Tuning for E85

[UTRacerX9]

Here's the deal... I'm trying to get my car registered and back on the road. Adam and I were talking about it, and one of the big hang ups is passing emissions in TX. He suggested I try tuning the car for E85, and he said a friend of his was able to pass with no cats/emissions devices on his car.

So I did some internet searching, and found some more cases where people have passed with no cats.

I'm not exactly sure how I'll need to tune for E85 though. Currently I have 550cc injectors. Using 35% as a guide to how much more fuel I'll need, I come up with approx. 490cc (360cc times 1.35.)

Now, I am NOT LOOKING TO CONVERT to E85. I know I don't have enough injector/fuel pump to be able to run a decent amount of boost with my 13T's. All I want is to tune the car to be drivable on 100% E85, at a stock boost level, to drive to the inspection station and back.

So, what should my settings be, ballpark? I have a MAFT to tune, currently it's set for 550cc. Do I turn it down slightly to 500cc and limit max boost, or do I set my MAFT to zero and turn the pressure down a bit on the 550's to equal about 500cc, and have no ECU correction?

[familyMAN]

If you have 550's in; 550 x .7=385. If you set the maft to zero out, plus lower you base fp a bit, your car should run as if it has stock injectors. I would think you would want to err on the lean side just a bit, for emissions. Hopefully they don't do a visual check also, because no cat=fail in AZ, even if you pass the testing portion.

[UTRacerX9]

If you have 550's in; 550 x .7=385. If you set the maft to zero out, plus lower you base fp a bit, your car should run as if it has stock injectors. I would think you would want to err on the lean side just a bit, for emissions. Hopefully they don't do a visual check also, because no cat=fail in AZ, even if you pass the testing portion.

That's what I was thinking, but another part of me is thinking that I still need to tell the ECU that I'm running 550's to match up with the airflow the ECU will be seeing.

There is a visual inspection, but I've seen several inspection stations that don't actually get under the car and look for a cat. If it passes, they assume it must have one. And of course, I'm not worried that they'll see my EGR valve is gone, who would even know where to look unless they owned one? Thanks for posting.

[familyMAN]

Just make sure you turn the boost down. 550's are only good for a max of 380ish awhp with E85.

[niterydr]

Why can't you pass with regular gasoline? I've tuned cars that have passed tailpipe w/o any cats and run on 92 octane....
Don't go to lean on idle or you will fail as well due to fuel trims and the higher hydrocarbons that may be obmitted.

Does your state do a readiness test?

[UTRacerX9]

Why can't you pass with regular gasoline? I've tuned cars that have passed tailpipe w/o any cats and run on 92 octane....
Don't go to lean on idle or you will fail as well due to fuel trims and the higher hydrocarbons that may be obmitted.

Does your state do a readiness test?

Each state sets different guidelines for emissions testing as to what is an allowable limit. I know a few guys who have tried to pass their cars running 93 octane and no cats/egr, and they've all failed over the years. Maybe your state doesn't have quite as low of a bar as we do?

Not sure what you mean by a "readiness" test. They do a quick parking lot drive, test the brakes, horn, wipers, etc. Then if you're OBD2 they plug you in. OBD1, they sniff the tailpipe. Supposed to do a visual inspection as well, but some stations are a bit more lax than others.

[Frostedbutts]

Is passing off a benjamin out of the question? I don't know how much time you have on your hands, but after the tuning and testing you're still just going to be crossing your fingers that you pass.

[Sin'sVr4]

why not just put the cats on for the test, then take em off? No emiisions here where i live :)

[DuTTch]

Each state sets different guidelines for emissions testing as to what is an allowable limit. I know a few guys who have tried to pass their cars running 93 octane and no cats/egr, and they've all failed over the years. Maybe your state doesn't have quite as low of a bar as we do?

Not sure what you mean by a "readiness" test. They do a quick parking lot drive, test the brakes, horn, wipers, etc. Then if you're OBD2 they plug you in. OBD1, they sniff the tailpipe. Supposed to do a visual inspection as well, but some stations are a bit more lax than others.

The readiness test is an OBDII thing, they plug in the pc and it checks if all is working, if it is, your are done! No sniffing tailpipe.

[UTRacerX9]

Well... after a 4-5 month hassle... I got my inspection done. :suspect:

Didn't end up having to tune for E85, though since there is a station not too far from me I still may end up going that route, if a hotwired Supra pump can supply enough fuel to run 17psi or so with 13T's. I would just need bigger injectors I think. Based on Jeff's site and his injector page, I think I could get away with a single Supra pump, but would it be worth it for just running 17psi? (Which is what I run now, 16-17psi on 93.)

[vr3.9]

I went with a half and half solution for a while. 550's and a walbro provide plenty of fuel. Turn up the fuel pressure. I used an SAFC, so doing the corrections was pretty easy.

[UTRacerX9]

I think I may do that fairly soon before going 100% E85. First things first though... I haven't changed the tune for years. Started it up the other day and drove it for just a bit, idled fine, accelerated fine, but didn't really hammer on it yet. Need to dig out my datalogger than I haven't even seen in years to make sure I'm not getting any knock before I start getting crazy with it.