i am interested in converting to e85 and was wondering if anyone could shed some light on what all i need to change to get everything set up
injector size?
computer tune?
afr?
i will be putting on the le2 heads and have the cc503 cam with 1.7rr. that makes the cam spec out at 224/230 dur and .570/.580 lift and 11.2 to 1 compression. i have a walboro fuel pump on the car also.

 

[QUOTE=kalebm22;12434999]i am interested in converting to e85 and was wondering if anyone could shed some light on what all i need to change to get everything set up
injector size?
computer tune?
afr?

All of the Above...

 

e85 is great.. you will need 30 % more fuel that my need on 93.. def a dyno tune. i have seen many cars make 20-25 more at the wheels with e85.. and that is a car that is tuned already for pump gas..

 

e85 is nice, just wish it was more readily available and I'd convert in a heart beat, nothing like $2/gal race gas

 

so do you think that 42lb injectors will be ok?
will i be able to just get a mail order tune?

 

42lbs will be more than enough I imagine

 

do not get a mail order tune. they are only good for when you remove emissions stuff, calibrate speedo, turning the fans on earlier ect. is someone is gonna be playing with your timing and air-fuel its best to be done on a dyno or or driving around with the tuner in the car.

 

ive had 2 mail order tunes for my other mods and so far so good, is it just the switch to e 85 that would be hard? there was an option for race gas in my tuner card i filled out so isnt e85 about the same octane? the only difference is that i need 30 percent more fule right? i just dont want to pay 550 dollars and drive 300miles round trip to get it dyno tuned. i will do that when i build a new motor.

 

if you're gonna run high octane fuel to run more agressive timing/fuel, why would you spend money on a mail order tune that will be very conservative and mild.

trust me you have no idea how much you're leaving on the table until you get on a dyno

 

yea i realize that but i dont want to spend a bunch of money getting the car tuned with this motor. it is the stock bottom end and i dont think it will last much longer then i will be putting a 385 in and that i will definately get dyno tuned. i just want to convert now so i can get a little more power and cheaper fuel.

 

No mail order tuners have enough info or tuned enough cars on the dyno to tune yours or any other E85 conversion via mail order.

 

I ran E85 on my bolt-on LT1 for about 7 months before I stopped driving it. Initial tuning for a new cam/engine can be done via mail order gasoline tune, however further dialing in IS required in person before you can get it right.

Starting with the tune, set your injector size to .7 of the actual size in the PCM as a starting point to trick the PCM to supply more fuel. I would find what size injector you would need on gas, then get a 50% larger injector. I was hitting 100% duty cycle at 5200 RPM with just bolt ons on E85 with 30# SVO's. While stoich A/F for E85 is approx 9.8 vs 14.7 for gas, lambda value (what widebands 'really' read) is the same no matter the fuel. So on a regular gas wideband reading 14.7 A/F on an E85 engine would actually be at 9.8 A/F ratio since the display shows the lambda (stoich) value for gas but Is reading a stoich mixture of E85. Most widebands will allow you to change the display reading to lambda instead of A/F, if not just divide the displays reading by 14.7 to get the lambda value. This MUST be understood before you begin tuning for E85. With cruising, just as with gas, the PCM will be able to adjust for stoich based on the stock O2's assuming you are close on your initial PCM injector adjustment, .7 is a good starting point. Now you need to adjust for WOT power A/F. The basic process in doing so is essentially the same as with gas, except you are looking instead of 13:1 (.88 lambda), E85 likes around .81-.82 lambda for best power. So then tune your PCM as close as you can first by adjusting the injector size until close, then fine tuning the tune by the PE and VE tables as you would a gas tune.

Generally the tuning for E85 is similar to gas, once you get the needed injector value close, then continue tuning as you would for gas, but shooting for .82 WOT lambda instead of .88 lambda as you would for gas. As far as timing, being very resistant to detonation and at 100-105 octane (depending on the blend) 2* can be added across the board, and dyno tuning would be suggested to see if any benefit would be gained to adding more at WOT. I only gained 2rwhp and 5-6rwtq adding 2* extra to the WOT above the initial 2* across the board change to my gas tune on my bolt-on car.

 

Set your stoichiometric air/fuel ratio for about 9.765. Make sure there are non-corrosive fuel lines (not aluminum) in the vehicle. There is speculation about paper fuel filters as well. Most fuel injectors on cars in the last ten years can handle the increased flow. My GTO's 42-lb injectors are not at all taxed. Even the 30-lb (I believe) injectors in my 350HP 5.3 only hit like 70% of maximun duty.

 

Tuning an LT1 is not the same as tuning an LS motor, different computers. An LT1 PCM doesn't have an adjustment for stoich value, thus the reason you have to set the injector value smaller than actual to "trick" the PCM. Also regarding injectors, 30# injectors flow more with the LS 60psi fuel system vs the 43 psi LT1 system.

 

here ya go

https://ls1tech.com/forums/lt1-lt4-m...n-t4p-car.html

https://ls1tech.com/forums/lt1-lt4-m...5-520rwhp.html

 

so will a mail order tune work or not, im confused. i dont have the software to tune the car myself.

 

I wouldn't try E85 until you at least have the ability to scan your car to check the results. If not enough fuel is being added, your car can run too lean. You could theoretically tell the tuner to set the injector value to .70 of your actual injector size and it should run ok for normal driving, and you want a target 12:1 A/F ratio at WOT (which is what a gasoline wideband would read for E85 at 8.0. However, without the ability to scan and where it is running at WOT, seems risky to me. You aren't going to gain anything on E85 over gasoline without a proper tune and changing fuels isn't something I would do without being able to do it right. Just my opinion.

 

I agree. You should invest in a wideband and tuning software to do this properly.

I already have the wideband and gonna get tuning software to do this myself.


The alternative for you is to pay to have it dyno tuned.

Get a mail order with the injectors set at .7 their actual size, and limp it to the dyno.

A dyno tune is the way to get the best gains anyway.

 

ok thats a no then. i just dont want to spend the money to get this engine dyno tuned. its not worth it. i just figured i could pick up 5 hp or so and run a cheaper fuel. but if its not safe for the car im not goin to do it.

 

Yeah its not that easy unfortunately.