Is it worth waiting for E85? Few Evo build questions

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Feb 19, 2012 | 07:53 PM

#16

evo8426

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From: Charlotte, North Carolina

Ok know it all! ha run e85 on your car and tell me that the air fuel ratio doesn't change when the temp changes. since you have personal experience with it. why are you asking questions since you are so smart? and yes e85 does change every several months that why there are 3 classes, you should check out the scheduling and you will see for yourself that it does in fact change. i seem to know more than you about this since you're the one asking questions. it has been stated many times by reputable tuners that the weather does affect the air fuel ratio. i tune my own car so i have 1st hand experience with it so im not "hoping" for anything. you dont need an ignition upgrade but feel free to waste your money, i was only trying to save it for you.

Feb 19, 2012 | 08:13 PM

#17

codgi

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From: Atlanta, GA

Quote:

Originally Posted by PatricksEvilEvo

Ok first of all, there is NO need for an upgraded intercooler with the stock turbo. Little do you know, the stock intercoolers these cars come with cool very well. SO to answer your question, yes I will be running the stock intercooler until I upgrade the turbo. Second, the temperature outside has NO influence on how the motor runs. Engines do not care what the temp outside is. The fuel companies change the octane level so normal flex fuel cars have easier cold starts. Again, the temp outside does not matter, it's the mixture of the fuel. Second, no the fuel mix does not normally change every couple months. Usually it's either 75% or 85%. Give or take a little but right around there. Yes I can tune it to run rich on 75 and it will lean out when it changes to 85 but I'd rather not do that.

Oh yea, FYI, getting your car tuned to run 70-75% and HOPING your car isn't gonna lean out on full 85 is NOT the safest or smartest thing to do but rather a gamble.
Also I do need an ignition upgrade, I do not want to max my stock ignition out and risk break ups and miss fires at 30+psi
Thanks for the useless facts tho!

1st of all, the stock intercoolers on the Evo do cool well if you keep the stock turbo and run it in its efficiency range. 30psi is well outside the efficiency range of the stock turbo and to run it that high with the stock intercooler is just going to blow hot air which means you have to run less timing to keep it safe.

I did this with the stock VIII turbo, logged IATs and they were through the roof. I actually heat soaked the stock IC on the dyno back in 07. 2nd run the car knocked like crazy and the chart just fell off. Switched to a 3" ETS IC ran the same tune and IATs went down dramatically. Allowing me to bump timing up safely and make more power and guess what? No heat soak on the 2nd run.

2nd of all the external temperature does affect how the car runs. Colder air is denser...so even off boost when the temperature drops you get more air into the engine...It also helps the IC cool the air better so when it is colder outside the car could run better than when its hot. And this does not even get into how any BCS system which doesn't understand temp will send your boost much higher in the cold than in the hot. The stock ECU has a temp compensation tables that are supposed to help even this out but I never noticed it to help as much as I would have hoped and I have been tuning/logging my VIII since 2006 in the Pacific NW at all times of the year. I can't speak to the later tephra hotness since I've never used it

I won't get into the fuel thing since I don't use E85 and can't speak to it

Last edited by codgi; Feb 19, 2012 at 08:21 PM.

Feb 19, 2012 | 11:42 PM

#18

gpfury86

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From: Indianapolis

Quote:

Originally Posted by PatricksEvilEvo

Ok first of all, there is NO need for an upgraded intercooler with the stock turbo. Little do you know, the stock intercoolers these cars come with cool very well. SO to answer your question, yes I will be running the stock intercooler until I upgrade the turbo. Second, the temperature outside has NO influence on how the motor runs. Engines do not care what the temp outside is. The fuel companies change the octane level so normal flex fuel cars have easier cold starts. Again, the temp outside does not matter, it's the mixture of the fuel. Second, no the fuel mix does not normally change every couple months. Usually it's either 75% or 85%. Give or take a little but right around there. Yes I can tune it to run rich on 75 and it will lean out when it changes to 85 but I'd rather not do that.

Oh yea, FYI, getting your car tuned to run 70-75% and HOPING your car isn't gonna lean out on full 85 is NOT the safest or smartest thing to do but rather a gamble.
Also I do need an ignition upgrade, I do not want to max my stock ignition out and risk break ups and miss fires at 30+psi
Thanks for the useless facts tho!

I guess all this time all these racing teams have been wasting their money on buying weather stations that inform them on temperature, density, and adjusted altitude, because it's irrelevant in tuning their engines. Good luck on running that much boost on a stock turbo and intercooler, the e85 might help keep knock down, but like was said u might have a hard time with consistency. I really don't think the stock ignition is gonna be a problem, I run e-85 on a stock viii turbo with 1200cc injectors and spike to to 28 psi and redline out at 23 or so and havent had any issues.