E85 and High Compression/Boosted Engines

I was running a fairly radical engine on the street, and decided to up the power more. With E85 being reasonable available here now, I redid my fuel system to supply the needed 30-35% more fuel at WOT, and added a very high output Vortech YSi supercharger. What a BLAST, the car screams now making 825 RWHP at only 15 psi of boost.

This Fall I upped the boost to 20 psi, and the car was just barley drivable with Drag Radials on it. The one down side, was I did not re-calculate the fuel pump needs for the added boost, and almost did some serious damage to the engine. I lucked out and only lifted the heads, and blew the gaskets.

The good thing is, after 3 years of use, the engine looks like it was just put together. This is with only wiping it down with some WD40.


 Engine after 3 years of E85 only use




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393bird's picture

I made up a web page about using E85 in High Performance applications.



1934ChevyRat's picture

nice work

if someone can invent it, you can repair it you, just need to try, Plus maybe have a repair manual

IrisHockey's picture

Question: How tough was it to convert the fuel system to be able to run E85? Are you EFI or carb? Block does look nice and clean.

"There are two ways to do things; the right way, and again." - Matt Melton

393bird's picture

Since E85 uses 30-35% more fuel at Wide Open Throttle (about 15% more at light cruise), the biggest thing is increasing the fuel system flow capacity. Pre 1980 cars had a lot of natural rubber, and paper gaskets and filters in the fuel systems, that will not hold up with E85. If you are increasing the HP with other performance parts, plus E85, you will most likely need larger fuel lines, a higher output fuel pump. and bigger injectors if EFI. If carbed, you need a carb that has been completely re-calibrated for E85.

Performance use of E85.

I am running a carb. Here is a bunch of carb info I put together

EFI use

Using it on a Supercharged EFI is slick. You can have a dual program chip, and one position set for 93 octane, and the other for E85.

DRC's picture

Great job, you sound like you have done A lot of homework on this and gained A lot of valuable information, thanks for the links and lesson. Glad you didn't totally detonate your engine, bet it was A scarry moment for you. Looked at your pic's and got to admit even though I prefer GM I would love to own A bird like that, it's awsome.

393bird's picture

Thanks, it has been a FUN Project. My very first car (in 1960) was a 1953 Henry-J, that I put in a 57 Studebaker Golden Hawk drive train. The GH came with a supercharger on it standard, so I have messed with SC engines for a long time.



grantb's picture

i have to ask ?????with  825 RWHP how do you keep it hook up with the back tires you have on it ??????

grant b

393bird's picture

The wheels are custom made, and are 9 inches wide, with a lot of back space, making them look near stock. I run 275/40/17 Drag Radials on the street, and 275/60/15 MT on the strip. With it being automatic, and a lot of suspension work, it does pretty good.

Rear Suspenion


If I had the shop space, I would back half it, and turn it loose.  Being Retired, I can not afford to pay someone to do it.


grantb's picture

THANK FOR ANSWERING!!!!!!!!!!!That's COOL and a  lot of work!!!!! WOW !!!   i had to ask ! i had 12" wide on mine before the tire upgrade it was "INSANE" to drive,i have  mine  set up so as the blower passes the 15lbs mark both 750 secondaries open  and it would literally BLOW THE TIRE OFF at  about 100 MPH i mean tire smoke  IMPRESSIVE  yes!!!! SCARY EVEN MORE!!!!!!   and i only drive one way   ALL OUT !!! LOL  yours must be a blast to drive? some thing is right if you put it to the ground !!!!!!!!! no need for a back half lol

grant b

393bird's picture

I checked out that beast of yours. I bet it is a blast. :)

I guess mine being a centrifugal super charger, it makes the power come on a little more linear. Your roots hits so quick, you have to have huge tires for the instant torque. If I had a roots or screw on this, I would have to back half it, or park it. :)

I was already told to slow mine down, or convert it to 10 point. I want to keep it a fun car, not a track only car. It is fun to drive into the strip, and put several guys on the trailer, then drive back home.



grantb's picture
to true, that why I asked, with the way you have it set up it perfect weight/ power /traction    i would love to watch it fly .i no what you mean about slowing it down ! i wont  do it ether mine is a street killer !!! it gets HORRIBLE GAS'S MILEAGE  but i love it . i can accelerate so hard  it leave almost all copilots "BREATHLESS" literally .it kinda mean but a lot of fun if you time it right !! lol lol

grant b