Rb20 Rpm Limiter?

[jazza08]

Hey peeps

My tacho and Apexi rsm are showing slightly different readings which vary up to 800rpm in the top end of the rpm range, im curious what a the standard rpm limiter is on an rb20det?

Ive been told 7500rpm but ive also heard 8200rpm??

My speedo is out due to 17' rims n 235 tyres etc, im just curious on wether the RSM or standard tacho is better to go on for the rpms (ie when i want to shift), funnily enough i hit the limiter and the rsm shows 7500rpm and the tacho shows 8200-8300rpm, so i couldnt figure it out by hitting the limiter either hahaha

Anyone know the standard rpm limiter and why the rsm or tacho is out?

Thanks all

Regards

Jaz

[Beer Baron]

i have NFI but reving it past 7000 is a useless excercise anyway. I would say the stock RB20 limit is under 7500, most likely 7200 or some where around there.

[Sydneykid]

Based on my experiences (R32GTR, R32GTST, R33GTST, R34GTT, Stagea) all Skyline tachos are optimistic, usually 5% or so.

cheers

Edited August 30, 2006 by Sydneykid

[jazza08]

Red LINE on an rb20 is 7500 according to the manual (and tacho), but that doesnt mean thats the LIMITER neccessarily...

My rb20 makes power at 8000rpm (tacho/dyno reading) due to the larger turbo, so reving up there is quiet pointful for me but i would agree useless on a stock turbo which is what im sure you are refering to.

Thanks for the help Gary, based on what your idea's are the rsm is more accurate thus the turbo is a little less laggy (than tacho/dyno reading) and the rev limit is abit lower (7500 instead of 8200).

[cogs]

G'day to Jazza if you see this thread! How's it going mate?

My rev limiter seems to be around 8000rpm? I dont rev the car out that much usually but I occasionally find it if the wheels are spinning. Can the stock internals handle this ok? I would've thought the revlimiter would be closer to 7000rpm?

[salad]

sam (dr drift) remapped my ECU and the previous (stock) rev limit was 7900.

then he raised it to 8800...

but on the dyno he revved it to 8000rpm and is has the same power at 8000 as it does at 5300, with only an rb25 turbo

and with max power at 6500, power doesnt drop off THAT fast

usefull to be able to rev the crap out of it for drift, but thats about it.

Edited October 10, 2006 by salad

[jazza08]

Rb20s need revs and boost to make power, everyone knows that so the longer you can safely hold it the better id say (in terms of how quick your goin, its not goin to be better for the motor hahaha)

I have learnt that the speedo and tacho seem to be close together

ie if speedo says 50kms it the tacho will say 3000rpm, if rsm says 50kms on it the rsm will say 3000rpm. Ive found the rsm from the dyno is perfect in terms of speed, so im using that as my rpm gauge aswell...

The speedo seems to be out more and more the faster you get, but you should note i have different rims/tyres to manufactor specs and thats probably why my speedo is out!

From the RSM i hit the limiter at 7500rpm If your usin 8800rpm you have balls unless you have a built motor LOL

Hope that helps Cogs

Edited October 11, 2006 by jazza08

[salad]

motor is stock as a rock... eeep

but nah, ive had it like that for ages now and bounced off the limiter a lot and its still as healthy as the day i got it.

pointless, but yeah.

drift... is... stupid...

haha

[mad082]

The speedo seems to be out more and more the faster you get

that because it will be out by.. lets say 10%. so at 50kmh it will be out by 5kmh, but at 150kmh it will be out by 15kmh. speedo's are usually out by percantage, not by a fixed kmh.

jazza, i'd say that your rsm is accurate. your tacho needle probably just bounces up to that sort of rpm, but the motor isn't actually going that high.

[jazza08]

Ye that seems to be the case

Either way i never get to 8800rpm even on the tacho! hahahah that'd sounds sweet

[salad]

rb20 up that high does sound pretty cool!

[shnaped_second]

RB20det in my cefiro only reved to 7500 and it was there very often