pulley. Bear in mind that as you go to smaller pulleys, your fuel requirements increase
- With more boost, there's a higher possibility of the belt slipping. There's been a few things that can be done to address that. One thing that many people have done and are happy with is a design by TIMROD1011 https://my350z.com/forum/forced-induction/94422-vortech-belt-slip-noise-solution.html
I posted some additional details about part numbers later in my old thread https://my350z.com/forum/showthread....179616&page=14
GT Motorsports also has an additional idler pulley to help prevent belt slip
- the vortech can make a "broken sound" at idle. It normally makes a clunky, rattle where something just sounds broken on the car. To solve that, you might try increasing your idle rpms up to at least 900 rpms. Going to a smaller pulley also helps because they spin the blower faster, even while at idle. A dealer can increase the idle on earlier model cars. There's other ways too like ECU flashes, AAM's Cipher tool, some shops carry Consult II's which is what dealers use, some aftermarket engine managements can raise the idle. Some people have drilled a tiny 1/8 inch hole in their throttlebody which generally isn't recommended because it's permanent and an expensive part.
- the vortech sounds like a jet engine and is especially noticeable at idle and parking lot speeds. When driving normal, you really don't hear it as much and especially from inside the car. When going WOT, you can hear it but your exhaust will probably be louder
- The stock tune on the SS box is ok and generally pretty safe for a stock car or with minor breathing mods, but there's room for improvement - usually 20whp at least
- If you upgrade the pulley, GET THE CAR TUNED! - it's incredibly important if you want your engine to even have a hope of lasting
- as you add higher flowing exhaust/headers/cats or test pipes/cams/plenum/etc the boost pressure will go down but power will go up. You're mainly interested in power/torque, not the psi number. IMO a lower psi is healthier on the engine than really high psi. As you add higher flowing parts, that changes the powerband to reduce low end power while increasing high rpm power.
- headers help the vortech breath better and help make your intake manifold work more efficiently. Get the headers HPC or jet-hot coated if possible because it makes a big difference. Also get a stainless steel clutch line for you 6MT people with headers or you'll boil your clutch fluid when driving hard or in rush hour when it's hot outside
-if you're looking for tons of torque or the most power you can possibly get, you might consider a turbo instead of the vortech.
- the vortech's boost increases as rpms rise. This means your torque will never be as high as your hp. The torque curve will be almost flat though
- if your goal is to reach 400whp, there's lots of ways for the vortech to reach it. All the normal NA breathing parts plus an upgraded vortech pulley will get you there. You have to look at your budget and buy the parts you're ok with changing. Generally, cams and headers are quite expensive so you might do the other parts first.
- Starting off by jumping to a more aggressive pulley will void the vortech warranty of the full kit. Vortech does not do quality checks on their kits before mailing them out so there's always a chance you might get a bad blower from the start
You might consider keeping the stock pulley on at first if you bought the full kit to make sure the blower and everything on the kit is working correctly. If you bought the tuner kit and have a good enough fuel system for one, IMO I'd just jump straight to the next size smaller pulley from the start.
Last edited by sentry65; 05-06-2009 at 10:51 AM.
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Noor93y (11-06-2015)
05-10-2007, 02:37 PM
#2
- the vortech tuner kit has a 1 year warranty that basically covers the individual parts, unlike the 3 year warranty that the regular full kit has. More warranty specifics can be read here:
http://www.vortechsuperchargers.com/...s/warranty.pdf
- the complete vortech install manual is on vortech's site here:
http://www.vortechsuperchargers.com/...s/4NZ218im.pdf
- the vortech is one of the easiest kits to install and usually takes around 8-12 hours from start to end. For people with the full kit, doing the wiring with the SS box is generally considered the hardest part. Some people have bought auxiliary harnesses so they don't have to do the wiring while down in the passenger seat floor
- gas mileage seems to vary with different people. IMO it's fairly close to stock. I'd actually say on my car I probably lost a slight bit of mileage. Some people claim the vortech improved their mileage by 4 mpg. Everyone's setup is different, it might have to do with the size of injectors and pulley size. Either way it's still much better gas mileage than a viper or Ford GT
- as far as how the vortech sounds, here's some videos that I know of off hand
http://videos.streetfire.net/video/3...9500d2b4bf.htm
http://www.youtube.com/profile?user=onelaststop (my car)
http://videos.streetfire.net/search/...0vortech/0.htm
- you will want 1 step colder spark plugs. The plugs I recommend are:
NGK part # LFR6A-11 for copper plugs
or
NGK part # NGKLFR6A-11 for iridium plugs
- gauges are always recommended. IMO A/F, boost, and oil temp are the most critical for the vortech in being able to monitor what's going on with the kit. G35's don't have oil pressure gauges, which is an important one too, but not as much if you check your oil regularly
- I recommend an oil cooler with thermostat since that oil is doing double duty cooling an engine and the supercharger. You don't really need a huge oil cooler though. A small one is fine and will lower oil temps about 20-25 degrees. It doesn't have as much oil heat to deal with compared to a turbo kit, so the cooler doesn't need to be as large unless if you really track the car hard
- I recommend getting an oil catch can and get a checkvalve installed with it. It'll save you the hassle of having to clean oil from the inside of the piping and intercooler should you get some oil blow-by. It'll also prevent oil from going back into the piston chamber which can possibly cause preignition or detonation. IMO it's money well spent and not all that expensive in the whole scheme of things
- another recommended option is water/meth injection. It can really help raise the engine's threshold against detonation, cool the engine, clean it, and help it last longer. Methanol is very cheap and you put some in mixed with 50% distilled water every couple weeks. Methanol is 107-113 octane depending on the type
- higher octane unleaded race gas is always recommended too if you want even more of a safety net against detonation. You can usually find race gas locally from a dealer or at certain gas stations, or buy it in drums online
- if you want to upgrade the radiator, the koyo 36mm radator is compatible with the vortech, while the larger koyo one isn't but you can probably get it to work if you cut into the fan shroud and fans a lot. It'll be a tight fit because of one of vortech intake pipes being in the way
- yes the vortech is CARB legal, the full kit anyway
- if you change the pulley or fuel system to something other than what comes with the full vortech kit, then no that's technically not CARB legal at that point, and you will get caught during CA inspection unless you hide things really well. I think a fuel pressure regulator from a return kit is usually the dead give-away that raises red flags at inspections.
- For more performance, I recommend the 3.7 or 3.9 final drive for 6MT people and the 3.5 for 5AT people. But only if you get a serious tire setup for traction. As you go up in power, traction becomes harder to get, so you'll have to balance power and gearing with how much traction you can muster up from tires, wheel alignment, LSD, etc. The more aggressive gearing gets you up into the high rpms faster and generally makes you drive the car at higher rpms than the stock gearing. Your gas mileage will take a hit but that's what a prius is for
- you can get by using the stock clutch with the vortech because the vortech doesn't generate massive amounts of peak midrange torque for the clutch to have to hold. IMO a light flywheel is awesome with the vortech because that helps you get up into the high rpm powerband faster. On a side note, having the idle set around 900 rpms or higher also kills any "rocks in a can" noise that light clutch/flywheels make as well as make the car easier to drive since you have more rpms to cushion you before stalling
-for 5AT people, valvebody and torque converter upgrades are always recommended but not required. A lot of people get by on the stock auto transmission just fine with sometimes up to 400tq, but it seems to vary from car to car. Often people have to use manual mode and shift at 400-600 rpms before reaching redline in order to shift in time at redline.
- the vortech makes most of its power at high rpms, but does add a little bit of power down low too. For instance at 2500 you will gain 20-40 tq depending on your breathing mods and vortech pulley. The vortech feels like it really kicks in around 5000 rpms with the stock pulley, 4500 rpms with the 3.12 pulley, and around 4000 rpms with the 2.87 pulley (for non-REVUP kits). When you want to feel pushed back in your seat, just downshift. It's a smooth acceleration and easy to control. People have compared its torque powerband to a Ferrari F430 and Porsche GT3.
- the 350Z and G35 vortech kits are a little different. Some custom fabbing of the piping has to be done to make one fit in the other type of car
- You should not be afraid to tighten the belt every so often - which isn't very often with a good belt. You or your mechanic can do it real quick when changing fluids etc. Belts do stretch some when they're new for the first 500-600 miles and have to be tightened about 2 times during that break in time, but you're usually good to go after that.
- you tighten the main drive belt the same as you would on with the normal belt tensioner pulley. You remove the plastic undertray, untighten the bolt holding the pulley on, then there's a vertical bolt that as you turn it, it actually tilts the tensioner pulley one way or the other which tightens or loosens the belt
- When you start up the car, and you hear a screech, that means the belt is a little loose. Tighten it until it stops doing it at startup, but not too tight or you'll wear out your bearings which cost $15-120. The belt does tighten some as the belt warms up so you need to find a happy medium between being loose and tight. My belt sometimes will make a quick 1 second screech when I start it up in the morning, but doesn't screech at startup when the car is already warm. Depending on how cold it is during the winter, you might want to tighten the belt slightly more.
- Use a GATES or Bando belt to help prevent slipping. They're heavier duty belts that are less prone to slip. Usually you can buy GATES belts at a local parts store like NAPA or CarQuest. They're anywhere from $30-55 depending on what deal you can get. Often times dealers have their logo on them, even though they were actually made by GATES or Bando. All you need to know is the length you want and that they're for 6 rib pulleys. The vortech comes with a Goodyear/Gatorback belt which is ok, but will stretch and slip more often
- For the original non-REVUP kit, you want a 93.5 inch belt for the stock 3.33 pulley and you want a 93 inch belt for the 3.12 or 2.87 pulley, though some people have have better luck with slightly smaller belts like 92 and 7/8 inches for the 3.12 or 2.87 pulley. If you try modifying the belt routing like TIMROD1011's design, you'll have to use slightly different belt lengths. I don't remember the belt lengths for the REVUP and new non-REVUP kits...
- the vortech has a "bypass valve" not a "blow off valve" but people call it a BOV anyway. Yes it's pretty loud when you shift under boost. And yes it's open pretty much all the time when you're not going WOT which is a lot of what makes the vortech sound like a jet as you drive down the street. It's the air escaping through the bypass valve to prevent compressor surge and damage from happening to the blower
- generally you want the bypass valve to show about 6-7 threads where you adjust it, but you can adjust it on a per-case basis if it doesn't seem to be opening/closing quite right
- the 2.87 pulley is "safe" on the stock engine, but only if you've really set things up right with a proper fuel system, good cooling, and a good tune. Anytime you add more boost you're lowering the threshold of safety
- attached is an arbitrary dyno chart to show the difference between the stock 3.33 pulley and 2.87 pulley. The 3.12 would be somewhere in between them. Mainly pay attention to the shape of the torque curves. The tq curve should be reasonably flat from mid to high rpms. I'm not including actual dyno numbers for the sake of avoiding debates on dynos and mods. Generally there's a 50-55whp and 50 tq difference between the 3.33 and 2.87 pulley.
http://www.vortechsuperchargers.com/...s/warranty.pdf
- the complete vortech install manual is on vortech's site here:
http://www.vortechsuperchargers.com/...s/4NZ218im.pdf
- the vortech is one of the easiest kits to install and usually takes around 8-12 hours from start to end. For people with the full kit, doing the wiring with the SS box is generally considered the hardest part. Some people have bought auxiliary harnesses so they don't have to do the wiring while down in the passenger seat floor
- gas mileage seems to vary with different people. IMO it's fairly close to stock. I'd actually say on my car I probably lost a slight bit of mileage. Some people claim the vortech improved their mileage by 4 mpg. Everyone's setup is different, it might have to do with the size of injectors and pulley size. Either way it's still much better gas mileage than a viper or Ford GT
- as far as how the vortech sounds, here's some videos that I know of off hand
http://videos.streetfire.net/video/3...9500d2b4bf.htm
http://www.youtube.com/profile?user=onelaststop (my car)
http://videos.streetfire.net/search/...0vortech/0.htm
- you will want 1 step colder spark plugs. The plugs I recommend are:
NGK part # LFR6A-11 for copper plugs
or
NGK part # NGKLFR6A-11 for iridium plugs
- gauges are always recommended. IMO A/F, boost, and oil temp are the most critical for the vortech in being able to monitor what's going on with the kit. G35's don't have oil pressure gauges, which is an important one too, but not as much if you check your oil regularly
- I recommend an oil cooler with thermostat since that oil is doing double duty cooling an engine and the supercharger. You don't really need a huge oil cooler though. A small one is fine and will lower oil temps about 20-25 degrees. It doesn't have as much oil heat to deal with compared to a turbo kit, so the cooler doesn't need to be as large unless if you really track the car hard
- I recommend getting an oil catch can and get a checkvalve installed with it. It'll save you the hassle of having to clean oil from the inside of the piping and intercooler should you get some oil blow-by. It'll also prevent oil from going back into the piston chamber which can possibly cause preignition or detonation. IMO it's money well spent and not all that expensive in the whole scheme of things
- another recommended option is water/meth injection. It can really help raise the engine's threshold against detonation, cool the engine, clean it, and help it last longer. Methanol is very cheap and you put some in mixed with 50% distilled water every couple weeks. Methanol is 107-113 octane depending on the type
- higher octane unleaded race gas is always recommended too if you want even more of a safety net against detonation. You can usually find race gas locally from a dealer or at certain gas stations, or buy it in drums online
- if you want to upgrade the radiator, the koyo 36mm radator is compatible with the vortech, while the larger koyo one isn't but you can probably get it to work if you cut into the fan shroud and fans a lot. It'll be a tight fit because of one of vortech intake pipes being in the way
- yes the vortech is CARB legal, the full kit anyway
- if you change the pulley or fuel system to something other than what comes with the full vortech kit, then no that's technically not CARB legal at that point, and you will get caught during CA inspection unless you hide things really well. I think a fuel pressure regulator from a return kit is usually the dead give-away that raises red flags at inspections.
- For more performance, I recommend the 3.7 or 3.9 final drive for 6MT people and the 3.5 for 5AT people. But only if you get a serious tire setup for traction. As you go up in power, traction becomes harder to get, so you'll have to balance power and gearing with how much traction you can muster up from tires, wheel alignment, LSD, etc. The more aggressive gearing gets you up into the high rpms faster and generally makes you drive the car at higher rpms than the stock gearing. Your gas mileage will take a hit
but that's what a prius is for- you can get by using the stock clutch with the vortech because the vortech doesn't generate massive amounts of peak midrange torque for the clutch to have to hold. IMO a light flywheel is awesome with the vortech because that helps you get up into the high rpm powerband faster. On a side note, having the idle set around 900 rpms or higher also kills any "rocks in a can" noise that light clutch/flywheels make as well as make the car easier to drive since you have more rpms to cushion you before stalling
-for 5AT people, valvebody and torque converter upgrades are always recommended but not required. A lot of people get by on the stock auto transmission just fine with sometimes up to 400tq, but it seems to vary from car to car. Often people have to use manual mode and shift at 400-600 rpms before reaching redline in order to shift in time at redline.
- the vortech makes most of its power at high rpms, but does add a little bit of power down low too. For instance at 2500 you will gain 20-40 tq depending on your breathing mods and vortech pulley. The vortech feels like it really kicks in around 5000 rpms with the stock pulley, 4500 rpms with the 3.12 pulley, and around 4000 rpms with the 2.87 pulley (for non-REVUP kits). When you want to feel pushed back in your seat, just downshift. It's a smooth acceleration and easy to control. People have compared its torque powerband to a Ferrari F430 and Porsche GT3.
- the 350Z and G35 vortech kits are a little different. Some custom fabbing of the piping has to be done to make one fit in the other type of car
- You should not be afraid to tighten the belt every so often - which isn't very often with a good belt. You or your mechanic can do it real quick when changing fluids etc. Belts do stretch some when they're new for the first 500-600 miles and have to be tightened about 2 times during that break in time, but you're usually good to go after that.
- you tighten the main drive belt the same as you would on with the normal belt tensioner pulley. You remove the plastic undertray, untighten the bolt holding the pulley on, then there's a vertical bolt that as you turn it, it actually tilts the tensioner pulley one way or the other which tightens or loosens the belt
- When you start up the car, and you hear a screech, that means the belt is a little loose. Tighten it until it stops doing it at startup, but not too tight or you'll wear out your bearings which cost $15-120. The belt does tighten some as the belt warms up so you need to find a happy medium between being loose and tight. My belt sometimes will make a quick 1 second screech when I start it up in the morning, but doesn't screech at startup when the car is already warm. Depending on how cold it is during the winter, you might want to tighten the belt slightly more.
- Use a GATES or Bando belt to help prevent slipping. They're heavier duty belts that are less prone to slip. Usually you can buy GATES belts at a local parts store like NAPA or CarQuest. They're anywhere from $30-55 depending on what deal you can get. Often times dealers have their logo on them, even though they were actually made by GATES or Bando. All you need to know is the length you want and that they're for 6 rib pulleys. The vortech comes with a Goodyear/Gatorback belt which is ok, but will stretch and slip more often
- For the original non-REVUP kit, you want a 93.5 inch belt for the stock 3.33 pulley and you want a 93 inch belt for the 3.12 or 2.87 pulley, though some people have have better luck with slightly smaller belts like 92 and 7/8 inches for the 3.12 or 2.87 pulley. If you try modifying the belt routing like TIMROD1011's design, you'll have to use slightly different belt lengths. I don't remember the belt lengths for the REVUP and new non-REVUP kits...
- the vortech has a "bypass valve" not a "blow off valve" but people call it a BOV anyway. Yes it's pretty loud when you shift under boost. And yes it's open pretty much all the time when you're not going WOT which is a lot of what makes the vortech sound like a jet as you drive down the street. It's the air escaping through the bypass valve to prevent compressor surge and damage from happening to the blower
- generally you want the bypass valve to show about 6-7 threads where you adjust it, but you can adjust it on a per-case basis if it doesn't seem to be opening/closing quite right
- the 2.87 pulley is "safe" on the stock engine, but only if you've really set things up right with a proper fuel system, good cooling, and a good tune. Anytime you add more boost you're lowering the threshold of safety
- attached is an arbitrary dyno chart to show the difference between the stock 3.33 pulley and 2.87 pulley. The 3.12 would be somewhere in between them. Mainly pay attention to the shape of the torque curves. The tq curve should be reasonably flat from mid to high rpms. I'm not including actual dyno numbers for the sake of avoiding debates on dynos and mods. Generally there's a 50-55whp and 50 tq difference between the 3.33 and 2.87 pulley.
Last edited by sentry65; 07-19-2008 at 08:22 AM.
The following users liked this post:
Noor93y (11-06-2015)
05-10-2007, 03:23 PM
#3
- the polished kit version only polishes the blower and the two visible pipes before and after the MAF housing. Is the bling worth $250 difference to you? Some people claim the satin finish grips the coupler bands slightly better since it's rougher. The clamps should be tight enough that it shouldn't really matter
- For engine management, I recommend the one that has the features you want and that your tuner is comfortable with. The SS box is fairly simple and basic and gets the job done, but it does have limitations. It can only do adjustments in 500 rpm increments, and maxes out at 16 psi. It is a piggyback and thus makes its adjustments based off of what the stock ECU is doing
- To safely get to a shop if you install the vortech yourself, you can either just not put on the rear cog belt so the blower doesn't turn and the car will drive NA. You can also just leave the stock belt on and not drive any of the vortech pulleys. Just don't go into positive boost on the drive there. Either way, go easy on the throttle until you're tuned
- The below picture shows where the upper cog Pulley is. It has teeth just like a traditional gear
- The non-REVUP kit has two cog pulleys. The top has 32 teeth and the bottom has 28 teeth. Often, people will switch to a 34/28 cog setup for more boost.
- The REVUP kit comes with 34 and 32 tooth cog pulleys. For this kit, people often switch to a 32/28 cog setup for more boost.
original Vortech belt layout for non-REVUP engines:
see attachments below for:
- revised stock non-REVUP engine layout with shorter belt
- modified belt layouts
- stock REVUP engine layout
see post #17 attachment for what's probably the "best" serpentine belt layout
- the vortech is not yet available for 07+ VQHR engines
this picture shows the right and wrong way to install the tensioner bolt for the cog belt (not to be confused with the stock tensioner pulley for the main belt)
- you do NOT want to use an underdrive pulley with the vortech or you'll lose boost. You want the diameter of the crank pulley to be stock (5.75"). I don't think the other accessory pulleys matter like in the case of the accessory UR pulleys
- the vortech puts a greater strain on the battery when starting the car. So those lightweight small racing batteries really won't cut it usually. You can maybe get one good start up, but if if the car doesn't start up in the first few seconds, the lightweight battery won't have enough juice left to start the car the 2nd try - trust me, I know. Relocating the battery is the next best option IMO. If you track your car, check with your track regulations before relocating it because they might be picky about having an external cut off switch.
- the vortech blower does not run as hot as a turbo which might benefit people in really hot climates. You can even place your hand flat on the blower after a minute after dynoing the car for an hour and not burn your hand
- no the vortech does not overboost or have boost surge problems. It's really not even possible since the belt drives the blower
- if you're on the fence between getting a full vortech kit and the tuner kit and have the extra money, IMO go ahead and get a vortech tuner kit, 650cc injectors, walbro fuel pump, an aftermarket engine management like UTEC, and leave the rest of the stock fuel system in place. It's a safer and a more upgradable setup (though more install time). Not to say the full kit isn't good because it'll be just fine for most people up to 380-400whp. But the tuner kit route is generally considered safer and capable of giving you a better tune than the SS box. It will cost slightly more and won't have the 3 year warranty the full kit has (if the full kit was kept completely or near stock)
- If you wanted to, you can change the vortech's bypass valve to something else, but everyone is going to be asking you why? Because generally they hold up pretty well and most people are really happy with the sound. It's possible to put some extra ducting on the bypass valve to quiet it down. You might even try recirculating the air back into the intake.
- for people concerned about being fully CARB legal and safe, you can have a vortech, exhaust, and tune and probably make 360-370whp and 290 tq on the stock pulley. You can try going to the 3.12 pulley and try pushing the stock vortech fuel system to get more power. The inspectors might not notice you have the 3.12 pulley since they almost look the same as the 3.33 but you never know. It's fairly easy to switch back to the stock 3.33 pulley anyway to pass CA inspection
- the vortech will generally have somewhat higher intake air temps than a turbo kit. I think it's usually around a 10-15 degree difference depending on the turbo kit. The vortech intercooler isn't huge and works fine for moderate power levels. If you want lower intake temps, look into water/meth injection and/or intercooler sprayers. I'd avoid using a larger intercooler until you really need it and are flowing way more air than a standard setup.
- the vortech, and all superchargers are more sensitive to ambient temp changes than turbo setups are in terms of the power they make. It sucks during the hot summer when the power and boost aren't as high. But in some ways you might consider that to be somewhat of a safety feature. Turbo setups can make up for the difference in power because of the wastegate makes sure the boost stays high, and lets more of the hot outside air into the engine. That can be harder on the engine because it's more forceful to constantly maintain a set boost psi
- for the vortech or any FI kit, if you've been abusing your car before going FI by doing things like going past the stock redline a lot or running huge shots of nitrous - if you then blow the engine with the vortech or whatever FI kit, you can't really blame the FI kit. Use some common sense. The vortech isn't going to magically keep your engine safe if you've previously abused it
- the vortech feels absolutely like an NA engine in how it reacts to what the throttle pedal is doing. When you dyno a vortech car, it doesn't matter what gear you're in, the power/tq/boost curve will be identical each time no matter what rpms or gear you dyno in. This is different from a turbo setup where a 5th gear run on a load based dyno starting at 2000 rpms will look dramaticallybetter than a dyno that started at 3300 rpms on a non-load based dyno in 4th gear. The vortech will always be consistent and positive boost is immediately available regardless of rpms, gear, or load. How much boost is immediately available depends on the rpms you're at. The vortech doesn't have lag because positive boost is always available, but because it's a centrifugal design, it's going to take longer to go from low boost to high boost
- how does it compare to the ATI procharger?
The procharger makes more power out of the box. It doesn't reduce timing which is probably a large reason for all the extra power (and danger). The ATI is noisier than the vortech because it uses gears directly turning gears instead of a cog belt turning the gears to drive the actual blower and also spins up to 80k rpms which is much faster than the 45-55k or so the vortech spins at. The ATI has a smaller impeller which is why it can spin higher. The procharger has a full cog belt setup and so it doesn't slip much, but has problems with belts breaking once you start getting over 400whp. Some people claim the bracket assembly on the ATI bends with lots of power. In contrast to the vortech, the ATI has it's own oil that you change seperately from the engine oil. This means you have to change the oil in two places and they way you have to change the ATI's oil isn't fun
- how does the vortech compare to the stillen?
the stillen is a roots blower and is all about low rpm power. IMO a stillen is going to be better than a bone stock vortech, but once you go up to the 2.87 pulley, the stillen's advantage down low really starts shrinking - especially if you went with shorter gearing with the vortech. The stillen's midrange and top end doesn't have near the potential as the vortech, but it will be better under 3000 rpms in most cases except the most severely modded vortech setups.
- how does/did the vortech compare to the original HKS supercharger?
Not much is known about HKS's new version of their supercharger kit, but it seems similar to the old version where it's sort of a hybrid between the vortech and stillen. It has better low end response than the vortech at the expense of worse high rpm power.
- the vortech has the capability of being possibly louder than a turbo car because it doesn't have 1 or 2 turbos acting as mufflers in the exhaust. Test pipes with a vortech are going to be LOUD as hell while they might be tolerable with a turbo or two to mute the sound a little
- when you wear out a bearing, it makes a kinda humming vibration sound. BeerViper has posted a video of his jackshaft bearings gone bad on streefire.net and has a few threads about it. It's not good to drive the car when the bearings are bad. They can seize and the belt can possibly get messed up and cause damage. The jackshaft bearing part numbers are 7S250-200.
- A vortech Z/G makes a pretty decent daily driver, but I always recommend you have a back-up or daily driver car anyway. It makes life so much less stressful because stuff WILL go wrong on occasion no matter what FI kit you have. You never know how long it'll take to get a replacement part shipped in.
- continued on post #17 in this thread...
.
- For engine management, I recommend the one that has the features you want and that your tuner is comfortable with. The SS box is fairly simple and basic and gets the job done, but it does have limitations. It can only do adjustments in 500 rpm increments, and maxes out at 16 psi. It is a piggyback and thus makes its adjustments based off of what the stock ECU is doing
- To safely get to a shop if you install the vortech yourself, you can either just not put on the rear cog belt so the blower doesn't turn and the car will drive NA. You can also just leave the stock belt on and not drive any of the vortech pulleys. Just don't go into positive boost on the drive there. Either way, go easy on the throttle until you're tuned
- The below picture shows where the upper cog Pulley is. It has teeth just like a traditional gear
- The non-REVUP kit has two cog pulleys. The top has 32 teeth and the bottom has 28 teeth. Often, people will switch to a 34/28 cog setup for more boost.
- The REVUP kit comes with 34 and 32 tooth cog pulleys. For this kit, people often switch to a 32/28 cog setup for more boost.
original Vortech belt layout for non-REVUP engines:
see attachments below for:
- revised stock non-REVUP engine layout with shorter belt
- modified belt layouts
- stock REVUP engine layout
see post #17 attachment for what's probably the "best" serpentine belt layout
- the vortech is not yet available for 07+ VQHR engines
this picture shows the right and wrong way to install the tensioner bolt for the cog belt (not to be confused with the stock tensioner pulley for the main belt)
- you do NOT want to use an underdrive pulley with the vortech or you'll lose boost. You want the diameter of the crank pulley to be stock (5.75"). I don't think the other accessory pulleys matter like in the case of the accessory UR pulleys
- the vortech puts a greater strain on the battery when starting the car. So those lightweight small racing batteries really won't cut it usually. You can maybe get one good start up, but if if the car doesn't start up in the first few seconds, the lightweight battery won't have enough juice left to start the car the 2nd try - trust me, I know. Relocating the battery is the next best option IMO. If you track your car, check with your track regulations before relocating it because they might be picky about having an external cut off switch.
- the vortech blower does not run as hot as a turbo which might benefit people in really hot climates. You can even place your hand flat on the blower after a minute after dynoing the car for an hour and not burn your hand
- no the vortech does not overboost or have boost surge problems. It's really not even possible since the belt drives the blower
- if you're on the fence between getting a full vortech kit and the tuner kit and have the extra money, IMO go ahead and get a vortech tuner kit, 650cc injectors, walbro fuel pump, an aftermarket engine management like UTEC, and leave the rest of the stock fuel system in place. It's a safer and a more upgradable setup (though more install time). Not to say the full kit isn't good because it'll be just fine for most people up to 380-400whp. But the tuner kit route is generally considered safer and capable of giving you a better tune than the SS box. It will cost slightly more and won't have the 3 year warranty the full kit has (if the full kit was kept completely or near stock)
- If you wanted to, you can change the vortech's bypass valve to something else, but everyone is going to be asking you why? Because generally they hold up pretty well and most people are really happy with the sound. It's possible to put some extra ducting on the bypass valve to quiet it down. You might even try recirculating the air back into the intake.
- for people concerned about being fully CARB legal and safe, you can have a vortech, exhaust, and tune and probably make 360-370whp and 290 tq on the stock pulley. You can try going to the 3.12 pulley and try pushing the stock vortech fuel system to get more power. The inspectors might not notice you have the 3.12 pulley since they almost look the same as the 3.33 but you never know. It's fairly easy to switch back to the stock 3.33 pulley anyway to pass CA inspection
- the vortech will generally have somewhat higher intake air temps than a turbo kit. I think it's usually around a 10-15 degree difference depending on the turbo kit. The vortech intercooler isn't huge and works fine for moderate power levels. If you want lower intake temps, look into water/meth injection and/or intercooler sprayers. I'd avoid using a larger intercooler until you really need it and are flowing way more air than a standard setup.
- the vortech, and all superchargers are more sensitive to ambient temp changes than turbo setups are in terms of the power they make. It sucks during the hot summer when the power and boost aren't as high. But in some ways you might consider that to be somewhat of a safety feature. Turbo setups can make up for the difference in power because of the wastegate makes sure the boost stays high, and lets more of the hot outside air into the engine. That can be harder on the engine because it's more forceful to constantly maintain a set boost psi
- for the vortech or any FI kit, if you've been abusing your car before going FI by doing things like going past the stock redline a lot or running huge shots of nitrous - if you then blow the engine with the vortech or whatever FI kit, you can't really blame the FI kit. Use some common sense. The vortech isn't going to magically keep your engine safe if you've previously abused it
- the vortech feels absolutely like an NA engine in how it reacts to what the throttle pedal is doing. When you dyno a vortech car, it doesn't matter what gear you're in, the power/tq/boost curve will be identical each time no matter what rpms or gear you dyno in. This is different from a turbo setup where a 5th gear run on a load based dyno starting at 2000 rpms will look dramaticallybetter than a dyno that started at 3300 rpms on a non-load based dyno in 4th gear. The vortech will always be consistent and positive boost is immediately available regardless of rpms, gear, or load. How much boost is immediately available depends on the rpms you're at. The vortech doesn't have lag because positive boost is always available, but because it's a centrifugal design, it's going to take longer to go from low boost to high boost
- how does it compare to the ATI procharger?
The procharger makes more power out of the box. It doesn't reduce timing which is probably a large reason for all the extra power (and danger). The ATI is noisier than the vortech because it uses gears directly turning gears instead of a cog belt turning the gears to drive the actual blower and also spins up to 80k rpms which is much faster than the 45-55k or so the vortech spins at. The ATI has a smaller impeller which is why it can spin higher. The procharger has a full cog belt setup and so it doesn't slip much, but has problems with belts breaking once you start getting over 400whp. Some people claim the bracket assembly on the ATI bends with lots of power. In contrast to the vortech, the ATI has it's own oil that you change seperately from the engine oil. This means you have to change the oil in two places and they way you have to change the ATI's oil isn't fun
- how does the vortech compare to the stillen?
the stillen is a roots blower and is all about low rpm power. IMO a stillen is going to be better than a bone stock vortech, but once you go up to the 2.87 pulley, the stillen's advantage down low really starts shrinking - especially if you went with shorter gearing with the vortech. The stillen's midrange and top end doesn't have near the potential as the vortech, but it will be better under 3000 rpms in most cases except the most severely modded vortech setups.
- how does/did the vortech compare to the original HKS supercharger?
Not much is known about HKS's new version of their supercharger kit, but it seems similar to the old version where it's sort of a hybrid between the vortech and stillen. It has better low end response than the vortech at the expense of worse high rpm power.
- the vortech has the capability of being possibly louder than a turbo car because it doesn't have 1 or 2 turbos acting as mufflers in the exhaust. Test pipes with a vortech are going to be LOUD as hell while they might be tolerable with a turbo or two to mute the sound a little
- when you wear out a bearing, it makes a kinda humming vibration sound. BeerViper has posted a video of his jackshaft bearings gone bad on streefire.net and has a few threads about it. It's not good to drive the car when the bearings are bad. They can seize and the belt can possibly get messed up and cause damage. The jackshaft bearing part numbers are 7S250-200.
- A vortech Z/G makes a pretty decent daily driver, but I always recommend you have a back-up or daily driver car anyway. It makes life so much less stressful because stuff WILL go wrong on occasion no matter what FI kit you have. You never know how long it'll take to get a replacement part shipped in.
- continued on post #17 in this thread...
.
Last edited by sentry65; 02-08-2008 at 02:35 PM.
Trending Topics
05-11-2007, 04:51 AM
#11
good write up, but I think those WHP are a little inflated. I would say that the complete vortech is only good for the 3.33 setup and the 3.12 (9psi) pully is going to need larger injectors / better fuel delivery.
with tightening the belt. I say and so does vortech, you should loosen it till you hear it slip when you start. then keep tightening it till you dont.
I highly recomend the ECU flash b/c you can raise your idle and increase your rpm. on the none revup you can gain another 1/2lb to 1 lb of extra boost while maintaining a higher redline by increasing it to 7100rpm.
I wouldnt recomend the vortech kit for anyone looking for more than 420-430 rwhp, b/c belt slipage becomes too big of an issue. plus at this time all the money you have spent = a good TT setup. what is 1-2k in a 10-15k setup?
and I do love my vortech. I drive it 100miles a day and love the way it sounds, I get compliments every time.
with tightening the belt. I say and so does vortech, you should loosen it till you hear it slip when you start. then keep tightening it till you dont.
I highly recomend the ECU flash b/c you can raise your idle and increase your rpm. on the none revup you can gain another 1/2lb to 1 lb of extra boost while maintaining a higher redline by increasing it to 7100rpm.
I wouldnt recomend the vortech kit for anyone looking for more than 420-430 rwhp, b/c belt slipage becomes too big of an issue. plus at this time all the money you have spent = a good TT setup. what is 1-2k in a 10-15k setup?
and I do love my vortech. I drive it 100miles a day and love the way it sounds, I get compliments every time.
05-11-2007, 06:07 AM
#14
Originally Posted by sentry65
I know I'm just repeating a lot of things, but I must get at least 1-3 PM's a day from people asking about the vortech kit
I still recomend that everyone read through all the vortech install threads and using the search button
But for the sake of trying to put some basic info together in a single spot here's my consensed recomendations/FAQ in bullet form about the vortech - hopefully it helps people out...
I still recomend that everyone read through all the vortech install threads and using the search button
But for the sake of trying to put some basic info together in a single spot here's my consensed recomendations/FAQ in bullet form about the vortech - hopefully it helps people out...
thank you for taking the time to post this information
05-11-2007, 09:33 AM
#15
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WOW !!! I have a answer for ALMOST all of my questions....
Thank you very much !!!!!
it is appreciated !!! for sure !
Thank you very much !!!!!
it is appreciated !!! for sure !
Last edited by JCstart; 05-11-2007 at 09:37 AM.
05-11-2007, 12:02 PM
#17
- some people make cold air intakes for the vortech that look similar to how the TN and ATI kits do their CAI. They're all custom jobs and really aren't that hard to do. Don't expect power gains or anything though. Mainly it's to try to have more consistent and slightly lower air intake temps
- when installing your vortech, you might want to take a look at the intercooler bracket and have something fabricated up to keep the intercooler in place better
- the vortech does not have a wastegate. It only makes a finite amount of air flow. Wastegates are used in turbo kits because turbos make way beyond the airflow your engine can normally handle and a wastegate is needed to vent all that extra air out. It also keeps that extra air from going into the intercooler so you can use a smaller more efficient one.
- the vortech does constantly vent out air when you're not on the throttle hard. The vortech is constantly spinning, even at idle which generates extra air that the engine can't naturally digest when the throttle plate is closed. So that extra air is vented out of the bypass valve to prevent it from backing up and damaging the blower. No need to be alarmed or to think there's something wrong with the bypass valve. This is normal behavior. What it does do though is make the car a little more powerful than NA at low rpms because that excess air is available to be sucked in the instant you push the gas pedal down by any amount. It's similar to if you had a giant plenum. When you get on the throttle hard, the bypass valve will seal and then all the extra air is completely sucked into the engine because the throttle plate is fully open.
- this link has some misc info on vortech and their superchargers
http://superchargeronline.com/content.asp?id=83
- SC-trim vs T-trim vs Si-trim:
The T-trim and Si-trim are bigger blowers than the stock SC-trim. They're more capable of making more power if you're able to prevent the belt from slipping. The T and Si-trim blowers are similar in size with the Si-trim costing a fraction of what the T-trim costs. The Si-trim is more efficient than the T-trim, but not quite as powerful. Both the Si and T-trim blowers can be reved to 55k rpms instead of the stock SC-trim's 53k rpms max
- belt slip is caused by the tensioner pulley not being tight enough. However if you're running more boost with a smaller pulley or larger blower, the belt can still slip even if the belt is extremely tight. Other factors that cause the belt to slip is when the psi number starts getting really high. Opening up the exhaust, going with a stroker kit, cams, and headwork are all things that will help relieve that high psi and ultimately puts less stress on the belt. Smaller pulleys give less surface area for the belt to grip onto. The type and brand of belt has an effect on the grip. Brands such as GATES or Bando offer more grip, are stronger, and stretch less.
- the crawford and APS plenum work with the vortech but their strut bars won't, unless you lower the engine by using shorter solid motor mounts. The stock strut bar clears just fine though with plenum spacers. Why do you see a lot of SSV intake manifolds with vortech setups? Because with headers, headwork, or cams, the SSV has proven to give gains for most people with them - which most basic turbo setups with stock engines or built shortblocks don't have. The SSV weighs 10 lbs less, and it allows you to stick with the stock strut bar which IMO is the strongest, and doesn't cost additional money.
- you can run just about any type of exhaust with the vortech. I don't think anyone is making enough power to recommend the dual 3 inch exhausts though. You'll actually lose overall power with an exhaust that's too big. When you move to a larger exhaust, you shift the powerband higher so you'll have less low end power and more high rpm power. If you go with an exhaust that's too big, you'll end up losing enough low end power that the extra peak power gain really isn't worth it. IMO an exhaust with an X or Y-pipe that briefly joins both sides together is going to give you the best overall power gain. Bear in mind that turbo setups behave almost completely differently than NA or supercharging. The vortech doesn't have the restriction of having a turbine in the way of the exhaust.
- you don't need a turbo timer for the vortech or any supercharger. The blower never gets hot enough to cook the oil when the engine shuts off.
- the stock 3.33 vortech pulley generally creates around 7 or 8 psi of boost, the 3.12 does usually around 8-10 psi, and the 2.87 creates 10-12 psi of boost. The psi number will vary though depending on your overall exhaust breathing mods. What's most important is the power the car makes, not the boost pressure.
- Yes my 11 psi setup is less safe on a stock block than a normal stock 8 psi setup. I don't expect my engine to last forever, but that's also why I've taken a lot of precautions with choosing good parts
- IMO I'd rather have lower psi and higher hp. So if you're trying to decide if you should open up more exhaust flow or not, it will put less stress on the engine at high rpms by allowing more heat out by optimizing the air flow for high rpms. The trade off is usually losing some low rpm power. The hp you "gain" with a larger exhaust was already being generated by the engine with a smaller exhaust, but you can't make use of that power if the exhaust is too small to let the exhaust escape as easily. An exhaust that's too small will trap the heat into the engine at high rpms. However an exhaust that's too big for the power you're making will make you lose power because it's optimized for more air flow than what you have. For most people, something like a nismo exhaust or dual 2-2.5 inch exhaust along with high flow cats works great for most vortech setups under 440whp
- No need to ask me what water/meth kit I use. Find one you like and go from there. People seem happy with the snow performance kits, but aquamist generally seems to be the best and most expensive. Water/meth injection cleans your engine from any oil or gunk residue, lowers intake temps by up to 40-45 degrees F, it raises octane if using methanol - which is 107-113 octane. It cools the intake charge by evaporating the heat. The cooler air and the higher octane helps prevent detonation and gives you more headroom for making more power. Maintenance is easy and also very low cost. Yes you should probably retune the car with it so you can make adjustments or at least to be aware of how the car's tune is with it.
- if you think about it, having more aggressive gearing with a shorter final drive swap, it'll put less high rpm stress on the engine when you're going WOT because you go through the gears faster. It's exactly the same reason redlining 1st gear is less stressful on the engine than redlining in 5th or 6th gear. The shorter gearing goes by faster so the engine doesn't have to be run hard as long
-to calculate the impeller speed:
[5.75/SC pulley] x [upper cog pulley teeth/lower cog pulley teeth] x [3.54 x redline rpm] = impeller speed
5.75" = crank pulley diameter
SC pulley = 3.33, 3.12, 2.87, 2.62 pulley etc
non-REVUP kit: upper cog pulley = 32, lower = 28, jackshaft pulley = 3.33
REVUP kit: upper cog pulley = 34, lower = 32, jackshaft pulley = 3.12
3.54 = step up gear ratio
stock non-REVUP kit = 46106.5 blower rpms at 6600 rpms redline
stock REVUP kit = 48522.5 blower rpms at 7000 rpms redline
some people claim centrifugal superchargers have the worst attributes of a turbo and a traditional supercharger. That's not completely true because they also combine a lot of the best features of both a turbo and supercharger
here's the worst qualities of centrifugal superchargers like the vortech:
- lower torque due to low boost at low/mid rpms
- more parasitic loss
- belt maintenance
- difficult to reach insane high power levels since power is limited by both the belt system, psi, and the displacement/flow of the engine
- mechanical blower noises
- more susceptible to change in ambient temps having an effect on performance
Here's some of the best qualities of centrifugal supercharger like the vortech:
- high power
- no lag, linear throttle response
- low heat
- easy install
- low cost
- no hood modifications
- flat torque curve
- bypass valve sound
- consistency with boost vs gearing or rpms
- generally considered safer for engine
- ballpark hp numbers for non-REVUP engine on a typical dynojet SAE corrected generally are in the neighborhood of:
320-335 whp, stock vortech tune with stock pulley and stock everything else on car (stock exhaust, cats, etc)
340-350 whp tuned
350-370 whp add exhaust, HF cats, plenum, and tuning
370-390 whp add 3.12 pulley and tuning
380-400 whp add headers and/or test pipes, and tuning
390-420 whp add 2.87 pulley and tuning
420-440 whp add cams and tuning
440-475 whp add water/meth injection, more timing, at least half race gas (96 octane or higher) and tuned
470-510 whp switch to Si or T-trim blower, and tuning
500+ whp (in theory) built engine with stroker kit, ported heads, compression ratio somewhat high around 9.5-10:1 raise the redline slightly, full race gas, and tuningtorque numbers are generally 70-90 less than the peak whp numbers
...hopefully this thread lays out a framework of useful info about the vortech and saves people time on researching it.
.
- when installing your vortech, you might want to take a look at the intercooler bracket and have something fabricated up to keep the intercooler in place better
- the vortech does not have a wastegate. It only makes a finite amount of air flow. Wastegates are used in turbo kits because turbos make way beyond the airflow your engine can normally handle and a wastegate is needed to vent all that extra air out. It also keeps that extra air from going into the intercooler so you can use a smaller more efficient one.
- the vortech does constantly vent out air when you're not on the throttle hard. The vortech is constantly spinning, even at idle which generates extra air that the engine can't naturally digest when the throttle plate is closed. So that extra air is vented out of the bypass valve to prevent it from backing up and damaging the blower. No need to be alarmed or to think there's something wrong with the bypass valve. This is normal behavior. What it does do though is make the car a little more powerful than NA at low rpms because that excess air is available to be sucked in the instant you push the gas pedal down by any amount. It's similar to if you had a giant plenum. When you get on the throttle hard, the bypass valve will seal and then all the extra air is completely sucked into the engine because the throttle plate is fully open.
- this link has some misc info on vortech and their superchargers
http://superchargeronline.com/content.asp?id=83
- SC-trim vs T-trim vs Si-trim:
The T-trim and Si-trim are bigger blowers than the stock SC-trim. They're more capable of making more power if you're able to prevent the belt from slipping. The T and Si-trim blowers are similar in size with the Si-trim costing a fraction of what the T-trim costs. The Si-trim is more efficient than the T-trim, but not quite as powerful. Both the Si and T-trim blowers can be reved to 55k rpms instead of the stock SC-trim's 53k rpms max
- belt slip is caused by the tensioner pulley not being tight enough. However if you're running more boost with a smaller pulley or larger blower, the belt can still slip even if the belt is extremely tight. Other factors that cause the belt to slip is when the psi number starts getting really high. Opening up the exhaust, going with a stroker kit, cams, and headwork are all things that will help relieve that high psi and ultimately puts less stress on the belt. Smaller pulleys give less surface area for the belt to grip onto. The type and brand of belt has an effect on the grip. Brands such as GATES or Bando offer more grip, are stronger, and stretch less.
- the crawford and APS plenum work with the vortech but their strut bars won't, unless you lower the engine by using shorter solid motor mounts. The stock strut bar clears just fine though with plenum spacers. Why do you see a lot of SSV intake manifolds with vortech setups? Because with headers, headwork, or cams, the SSV has proven to give gains for most people with them - which most basic turbo setups with stock engines or built shortblocks don't have. The SSV weighs 10 lbs less, and it allows you to stick with the stock strut bar which IMO is the strongest, and doesn't cost additional money.
- you can run just about any type of exhaust with the vortech. I don't think anyone is making enough power to recommend the dual 3 inch exhausts though. You'll actually lose overall power with an exhaust that's too big. When you move to a larger exhaust, you shift the powerband higher so you'll have less low end power and more high rpm power. If you go with an exhaust that's too big, you'll end up losing enough low end power that the extra peak power gain really isn't worth it. IMO an exhaust with an X or Y-pipe that briefly joins both sides together is going to give you the best overall power gain. Bear in mind that turbo setups behave almost completely differently than NA or supercharging. The vortech doesn't have the restriction of having a turbine in the way of the exhaust.
- you don't need a turbo timer for the vortech or any supercharger. The blower never gets hot enough to cook the oil when the engine shuts off.
- the stock 3.33 vortech pulley generally creates around 7 or 8 psi of boost, the 3.12 does usually around 8-10 psi, and the 2.87 creates 10-12 psi of boost. The psi number will vary though depending on your overall exhaust breathing mods. What's most important is the power the car makes, not the boost pressure.
- Yes my 11 psi setup is less safe on a stock block than a normal stock 8 psi setup. I don't expect my engine to last forever, but that's also why I've taken a lot of precautions with choosing good parts
- IMO I'd rather have lower psi and higher hp. So if you're trying to decide if you should open up more exhaust flow or not, it will put less stress on the engine at high rpms by allowing more heat out by optimizing the air flow for high rpms. The trade off is usually losing some low rpm power. The hp you "gain" with a larger exhaust was already being generated by the engine with a smaller exhaust, but you can't make use of that power if the exhaust is too small to let the exhaust escape as easily. An exhaust that's too small will trap the heat into the engine at high rpms. However an exhaust that's too big for the power you're making will make you lose power because it's optimized for more air flow than what you have. For most people, something like a nismo exhaust or dual 2-2.5 inch exhaust along with high flow cats works great for most vortech setups under 440whp
- No need to ask me what water/meth kit I use. Find one you like and go from there. People seem happy with the snow performance kits, but aquamist generally seems to be the best and most expensive. Water/meth injection cleans your engine from any oil or gunk residue, lowers intake temps by up to 40-45 degrees F, it raises octane if using methanol - which is 107-113 octane. It cools the intake charge by evaporating the heat. The cooler air and the higher octane helps prevent detonation and gives you more headroom for making more power. Maintenance is easy and also very low cost. Yes you should probably retune the car with it so you can make adjustments or at least to be aware of how the car's tune is with it.
- if you think about it, having more aggressive gearing with a shorter final drive swap, it'll put less high rpm stress on the engine when you're going WOT because you go through the gears faster. It's exactly the same reason redlining 1st gear is less stressful on the engine than redlining in 5th or 6th gear. The shorter gearing goes by faster so the engine doesn't have to be run hard as long
-to calculate the impeller speed:
[5.75/SC pulley] x [upper cog pulley teeth/lower cog pulley teeth] x [3.54 x redline rpm] = impeller speed
5.75" = crank pulley diameter
SC pulley = 3.33, 3.12, 2.87, 2.62 pulley etc
non-REVUP kit: upper cog pulley = 32, lower = 28, jackshaft pulley = 3.33
REVUP kit: upper cog pulley = 34, lower = 32, jackshaft pulley = 3.12
3.54 = step up gear ratio
stock non-REVUP kit = 46106.5 blower rpms at 6600 rpms redline
stock REVUP kit = 48522.5 blower rpms at 7000 rpms redline
some people claim centrifugal superchargers have the worst attributes of a turbo and a traditional supercharger. That's not completely true because they also combine a lot of the best features of both a turbo and supercharger
here's the worst qualities of centrifugal superchargers like the vortech:
- lower torque due to low boost at low/mid rpms
- more parasitic loss
- belt maintenance
- difficult to reach insane high power levels since power is limited by both the belt system, psi, and the displacement/flow of the engine
- mechanical blower noises
- more susceptible to change in ambient temps having an effect on performance
Here's some of the best qualities of centrifugal supercharger like the vortech:
- high power
- no lag, linear throttle response
- low heat
- easy install
- low cost
- no hood modifications
- flat torque curve
- bypass valve sound
- consistency with boost vs gearing or rpms
- generally considered safer for engine
- ballpark hp numbers for non-REVUP engine on a typical dynojet SAE corrected generally are in the neighborhood of:
320-335 whp, stock vortech tune with stock pulley and stock everything else on car (stock exhaust, cats, etc)
340-350 whp tuned
350-370 whp add exhaust, HF cats, plenum, and tuning
370-390 whp add 3.12 pulley and tuning
380-400 whp add headers and/or test pipes, and tuning
390-420 whp add 2.87 pulley and tuning
420-440 whp add cams and tuning
440-475 whp add water/meth injection, more timing, at least half race gas (96 octane or higher) and tuned
470-510 whp switch to Si or T-trim blower, and tuning
500+ whp (in theory) built engine with stroker kit, ported heads, compression ratio somewhat high around 9.5-10:1 raise the redline slightly, full race gas, and tuningtorque numbers are generally 70-90 less than the peak whp numbers
...hopefully this thread lays out a framework of useful info about the vortech and saves people time on researching it.
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Last edited by sentry65; 05-06-2009 at 10:42 AM.
