ttbestas

"I've still been working on a timing map. First thing is I'm not too proud to say I rely on the kindness of others in posting good info to help me out. I downloaded ECUFlash and I was just going off a conservative mix of the latest stock 3/S Evo8, 9, & 10 roms but I stumbled on a thread on the EvoM forums where alot of the guys making good power (450+RWHP) posted their E85 timing maps. Been doing lots of digging on there. Some interesting stuff I stumbled on that was said (and repeated) often:

1. Regardless of timing you probably will get on the wrong side of MBT before you hit knock (I know that was already mentioned in here). The kicker is that's true only if your AFR's are in the 12.0-13.0 area at WOT.
2. E85 is quite a bit more likely to knock at 11.5:1 than it does at 12.0:1. Multiple people making good power made it sound very significant...like you should never run anything richer than 11.8:1.
3. Leaner is meaner doesn't apply much on E85. Hardly any extra power will be found from going from 12.2 to 13.0:1. The exhaust tone will change, it probably won't knock any more...it just won't pick any more torque.
4. You really shouldn't put too much (if any) extra timing in it in the low RPM/high boost area. Again...you'll end up on the wrong side of MBT. They do alot of single digit numbers at <5300 RPM at >19 psi. That's kind of the opposite compared to what I was thinking. Alcohol burns much slower than gas so you usually want quite a bit of extra advance. Not true in the low end on E85.
- Now as the revs go up you can get agressive with additional advance. You want the ramp up rate to be steeper than on gas."
I would like to know what is your expierence with timing on e85 turbo or supercharged LS1. is evo stuff apply to our engines as well? thanks

JAX04

iTrader: (17)

first of all, every motor is different,

I can tell you that i made more power the richer i went. Just personal experience. Now, i wasnt on a dyno to prove this, but seat of the pants feeling picked up alot of **** and get each time we launced it.

in my thread zombie stated he liked 10.8 at wot with his build. We started at the usual 11.5ish and started throwing more fuel at it. already pushing around 22degrees at wot. And by the seat of the pants, It got stronger the richer we went, IN BOOST up top.
I will tell you that timing maps are going to be different between turbo and SC cars, most turbo guys using timing tricks to help spool there turbo. By reducing timing during the spool up, you help spool the turbo faster. Just a little trick turbo guys run.


My timing map is basically around stock below 3200 rpm ( a little more aggressive, not much) and starts getting going from there. I have a 3200 stall in my car, so from 3200 up to around 4200 timing is reduced some then and start ramping back in fairly aggresiviley from there. We are going to try a suggestion made by a local turbo guy, leaning it out A TOUCH during spool up to help as well.

now i dont know if the leaning trick will help E85 or not. but we are going to try it anywayz. As we have hit 13.5 before by accident and still saw zero knock during logging.

im no tuner at all. These are things ive picked up on by watching my tuner, reading other peoples experiences

hellbents10

iTrader: (10)

I will say this E85 does not take to the timing as much as people think. I tune it in the 11.5 area with heavy boost and 12-12.5 on lighter boost (less then 15psi). This is just to give you a very general idea, also most of the little engines like less timing and less fuel. Every single combination will like something different.

ttbestas

also how you modify cranking tables, transition fuel if at all. whats the idea behind that?

98Z28CobraKiller

iTrader: (17)

Good info on this subject as it relates to the LSx platform is hard to come by. There is no set formula for success. I have seen relatively no difference between 11.0 and 12.0 AFR going down the track on Steve's twin 78 car.

I can tell you that the above advice might work at lower power levels with a loose converter but once you start going fast, the converters need to be tighter and tighter. In order to get a quick spool, we have to add a shitload of timing and fuel on the tbrake/2 step. I think low timing is an artificial load trick for the M6 guys.

The e85 seems to be very resistant to knock. We really haven't pushed hard on his timing yet. Only running 18* over 20psi. I'm trying to get him on a dyno but he is wishy washy about it. Seems like there is always something more important going on. I think that we are finally going back to the track tonite to test out a few cooling changes that he made which may result in better ET as it was the transmission that was getting too hot and causing the converter to slip a little extra up top. If not, it has to go back again to get restalled more tighter.

TurboS10

iTrader: (12)

Some OS use the injector size to modify crank and transifion fuel.(guess)
Others, GM OBDI for sure, use strickly a pw value. So if you double the injector, you ~ double the crank fuel and transtion fuel. So you have to at least cut the crank/trans fuel by the % of the injector change. I've yet to get into the that part of the LSx based OS so I don't know if they use injector size comp in crank and/or trans. fuel.

If you need 30% more fuel due to the E85 and you go 30% bigger on the injector, then it's about a wash ignoring the difference in low pw response between the two injectors.

Zombie

iTrader: (2)

Don't compare different motors when tuning either. I believe the Evo uses a penta roof fast burn head. I do know from watching many be tuned that they don't like mutch timing at the torque peak, most run 3-5 degrees on 91 octane and only around 10 on e85 if I remember correctly. They also like being run leaner than LS1's, most E85 Evos I've seen tuned locally usually run a 12.0:1 af on e85. Running richer doesn't seem to really hurt or help them so most seem to run that a/f.

On my car it seems like being on the richer side 10.8:1 is where my LS1 is happiest. I've tried leaner with no knock, but no difference in ET or MPH.

The statement about being on the wrong side of MBT before knocking is very true with e85 because it so resistant to detonation. More isn't always better. As a general rule of thumb I don't usually go over 22 degree at 15psi. Need some dyno time to see what the timing is really doing though since my butt isn't a good indicator.

Running leaner for the first few psi of spool up does seem to cause faster spool just like on gas, especially in combination with lots of timing. I think i'm in the 28-32 timing range until 5psi. Would have to log it again since I haven't messed with my tune in over 6 months.

Playing around on a load based dyno (if you have the luxury) is by far the best way to learn what the car likes. I've done it a few times and also tuned by stepping up the boost from as low as 5psi all the way to 15 so I could maximize the map for spool/power. It also kept me from killing myself from hopping into a high hp car.

JAX04

iTrader: (17)

So using alot more timing here actually helped more then reduced timing?? or did you get a chance to try it both ways when you did this??

Zombie

iTrader: (2)

retarding the timing makes it really laggy.