Inigma

Hopefully this is the right section for this question. What does it take to convert a blown C5Z to E85?

Is it as simple as something like a proflex commander, possibly bigger fuel pump, bigger injectors, and a tuner familiar with E85?

Or is it way more involved than that?

Can someone point me in the right direction?

I know the meth injection is a lot more common, but I’m trying to avoid having to hide the methanol injection line every other year for smog visual inspections here in CA. I don’t want to have to rely on a guy that knows a guy who knows a guy for smog either.

Thanks in advance for any help.

mykream

Do you want flex fuel or straight e85?

Inigma

Flex fuel would be nice, but straight E85 would be just fine too.

The car is not a daily driver and I have E85 near me. So the only thing I’d potentially lose is out of town trips. Which we don’t really do those any more since the kids.

Also, it’s not a track car. Just an around town fun car. Not likely to ever be a track car, but who knows how I’ll feel in the future.

mykream

I would go straight e85. Because converting to flex fuel on these cars is no simple task. The proflex is not true flex fuel.

So with that said, pump, injectors, and possibly an external regulator depending on pump.

neutron82

for straight e85 just build a system for it with compatible pumps and injectors that won't corrode and get it retuned, you will need to keep an eye on the mixture you put in the tank though since your tune won't make changes like a flex setup will... I have been running mine for close to 2 years on e85 full time and haven't had any issues, luckily the place I buy mine from is pretty consistent

chris308

OT, would you suggest E85 for a non daily car? Maybe driven once or twice a week...

I was talked out of going E85 by my builder/tuner since I don't drive my car very often.

mykream

Nothing wrong with that at all.

neutron82

I only drive mine on nice days so not all the time, nothing wrong with that as long as you have the right parts... if you leave injectors and pumps submerged in ethanol for extended periods of time and those parts don't have stainless internals then they could corrode and cause problems

ysb02

There’s an ecu hack/swap that brings some flex fueling to the c5 but otherwise it’s 3rd party ecu time. You can get away with running e85 and just monitoring the % via a sensor. If it deviates too far from what % you tunes it at you can just turn it off.

C5-4LV3

I was able to find a true Flexfuel sensor for Fbody/C5 Stock PCM, our PCM only reads up to 14psi of boost if you’re FI.

I have a friend running it, and works fine between pump 91 and corn. He has a 01 base, H/C/I
our tuner was able to flash 04 z06 tuning tables to the car through some kind of wizardry, he was able to adjust off of the 04 tables as they included flex fuel tables in 04+ for tuning.

i will be going in for Tune Tuesday with my LS3 swapped C5 with a little boost..
Ill be using the same flex fuel sensor so I’ll keep some results posted around once I get them, I’m on Snakeeater Performance 1500CC’s, a walbro high pressure 450 e85 pump, and “TheTuningLab” flex fuel sensor, I have upgraded Holley rails but the sensor worked fine with stock rails/system

here is the link for all my C5 friends to unlock the solution to the flexfuel issue..they also have a p59 pcm upgrade option for more boost!

https://www.thetuninglab.com/product...r-99-02-f-body

nullpointer

Site says 2 bar is 14psi but that's only 1 bar. It doesn't work with an OS flash for 2 bar?

TimbrSS

2 bar Map sensor: 1st bar is Vaccum-Atmospheric ( 0 to 105 Kpa like NA stock setup), 2nd bar is 105 to 210 Kpa (Atmoshperic-14.7 psi boost.)

I'm guessing they can't do a 3 bar setup with the flex fuel segment because the older PCM doesn't have enough room for the expanded 3 bar table.

neutron82

mine is setup for 3bar using a zr1 map and my tuner had to rewrite the os and scale the table... there is an option in hptuners to upgrade to 3bar sd os, is this not possible on some cars?... I have no idea just curious

Toys4Life C5

Alternatively you could experiment with different levels of ethanol (provided you know how to tune) to find the amount that prevents you from being spark limited with your particular boost level. It might be less than 85%. Here is an excellent video on the topic to better explain what I am getting at.

Podium

Some Operating Systems have limits to what they can run. Some cars can only run a 2 bar some 3, some none.

FourG63 97GST

simply put, you need injectors and a tune, if you're going to run straight E85.
I have a secondary fuel system. but that only comes on on the demand. My oem system have been doing the primary work since 2014. I only just replace my stock intank because I wanted a bigger pump.
the downside to E85 is if you dont drive the car. people experience injector clogging, and that's the smallest part of the system.
I drive my car weekly, so i've never experience that. if im doing a build, generally i'll pull the injectors as a precaution, and have them flow checked every year or so.

neutron82

or get good injectors with stainless internals, they won't be cheap though as we all know lol... personally I have had good experiences with fic

Toys4Life C5

My 87 3800 supercharged fiero has been on e85 for 5 years. I was told it would eat the rust out of my tank and clog my fuel filter and clog my injectors. I simply added 60lb injectors, ethanol compatible hoses and have had no issues. The car is rarely driven from Dec - April each winter. With that backdrop, I call BS on the injector clogging issue. Just make sure your new injectors are E-85 compatible.

FourG63 97GST

I wont go as far as saying it's BS, I've seen build up on injector tips before and clogged fuel filters on other cars. if your fuel system is dirty, i'll clean it out, which then clogs paper filters

Podium

Agreed. It’s not BS about the clogging. I’ve seen it on multiple cars. If you let it sit, it WILL clog. I’ve been running E85 since 2006. It takes awhile to coagulate, but it will and ruin parts of your fuel system if it sits.