Does anyone have thoughts or experience on running E85 with entirely stock fueling (stock pump, injectors, etc etc) but higher-than-stock boost?

If so, I'd be looking for what boost/ psi was possible and any dyno numbers.

Please no comments on "upgrade this" or "upgrade that;" that's not what I'm looking for and not an option.

 

I don't have any direct experience with this... But I reckon you'll be outta fuel before 20psi. Remember it takes about 30% more e85 to achieve the same amount energy as gasoline or "pump".. Thus you need a system that can compensate, which I'm sure you're very aware of.

I believe your first weak link would be the fuel pump, or you'll max this out before anything. Like before the injectors IDC% are maxed out..

 

Hopefully someone can chime in who has tuned such (stock fuel supply) an Evo on e85.

I'm very curious to see if people have gotten away with a low boost and aggressive timing, taking advantage of the e85 benefits.. Of course, while on the stock fuel system.. Or at the very least an upgraded fuel pump, like the Walbro 255

 

Just out of curiosity what are you trying to accomplish? I ask this simply out of curiosity and dont mean to come across as negative.

I dont believe anyone has attempted to run e85 on a complete untouched fuel system due to what has already been stated. You certainly will not be able to up the boost. If anything, I'd guess you would only be able to run wastegate pressure(12-13psi) which will end up creeping to ~18psi at redline and run far too lean.

Just thinking out loud here but and keeping the numbers simple you will be capped at ~270whp on the stock injectors on e85. Assuming PTE1000 (950cc actually) is good for 450whp on e85 (with a wally 255) the factory 560cc is 40% smaller which yields ~270whp potential.

 

I'm prepping for STU class in autocross which requires all stock fueling and stock boost control, as well as stock boost maps. With that, power potential is quite low so I was hoping to run dual tunes via a map switching harness-- one for autocross with stock boost, one for street with more boost. Ideally, both tunes would be on the same fuel. Technically, rules prohibit dual tunes but I only plan on competing locally where I shouldn't be protested.

I personally know someone who has run E85 in STU (ie, untouched fuel system, untouched boost control, and untouched boost maps) and he got 282whp on a Mustang dyno.

 

I say go for it

Have a good tuner who can find the limits of boost & the stock injectors which I think are 550cc. Run the duty cycle to 98%

My first run at E85 was 750cc injectors & the Walbro which netted 380 on the Dynojet

 

Very cool, I understand.. Let us know how it goes! I'm interested in some results. Please post if you do. Just be careful as others have mentioned. Watch your AFR and IDC%.

 

Have you thought about mixing it? Like 30/70 etc..

 

I'm running PTE1000's, and at 430whp, it's running 83% IDC .

 

I have thought about that, I've also thought about mixing pump gas with an octane booster since 2014 SCCA rules will ban E85 in ST* classes. What steers me away from mixing is the inconsistency, both due to varying fuel mixtures and the strong possibility of my own human error.

I'm still really debating all options and haven't landed on just one. I go between having one tune on stock boost with E85, two tunes on E85 and seeing how far we can push, one low-boost tune on E85 and another high-boost on pump, and even two tunes on pump.

What keeps ringing in my head is a buddy saying he always tries to prep the car as best as possible so results can't be blamed on the car, only the driver. That, then, would push me towards E85.

I think it'll come down to me determining if I can be okay with ~300whp Dynojet on a daily basis. I think I may be since I'm only around 340-350 currently.

 

I'd be very happy with 340hp in STU How did you get there? I need to get my HP up to increase my chances against National Tour level guys. Hopefully we'll learn abit from this thread.

 

I think Andrew Pallota ran e85 in his STU car, but I could be wrong.

 

Keep in mind, e85 is banned in ST after this year...

Edit: didn't realize you'd mentioned this already

 

the problem I see with a high/low boost plan is that the restrictors in the stock boost control hoses effectively set your max boost at very near the stock boost level regardless of WGDC. so unless you make an STU illegal modification to your car (specifically changing the size of/eliminating the restrictors) you're not going to be able to effectively switch to a "high boost" map with a simple reflash.

 

I modded my car then got into autocross. So I'm tuned above stock boost right now and have run ASP the past couple years because of that. I was very, very uncompetitively prepped for ASP so now I'm working on getting very competitively prepped for STU.