Vortech s/c plans
doing the 1/4 mile, pump gas might be fine cause it goes by so quick and there's lots of time in between runs, but a 20-60 minute road course session in 90-100 degree heat is going to heatsoak your engine which will bring you closer to the detonation threshold.
The whole point of using race gas is to raise your detonation threshold. You might try getting away with normal pump gas, but for one thing when you're at a road course event and do like 4 or 5 20 minute sessions, you go through a LOT of gas. You'd be supprised. And usually there's a gas vender selling gas there on site and what are they selling? That's right race gas, cause who's going to risk running a "street tune" intended for street gas in a race environment?
if you're on the street though, well 91 octane still sucks which a lot of us are stuck with at the pump. $h!t happens and you might get a bad tank of gas, your tune might shift somehow depending on the weather and your engine management. It's just insurance that you won't detonate. BTW I've read lots of posts about people who blew their engine say how they noticed some detonation here and there out on the street that wasn't present on the dyno.
Lots of people who tune on a dynojet might run into this sorta thing since dynojets don't put any real load on the engine for real world environments. Even a load dyno don't always tune for things like going WOT up a hill. Things are slightly different on the street than on the dyno.
It's not like you have to run full out race gas. You can just mix some 101 octane in with your crappy 91 to get to 94-96 octane. The Z was intended for 93 octane bone stock. The whole point of running really rich is for the sake of extra cooling, but that's just burning through more and more gas than what's needed. You can lower your intake and EGT's with water injection. You can lower oil and coolant temps with coolers and you can lower overall heatsoak a little with a vented hood, but the whole point of running richer is because people are stuck running pump gas. Some of us access to gas stations where they sell 101 octane at the pump right near our house
turbo guys especially have to deal with unexpected things like boost spikes which can cause some detonation during that time especially in the winter months when the air is denser.
I'm pretty sure running a 96 octane mix has saved my engine more than a few times even when on the dyno getting tuned. You can always tune in more timing and power with it, or you can use it just for the sake of extra safety. BTW can anyone think of someone who has blown up their stock engine with less than 500whp out on the street who was running more than 94 octane???
The whole point of using race gas is to raise your detonation threshold. You might try getting away with normal pump gas, but for one thing when you're at a road course event and do like 4 or 5 20 minute sessions, you go through a LOT of gas. You'd be supprised. And usually there's a gas vender selling gas there on site and what are they selling? That's right race gas, cause who's going to risk running a "street tune" intended for street gas in a race environment?
if you're on the street though, well 91 octane still sucks which a lot of us are stuck with at the pump. $h!t happens and you might get a bad tank of gas, your tune might shift somehow depending on the weather and your engine management. It's just insurance that you won't detonate. BTW I've read lots of posts about people who blew their engine say how they noticed some detonation here and there out on the street that wasn't present on the dyno.
Lots of people who tune on a dynojet might run into this sorta thing since dynojets don't put any real load on the engine for real world environments. Even a load dyno don't always tune for things like going WOT up a hill. Things are slightly different on the street than on the dyno.
It's not like you have to run full out race gas. You can just mix some 101 octane in with your crappy 91 to get to 94-96 octane. The Z was intended for 93 octane bone stock. The whole point of running really rich is for the sake of extra cooling, but that's just burning through more and more gas than what's needed. You can lower your intake and EGT's with water injection. You can lower oil and coolant temps with coolers and you can lower overall heatsoak a little with a vented hood, but the whole point of running richer is because people are stuck running pump gas. Some of us access to gas stations where they sell 101 octane at the pump right near our house
turbo guys especially have to deal with unexpected things like boost spikes which can cause some detonation during that time especially in the winter months when the air is denser.
I'm pretty sure running a 96 octane mix has saved my engine more than a few times even when on the dyno getting tuned. You can always tune in more timing and power with it, or you can use it just for the sake of extra safety. BTW can anyone think of someone who has blown up their stock engine with less than 500whp out on the street who was running more than 94 octane???
Last edited by sentry65; Apr 12, 2007 at 02:00 PM.
running race gas alone won't cool the engine in any real significant way more than normal pump gas, but it does help some. It burns cooler and cleaner, but I wouldn't really call it anything significant like how much an oil cooler or water/methanol injection will cool the engine. Mainly IMO running higher octane is wanted as a preventative insurance against motor damage from detonation or preignition
If your car detonates or preignites at all with pump gas, that'll damage the engine and spike temps up real fast. It's all down hill from there. Detonating and preignighting can happen at any time. In a perfect world if you tune it right, it never should detonate, but you just never know if you'll end up with some crappy gas, or the conditions you're running in somehow heat up the engine bad - what if you have a coolant leak or something that happens without you knowing it and slowly raises temps.
Especially if you're racing, you're not paying super close attention to all your gauges and trying to listen real closely to the engine for signs of problems - first of all you might have the windows down and you're wearing a helmet. You're looking at the turns and other cars mostly trying not to crash, and not looking at your gauges as closely as you normally would like. You could be lightly detonating for 5 laps and you might not even be aware of it. You could somehow start running lean for a million different reasons and when that happens, THANK GOD FOR RACING GAS cause it might prevent your engine from blowing up.
running richer runs the engine cooler, but you can only do it to a point. If you have 15 lbs of boost on a stock block with 91 octane, you're probably not going to be able to avoid preignition because you can only cram so much gas and air into the cylinder chamber before you get preignition from the increased pressure. If you had race gas that doesn't ignite as easily then you can safely run that power level assuming the temps never get too hot to make parts fail.
it's kinda like overclocking computers if anyone has ever done that - they work just fine overclocked as long as the cooling can keep the processors overall running in a safe temp range
running really rich is slightly bad for your cats and even sensors, but is ultimately the lesser evil when we're talking about your engine living vs some comparitivly cheap sensors having slightly shorter lifespans. Lots of people run test pipes too instead of cats.
running rich is a bandaid fix - using more normal pump gas vs less high octane race gas. People do this for the convenience and cost savings of using pump gas.
By retarding timing, you're increasing EGT's. So more fuel is added in to compensate. If you run race gas you don't need to retard timing in the first place, and because of that, it won't raise EGT's. Well actually it will because you're running more power at that point so you'll still want to run richer than a NA setup. Most people reduce some timing anyway to reduce stress on the parts.
It partly depends on what engine management you're running like whether it runs the fuel by offsetting the ECU or if it has it's own sensors that it uses to adjust the fuel to reach a target A/F ratio. I'd be more willing to trust the target method vs the offset method. Because the stock ECU is more concerned about emissions and being in stock "safe" parameters than giving you power and being consistent.
If your car detonates or preignites at all with pump gas, that'll damage the engine and spike temps up real fast. It's all down hill from there. Detonating and preignighting can happen at any time. In a perfect world if you tune it right, it never should detonate, but you just never know if you'll end up with some crappy gas, or the conditions you're running in somehow heat up the engine bad - what if you have a coolant leak or something that happens without you knowing it and slowly raises temps.
Especially if you're racing, you're not paying super close attention to all your gauges and trying to listen real closely to the engine for signs of problems - first of all you might have the windows down and you're wearing a helmet. You're looking at the turns and other cars mostly trying not to crash, and not looking at your gauges as closely as you normally would like. You could be lightly detonating for 5 laps and you might not even be aware of it. You could somehow start running lean for a million different reasons and when that happens, THANK GOD FOR RACING GAS cause it might prevent your engine from blowing up.
running richer runs the engine cooler, but you can only do it to a point. If you have 15 lbs of boost on a stock block with 91 octane, you're probably not going to be able to avoid preignition because you can only cram so much gas and air into the cylinder chamber before you get preignition from the increased pressure. If you had race gas that doesn't ignite as easily then you can safely run that power level assuming the temps never get too hot to make parts fail.
it's kinda like overclocking computers if anyone has ever done that - they work just fine overclocked as long as the cooling can keep the processors overall running in a safe temp range
running really rich is slightly bad for your cats and even sensors, but is ultimately the lesser evil when we're talking about your engine living vs some comparitivly cheap sensors having slightly shorter lifespans. Lots of people run test pipes too instead of cats.
running rich is a bandaid fix - using more normal pump gas vs less high octane race gas. People do this for the convenience and cost savings of using pump gas.
By retarding timing, you're increasing EGT's. So more fuel is added in to compensate. If you run race gas you don't need to retard timing in the first place, and because of that, it won't raise EGT's. Well actually it will because you're running more power at that point so you'll still want to run richer than a NA setup. Most people reduce some timing anyway to reduce stress on the parts.
It partly depends on what engine management you're running like whether it runs the fuel by offsetting the ECU or if it has it's own sensors that it uses to adjust the fuel to reach a target A/F ratio. I'd be more willing to trust the target method vs the offset method. Because the stock ECU is more concerned about emissions and being in stock "safe" parameters than giving you power and being consistent.
Last edited by sentry65; Apr 12, 2007 at 01:50 PM.
Thank you Sentry for the writeup. If you want the most power out of race gas, you should also think of doing a tune specifically for race gas. Not only will you get more power, but it will also be safer than pump gas. Race gas is basically insurance against detonation and if you put race gas in a pump gas tune, the extra octane points help since the gas is better refined, cleaner, etc. A side benefit is that you will also make more power than normal gas on your pump tune.
As a test you can also put race gas in your stock car and see if it runs better. I guarantee you will be able to feel a difference.
As a test you can also put race gas in your stock car and see if it runs better. I guarantee you will be able to feel a difference.
yeah I've always felt a difference even when NA with race gas after resetting the ECU or when doing a road course day. Driving around super hard with great gas and no detonation, the stock ECU gives you EVERYTHING it has and you can really seriously feel it even long after you're off the track and still driving around the street using up the last of your tank of race gas. Aggressive timing makes a really big difference. Race gas does contain more energy than normal pump gas which has all the extra additives etc
If you were running regular pump gas, the ECU might not advance the timing as much because it'd probably detect some knock and cap things off right there to prevent damage.
Right now I run half 101 octane and half 91 pump gas to equal about 96 octane for my "91-94 octane" tune. If I was on a built block, I'd probably consider running 100% full race gas with a race gas tune for the street. But because the stock block can only take so much abuse and I feel like I'm living on borrowed time as is, I won't do a 101 octane race gap tune. Using 100% race gas is something I'll only do when tracking the car and that'll be on my normal tune just for added safety at this point. If I thought the stock bottom end would put up with it for awhile I really would do a full aggressive high octane race tune right now for the times I want to be extra fast
If I had a built engine and had a full race gas tune, I actually wouldn't run the aggressive race map on a road course. I'd run a "96 octane" tune with 101 octane gas on a road course. For drag racing, autox, drifting etc and anything else that's shorter times, then I'd run an aggressive race map or even out on the street when I just feel in the mood for the extra power.
the other thing, in the case of superchargers, they have more parasitic loss than a turbo, so even though you might make 400-450whp with a vortech, the engine in reality is working harder than that. So that's another reason I feel better about using partial race gas is because the engine is closer to the breaking point than the dyno numbers might lead you to think
If you were running regular pump gas, the ECU might not advance the timing as much because it'd probably detect some knock and cap things off right there to prevent damage.
Right now I run half 101 octane and half 91 pump gas to equal about 96 octane for my "91-94 octane" tune. If I was on a built block, I'd probably consider running 100% full race gas with a race gas tune for the street. But because the stock block can only take so much abuse and I feel like I'm living on borrowed time as is, I won't do a 101 octane race gap tune. Using 100% race gas is something I'll only do when tracking the car and that'll be on my normal tune just for added safety at this point. If I thought the stock bottom end would put up with it for awhile I really would do a full aggressive high octane race tune right now for the times I want to be extra fast
If I had a built engine and had a full race gas tune, I actually wouldn't run the aggressive race map on a road course. I'd run a "96 octane" tune with 101 octane gas on a road course. For drag racing, autox, drifting etc and anything else that's shorter times, then I'd run an aggressive race map or even out on the street when I just feel in the mood for the extra power.
the other thing, in the case of superchargers, they have more parasitic loss than a turbo, so even though you might make 400-450whp with a vortech, the engine in reality is working harder than that. So that's another reason I feel better about using partial race gas is because the engine is closer to the breaking point than the dyno numbers might lead you to think
Last edited by sentry65; Apr 12, 2007 at 01:55 PM.
that depends
if you're going with the vortech, the radiator will maybe help coolant temps slightly, but in most cases it's not going to be a big deal unless you do roadcourses. The APS turbos are water cooled, so I can see a bigger radiator being a little more useful for their kits in situations that are not just roadcourses
vented hoods do more good for turbos since they get hotter under hood temps than a vortech does. My vented hood I can't say made the temps all that much cooler much out on the street according to my oil temp, aftermarket coolant temp, EGT, and the stock ambient temp gauges
We're really talking about road course stuff here because for 1/4 mile, autox, street driving, really won't stress the coolant temps much to care about
but road courses and possibly drifting depending on how long you drive and extreme you get with it are going to be the things where a radiator and vented hood will actually do something worthwhile. Going sideways with drifting doesn't let air into the front of the car as easily as going straight. Of course a vented hood and bigger radiator would never hurt to have anyway. Turning the heater on full blast will usually cool the coolant more in most cases other than road courses
Primary cooling to look into in all cases is an oil cooler, bigger oil pan - with baffles if possible, and also Water/methanol injection
I like using Redline WaterWetter, but some people would debate if it's worthwhile or not.
if you're going with the vortech, the radiator will maybe help coolant temps slightly, but in most cases it's not going to be a big deal unless you do roadcourses. The APS turbos are water cooled, so I can see a bigger radiator being a little more useful for their kits in situations that are not just roadcourses
vented hoods do more good for turbos since they get hotter under hood temps than a vortech does. My vented hood I can't say made the temps all that much cooler much out on the street according to my oil temp, aftermarket coolant temp, EGT, and the stock ambient temp gauges
We're really talking about road course stuff here because for 1/4 mile, autox, street driving, really won't stress the coolant temps much to care about
but road courses and possibly drifting depending on how long you drive and extreme you get with it are going to be the things where a radiator and vented hood will actually do something worthwhile. Going sideways with drifting doesn't let air into the front of the car as easily as going straight. Of course a vented hood and bigger radiator would never hurt to have anyway. Turning the heater on full blast will usually cool the coolant more in most cases other than road courses
Primary cooling to look into in all cases is an oil cooler, bigger oil pan - with baffles if possible, and also Water/methanol injection
I like using Redline WaterWetter, but some people would debate if it's worthwhile or not.
Last edited by sentry65; Apr 12, 2007 at 05:58 PM.
yeah i was looking at stillens oil cooler. The place i go to have fun is The Dragon. which is 11 miles with like 318 some-odd curves, so its alot of hard running the engine. I always pop the hood when im taking a break but i'd like to do more to take some stress off the engine.
I wouldn't really be concerned with the oil and coolant temps unless you have an oil temp and aftermarket coolant temp gauge showing that you're going above say 240 degrees. The engine will be just fine at 200-230 degrees for either
Originally Posted by MUZZY
your going to do great man.... you got all bases covered.... make sure you read the part on my thread forthe selant and 3/8" NPT tap... u will hit 400 easilly with a good tune. im still using the SS box and will hit around 420rwhp hopefully monday with a conservative tune. goodluck!
Im glad my thread is helping ppl out
Im glad my thread is helping ppl out
where is this thread located at. i did a quick search but you have so many posts.
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