Getting the most out of E85 - How much better is custom vs OTS
 

Hey guys,

I am striking out with the search box, and my STI friends are giving me conflicting answers.

I am currently running the OFT with an UEL header and the OTS E85 tune.

I do not have a flex fuel kit, but am considering buying the kit if I find it is worth it.

My question is for the experienced E85 users, is there power gains to be had by going with a custom E85 tune and or investing in a flex fuel kit?

I absolutely love the E85 maps, but after getting Shiv to custom make a 93 tune for me and falling in love with the reliability of the custom vs canned tune, does the same thing apply to E85?

I am not opposed to upgrading the fueling system if it helps.

Currently have a Mishimoto CAI, UEL Catless header, HFC in the front pipe, and magnaflow catback.

While I learn to track an N/A car, I am just trying to maximize the HP that can be safely found in our cars.

Thank you guys for all you do and any input you have to the matter.

- Balakay

Check fot knock and afr

Can help you with tuning if needed

My car runs so nice with the ots tune especially when I get a tank of real e85. When I can really smell the aroma of corn I know the ecu is gonna be happy.

If you 1) have reliable access to E85, and 2) you don't switch between 93 and E85 alot, I would personally just get a custom E85 tune. If both of those don't apply to you, a flex fuel kit might be beneficial to you. The car's ECU adapts very well to variances in E85 either way. On my E85 tune, I've driven around with as low as E62 before with no problems/knocking, but I don't track/race either so maybe I don't put the same amount of stress on my engine as others do.

As far as power gain differences between a flex fuel tune and E85 tune, the only way to really compare is if you get the E85 tune first & get it dynoed... Then install a flex fuel kit on the same car, & tune/dyno it again on the same dyno under the same circumstances. Which I haven't seen anyone do yet... Seems like too much effort & money for too similar of an outcome.

I’m pretty sure @Xxyion had an OFT OTS E85 tune originally, but then switched to the Delicious E85 flex fuel tune. Maybe he can chime in on this.

I wouldn't even consider not getting the flex fuel kit. I try to run e-85 most of the time but it's nice being able to run what ever you want and any mixture of either.

Same here. I won't touch the corn juice until I can get a flexfuel kit on.

FF kit + delicious tune ftw

I’ve been running E85 OTS tune for a couple years now. I made several tweaks to it (cold start, transient throttle settings, AVCS for my header, etc) but still have to limit timing to E60 levels since that is what we get in the winter in Arkansas. A flex fuel kit should allow the tune to be optimized for any fuel quality. The OFT is less flexible than Ecutek with custom maps. You can look up Ztan’s flex fuel work that was ported to OFT and decide whether or not that works for you.

I finally bit the bullet and purchased a delicious mk1+ flex fuel kit and Ecutek from HRI Tuning. The flex fuel kit is easy to install. I’m using HRI for the tune because of overwhelmingly positive customer feedback and unlocked tunes. I’ll post here to let you know the difference in how it drives if any once the tune is complete.

I’ve been running E85 OTS tune for a couple years now. I made several tweaks to it (cold start, transient throttle settings, AVCS for my header, etc) but still have to limit timing to E60 levels since that is what we get in the winter in Arkansas. A flex fuel kit should allow the tune to be optimized for any fuel quality. The OFT is less flexible than Ecutek with custom maps. You can look up Ztan’s flex fuel work that was ported to OFT and decide whether or not that works for you.

I finally bit the bullet and purchased a delicious mk1+ flex fuel kit and Ecutek from HRI Tuning. The flex fuel kit is easy to install. I’m using HRI for the tune because of overwhelmingly positive customer feedback and unlocked tunes. I’ll post here to let you know the difference in how it drives if any once the tune is complete.

I'd go flex fuel...
 

It cost me $150 to go flex fuel and it's definitely worth it to not have to worry about flashing back and forth...

Jaden

p.s. There is no reason to spend $2000 on a flex fuel kit and tune. Especially if you already have an OFT. If you need help, let me know. I can get you a fuel analyzer and tell you everything you need for the most bang for your buck.

ummm why couldn't you...
 

Why couldn't you just make a summer tune for better than e60? Also, it has been explained that there REALLY isn't any real gains to be had over e60.

The amount of additional timing you can run is negligible.

Jaden

Just to play devil's advocate, if you don't get a FFK, don't get a custom tune, save the money and stay with the OTS Stg 2+ E85 tune.

The biggest draw back with E85 is varying % of ethanol by time of year and sometimes by different gas stations. So a custom tune on E85 from pump A will maximize your gains... For pump A. It may be better, or the same or even worse for pump B.... It all depends on how much ethanol is in the pump you used last.

gyubo: not so bad. IIRC i recall reading, that it's enough to have E70 ethanol content for max gains on twins, engine of whose wasn't designed originally to run on ethanol. Even more ethanol content, even higher octane number won't allow to gain even more performance. So that "For pump A" should work for 90% of E85 pumps imho. I might be wrong, and also maybe it's different with forced induction though.