I've got my road settings dialed in and now I wanted to find out what people have been boosting on race gas? Thinking the turbo is only efficient up to 21-22psi I imagine you could boost all the way up to 22 easily.

 

Sounds like a dangerous approach to me. The only safe way to find the upper limit is on a dyno. Every car is different. I wouldn't trust your imagination or anyone else's with a $30K car with more in mods...

 

With 117 octane leaded race fuel, I run around 24psi peak, falling to 20psi at redline in my car. I also have a 16G turbocharger. I'd invest in a datalogger and learn how to use it and interpret the results first, though.

Don't listen to the guys who say that the only safe place to tune a car is a dyno. My car has never been to a dyno. I tune my car at the track with a datalogger.

 

What WAS I thinking?

I just assumed that he probably didn't want to pay to replace his engine if it blows up.

Silly me. Ignore me.

It's just an engine.

 

Why do you assume that someone who turns up the boost on their Evo with race gas in the tank will blow up their engine?

This isn't some fragile WRX with a crappy intake manifold design and a crack-tastic #4 piston. -> http://forums.nasioc.com/forums/show...hreadid=364230

4G63Ts can take punishment. They are VERY strong engines. They are very detonation resistant. I got just about zero knock when I went to the track last week with a 24psi boost spike. And the Evo arguably has a better intercooler setup than my car does. And I know that it has a larger turbocharger than my car does.

I'm not saying that this guy should go right out and run 24psi blindly. Get a datalogger. Get an AFC. Dump in some race gas. See how the car likes it. Then try turning up the boost a pound. See if the timing curve dips. If it does, you are getting knock. But there are different levels of knock. A DSM ECU can yank up to 12 degrees of timing. 1 or 2 degrees isn't all that bad. 5 degrees of timing pull is where I would draw the line.

Learn this stuff yourself. Personally, I don't trust any "engine tuner" to tune my car. How do you know that he knows any more than you do? The only way to do something right is to do it yourself.

 

Ahh the quote I live by...

 

The last two cars I saw "go boom" were on dyno's and my point is the skill of the tuner is very important and even then, sh*t happens.

speedlimit..

 

Did I say that? I think not.

I can see from your comment about the WRX and the "why do you assume" comment that you're not particularly objective.

Nevertheless, you seem very experienced in tuning. But I would suggest that not everyone has your level of expertise.

My mistake: assuming the original poster did not have your level of expertise

Your mistake: assuming the orginal poster (and others) does have your level of expertise

I take back my "only way" but add the caution: be careful testing the upper limits of boost. It's not a trivial task, especially if you aren't experienced. Work with someone who's been there and done that before. Starting with a reputable tuner is a good idea if you aren't confident.

 

I know every car is different but the same car with the same mods will run fairly similar. I'm not leaning the car out at all. Stock setup with an added EBC. The car runs very rich, so I imagine it could handle a few extra pounds. Especially with race gas. I thought that was common knowledge and would've been an easy answer but I guess I was wrong. How much would a datalogger cost? I've never used one before. THe last shop that tuned my Supra blew the motor so my choices around here are thin. I've taken the "Do it myself" approach. At least I'm to blame if something goes wrong.

 

**** .. blew the supra motor .... I would be thinking sue the bastards

 

I know absolutely nothing about tuning turbo cars. I DRIVE cars. I came up in karts, moved to formulas, then grew 5 inches in one summer which all but ended my open-wheel racing career. I'm now relegated to track days, and SCCA club events (which isn't bad--not flaming). My point is, this is my first experience OWNING a turbocharged car, and I would love to learn as much about tuning as I can so that I could in fact, as ShapeGSX suggests, do it myself. Two problems I have though : turning wrenches (which I do on my '66 coronet) is a lot easier than using a computer and I don't know where to start. I know it's a little off-topic, but what resources are you guys using to get all your info? Where should one who is interested start on the road to proficiency?

 

and if possible give me something more specific than "Read ****", or "Read the forums" because god knows that for as many people who know what they are talking about on this site, there are just as many "Why do our EVO's come with such ****ty tires from the factory" type people as well. Thanks

 

ricardon: Would I be correct in assuming that you have basic knowledge of engines; just not turbocharded ones?
You know: pistons, cranks, cams, sparkplugs, distributors
Don't know: BOV, OBDII, wastegate, boost control solenoid, engine computers

I'm just trying to see what you DO know, so I can tell you or tell you where you can find information that you DON'T know. I'm no expert, but I've learned a lot in the past couple of years.