What Is Required To Raise Rev Limit

williaty · 01-02-2008, 05:09 PM

OK, so I want to raise the rev limit on the car I'm working on right now. Stock redline is 6200RPM. Obviously, just raising the Rev Limit Fuel Cut table values would allow the car to rev higher. However, I suspect that's not all that should be done to raise the rev limit correctly/safely.

The fueling and timing tables go to 6400RPM with an average step size of 400RPM. Does this mean the rev limit can be raised to 6800RPM (or even 7k) without needing to re-scale RPM rows of the tables, or does there always need to be a row above redline for these tables?

Feedback Correction Range (RPM) currently Disables above 6300 RPM. Should this be raised to new_redline+100RPM to keep the same relationship as stock?

The CL Delay Maximum Engine Speed A table (Above) Clear CL Delay is set to 6200RPM. Should this be raised to the new redline even though I currently have the CL Delays set to 0?

Per Cylinder Timing Comp also tops out at 6400RPM, does this need changed too?

Are there any other subtleties I'm overlooking?

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Tea cups · 01-02-2008, 05:41 PM

The ECU will only interpolate between the minimum and maximum axis value. Outside of that, it will continue to use the last value in the last row or column. It is not required to rescale an RPM axis to the rev limit, unless the values in the last row (ex. timing) are not appropriate for your tune between the largest RPM and the rev limit.

Soon2BturbodRS · 01-03-2008, 02:52 PM

Did you raise your rev limiter yet?

williaty · 01-03-2008, 02:57 PM

Nope, without anyone giving any insight on what else needs changes (knock tables, etc) I don't feel comfortable doing it.

Tea cups · 01-03-2008, 03:12 PM

Quote:

Originally Posted by williaty

Nope, without anyone giving any insight on what else needs changes (knock tables, etc) I don't feel comfortable doing it.

I would at least extend the feedback correction RPM range and per cylinder max rpm (since it is already extended to current redline) to the new rev limit. CL delay Maximum engine speed doesn't need to be changed. As far as rescaling the fuel/timing RPM axis, I don't think that would be necessary in this case. I would guess that raising the rev limit on a stock 05 RS isn't going to make a difference in acceleration, though I could be wrong.

01-02-2008, 05:09 PM	#1
williaty Scooby Guru Member#: 71092 Join Date: Sep 2004 Chapter/Region: MWSOC Location: Delaware County, Ohio Vehicle: 2005 2.5RS Wagon Regal Blue Pearl	What Is Required To Raise Rev Limit OK, so I want to raise the rev limit on the car I'm working on right now. Stock redline is 6200RPM. Obviously, just raising the Rev Limit Fuel Cut table values would allow the car to rev higher. However, I suspect that's not all that should be done to raise the rev limit correctly/safely. The fueling and timing tables go to 6400RPM with an average step size of 400RPM. Does this mean the rev limit can be raised to 6800RPM (or even 7k) without needing to re-scale RPM rows of the tables, or does there always need to be a row above redline for these tables? Feedback Correction Range (RPM) currently Disables above 6300 RPM. Should this be raised to new_redline+100RPM to keep the same relationship as stock? The CL Delay Maximum Engine Speed A table (Above) Clear CL Delay is set to 6200RPM. Should this be raised to the new redline even though I currently have the CL Delays set to 0? Per Cylinder Timing Comp also tops out at 6400RPM, does this need changed too? Are there any other subtleties I'm overlooking? * Registered users of the site do not see these ads. Last edited by williaty; 01-02-2008 at 05:25 PM.

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01-02-2008, 05:41 PM	#2
Tea cups Scooby Specialist Member#: 103136 Join Date: Dec 2005	The ECU will only interpolate between the minimum and maximum axis value. Outside of that, it will continue to use the last value in the last row or column. It is not required to rescale an RPM axis to the rev limit, unless the values in the last row (ex. timing) are not appropriate for your tune between the largest RPM and the rev limit.

01-03-2008, 02:52 PM	#3
Soon2BturbodRS Scooby Specialist Member#: 35868 Join Date: Apr 2003 Chapter/Region: NWIC Location: Pdx, Or Vehicle: 06 Impreza OBS GG6 Corolla GT-S Hachi Broku	Did you raise your rev limiter yet?

01-03-2008, 02:57 PM	#4
williaty Scooby Guru Member#: 71092 Join Date: Sep 2004 Chapter/Region: MWSOC Location: Delaware County, Ohio Vehicle: 2005 2.5RS Wagon Regal Blue Pearl	Nope, without anyone giving any insight on what else needs changes (knock tables, etc) I don't feel comfortable doing it.