DrCold

From my experance of installing, owning, and maintaining a twin screw blower (Kenne Bell Twin Screw). Everything they say is correct. Again, there are probably some engineers out there who will disagree, but after 50k miles, my heads, pistons, rings, everything, looked great.

Before i decided to get rid of the truck, i was going to get a water injection kit for my blower. There was no way to add an intercooler to the twin screw blower with out having the blower sticking out of my hood 2 feet. From listening to others, havign a cooler air charge alowed them to up the boost from 6.5 to almost 10. ATI with its centrifugal blowers have really good gains, the ability to be intercooled, and are very easy to install.

Everyone asks why i chose the twin screw over a centrifugal. My number one reason? Full boost at 2000rpm. The twin screws have amazing power accross the whole band. It may not have the extreme peak numbers as a centrifugal, but it had great numbers all they way from 2000 rpm up. Go read about their blowers at www.kennebell.net. They have alot of good information on their site. Take a few and read thru most of it.

I am very interested in the ATI kit because i know and understand the tuning of superchargers, and hell, everyone else is going to have a turbo, i might as well go blower. ATI knows their sh*t. I look foward to seeing a kit soon.

-DrCold

joeshow750

Yes, intercoolers allow for more boost by lowering the temp of air entering the throttle body. Of course, they have some pretty liberal numbers. Detonation is more likely with higher temps, especially on sh!tty pump gas and high compression ratio. One thing that I don't agree with is what they said about injectors being a poor bandaide. Of course there are people out there who just keep throwing the fuel on to keep down temps, at the sacrifice of driveability and fuel consumption, but at some point, which is usually very early in on in the boost, you're gonna need bigger injectors. Companies size injectors for that car, not for that car with a supercharger.

zland

To be accurate, it was my interpitation of their data that formed that statement. They do use larger injectors on some of their kits for cars. They usually have 2 versions, one running a good HP gain (50% increase in HP lets say), and then another with super HP gains (75-80%) gains. Check out the Mustang and Vette cars for example on their webpage.

I hope this helps, again read the data, it is helpful

Jeff

DrCold

I think thats a givin. My Kenne Bell added 2 more ports to compensate for the small stock injectors. What i think they are talking about is much much larger injectors to keep down the detonation.

*EDIT*
Im slow, and Zland beat me to it.

Boomer

A properly tuned factory installation, like my 91MR2T, 8:8.1 CR lasted me 7 yrs and 128,000 miles and was still going to redline when I traded it. However, the 3S-GTE block was a factory racing block at 2.0 liters with 7psi and 200 hp and 200ft lbs of torque. Dan Gurney's All American racers was running the block with 700hp and 20+psi in GTP racing.

The 350Z has little displacement? Not to me and its stock NA 10.3 CR will eat my stock MR2T for a snack. Never go back to NA, even if the 3.5 liter V6 has the HP and Torque of many of the small block old muscle cars? I disagree strongly with your analysis and have to support westpak's thesis. The VQ 3.5 can be FI'ed, but I would want a factory installation with beefed up internals and much lower CR, before I would consider an SC or Turbo, no matter how good a reputation an aftermarket company has in the business.

Also, I would not want to have the HP/Torq. overwhelm the chassis, which issue is currently in doubt. Last and certainly not least, how long would the bolt-on last with your stock internals? 3yrs and 50,000 miles, maybe. The additional stress of how many times you used all that power would have the greastest bearing on engine life and other parts of the car.

Just trying to add a bit of perspective. BTW, my MR2T was purpose-built for a turbo, but it was only warranted for 5yrs and 60,000 miles and the 3S-GTE was Toyota's small displacement racing block, they used it in rallys, mostly.

Ez350

This brings up an interesting point. I know there are plenty of companies out there that make performance injectors to allow for more fuel input. I wonder why Stillen opted for a "7th injector" in their SC setup.

Anyone have any thoughts on this?

DrCold

Probably price. Adding 6 new higher flowing injectors is much more expensive than adding just 1 high flow.

Kenne Bell did this with my blower. They added 2 on the back of the blower.

-DrCold

Boomer

OK, I jumped into the middle/end of this very interesting thread and I would like to ask a question. When I traded my MR2T for a commuter 97 Accord EX coupe w/5 mt and 145hp of VTEC 4, I know, I lost my mind for a while. Within 2 months, I hated the car. It was too soft, too slow, wallowed in the turns and generally made me unhappy whenever I drove it which was 5 days a week, 48 weeks of the year. I was upside down on payments and changing cars was out of the question.

I started changing things, Tokiko shocks, Suspension techniques anti-roll bars, Nitto tires and a Neuspeed front strut bar. After I added the strut bar, bingo!, I had one of the best handling/riding sports coupes I'd ever owned. I even flirted with the idea of getting a JM spec R motor to replace the smooth, but slow 2.3 vtec 4 with an 8.8:1 CR. The same CR as my MR2T!

What could have I have done in FI to that car and what could I have expected to gain in real world hp and torque, with reasonable reliability? S/C or Turbo intercooled as a kit and the price tag for the mod. I know this is a 350Z forum, but please humor me, I would like to know more about increased power options and this was a real world car with sublime handling and a very firm, not harsh ride. Power was all I needed, what would have given me that power?

Boomer--insight, please. I need a broader perspective.

Stop7alkin

you guys are stupid and you act like all you can do is add FI and watch ur engine die....there are so many more options WITH FI, you want ur engine to be safe ADD SOME better internals dont just say your engine will blow up

not everyone is going to go to the race track so stop using that as an example, if people where serious and went to the race track then they wud get better internals, pushing your car to redline down the racetrack all the time will also deplete engine life, so going to the racetrack will kill your engine no matter what (kill it faster)

Mr B

iTrader: (2)

All I wanna say is this. The SLOWARA you see in my sig (yes I should take it out, but I loved the car) was FI with a TRD S/C without an intercooler cuz there just wasn't an application for it and was impossible to be able to use one. Anyway, it ran 13psi for a pretty good amount of time (9 months) and finally, a rod took a crap when I crammed a 50hp shot up its ***. Anyway, I dropped in my motor that was being built that had rods with stock pistons and other stuff in it. That motor ran awesome and I posted some times that were pretty good. It wasa daily driver and there wasn't one day I didn't beat on the engine and it ran for over a year without any problems. FI is a good way to make power, but you just have to know how to tune your engine and prepare it for boost. The Dyno was made when I only had 8psi of boost with no nitrous. The 1MZ-FE was a good engine, but I really think the VQ35DE has much more potential. For those that don't wanna risk their engine or complain about driveability, don't look at FI cuz it's not for you. Stick with bolt ons and let us have our fun.

Soon2BMaxed

hi all, yes, i AM indeed a newbie to this forum but i thought i'd chime in on this thread a little....



i personally know one of the guys from procharger and i have seen that JIC magic Z they're working on in person (and my god is it freaking sweeet )

the have the little procharger that they made for their civic on it right now running 6psi (i think) and the car ran a 13.12 @109 last weekend at the high school drags running extremely rich and having little traction.

cant wait til they have the "big" procharger for the 3.5 on there. its gonna be scary


and just so you guys know they have an EXCELLENT rep here in KC.


Trevor

Boomer

Not exactly what I had in mind in terms of perspective, but not an uninformed one. OK, use=wear. What else is new?

D'oh

From an engineering perspective, the ATI website is accurate. I don't know exactly how accurate their % gains are, but the science is sound (my thermo is pretty rusty, but I don't have any warning bells after reading their website).

One thing that many seem to talk about, is how the high compression engines can't be FI'd without changing the internals. This statement may be true on average, but it is merely because the higher compression ratio generates higher temperatures inside the combustion chamber, not because of some special attribute that only high compression engines have. That is why you can still safely FI a high compression engine if you control heat.

Also, remember that detonation is nothing more than combustion of the air-fuel mixture before the spark is set off. This occurs because the tempurature inside the chamber exceeds the ingnition point of the gas. This is also why higher octane gas is more resistant to detonation: it has a higher ignition point. By reducing the tempurature of the incoming fuel mixture, you can reduce the chances of detonation. This stuff is all pretty straighforward.

However, even if you account for detonation, you will still be creating far more torque, which means greater loads on the rods, crankshaft, cylinder, seals, etc. I think this is the area that most people are talking about when they say FI will reduce engine life. The one thing to keep in mind though, is by how much? Are you taking the life from 200K miles to 20K miles? Or from 200K to 180K? Or from 500K to 250K? That all depends on how the engine was designed, something that no one seems to be able to answer at this time (and probably not for anther couple of years - when car's start failing).

Anyhow, the point of all this rambling is the following:

There are no definites here yet. No one knows enough about the car to know what levels of boost the engine can take. At least no one has posted that level of detail yet. I applaud all you "early adopters" who are going to go out and push the car up to and beyond the limits so the rest of us can wuss out and learn from your mistakes. And, while we all have the right to be skeptical, there is nothing yet to say that FI will cause a motor failure in 10K miles either.

At least the ATI Pro Charger folks have a strong argument for the quality of their system.

-D'oh!

zland

D'oh:

Thanks for input! Nissan has alway made a stong motor so my bet is it is stronger than most are giving credit for at this point.

Jeff

350Z33

Good call. Afterall my old 4 banger can take 20psi on the stock 9.5:1 CR with cast pistons.

zland

In other posts, people are stating a TT is better because it does not build up as much heat as a SC. Is this true considering ATI is putting an intercooler on this unit?

Jeff

BriGuyMax

iTrader: (4)

For all the people that are talking about this mostly FICTIONAL excessive wear on a motor from FI...I have a little tid-bit for you.

I used to have a 1997 Nissan Maxima with a VQ30DE motor in it running a 10:1 comp ratio. I added a bunch of bolt-ons and a 100-shot of nitrous. I did an oil analysis through Blackstone Laboratories before and AFTER 10 bottles of juice, and the oil analysis after showed nearly NO extra wear in the motor from the juice. They actually commented on how well the motor was wearing considering the percieved "abuse".

The fact is most "extra wear" and "engine failure" comes from poor tuning...NOT actual power output from FI or Nitrous. I personally know of two Maximas in the chicagoland area that have been running OVER 10lbs of boost with no problems to date for nearly 3 years. They are both well tuned and intercooled. The VQ motor is a very capable motor as power adders go and I can attest to that from personal experience.

I bet not many people know that over in Japan there is a production turbo VQ used in nissan sedans.....it's the VQ30DE-T.

Boomer

I think it would depend on the intercooler, the bigger the better, either S/C or Turbo. I can guarantee my MR2T generated gobs of heat w/7psi, considered a light pressure turbo by most. I would prefer a water to air intercooler, but isn't API using an air to air? Where are they putting the intercooler, in front of the radiator or behind it in that large space someone alluded to earlier? Why doesn't someone w/deep pockets load it up until it blows and then analyze the damage?

I know, it isn't elegant, but it should be very enlightening for the analyzers. Why is API going with an S/C instead of a Turbo, I missed their reason if they explained it earlier, or do they use S.C only? If they use a big intercooler, 5-7 psi shouldn't kill a 10.3 CR like the Z. The intercooler on the MR2T got air in through the louver on the passenger side, so if you were stopped the IC didn't get much air. I think the placement and the size of the IC are critical for the survival of the VQ35. I would examine both factors very closely before I would plunk down a dime on either type of system. Also, replacing the pistons in the VQ35 could lower the CR by a full CR point, maybe.

Boomer--just thinking.

joeshow750

It depends on what kind of SC it is. The roots style, which is a positive displacement SC (displaces a certain amount of air per revolution), typically have poor adiabatic efficiency, so they generate alot of heat for the boost level you get.

Centrifugal SC's work the same way on the compressor side as a conventional turbocharger does...it's merely belt driven rather than exhaust. Boost rises with rpm's and falls off quickly without rpms on Centrifugal SC's. But temperatures will be the same as a
TC of the same trim/size at the same level of boost (adiabatic efficiency).

Srew type SC's (also positive displacement) generally have good adiabatic efficiency and need no internal lubrication.

Vane type SC's (also positive displacement) also have good adiabatic efficiency but wear out more quickly than other SC's due to the vanes contacting the case.

These are the most common types of SC's. I would stay away from the roots style.

zland

Joe:

Which of the 4 types do you prefer and why? Do you think ATI's type with a air intercooler is the best of all worlds? I am still trying to gather as much info as possible so I am able to later selct the best FI system for my needs later when these products are offered.

Jeff