Yep with the new motor once it's broken in fully(since it is at < 100miles). I'll be going this route. I already have 750cc injectors in the car, the only bit I didn't have was the fuel pump. I had concerns about the walbro pump being truly e85 friendly. But really it's the only way to really use the 12.7 compression, the timing is very conservative on 91. Too bad we have piss poor e85 availability in CA. Which is actually really odd since it does burn much cleaner.

 

I wouldn't waste my time doing fuel upgrades for e85 on a stock N/A motor. The gains won't be worth it, especially for the drop in fuel economy

 

I definitely wouldn't have bought bigger injectors ONLY for the oportunity to run e85. However, since I already need bigger injectors, and found a good price on injectors that are definitely big enough for e85, I figure it will be worth a try. Besides, I really enjoyed tuning my car the first time, so I'll enjoy tuning it all over again for e85.

 

Well to be fair, people make the mistake of thinking e85's benefit is for its octane rating. Frankly other than people running crazy compression on the street, that's mostly irrelevant. The benefit of e85 for any car is that it carries oxygen in the fuel. If your fuel carries oxygen then it's like gaining increased displacement from the fuel itself. The fuel provides ~8% of the oxygen it needs to combust, so it should be similar to ~8% gain in displacement.

If you start out with 210whp in theory using e85 alone should boost that to 210*1.08 or ~226. Not bad for a computer + injector + fuel pump. for those of us who needed computers + injectors already it shouldn't be a bad gain for a fuel pump alone.

Now the 8% is what the chemistry says, once my new engine breaks in more I'll do a back to back 91 and e85 dyno with tune to see what the real delta's are.

 

On a n/a motor with e85 can u just use a walbro and bigger injectors? Would u need an external pump too?

 

I don't think this is right. From what I've been reading, ethanol has a lower power density than gasoline, so 1 unit of E85 will not make as much power as 1 unit of Gasoline. However, you are correct that E85 doesn't require as much oxygen to burn, so you can burn more of it in the same sized cylinder. This ability to run much richer supposedly offsets the lower power density enough that more power can be made, but I don't think you can assume it's 8% for the reason you mentioned.

BTW, this is similar to nitro methane.

 

I'm going to try it with the stock pump and larger injectors.

 

Throwing in a walbro only took half hour I believe.

The fuel pump was 90 bucks.

Not bad at all I would say.

BTW doubt it's worth it for n/a, but boosted cars love it and seem to be making massive power with a cheap price. I've done my research and talked to enough people to be making the switch next spring. This winter I will be taking out my ID725's and selling them to get ID1000

 

yes ethanol has ~70% the energy per unit volume that gas does. This is why from a gas replacement point of view it's somewhat silly given that the economics of e85 don't really make it cheaper.

However this is about engine power. Fundamentally generating power requires two things, air and fuel. In pure combustion it's oxygen + hydrogen = water + energy. Your motor's power output isn't limited by the fuel it can take since it's a small fraction of volume is used by fuel, it's limited by the amount of oxygen we can take in. That's why we have forced induction, high flow exhausts and freer flowing intakes. All designed to get more fresh oxygen in the chamber to generate more power. That is the beauty of ethanol it's bonded with it's own oxygen so you need less from the outside air per unit of fuel. That's why it runs richer because you can put more fuel per unit of outside air. Now if the volume of the chamber were significantly consumed by the fuel then the density would start to matter more.

NitroMethane is a great example. It is highly combustible because it needs so little oxygen to burn. This makes it dangerous even in low oxygen environments. The AF ratio for nitromethane is 1.7:1 which means it only needs 1.7lbs of air for every 1lb of fuel to burn. Gas is 14.7:1 and ethanol is 9:1

Now the 8% was calculations I did a while ago, even if we rebate it by 70% density of gas that's still 5-6% better output. You'd still have a 10-12hp gain on a 200whp motor.

 

There are sensors for e85, could you wire that and relay the tables for an timing kludge? Say run it main tables for e85, sensor trigger for normal gas cuts the timing back and leans a bit as a failsafe?