KA-T E85 Fuel Jetting Charts

[spank044]

This year I am switching to E85 and plan on launching with a 100 or 150 shot and can't find any reliable information pertaining to the direct port fuel jetting. I have contacted Holley (NOS), NX, and Zex for jetting tables, but none of them have gotten me the info I need. They have charts for single port foggers, but not direct port utilizing the factory fuel pressure and a rising rate FPR. They have all been working on it for a week now and when I call to get an update, they still don't have an answer. I have done a fair amount of math and flow testing, but I just want to be sure before I spray. I'd rather be safe than needing a tow home from the track.

So does anyone have any jetting charts for a direct port E85 setup

[nelson8708]

Most say that e85 uses about 35-40% more fuel at WOT. So for a base i would use a 40% bigger jet. If this doesn't make sense its probably because i dont know much about spray

[spank044]

I've done the math, but I just want to know what jets others are using. Thanks.

[nelson8708]

Seems like spray i pretty rare in the ka-t world but, spray + e85 is very rare. You will probably have to hit up a e85 tuning forum or a dsm forum were e85 is super common. Found this after a quick google search....

I think your asking about how much N2O you need with ethanol.For a wet setup you ignore the atmospheric O2 and just jet for the nitrous and the fuel as I understand it.

For pure Ethanol it should be:

1(C2 H6 O ) + 6 (N2O ) = 2( CO2 ) + 3 (H2O ) + 6(N2)

That gives you a ratio of 1:5.28 by weight.

The problem is that figures the stoich mixture and you want to be rich of that to be sure you don't melt the engine. The usual recommedation for gasoline is 6:1, so you need to go quite abit richer if your using E85.

I would call the folks at Holley (NOS), Zex or Nitrous express and ask them for jetting. If all they have is jetting info for gasoline and Methanol, E85 should be about half way in between. I would trust their recommendations a lot more than our speculation about proper jetting.

They can also probably give you guidence on how to work up a jetting mix for a new fuel. Actually I'd probably send them an email so you get the answer back in writing.

If you look at it from a different perspective, the usual recommendation is to start with about a 5:1 or 6:1 nitrous/fuel ratio on gasoline. This gives an effective AFR or 11.4:1 for the nitrous on gasoline.

We know that E85 requires about 1.3x the fuel as gasoline for the same equivalent mixture, so that would imply you want to start at around a 4.6 : 1 nitrous/E85 ratio to have the same equivalent mixture as the 6:1 on gasoline.If you prefer starting at the 5:1 equivalent jetting that would be 3.8:1 nitrous/fuel ratio on E85.

I'd be tempted to take the recommended jetting for gasoline and reduce the Nitrous flow to 76% of the gasoline recommendation as a starting point.

The book "Sport Compact Nitrous Injection" has a pretty good detailed discussion about figuring out what you need. It's been a long time since I read my copy so would suggest you pick one up and dig into it a bit in case I missed something.

(caution -- I have not done this "yet" so am speaking theoretically here)

Larry

[WDRacing]

Just use 30% larger jets and a wideband. Thats how you should be doing it no matter what others tell you. Since fuel pressure almost always changes as rpm and boost rises on different vehicles. Start with a smaller shot and move towards your end goal.

WD

[WDRacing]

I forgot to add, tune for Lambda not AFR. But I'm pretty ure you know that anyway. So that's more for the other guys reading this.

[spank044]

Nelson,I've been on the DSM, Nitrous, and E85 forums lifting every rock I could find and I cannot find any solid info.

WD, I am going to be using my wide band on Lambda and have what appears to be a pretty good starting place, but I was just curious if anyone else was using NO2 and E85 together.

ThanksGuys

[GTR PrYdE]

Maybe this is the wrong advice but...

Why even use N20 when you're going to use such a bada$$ fuel like E85.

You can make just as much power as you would on C16, so are you past the point of making stupid high power? (700+)

[spank044]

You missed in the opening line where it says I will be "launching on nitrous" to help the turbo spool quicker and get my 60' down.

[GTR PrYdE]

You missed in the opening line where it says I will be "launching on nitrous" to help the turbo spool quicker and get my 60' down.

That I did... lol