The Lotus Cars Community banner

1 - 17 of 17 Posts

·
Registered
Joined
·
787 Posts
Discussion Starter #1
Finally getting the turbo kit all together and installed, but to start out with, I will be on a stock motor untill the hole in my pocket gets sewn up :D

Anyhow, looking for some insight on how practical tracking the car on a FI stock motor is? I'd hate to take a 'trackable' stock car and add the turbo just for a little extra kick, then turn the car into something that is completely unsafe to take on a track without blowing the motor.

Would turning down the boost to something really low (3-5psi) still allow it to be tracked, or does I now can't set foot on a track without a huge risk of blowing the motor? (I was originally planning on setting up a track map (very rich 3-5psi) and daily map (6-7psi))

Thoughts? Experiences?
 

·
Registered
Joined
·
51 Posts
Kind of a loaded question as there are a lot of variables at play here. All things considered I don't see a 7psi 2zz being a ticking time bomb on the track as long as your tuning and IAT stratagies are effective.

Out of curiosity, what turbo and manifold are you running?
 

·
Absolute power does what?
Joined
·
3,201 Posts
The main issue you're going to have is heat - I will never own another FI track car, and if I did I'd only consider superchargers, not turbos. All the turbo Elise's I've seen at the track have wound up with one problem or another - all heat related. At a minimum they've all had melted (or warped/damange) trunk areas from the heat of the turbo and exhaust headers.

If you're looking for more speed on the track there are 3 things that will give it to you - instruction, Hoosiers/slicks, and instruction. Unless you're running at the limits of your car already I think a turbo is a really bad idea for a track car.
 

·
Registered
Joined
·
787 Posts
Discussion Starter #4
I have the ForceFed 380 kit (GT2860RS) with Radiums AEM EMS. Will be running speed density setup using AEM MAP sensor and the BOE IAT sensor, with Tial Q and stock internal wastegate. Tuning will most likely be done by Forged Performance with a track map and a daily driving map.

For heat management, headers were sprayed, wraped, then sprayed again using the DEI titanium wrap and DEI silicon spray. Turbo has a slightly modified PTP turbo blanket, and I plan (before tracking it) to set up ducted blower fans to help draw the heat out.

I actually just added the turbo more for a little kick to the daily driver side of it. Basically if it wasn't such a hassle to take everything off, I would swap it back to stock to track it. I was hoping that turning down the boost low enough to have almost no impact on the motor would keep the threat of blowing the stock motor down to a minimum, at least till I can get it built. So would setting it at 3-5psi be still at a big risk of a blown engine on the track?
 

·
Registered
Joined
·
577 Posts
What's the spring on your wastegate? I think most internals are somewhere around 5-6 PSI, so can you even get it down to 2-3 PSI?
 

·
Registered
Joined
·
787 Posts
Discussion Starter #6
Yea... that was the one problem... but I figured I should find out if it's even practical to turn it down to 3-5psi to keep it track-safe even if I could. (I was thinking about possibly making an adjustable spring that would "assist" the internal spring, though it seems like kind of a bad idea)
 

·
Registered
Joined
·
417 Posts
A friend of mine has tracked a FF275 with stock internals, around 245whp on race gas, and he had fairly good success. The only issues I can remember are his shifter cables melting and his trunk catching on fire (separate occasions). I'll try to point him to this thread.
 

·
Registered
Joined
·
457 Posts
I would run 5 PSI and wrap everything. Also insulate all lines that are close to the turbo and even the wastegate. Switch to external if possible.

The less PSI you are running, the less heat you are generating. Five sounds good to me. A water injection system would definitely help with possible detonation and greatly reduce EGT.
 

·
Less is Better
Joined
·
2,632 Posts
A friend of mine has tracked a FF275 with stock internals, around 245whp on race gas, and he had fairly good success. The only issues I can remember are his shifter cables melting and his trunk catching on fire (separate occasions). I'll try to point him to this thread.
LOL. What do you consider unsuccessful?
 

·
Registered
Joined
·
959 Posts
A friend of mine has tracked a FF275 with stock internals, around 245whp on race gas, and he had fairly good success. The only issues I can remember are his shifter cables melting and his trunk catching on fire (separate occasions). I'll try to point him to this thread.
If that's called fairly good success then I think we all know the answer here..
 

·
Registered
Joined
·
417 Posts
Ha, I probably could have worded that a bit different..

I was meaning more along the lines of no engine failures due to running FI on stock internals. Based on the issues he went through, I would think you would be good to go as long as you properly insulate the problem areas.
 

·
Registered
Joined
·
787 Posts
Discussion Starter #12
Only I wouldn't have much access to race gas for the average autocross :/ Though hopefully I can reduce the risk of fire
What psi was he running for 245whp?
 

·
Registered
Joined
·
417 Posts
He had a different map for street gas that he used for autocross, and I believe he was around 230-235whp on that. I want to say he never had a turbo related problem while autocrossing. I don't want to give any wrong information, so I will send him a message to chime into this thread.
 

·
Registered
Joined
·
2,969 Posts
I would think you would have problems trying to get "only" 3-5 PSI. The turbo will probably overshoot that quite easily everytime you jab the throttle. So I would be concerned with an erratic torque curve. 6-7 PSI should be more manageable and should still be well within the limits of the stock motor.
 

·
Registered
Joined
·
787 Posts
Discussion Starter #15
Ok, that makes sense. Though if 6-7psi is well within the limits of the stock motor, where does one draw the line for At the limits of the stock motor? (say on 93 pump gas) I guess it depends, but any ballpark? (8, 10, 12?)
 

·
Registered
Joined
·
2,969 Posts
I would look more at power levels. Upper 200's (270+) is going to start pushing the limits of everything (clutch, engine, transmission). If I were a betting man I would stop at 250WHP for track stuff. For street driving 280-300 is a pretty popular number and works very well for most people. Plus you exceed the traction abilities of the rear end and it would not be trustworthy on the track as a normal Exige.
 

·
Premium Member
Joined
·
3,738 Posts
Ok, that makes sense. Though if 6-7psi is well within the limits of the stock motor, where does one draw the line for At the limits of the stock motor? (say on 93 pump gas) I guess it depends, but any ballpark? (8, 10, 12?)
It is sorta a loaded question (as pointed out). How you drive will influence longevity. The 2ZZ motor "as is" was NEVER designed for FI (be it supercharged or turbo) hence the 11.5:1 compression in a stock motor. The motor may not be your biggest concern, the stock tranny doesn't hold up very well to increased torque (and that's where FI shines, much more torque over broader RPM range) and heat from track use.

On my old SC setup I was putting down about 170-188 TQ and I tracked/raced the car a lot at a "moderate" pace. I changed trans fluid every month (Redline shock proof heavy weight at the time) and did my best to survive the trans and it worked for the most part for TT and HPDE type track events. But didn't last long for race type events, especially qualification.

If you need want to extend motor/trans life I'd recommend:
  • Stay below 7800 rpm
  • Try to avoid using 2nd gear on track
  • No gorilla shifting
  • Monitor your IAT and AFR
Lap times will suffer, but that's the price for keeping the motor/trans together. But I think you'll still have a lot of fun regardless.

Rob
 
1 - 17 of 17 Posts
Top