Hey guys, so I did something a little crazy last night, I swapped to E85 on a whim. I want to hear opinions and experiences.

2005 z51, jerry formato spec'd cam, fast 92, ported throttle body, vortex intake, kooks headers, borla exhaust, still has cats, jeremy formato dyno tuned to 453rwhp/417rwtq at about sea level... car now resides at 4500ft... runs a tad rich I'd say by sound and exhaust tips because of elevation change I'd guess... I had a car scanner on it one time and noticed it has very aggressive timing, but I dont remember the exact numbers.

So last night I swapped out the ls2 33lb injectors for ls7 42lb injectors, added 2 gallons of vp110 to a nearly empty fuel tank, then babied it to gas station and got 14 gallons of e85 in it...

I continued to baby it for a few miles to mix gas tank and then proceded to slowly get in to it. I drove at least 40+ miles of mixed driving including a few ramps to top of 4th gear. Car seemed to run amazing. Pulled the nose in all 4 gears.

What do you guys think? Should I continue to run it? Do I need a different tune? Any major negative? I know you get less fuel mileage...

I do take the occasional couple hundred mile roadtrip and have looked at e85 maps, looks like i'll be good on finding it in my area...

 

So, you changed injectors, changed fuel. YES you need it retuned.

The 42lb injectors are 27% bigger and E85 uses 33% more fuel. thats the only reason you are running OK or why the engine didn't go pop.

Is your fuel pump stock? double check your fuel psi at WOT to verify you have enough pump.

-Carl

 

Yes, you should tune it. You may look for the one person who is going to say that you don't need to, but they aren't giving you optimal advice.

 

of course you should dyno tune it-- to take full advantage of the e85....

 

I would not do anything until I got more fuel flow from the pump.

 

I would never consider doing this without getting a tune, it's a different octane rating. I would limp it to a tuner before I beat on it anymore. Also, you have no clue what your injector duty cycle is..

 

check your fuel pressure. you don't want to run it lean and burn a valve

you need to TAKE IT EASY until the car is tuned or you will LET THE GENIE OUT

 

Well put!

 

Did about 400 miles this weekend of city/highway/interstate and some very fast(spirited) carving in some mountain highways... Runs amazing... I am def getting about 5 less mpg's on interstate and it does idle a little different...

If I decide to stay with it, I will order a bigger fuel pump next...

About getting it tuned, I emailed jeremy formato and am waiting for a reply... I think you guys underestimate how much of an aggressive tune I already have... On 91 octane with 33lb injectors I believe the car was maxed out on fuel, and would spit and sounded all kinds of good pissed off when you reved it, now it is smooth sounding as if about perfect fuel ratio.

I can not say enough about the seat of the pants feel, it seriously pulls the nose up like crazy in the first 4 gears...

Yes, Im def wary about not having a wideband on it or a fuel pressure gauge. Maybe even scared enough might convert it back to 91 octane until I do and get bigger fuel pump. But I def think e85 is a good option for our cars wether n/a or boosted if its available in your area.

 

 

Yeah man you are strumming the trip wire with what you are doing. You are INSANE not to run a tune that is specifically set for E85. Its totally different than gas. Wow, this is crazy what you are doing.

 

Whatever you say, champ. It's not like e85 and gasoline have different stoichiometric AFRs

And though you may not understand any of this:
http://www.hptuners.com/forum/showth...our-LS1-on-E85

 

Other then afr's, this article backs up what I'm saying... For the most part, just aggressive timing and bigger injectors is all that is needed.... I haven't experimented with tuning my car myself yet, but I'm far from stupid. Fuel injected cars have computers with sensors and can do a little changing of their own parameters... As if the millions of flex fuel cars/suvs/pickups on the road magically have 30% or more bigger injectors and fuel flow when you fill them with e85... If i'm wrong then so be it, i'll just build a high compression stroker engine and get it tuned for e85 once rebuilt. For now, it definitely seems to run fine and def seat of the pants is better...

 

Flex fuel cars have flex fuel sensors and blended fueling tables that handle the different levels of ethanol. The C6 does not. Yeah the tuning can be turned on, but the sensor is not there for what you are doing now. You will need an e85 specific tune. Sorry but you are way wrong.

 

I switched to E85, and think you're an idiot.

 

 

That article did not back up what you said. Not did it say that you need more aggressive timing. It said that an advantage of the fuel is that it is equivalent to a 104-105 octane gasoline fuel, which gives you the option of more aggressive timing without detonation.
You need bigger injectors AND fuel pump, depending on your build. But you have no idea what your fuel pressure is doing.
What you're doing is asking for trouble, when you could solve it with a simple tune, wideband, and a fuel pressure gauge.

 

I may be wrong, but I heard that unless a fuel system is designed to run E85, that the higher concentration of alcohol can prematurely degrade fuel system components? Seems as though that might be an issue.

Definitely get that thing tuned. Computers are good for a lot of things, but they are only capable of following the instructions they are given. They don't do well when you change the knowns without updating the program.

 

Lol.. wow.

IBBB (In before "Boom Bitch!")

 

Fault codes today finally after a little over 500 miles... Bank 1 lean faults... Probably gonna run half 91/half e85 with the 42lb injectors or swap back to 91 and 33lb injectors until I get a bigger fuel pump and an hp tuner ordered...

No boom yet, and like I said, If I blow it, then perfect excuse to build a forged stroker...

Someone needs to test stuff like this every once in a while to see for himself. Too much I heard this and I heard that on the internet, even on this forum.