Disconnecting RPM Limiter,How and Result?

[tacz]

On my 00 RS I have pondered disconnecting the rpm limiter that prevents you from revving beyond 6000 rpm. How do I do it and are there any consequences to doing this?

[MattB]

Don't do that. You will not make any extra power and you will just get valve float.

[Skidd]

Uh... disconnect teh rev limiter?
There is no single "wire" or little module or anything that you can just disconnect.
It's built into the programming of the ECU.
You can't do it. Not without an ECU Reflash.

[Gooshin]

Originally Posted by tacz

On my 00 RS I have pondered disconnecting the rpm limiter that prevents you from revving beyond 6000 rpm. How do I do it and are there any consequences to doing this?

your rev limited is around 6200 actually, and you dont want to remove it, because if you forget to take your foot off the gas in the heat of the moment you'll get a big bang and sticky hot liquid all over your engine bay, the loss of power may kill your vacuum, making the steering extremely difficult and your brakes will have 2 maybe 3 charges in them before running out of booster pressure, making you a big smoking chunk of metal on the interstate, potentially killing a few people.

ohh and you stopped making power some time around 5400 RPM so..

and as skidd pointed out you'll need to override it VIA reflash or similar (standalone or something)

[Auslander]

If you upgrade the hardware in the heads, you can safely take the limit up to 7000 rpm or so; one member on here actually had his set to 8000 for the longest time. But you'll be slower in *most* circumstances than shifting in staying in your power band. You need cams, a lot of porting/polishing, and some other goodies to keep making power at that range, and it's nothing magnificent without forced induction.

[Gooshin]

Originally Posted by Auslander

If you upgrade the hardware in the heads, you can safely take the limit up to 7000 rpm or so; one member on here actually had his set to 8000 for the longest time. But you'll be slower in *most* circumstances than shifting in staying in your power band. You need cams, a lot of porting/polishing, and some other goodies to keep making power at that range, and it's nothing magnificent without forced induction.

actually if you're boosting you are better off shifting your powerband lower

high RPM + low boost is more destructive than lower rpm + high boost

[Auslander]

I agree; my point was that it takes boost to make real power at higher rpms with our Subie engines, however.

[Gooshin]

Originally Posted by Auslander

I agree; my point was that it takes boost to make real power at higher rpms with our Subie engines, however.

i'll disagree.. if our NA subies could be made to rev to 7000/8000 RPM safely (bearings, rods, seals, cylinder wall reinforcements, all that crap)

then supplemented with proper race camshafts (that will make your car bog below 2K), and 11:1 or 12:1 compression... you can easly make gobs of power without any need for boost...

[Auslander]

You can disagree, but a member has done it. He hasn't really talked about it in at least a year or two, so I can't recall the handle, but it was done. He raised it to autocross more effectively by keeping in second gear and went hog-wild with the engine. The powerband stays flat at best at that point, it doesn't keep increasing.

[zze86]

from some recent reading of old N/A threads it seems like the intake manifold itself starts becoming a restriction after so much. There is indeed some sort of wall that people hit. IIRC, Cobb's guess is the intake manifold.