custom 5 limiter kicking in

[69camaro5speed]

I have a tune and a log guessing I missed some thing not sure what it could be but have a revlimiter kicking in 2 spots once in low gear for a split second other time in high gear hear is the log.Car info ,6 speed, 488 gears ,l92 heads bes ported and bes cam, 6.0 stock short block with pistions cut for cam. I have tryed putting limiter at 8300 it still came on on back half of track little earlyer .If I lock timing out with b5915 it is fine but there is no limiter then.any ideas ?

[69camaro5speed]

hmm any ideas anyone helppppppp lol I been using b5915 for a crutch but when I do that there is no revlimiter,This car has nos on it allso I lower b5915 for nos and use timing tables in custom 5 but there is no revlimiter that way.
on that pass if nos was on it could have been bad with it doing wierd stuff like that, any ideas?

[Chuck CoW]

Ross and Paul....Hope you're watching this!

Hey fella... It isn't often that I see anyone having problems like I've had before....


Here's my experience...I think it's the same for you.

I noticed you have 4.88 gears. Not very common for LSx cars, but fun!

Anyway...In trying to get EFI LIVE to successfully change the rear diff ratio in automatic C5 Corvettes, I ran into the same problem...The rev limiter was kicking in very early in my RPM pulls to redline.

I had manipulated the H1002/03/04 numbers in the speedo section and found that it causes this problem.

Somehow, I suspect that changing the diff ratio or TOS (transmission output shaft) revs is the culprit.

I suspect that somewhere in the pcm the code is backwards calculating engine RPM or some mess up in delivered torque which we've screwed up by changing the diff in the car and not getting the tune file #'s correct.

Try messing with the speedo section and let me know what happens.

Chuck CoW

[69camaro5speed]

OK I am going to change every thing back to old setting except h0101 and see what happens, looks like it just uses some stuff to figure tq.tables so maybe some things wrong there,I turn the revlimiter up and it hit it earlyer but I lost the log in my v2 some how,yes this thing has been though hell pulls good to 7800 rpms on engine dyno but trying to get a good pass using b5915 to lock timing makes limiter not work so one pass he left at 8400 hitting 8300 on shifts it was a rocket poor stock pistions and rods taking a beating

[Chuck CoW]

OK I am going to change every thing back to old setting except h0101 and see what happens, looks like it just uses some stuff to figure tq.tables so maybe some things wrong there,I turn the revlimiter up and it hit it earlyer but I lost the log in my v2 some how,yes this thing has been though hell pulls good to 7800 rpms on engine dyno but trying to get a good pass using b5915 to lock timing makes limiter not work so one pass he left at 8400 hitting 8300 on shifts it was a rocket poor stock pistions and rods taking a beating

How did you make the change for the gears?

Feel free to call me any time, I'd like to know more and talk about your problem.

Chuck CoW 914-332-0049

[69camaro5speed]

ok I will give you a call when I get back to this I am busy with engine masters challenge motor and some other customers stuff plus us nationals stuff

[joecar]

Let us know how you do at Engine Masters, good luck with it...:cheers:

[69camaro5speed]

thanks we are way behind like normal. I have a lot of efi stuff to figure out with it to see what works,I am hoping to get at least couple weeks dyno time be for we go,we won with a ford and a chevy love to do it with ls7 also, this thing is tuff to do we never get the time that others do to dyno test because of working so many hours with customers helping them win races and championships,this is a after hours thing we do but not allways any after hours left lol thanks again

[69camaro5speed]

Well after a week of engine masters we got second place by .56 avg. less hp.Comes down to being out worked,after only getting around a weeks time to dyno at home kaasse should be the winner.The bad side to it is with all the restrictions on efi we couldn't use it because a carb made more avg.power (not peak, not low end,not as smooth)maybe with months of testing it maybe better.so with one carb we where 1.5 points away from beating a all multy carb finalest.

[joecar]

Wow, your score was very close... pity EFI couldn't be used (are you saying because of the rules...?).

[69camaro5speed]

we tested some efi stuff efilive made best power but over the 3000 rpms to 7000 rpms a dominator made 8 avg more power.I think with moving injectors, trying differant size injectors,multable throttle bodies,high fuel pressure,there is some power there (not legal)efi is still sweat starts right up and shuts off with out running backwards lol