rev limiter

[jessem]

Just ran across my brain today, does anyone bump the rev limiter up in a rb20? I know the gtrs have a higher one, and im aware the oil and water pumps wear out much faster at higher rpms, but regaurdless is there potential power to be had in the higher rev range, or can that be unlocked via cams and adjustable gears and what not.

[kyles_r32]

bumpin the rev limiter up on a stock setup is pointless bigger turbo, bigger cams. then you will need a underdrive pully set fopr the high revs.

[love_boost]

bumpin the rev limiter up on a stock setup is pointless bigger turbo, bigger cams. then you will need a underdrive pully set fopr the high revs.

bingo haha.
stock turbo the boost falls off around 6000rpm
i wouldn't mess with it unless your building a race car.

[M13]

rb20 head won't flow well enough at high RPM anyways.

[Skym]

Higher rpm = higher inertial load, which is bad for conrods, bearings, conrod bolts, etc. The result of higher inertial load is a hole in side of shortblock as conrod snaps or conrod bolts fail. You have to have conrods, head upgrades (solid lifter, etc) that are capable of handling the higher revs and balanced bottomend, etc. RB26 has solid lifters, solid cams inside head, so can rev slightly higher hence the high rev limit.

On turbocharged engine it's best to drop revs (common trick used by ECU tuners) where peak power is created at 6000rpm (reduces inertial load) and increase the boost level. Load on bottomend from increase in boost level is less harmful than higher inertial load from reving engine. Just reving 1000rpm more has been worked out to something like 3.5 ton of inertial load. You can see why it snaps conrods (even H beam conrods).

Nismo know all of this and is why they keep stock rev limiters on R34 Z tune, etc when running stock or similar to stock conrods.

When tuned correctly, stock RB20 turbo is good to 7000rpm. But safe at 6400rpm where factory car produces peak hp and fuel, ignition map adjustment points end. Power dropping off can be ECU tune, airleak, octane of fuel used, etc, not turbo related.

[BrianV8]

ya i bumped mine up to 8200 think factory is 8000 but anything over 6 grand on a stock turbo your just making noise

[Skym]

There's more than one revlimiter. There's a hard cut revlimiter at around 7550rpm. The soft cut revlimiter is at around 7800rpm.

[overboostedlebaron]

hmm lol. then why does my gts-t redline at 8200? lol

[whiteboy87]

has your ecu been retuned? when i got my car its rev limit was at 8 grand but it has a mines ecu in it. im still running the mines ecu, but now i have a bee*r rev limiter. I set it to 7500 to save my engine from blowing up at 15psi lolzzz

[BrianV8]

Here is a kind of off topic question. Which rev limiter is better: factory ecu rev limiter that cuts fuel or Bee*R Rev limiter that cuts spark and sounds like your engine will blow up?

Its really one extreme to the other and i don't know which is the better one to use.

[Skym]

Apexi used to have ignition, fuel cut on the drag version of Apexi PowerFC for RB20DET. On road version, fuel cut only. I forget the names they gave the ECU's.

If you search the internet (might be on Apexi's website), you should find the reason behind why the drag version of PowerFC had ignition.

On some chipped stock ECU's, they raise the rev limiter to around 8200rpm. As far as I know Nismo don't touch the factory rev limiters on their tuned ECU's.

[BrianV8]

So which is the better of the two evils? Fuel or Ignition Cut?

[jessem]

ignition cut=flames that is the better evil

[overboostedlebaron]

no stickers on ecu so who knows lol

[BrianV8]

Well according to this thread. The Bee*R is great for breaking stuff, such as turbos, cats, oil pumps etc due to its harshness. So sticking to a factory fuel cut rev limiter thats less aggressive is a better way to go.

http://www.skylinesaustralia.com/forums/Bee-Rev-Limiter-t149370.html