Rev Limiter

Gholdwayne · Post by **Gholdwayne** » Sun Jun 28, 2009 1:03 pm

Hey guys, i wanted some information on the rev limiter..

Now i understand that the revs are limited to 6000 when cold and can redline when warm since i can reach 7500 when it is.

One time on operating temperature, i stalled(

yeah i did) on a roundabout when i wasnt concentrating, reignited the car and had to gun it since there were cars behind waiting, and as i revved it, it limited to 6000, at operating temperature....

So i got the impression and made a theory that the rev limiter is active with a timer after reignition. No idea if there really is a timer, i suppose this is for safety as well, but can you guys fill me in on how the rev limiter works ? Its a 97 gpx mivec by the way.

Cheers...

mrmitsi88 · Post by **mrmitsi88** » Sun Jun 28, 2009 4:25 pm

yeh i get the same with my 95 gpx ive got no idea. and never rly thought bout it before..

evoman · Post by **evoman** » Sun Jun 28, 2009 6:49 pm

Hmm....interesting. I've only noticed this once when test driving a cold car from a dealer

, so I'm not sure.
I'm more confused as to why you have a 7500rpm rev limiter on a GPX manual? I thought they were all at 8250?

mrmitsi88 · Post by **mrmitsi88** » Sun Jun 28, 2009 8:01 pm

well my limits out at redline not sure bout old mate coz i wonder bout the whole six hlf limit

Gholdwayne · Post by **Gholdwayne** » Sun Jun 28, 2009 8:22 pm

oh no no, my limit isnt 7500, its just that thats all i want to reach as i don't want to redline it or blow my engine - so i dont really know if my engine's limit is 8250 or what since i dont want to try it. but i want to know some info about this cold start/reignition rev limitations.

I want to at least be able to go 7500 after a reignition(from a stall or if i had to turn the engine off for 5 mins for an errand or something)...

Post by **vipfto** » Sun Jun 28, 2009 10:30 pm

Gholdwayne wrote:oh no no, my limit isnt 7500, its just that thats all i want to reach as i don't want to redline it or blow my engine - so i dont really know if my engine's limit is 8250 or what since i dont want to try it. but i want to know some info about this cold start/reignition rev limitations.

I want to at least be able to go 7500 after a reignition(from a stall or if i had to turn the engine off for 5 mins for an errand or something)...

limit is 8250 on gpx

Gholdwayne · Post by **Gholdwayne** » Mon Jun 29, 2009 12:55 pm

sweet... now i know i can gun it to 8000 safely... now ill just need to know how this rev limiter works. there seems to be no documentation that explains this.

Dan25 · Post by **Dan25** » Mon Jun 29, 2009 8:26 pm

Exact same thing happened to me after I stalled at a toll booth once. I floored it and then it cut out 6000.

Out of common sense, the obvious explanation is that it's going into protection mode. One plausible reason for this would be that the temporary shut-down of the engine has starved the engine of the necessary fuel to go past 6000. The fuel pump simply needs a bit longer than 5 seconds to catch up lol. In addition, once the car has started, the ECU needs time to run diagnostics and I'd assume that this takes a little longer than 5 seconds also, so once again, it's protecting the engine in case there are any issues.

Whatever the reason, the solution is simple: Don't rev the sh*t out of your car once you start it

Tippin · Post by **Tippin** » Mon Jun 29, 2009 9:35 pm

Dan25 wrote:Whatever the reason, the solution is simple: Don't rev the sh*t out of your car once you start it

correct, atleast wait till the engine gets to normal operating temps

Gholdwayne · Post by **Gholdwayne** » Mon Jun 29, 2009 10:47 pm

so how much time does the car need from a stall reignition to be able to go past 6000 ?

and how much time from a cold start ?

Post by **vipfto** » Mon Jun 29, 2009 10:53 pm

Gholdwayne wrote:so how much time does the car need from a stall reignition to be able to go past 6000 ?

and how much time from a cold start ?

well dont use the water temp gauge as meaning its up to temp. It takes around 5 to 8kms before oil pressure is at normal operating pressure and oil temp is normal that is when car is warmed up

Post by **Bennoz** » Tue Jun 30, 2009 12:39 pm

The bit that takes the longest to get to optimum operating temp is the gearbox oil. Usually take twice as long as the engine water temp. I wait a good 15-20 minutes before letting loose on the throttle.

The FTO rev limiter is fuel operated by the ECU. When it senses you're heading up that way, it staggers the voltage going into the fuel pump.