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Can't raise rev limit beyond 7500rpm - RB20 ECU

Posted: Thu Apr 29, 2010 6:01 am
by Marshall
I've been fighting this problem for a long time now, I can't raise my rev limiter beyond 7500rpm. I can adjust it to any rpm under 7500 and it works fine. If I adjust it to 8000, I still get limited at 7500.

For awhile I thought it was a misfire so I reduced plug gap and added a DLI. Made no difference. It absolutely sounds and (in the datalogs) looks like rev limiter, there is no indication anywhere else that it amy be an ignition problem.

I'm using an RB20 ecu to control my RB26.

I have tried other rom editor programs to raise/change the limit but still hit limit at 7500. It's like there is a hidden rev limiter that I haven't found yet. My address file has the main and parked rev limiters that I can adjust, and I've tried adjusting them both.

Any suggestions would be appreciated. I'm going to try to hunt a previously modified RB20 bin with raised rev limiter and plug my maps in to see if that fixes it. Beyond that I'm out of ideas.

BTW, my 711whp dyno was made with this limiter stopping the fun at 7500, a pull to 8k+ would easily top 800whp..

Thanks for any suggestions,
Marshall

Posted: Thu Apr 29, 2010 10:37 pm
by yoda69
If it is the same definition for your old RB20 bin, why not use TunerPros bin compare with the one your using and the olde one?

If anything is undefined in the compare, that may be the culprit, ot at least may narrow it down.

Would probably be quicker and easier than moving all the tables.
If it is a different definition however, this won't work, or if there is a signficant amount of undefined terms.

yoda69

Posted: Fri Apr 30, 2010 2:01 am
by Marshall
I've never had a tune that allowed me to rev beyond 7500. I was hoping to find someone else's bin with a rev limiter that has been adjusted to 8,000 or more and has been verified on another car. Then I could just copy my timing/fuel maps into that bin and see if that fixes the problem.

Thanks for the reply.
Marshall