172 rev limit

[Tom84]

right well my car never used to rev to the limit which i take is 7.2k, used to only go to 6.8k ish

changed the cts and all was fine again went to 7.2k but took it out for a long run yesterday and now its back down to 6.8k again now i will check the sensor tomorrow but its just strange how its not working again.
the car was deff up to temp lol but still cut in early??

any ideas before i get too involved checking things 2mo?

 

[Jamesstone]

Have heard that 1st & 2nd gear give a higher rev limiter than the above... cant remeber where it came in now though... Re-map, 7,800rpm now days

 

[cat171]

Your peak torque figure will be a lot before the rev limiter tbh. So really you don't need to go round redlinnig it all the time.

 

[john.med]

Tom are you sure it was up to temp? (I know you said you were). It reads oil temp and not water temp IIRRC. Can take a good while to get upto temp' depending on the type of drive.

 

[Tom84]

ive had a few cars fitted with oil temp gauges and i know for a fact it was deff up to temp. think im gunna plug it into the scanner at work and check what the ecu is reading from the temp gauge, at least then i will know where to start.

 

[caister]

As said 1st and 2nd have higher rev limits and TBH there's no need to rev to the limit as the drop in power towards the limit is considerable.

The car will take upto 15-20 minutes of driving before its warm enough to rev that high

Also the temp gauge in the car read the water temp but the engine only allows higher rev limits when the oil temp is high enough yet there is no indication of this in the car.

 

[benmore]

imo the rev limit should be below 3k when the oil is not warm enough.

reving a car when cold is asking for trouble. staggering how manufactures haven't done this a long time ago tbh

I know this doesn't help you and is completely off topic. just my opinion.

sorry

(and I know you're not reving it when cold - so don't take it the wrong way)

 

[caister]

4k would be a bit more sensible imo especially if your going to be on the motorway before the car is properly warm

 

[Russ_16v]

the rev limit is the same through all gears guys, the car doesnt know which gear your in,so cant alter the rev limit. when warm it should limit at 7200 rpm, and this is measured by water temp which has to be at 85 degrees(iirc) to let the engine rev that high, when it is under this temp it will limit at 6800 rpm. so id hazard a guess that you moght have a fault with your coolant temp sensor, as the engine could be thinking its not up to temp

 

[caister]

the rev limit is the same through all gears guys, the car doesnt know which gear your in,so cant alter the rev limit. when warm it should limit at 7200 rpm, and this is measured by water temp which has to be at 85 degrees(iirc) to let the engine rev that high, when it is under this temp it will limit at 6800 rpm. so id hazard a guess that you moght have a fault with your coolant temp sensor, as the engine could be thinking its not up to temp

I'm still 99.9% sure that its done on oil temp not water temp

 

[john.med]

Same here^

 

[Christopher]

Water temp means bugger all from cold start really.

Oil takes at least four times longer to come up to full operating temperature. Longer than most people think. RS Clios have a soft limiter of 6800rpm until the engine's fully up to temperature.

 

[caister]

1st and 2nd rev limit is 7250rpm and 3,4 and 5 its 7000rpm

 

[Russ_16v]

1st and 2nd rev limit is 7250rpm and 3,4 and 5 its 7000rpm

it doesnt matey, most def 7200 rpm through all gears, iv tested

Seriously though the ecu cant tell what gear your in,so it cant limit differently in certain gears

And im pretty sure its water temp related, though i wish it was oil temp

 

[edde]

1st and 2nd rev limit is 7250rpm and 3,4 and 5 its 7000rpm

it doesnt matey, most def 7200 rpm through all gears, iv tested

Seriously though the ecu cant tell what gear your in,so it cant limit differently in certain gears

And im pretty sure its water temp related, though i wish it was oil temp

It can its given speedo unput form the abs computer/gearbox sensor depending on model.

 

[db]

do they not have a gear position sensor?

 

[edde]

do they not have a gear position sensor?

Nope.

works off the ABS computer/gearbox speedo sensor.

 

[Russ_16v]

And as far as im aware the clio dosnt do that matey, i know mine revs to 7200 rpm in the 1st 5 gears, anyone have any literature on this? there must be something from renault somewhere

 

[edde]

And as far as im aware the clio dosnt do that matey, i know mine revs to 7200 rpm in the 1st 5 gears, anyone have any literature on this? there must be something from renault somewhere

Its the tech manuals.

Not that it matters rpm counters can be inaccurate etc.

 

[Russ_16v]

sorry i should have said, yeah i realise rev counters are never accurate, but iv had mine tested (mates £35,000 worth of diag machine) and its within a few hundred rpm accurate

 

[john.med]

And as far as im aware the clio dosnt do that matey, i know mine revs to 7200 rpm in the 1st 5 gears, anyone have any literature on this? there must be something from renault somewhere

We don't need literature from Renault. We have edde. End of.

 

[sammyhale22]

I have taken this from the renault literature.
Engine Temp <75C max rpm 6700rpm in all gears
Engine Temp >75C max rpm in 1st and 2nd gears 7200rpm
Engine Temp >75C max rpm in 3rd, 4th and 5th 7000rpm

Sam