E85Forum.com

EddieCNC · Joined: 19 Feb 2011 Posts: 3

Hey Guys, new to the forum my 1st post. A few years ago I wanted to know what the power difference would be with a performance street engine built from the ground up to utilise Pump prem. gasoline vs. E-85. I built the stroker V-8 at 500 cubic inches, hyd. roller cam, ported alloy heads with closed chambers and a comp. ratio of 11: to 1 with a .040 quench. On the dyno I used 2 different carburetors with the same approx. Airflow flow rating. 870 CFM Gas 850 CFM E-85 Carb. The gas carb made 577 HP and the E-85 made 617 HP. The torque was 605 Foot pounds at 3800 RPM, peak power occured at 5800 RPM's. The engine sounded 'Crisper' on the E-85. I am going to install this engine in a project car this summer and drive it out to Seattle, Denver, Las Vegas from Indiana. I really enjoyed my E-85 experience, it is a bit harder to read the plugs but I dont really consider this a disadvantage as I use a LM-1 Airfuel monitor and try to keep it near the 7-9:1 stoich. range anyone else have any suggestions as to the ideal AF range is? Thanks

hotrod · Joined: 19 Apr 2005 Posts: 872 Location: Colorado

Welcome to the board.

Thanks for your comparative power/torque numbers.

You will find lots of discussion here on the forum regarding ideal fuel air mixture.

If you do a search for "lambda" you will find a whole page of threads to browse through.

Here are a couple of them:

http://e85forum.com/viewtopic.php?t=1146

http://e85forum.com/viewtopic.php?t=998

My best performance was with fuel air ratios near 0.76 to 0.82 lambda on an LM1.

Lots of folks discuss fuel air mixtures using the gasoline AFR as reference because not all have the ability to convert to or calculate the true E85 AFR. So be sure you know which AFR reference point folks are using. I prefer to think in terms of Lambda now but in the beginning I also tended to use my previous experience with gasoline and just used those numbers to understand where I was at.

My first conversion was at an AFR of 11.5:1 (gasoline AFR) or about lambda 0.78. I then tried richer mixtures but the car seemed to get lazy when the mixture got down to 0.76 and richer.

This is on a turbocharged Subaru WRX so you should check out some other of these threads that have more similar engine setups to what you have.

Larry

EddieCNC · Joined: 19 Feb 2011 Posts: 3

Thanks a bunch Larry. I really like E-85 and want to do a bit more tuning. When I get the engine installed I have access to a SuperFlow Chassis dyno and can make as many runs as I wish. I'll be sure to place dual bungs in the collector tubes and my LM-1 although a little long in tooth, can read in Lamda or Stoich,Gas/Ethanol Blend. E-85 around here is currently 2.89/Gall. Thanks for the links,,great reading!