I have a friend with a TVS running 35% ethanol on 60s, we are planning on throwing some 80s in there and possibly bumping up the ethanol mixture to full E85. I was curious on how much fuel is the limit before a bigger fuel pump and an updated fuel system is required?

I am assuming if we ran E47 instead of full E85 it should have alot more room fueling wise as the WOT commanded AFR would be approx 10 instead of approx 8.

Hoping I can still get 25-26deg of timing out of E47 to be easier on the fuel system.

But there is also the benefit of accurate fueling above 17.5psi with Brfps or rsfs

The first log i could find from when we were MAF tuning has his 60s getting up there on a colder night.

 

I have a turbo lsj running e85 and 80s with stock pump/no return system. Maxed out the fuel system at 20psi.. A return system will help you quite a bit and the pump is going to depend on what year the car is since the stock pump in 06-07 is similar size as a 255 but a bigger pump would always help.

 

The return style will do more for you than a pump, but since you have to drop the tank to remove the stock regulator, most people upgrade the pump when they go in there.

Full e85 on 80's you will still run out of injector before you run out of pump, but the return style alone might then be enough to overwhelm the pump.

 

Anybody know about E47? Should be able to get more out of it, but then I would be worried about issues going off the stock IFR table. Timing on E35 is pretty impressive

Here is a picture of his WOT timing



If we could get timing up to that sweet spot around 25-26 on like a 2.9 that would be awesome.

 

Usually anything more than about 35% ethanol yeilds very little gain in timing. So i'd bump it to 27 if the fueling is solid and see if there's any knock. There shouldn't be. Granted I had a little more injector, but we ran a lot of timing on a 30psi LSJ-t and had no issues with straight e85. You should be fine on a 2.9 by a mile.

Just checked my last e85/2.8 car and it's at 24 on a nice safe tune.

 

It started knocking at 25-26 but the e85 is mixed with 91 octane gasoline. Usually 2nd gear pulls made it without knock but after 3rd gear pulls heat soak allowed knock to come in.

It would be a pita to mix with 93 because they only sell e85 at one gas station that has 91. I think 80s and a 50/50 mix on a 2.9 pulley would do very well.

 

When tuning on 93 the most we could get was 16deg, iat2 would only get to about 150. I have seen others hit 19 on gas

 

alky is harder to light then gasoline from ive read e85 s mixed with 87 octane to help the alky light off faster mixing e85 with 93oct will make it harder to light the alky off if your going to do e47 then mix with 87 instead of 93 if you put a return system on the car you can stretch the 80s a little farther also

 

Interesting, I will definitely try that and bump up timing if no knock. Hell that's cheaper anyways