Hey guys,

My boss bought an STI about 3 months and has already started the tuning...SCARY

 

He was asking me today (since I know more about his car than he does) about octane ratings and tuning.

 

Matrix Engineering on Macaddam in Portland Oregon was supposed to be having dyno day Friday for EVO's and Saturday for Subarus...Shiv from Vishnu was going to be there to tune and dial in everyone's cars but, had a family emergency and the AWD dyno day has been pushed back a few weeks...But, that's besides the point.

 

He wants to run race fuel, like way high octane in his STI, but we were wondering if he tunes his car (via Vishnu electronic goodies on the dyno) will his car run ok without race fuel down the road?

If the car is ran on the dyno and street with race fuel, tuned to take the extra high octane, won't this mess up his ECU/MAF mapping???

 

Thanks,

Dan

If he can educate himself on how to adjust the 'piggyback' between one or the other I think figuring out a way to run both would be OK. If you can regularly get race fuel, or mix your own with toluene, then it is probably easier to run it all the time.

 

Also, try posting this at http://www.nasioc.com and http://www.i-club.com . LOTS of tuners there.

Originally posted by Boosted84Wagon

Hey guys,

My boss bought an STI about 3 months and has already started the tuning...SCARY

 

He was asking me today (since I know more about his car than he does) about octane ratings and tuning.

 

Matrix Engineering on Macaddam in Portland Oregon was supposed to be having dyno day Friday for EVO's and Saturday for Subarus...Shiv from Vishnu was going to be there to tune and dial in everyone's cars but, had a family emergency and the AWD dyno day has been pushed back a few weeks...But, that's besides the point.

 

He wants to run race fuel, like way high octane in his STI, but we were wondering if he tunes his car (via Vishnu electronic goodies on the dyno) will his car run ok without race fuel down the road?

If the car is ran on the dyno and street with race fuel, tuned to take the extra high octane, won't this mess up his ECU/MAF mapping???

 

Thanks,

Dan

 

Some race fuels contain lead. They'll ruin his cat in a hurry!

It's already cat-less dude...hahaha, like I said, scary

Unless he gets a dual map/switchable map ECU, or learns how to retune for lower octane fuel it's a really bad idea. Running lower octane fuel on a car tuned for higher octane fuel means you get lots of knocking or detination, and that means by by main bearings.

 

Honestly, if he doesn't know or understand anything about it then he is going to be a danger, and he should start putting away money to replace the motor cause it's gonna happen.

 

Keith

With a good quality adjustable boost controller he can probably avoid detonation by keeping boost low on pump gas and kicking it up when he's got the good stuff. He'll also need to verify that his injectors can handle the supply side of the equation or even race gas won't save his engine (will depend on how much he's increasing power).

 

Assuming his engine has stock internals (he hasn't messed with CR) it's likely he's making more power by simply turning up the boost (bolt-ons, intake, exhaust, etc...), the above solution with work fine in that instance.

 

Everything I've read indicates that the Soobs are pretty particular when it comes to adding boost... very easy to break em. Your buddy should already know the answer to your question or maybe he's not quite ready to play those games (unless he's got the cash to blow on a new engine).

 

Finally it won't hurt to consult an expert... find a local shop that specializes in forced induction setups. I know enough to be dangerous (my soobs are both NA, but my Z28 is a 600hp blown beast), but I didn't put that rig together without a lot of help from guys who've been there.

Originally posted by Dave K

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Everything I've read indicates that the Soobs are pretty particular when it comes to adding boost... very easy to break em. Your buddy should already know the answer to your question or maybe he's not quite ready to play those games (unless he's got the cash to blow on a new engine).

 

 

There not easy to break, just as long as dont detonaite.