rev limiter

[W17GLE]

may sound stupid this but how come sometimes my car will rev to 7250 rpm other times it will cut out at 6750 rpm? anyone know?

 

[Gumby]

6750 is when the engine is cold, 7200 is when it's warm

 

[W17GLE]

mine is doing both even when at full running temp could there be a problem?

 

[Dan@SJM]

its done on oil temp if its below 90degrees

 

[W17GLE]

another stupid question then... could the induction kit be taking the running temperature lower due to the cold weather, i've only just noticed it doing it

 

[Dan@SJM]

no mate, isit doing even after an hour or so of driving?

 

[W17GLE]

i'm going out for a good drive later i'll experiment and report back

 

[Dan@SJM]

if it does mate, before you turn the IGN on hold down the button of the wiper stalk and turn on the ign, it'll go into diagnostics, and if you scroll along you will get to a display right at the end usually like this - - - -
If it has an h there it means there is a fault with the oil level and temp sensor.

 

[W17GLE]

i'll give it a try thanks for the advice

 

[GordonD]

Note that whether the ECU considers the engine is warm enough to increase the rev limit to 7250 does not depend on the water temperature. It depends on the oil temperature. And in cold weather that can take quite a while to come up. I was doing some fuel economy testing of a claimed aerodynamic device - no, it didn't work - and it took about 15 minutes in 4 degrees C temperatures (that's mid-winter here) for the ECU to switch out of the cold start fuel mapping.

 

[si_from_earth]

Just been reading about the wiper button diagnostics feature.

Does anyone know what order the checks are done and what the letters stand for etc as I'd like to experiment.

Thanks

 

[Dan@SJM]

do a search for dashboard fault finding trick, it tells you everythign in there.

 

[si_from_earth]

Cheers Dan

 

[D1CKY]

6750 is when the engine is cold, 7200 is when it's warm

Thats why i dont thrash my car for a good 10/15 minutes after starting from cold in normal weather and a good 20/25 minutes in cold weather we have now.

After the time i wait before hammering my car the water temp is usually in middle of gauge and the heaters are really hot. (If it means anything)

I don't want my engine to sound like an old fiesta chapping due to premature wear by thrashing when cold.

 

[Dan@SJM]

the 172 engines are very very strong. especially with modern oils, that are protecting as soon as they have pressure. My 172 engine was nailed from cold everyday(Ok, I was young and stupid back then lol) but Beofre I put it in this car, i pulled the big ends off, just to check them...

Untouched. still had the protective layer on them!

 

[bmh.01]

The low limiter is actually done off water temp according to the renault manual. The level sender doesn't have the temp sensing ability like the valver/williams one. Was thinking of fitting a valver one to mine to have an oil temp gauge.

 

[bmh.01]

Details: http://www.getflat.co.uk/pics/3286A-88.pdf

 

[alexm]

i dont think iv ever revved my 172 past 6.5k. didnt realise it would rev past 7k! dont think im gunna try either, scared of blowing it up lol

 

[DrR]

Rev the living s**t out of my car all the time, just had £950 engine work done it.....

Revs lot better and higher when warm.

 

[alexm]

ill remember not to buy a car off u then lol

 

[DrR]

Not much left on it thats not new lol/

 

[StevieGreenstuff]

i dont think iv ever revved my 172 past 6.5k. didnt realise it would rev past 7k! dont think im gunna try either, scared of blowing it up lol

It's a modern, well (sic) toleranced engine in a modern performance hatch. Give it some beans, the rev limiter is there to stop you going too far, the standard internals are good for 8k iirc.

Your kinda missing the best point of the engine as it all happens after 5k, but I would let it thoroughly warm up 1st. As long as it's serviced (esp timing/aux belts!) correctly it should be fine...

S.

 

[clio_luke]

i dont think iv ever revved my 172 past 6.5k. didnt realise it would rev past 7k! dont think im gunna try either, scared of blowing it up lol

It's a modern, well (sic) toleranced engine in a modern performance hatch. Give it some beans, the rev limiter is there to stop you going too far, the standard internals are good for 8k iirc.

Your kinda missing the best point of the engine as it all happens after 5k, but I would let it thoroughly warm up 1st. As long as it's serviced (esp timing/aux belts!) correctly it should be fine...

S.

well said. very true

 

[hawk2327]

hi i have just remapped my 172 to 200bhp and taken the rev limiter from 7250 all the way to 8450rpm!!!!

 

[DrR]

hi i have just remapped my 172 to 200bhp and taken the rev limiter from 7250 all the way to 8450rpm!!!!

You got 200bhp with just a remap?

 

[bmh.01]

hi i have just remapped my 172 to 200bhp and taken the rev limiter from 7250 all the way to 8450rpm!!!!

You got 200bhp with just a remap?

Either had waaaay more done or the place that remapped it is "optimistic" (read lied through their teeth) to say the least. And 8450 will soon see the pistons/rods fall apart.

 

[edde]

hi i have just remapped my 172 to 200bhp and taken the rev limiter from 7250 all the way to 8450rpm!!!!

Welcome to the broken engine group.

Depending on engine state your Coil packs the first to go.

Won't get that much power on stock engine from a remap though sorry.