Thread: Thinking of converting to E85.. Yes or Ne??

Originally Posted by darkhorizon

"factory issues"? I use a basically stock pcm in my fiero... I changed less than 6 tables from stock. Megasquirt is not easy to deal with at all, trying to do a base tune on a car like mine would take quite some time, while the maf sensor and stock ecu was tuned in 2 runs.



Yeah, but it just pulls timing, it doesnt show as KR.

Agreed with this guy (again). L67's PCM is about the easiest thing to tune on this planet.

When you get into tuning newer **** that has 27 timing modifier tables that all interact differently you'll be crying for your old L67 PCM file.

Originally Posted by 98GrandPrixIraqVet

All of this makes me want to buy a DIY megasquirt kit more and more and do it that way fvck all the factory issues to work around........

LOL, megasquirt is a true PITA.

Local brainy techy guy did it. Hated it.

Car ran slower than stock, all the time.

Im not second guessing anyone cus im unsure but im asking. Isnt that torque reduction during shift points in spark and fuel retard not timing? I thought kr was timing retard. Im lost on how that works exactly.

Originally Posted by Ginseng

Im not second guessing anyone cus im unsure but im asking. Isnt that torque reduction during shift points in spark and fuel retard not timing? I thought kr was timing retard. Im lost on how that works exactly.

KR is timing retard by the PCM from signals of detonation given by the knock sensors.


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Shayne, the way GM designed the pcm etc. They toss that amount say 2 degrees of retardation (removal of 2 degrees of timing) by injecting it as kr to decrease timing at the shift point in order to reduce power. As seen in the picture, it's dependent on the foot pounds of torque and the shift point.

Thanks crb but thats not quite what i meant.

Bill thats what i was looking for so basicly if im gradually accelerating the timing will be less adjusted during shift points by the pcm compared to if i was full throttle?
Does this apply to say going up hill or down hill in both equations? Cus i imagine more load= more torque needed going up hill= more retard? If this makes sense lol

Edit: What im getting at is i wont really see any kr when i first get my car to operating temp and start gunning around. When i have been driving the car awhile and my trans temp get up to say 180-200 i will start seeing knock. That knock will raise further when going up hill.
Is this due to the added friction in the trans from being so hot? Causing more load on the engine, and causing more torque needed from the engine because of?

Originally Posted by danomite02

damn GM and their pcm's, i dont need any more retardation tossed at me!!!!! im retarded enough LOL

I concur..


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^LOL^

hey crb, so you filled up with e85 and your car ran fine without having to make tuning adjustments? bc im gonna swap soon and was wondering how i could get 100% e85 by the time i get it tuned and have the fuel filter changed and ready to go.

Originally Posted by TEK310

hey crb, so you filled up with e85 and your car ran fine without having to make tuning adjustments? bc im gonna swap soon and was wondering how i could get 100% e85 by the time i get it tuned and have the fuel filter changed and ready to go.

Correct.. Just fill her up and make sure you don't hit the skinny pedal too hard LOL. Naw, you'll be fine, just noooo boost until you tune!


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okay, sweet. thanks

Sorry to bring up the whole timing debate again.... Iv been gone from the forums for a while and haven't had a chance to pipe in. One thing you guys have to remember is that I am running a high compression setup.... Higher compression = me hitting peak combustion in a shorter amount of time. I need less time before TDC to reach peak combustion. I rolled into the dyno session with a 3.8" pulley, 230whp, and 19* of timing. Left with 15* of timing, a 3.6" pulley, and 260 ish whp. On a low compression setup I have NO DOUBT WHATSOEVER that more timing would be very beneficial. Now on e85 you do get more headroom to add timing if you arent already at your maximum useful timing. So if you are still rocking stock timing by all means take advantage of the additional octaine and crank the timing up.

I always thought the blip of KR I get at shift point here and there was false KR because sometimes it happens and sometimes not. It also occurs as the tranny shifts not pre shift. If the PCM was doing it wouldn't it happen every time I went wot? Not trying to contradict anyone's claims here, it is just what I've noticed with my own application.


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Originally Posted by SnowFlake

False knock is when the knock sensors pick up on a noise in the same frequency range as real knock, but knock never actually occurred.
It's my goal to ensure that people can find and read information that is both relevant to the topic and correct.
What you're propagating is irrelevant and false.

Chris, your car isn't "knocking" during the shift because of the torque management. I hope you understand this concept is ridiculous.

Lol I understand the concept. The KR I'm seeing, to me anyways, is most likely not actual detonation. I'm just glad that my 14 year old KR sensors are still working..


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Nick, post some proof.

Again im just trying to understand this. The timing retard programmed in the pcm during shifts is torque management to save the trans life not to combat knock?. But does or doesnt show on a scan gauge as actually kr? If it did i imagine everyone would see kr during shifts but not everyone does. But i thought the scan gauges read timing retarded in degrees to combat knock. Now is kr on a gauge reading retard only during actually knock or false knock? or is it reading the actual knock or false knock thats accuring in degrees? Now its possible gm programmed that retard to combat knock that is more probable during shifts.

Edit: So if we took those values of what bill posted and set to zero would the car be more prone to knock or would it just put more stress on the tranny?