-Z Yaaaa- wrote:i know its kind of ghetto but what about running some kind of port fueler setup to add fuel to get the correct AFR for E85?

As long as the factory ECU is involved you will have issues.

You would need complete standalone fueling.



FU Tuning

Leafy (Club Jeffie FEA man) wrote:

SLO CAV (autocrossing dude) wrote:See what e85 can do here.... He was tuned for 12.5 hmm

http://www.j-body.org/forums/read.php?f=46&i=434684&t=434288#434684

Thats actually 8.2:1. Which is a lambda of 0.85, either way not a afr that I would tune a boosted car to. Unless he was trying to eek everything he could out of a low boost setting, then with the assistance of a dyno and egt probe it would be acceptable. Though 0.80 lambda would safer and depending on setup provide more power. In order to get a lambda of 0.80 you would put 11.8 in the AFR commanded table, which with e85 would result in an afr of 7.8:1.

WRONG! And all our AFR command table does is provide a target, it does nothing with the actual fueling.....





P&P Tuning
420.5whp / 359.8wtq

Yes, exactly. If the tune is dialed in, it will give you the exact lambda value you specify (assuming that it is re-tuned for e-85) when you are in PE mode. We do have the distinct disadvantage that we do actually have to change our fuel mapping when switching between the two fuels while cars which can specify their stoich AFR only need to adjust that value.


1994 Saturn SL2 Home Coming Edition: backup car
2002 Chevy Cavalier LS Sport Coupe: In a Junk Yard
1995 Mazda Miata R-package Class=STR
Sponsored by: Kronos Performance

WPI Class of '12 Mechanical Engineering
WPI SAE Risk and Sustainability Management Officer

QWK LN2 (P&P Tuning) wrote:This thread is really starting to crack me up... You guys just don't get it. Go ahead and run corn without the proper tables. Can't wait to see meltdown pics. And SAFC?!?! WoW! Guess some people just have to learn the hard way. And for the record, I would not let Leafy touch your car .......

Haha! I just came across this thread. I am all for educating people myself and I actually rather enjoy it but some people do have a hard time understanding the "technical side" of auto sports and you're right, they likely will just never get it. I was actually surprised how well some do know there stuff but this is why I try to avoid the tuning threads like the plague. Once you start getting into this stuff it's an entirely different level of understanding. These types of discussions are why I disappear from forums for months on end because I too get frustrated beyond belief trying to explain it.

Evofire in all reality given what you are currently working with, your best solution to the issue you are having with the least amount of hassle and the least amount of cost long term is to just run methanol injection. It will help to suppress that knock. Are you actually data logging the knock? Is it just a blip of knock? If so that is not uncommon especially with some of the scenarios you described. The GM reflash is rather conservative in regard to the knock retard. After the ECU pulls max 8* of timing does the knock retard go away as you power through it? Typically it will make the quick retard to extinguish any knock and then jump right back to normal timing once the knock dissipates (usually pretty instant). If it is maintaining knock retard then there is more to be investigated. The fact you mentioned it was pulling around 3* I suspect it is doing essentially preventive knock suppression per se upon rapid throttle changes (I would need to data log). The ECU is quick but not always instantaneous to make adjustments to your foot haha. Of course given your setup you will not be able to take full advantage of methanol use but it will get you through any little bumps you may be getting with your current setup. Your engine mods are really not that extensive and I question the severity of the knock you are seeing. If you are using the Aeroforce gauges remember there is a slight delay in the refresh rate on those particular guages. Meaning if the knock is going away right away its actually going away even faster than the gauges are indicating. I am by no stretch of the imagination advocating that knock is not a problem regardless of the level but it also depends on what exactly is causing the reading and when to determine if it should raise alarm. In your case I suspect your fine and I agree stop putting E85 in your tank.



ASE Master Certified Automotive Technician

yeah KR goes right to 8, then drops in .5 degree incriments.

EvoFire wrote:yeah KR goes right to 8, then drops in .5 degree incriments.

That actually sounds like it may be false knock.


1994 Saturn SL2 Home Coming Edition: backup car
2002 Chevy Cavalier LS Sport Coupe: In a Junk Yard
1995 Mazda Miata R-package Class=STR
Sponsored by: Kronos Performance

WPI Class of '12 Mechanical Engineering
WPI SAE Risk and Sustainability Management Officer

Leafy (Club Jeffie FEA man) wrote:Yes, exactly. If the tune is dialed in, it will give you the exact lambda value you specify (assuming that it is re-tuned for e-85) when you are in PE mode. We do have the distinct disadvantage that we do actually have to change our fuel mapping when switching between the two fuels while cars which can specify their stoich AFR only need to adjust that value.

Please stop giving advice... You are not helping, you are just confusing people with inaccurate information.... Oh yeah, "With all due repect......"





P&P Tuning
420.5whp / 359.8wtq