I am going to pull the old EVO onto Road Atlanta in early may. My question is my brother is going to be out there with an Audi S4 with exhaust (full), computer mod and setup for 100 octane, lowered and wheels. I know we will probably end up racing. How bad will I get eat'n? Also, can I run the 100 oct. without any mods, the little beast is all stock??

thx, all...

Oh, I am from Tampa...

 

Will be somewhat close. From a roll i would prolly lose to that setup. From a dig it should be close. Good luck

 

From my experience of owning an S4 with MTM computer and exhaust, a stock Evo can't compete on the top end. IIRC the S4 should be putting about 320-340bhp with about 370-390lb/ft. The S4 is a whale and would need full coilovers and other goodies to give the Evo a run on the corners. A stock Evo will take advantage of higher octane up to 94, 10gal of 91oct + 4gal 100oct will give desired result. An Evo running on 94 will put up more of a fight on the top.

 

With 91 pump gas being the norm in Cali, I run a blend of 91/100 to keep it around 94...

The Evo has an aggressive knock sensor and I'm sure I get more timing running higher octane... in fact, I think we would benefit from higher octane than 94...the ECU would advance a little more timing...the manual says 94 minimum...

Plus it's good insurance against detonation on a hot Cali day or a summertime Vegas run

 

No, it doesn't.

[EDIT: Read below for clarification.]

 

It's going to pull timing running 91...

 

with 100 oct you will notice cleaner/harder pulling on the top

 

I never said it wasn't. I simply stated that you are incorrect in saying the manual says 94 minimum. In fact it says in both the shop and owner's manual that 87 ([R+M]/2) is the minimum octane.

 

Based on my experience, the stock Evo will take advantage of octane levels higher than 94.

I ran a tank of 100 octane last October... Then when I went back to 93 octane from the local station, the car drove like crap initially upon leaving the service station -- like it had to retrain to the lower octane fuel. I've never had that happen going between 94 and 93 octane. I took that as rather convincing evidence that octane levels above 94 actually do make a difference on a stock Evo.

 

The real only way you will experience much HP gain would be with the use of a boost controller with the 100+ oct. Pump it up to 23 psi and roll. With just race gas in the car you wont experience much more power. From my experience a S-afc and Boost controller are you best freinds when it comes to the race gas.

 

The manual says the car is designed to run on 98 RON...that is 94 PON (or pump octane)...

"Designed to run" is minimum for the car performing as intended... anything less and the ECU pulls timing...

I did not mean minimum "safe" as in you can get away with it...the ECU will protect the engine and pull timing...run what you want, its your car...

 

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Well, Jamie , when I decide to let you start calling the shots I'll tell you...

Make a contribution to the thread or don't...you are posting worthless flames instead of adding to the topic...

bbuevo...sorry for the hijack bro...

You can use the search function...there are other threads on the topic...all of them support my take on it...run a blend for best performance...I run $20 of 100 (at $4.49/gal) to every fill up of 91 for the reasons stated above...

Enjoy your Evo

 

Dear ______,

Please forgive my attempt to try and halt the continuous influx of misinformation that is haunting this forum. Your post which stated 94 was the minimum required by the manual is grossly incorrect. As I stated, the manual clearly dictates that 87 PON is the minimum. It also mentions that performance may be diminished with fuel rated less than 98 MON—something that you mentioned and I never refuted. Now onto another error: You state 94 PON=98 RON, which is not always correct. PON depends not only on RON, but also MON. Since PON=(RON+MON)/2, your statement is only true if MON=90. But if MON is 88, PON becomes 93 and so on…

Now, from personal experience, I realized minimal gains in going from 93 PON to 100 PON on a stock setup (the ability to up the boost would alter this, but that’s a whole other threadjack). However, once I moved from 93 PON to 91 PON, I noticed a decrease in performance and long to get it back. You can still have fun on 91, but if you have the means, I’d also recommend some mixing.

 

All: Please speak freally, I am just looking for information. I guess we will see what happens in may. I will probably go with a mixture (93 and 100) just because I will not be able to drain the tank (obviously). I will take some pictures and add to the database of EVO info. My whole intent is to have fun and not brake anything. One more thing, my bro picked up one of those 0-60, 1/4 mile meters from Circuit City, he wants to guage his times. What he told me was that he did a 0-50 @ 4.2 - 4.3 (according to the meter). I know this cannot take the place of a hard run, just an informal guage. Take care all...