dan l

iTrader: (3)

I was wondering how you people are tuning your E85 cars. I can't realistically get this car to knock now and I don't want to go crazy with timing. It seems that you need to watch the torque curves on the dyno. Does anybody lean on the knock sensor on E85 or what do most people do?

RazorLab

iTrader: (8)

welcome, you aren't going to want to go back to pump.

I've noticed, depending on AFR, etc that E85 can sometimes (depending on car/mods) go beyond MBT without knock. So you have to be very careful and not get greedy.

Obviously this is easy to see happen on the dyno. Street software might work but YMMV.

90% of the cars I have tuned so far on E85 I have been able to go beyond MBT without knock, and of course I dial it back after that.

dan l

iTrader: (3)

Trust me, I don't want to go back. I now know why E85 gets worse gas mileage, its because I can't keep my foot out of it. I think I got some "E70". I can get it to 1-2 counts of knock at boost threshold aka peak torque, but that's it. I just added about 4 degrees up top and 1-2 at peak torque as well as bumping up my idle and low load timing. The dyno is about an hour away and is gonna cost me a few hundred to spend the time to make an E85 tune, perhaps in the spring I'll do that.

edit:

I'm running about 10.8-11.2 AFR. I have it going a tick rich at peak torque then I try to hold 11 flat to redline. The idle is amazing, very strong idle and off idle power. The fuel trims really shaped up. I'm at -1.5 low and -2.0 mid and it has been holding like that for 150 miles, really nice and consistent.

RazorLab

iTrader: (8)

yea I tend to get a little noise sometimes at peak torque as well.

What peak timing are you running currently? (peak meaning highest timing at WOT)

What peak boost #?

What AFR are you running with it?

dan l

iTrader: (3)

I come in at about 7-8 degrees at 250-260 load and 3500-4000rpm (depending on what gear I'm in boost hits sooner or later). I then take it fairly easy only getting to about 12 degrees at 6000rpm where I'm able to hold 22psi and 250% load. Then load and boost falls off and I really run the timing up, 18-20 at 7000+ rpm. I'm trying to keep afr's below 11.5 for now. I tried to add an attachment, the arrow is pointing at 7000rpm's at the end of the third gear on this third-fourth log really pounding on it.

Right now I'm going through the stock downpipe and cat. I only have a catback exhaust and FIC 1150's that flow 1190cc/min and of course a 255HP and GM 3 port for boost. Other than that stock down to the paper air filter.

RazorLab

iTrader: (8)

What peak boost are you running? Try taking a degree or so out at peak boost if you are running 24psi+ and see if it cleans up that noise you are getting.

It's amazing how much smoothing the whole car runs with E85 isn't it?

If you go a little leaner it will start clearing up as well.

dan l

iTrader: (3)

I run 20psi till 5000rpm's at which point I try to run 22psi to redline. In reality at 6500 or so it starts the taper to 20psi at redline as the stock cat is killing me. I don't really need any more low end grunt, the stock clutch complains a lot as it is. Is 11 flat rich on E85? I'm accustomed to running 12.0-12.5 on pump fuel. On race fuel I strictly run 12.5-12.6 when I'm trying to go fast. Those shenanigans are usually left for my DSM as I don't care about it so much. But the motor looks fantastic when I inspect it and the reliability has been top notch in that car with those AFR's.

Yes its amazing how smooth this stuff burns. I pulled all my plugs to do "old school tuning" and it looks like its doing the scrubbing bubbles to them.

RazorLab

iTrader: (8)

I've been running 12.0 on my personal Evo. It seems to like it.

Gasoline calibrated

mrfred

iTrader: (50)

That sounds like really high timing with a stock DP and cat. I did a bunch of timing observations, and at say 7000 rpm and 20 psi, I made no additional power beyond 15 deg advance. And that is with a 3" TBE with 100 cps cat. I'm running fairly converative timing at low rpm because I get a consistent few knock counts if I set the timing to anything more than say 2 deg adv at 3000-3300 rpm.

E85 is kinda odd about knock and AFR. Anything below about 12:1, and the car is more knock prone in the mid-rpms. It reminds me of the "rich" knock I would see running pump gas with an afr of ~10:1. With AFRs between 12:1 and 12:5:1, its knock free out to MBT with exception lower rpms where I can see some knock if I push up the timing.

Here is close to my current tune:

https://www.evolutionm.net/forums/sh...88#post6146288

I'm up to about 360 whp now by running less MIVEC in the mid-rpms.

dan l

iTrader: (3)

I'm going to dial back the timing a bit. I gave 5 gallons to my friend last night and it has seemed to take away any and all knock that he had with no other changes other than scaling for E85.

oldevodude

iTrader: (3)

Higher octane and cooler burn can do that

Grats man on your E85 have fun and as others have said and implied E85 will be more knock prone with richer mixtures

dan l

iTrader: (3)

Just got back from doing about 25 tuning pulls utilizing DLL to look at my torque curve. I toned down the timing a bit up top. It seems like it really likes peat torque timing but more than that it loves midrange timing. Right now I have it coming it at 7-8 degrees at 3500-4000rpm and almost linearly getting to 16 degrees at 7000rpm even though boost drops to 20psi from the 22psi it can run up till about 6000rpm's. The more mid range timing I run the more torque it makes, but I decided to just keep it tame for now. Before the fuel I was at right around 300whp and 300tq on 93 octane. Now I'm at consistently above 350whp and 330 torque.

dsmfan95

iTrader: (27)

Crank the boost up a bit

dan l

iTrader: (3)

It won't go any higher up top. If I run more boost down low, well the clutch complains.

diiirk@AwdMotorsports

iTrader: (12)

if you guys are running 11.9 - 12.0 accross, what kind of afr are you at on spool up, compared to gasoline with a target of 12.5ish on spool up down to 11.5 at peak boost