Cup/172 - shift light and limiter

[BikeMan]

Got my Cup run in now and Im enjoying giving it a good thrash. I change up at 7000rpm and never see the shift light come on. I think peak power is at 7250rpm (where the redline starts) so when does the shift light come on? When does the rev limiter kick in?

 

[Rich-D]

Peak power is way before the redline mate, roughly around the 6250rpm mark, although this can and does vary between cars.

Only real way to tell is get it on the rollers and look at the power curve.


Anyway, I thought the shift light came on quite early actually, certainly earlier than 7000rpm so if you aint ever seen it light up then it may not actually work!

 

[McBunny]

well not all 172s have it so maybe not all cups do either does the light come on when u start the car ??

 

[geordiepaul]

Depends on whether the car is warm or not. Mine comes on just above 7200rpm when warm and it can come on well below 7000rpm when cold!!

 

[Rich-D]

So the shift light varies with the limit...

Makes sense really.


WIll soon find out anyway as I pick mine up in a few hours!

 

[Lee]

While were on the subject of the shift light Im sure I noticed something odd last night.

I was heading home from work and decided to give the car some stick!! In first it was hitting the limiter at around 6750rpm and there was no shift light. In second I was able to rev to around 7250rpm, just into the red of the rev counter, and the shift light was coming on. Due to traffic I only got to try this a couple of times. A loud Clio in traffic really does draw attention to itself!!

Anyway does sound right, has anyone else noticed this?

Lee

 

[geordiepaul]

Yeah the light comes on at different limits depending on the gear. I cant remember the figures off the top of my head though!

 

[BikeMan]

Sorry my mistake - 6250rpm is peak power

My shift light shines when the ignition is switched on, but Ive never seen it come on in anger. From what youre all saying, the light comes on around the 7250rpm mark and is fixed. However, the actual rev limiter must be slightly above that, except in first when it kicks in earlier. Interesting...

So does anyone know what revs the limiter kicks in at in each gear? Sounds like 6750rpm in first and 7500rpm in second to fifth?

 

[GPRIM]

Varies depending on oil temp, mine when cold rev limit is a lot lower than when it is fully warmed up.

 

[Roamer]

When warm on an unchipped 172/cup the limiter should come in at 7250 in first (and maybe second) and 7000 in all other gears, and when cold it should be 6750 & 6500 respectively.

BUT remember that this is controlled by the oil temp not the coolant temp, the coolant may warm up v.quickly but the oil could still be fairly cold and the engine could still suffer from the higher limiter until the oil is completely heated through (shame it doesnt have an oil temp gauge like the williams/16v really) .

 

[BrynO]

Is the shift light on all 172s? only had mine a few days but not noticed it yet.

 

[simonjones10]

Its all become clear now, Experienced this on my test drives but the salesmen couldnlt explain why! Nobbers!

How long should you leave it B4 raggin the tits off it? 15 mins?

 

[simonjones10]

My mate just leaves his full beam on!!



Hes got a Vectra company car

 

[Roamer]

Erm, depends, about 10-15 miles from what Ive seen in the williams

 

[BikeMan]

Cheers Roamer - that clears up when the limiter kicks in. Based on that, when should the shift light come on then? 250rpm earlier?

 

[Roamer]

erm I think its either 250 or 500rpm earlier yes, but best off getting a rolling road printout of your bhp and torque graph and calculating best change points, it should be about 6500 in reality, but you can hang longer in a gear if needed (like I can hang long in third on the 1/4 mile - but my limiter is 7800).

 

[compocup]

7250 rpm 1st and 2nd gears

7000 rpm 3rd, 4th and 5th (believe me it red-lines in 5th too ! - oops)

 

[hype]

Quote: Originally posted by BrynO on 16 July 2003
Is the shift light on all 172s? only had mine a few days but not noticed it yet.


Took me a while to notice mine - its green, shaped like a gear stick and in the top right (i think) of the dash. Im normally paying more attention to the road than anything else so often miss it.

 

[Frosty]

With the standard ECU the following happens once oil is warm:


1st and 2nd gear

6750 shiftlight
7250 limiter
3rd 4th and 5th gear

6750 shiftlight
7000 limiter
With the R-Sport ECU upgrade the following happens:


1st, 2nd, 3rd and 4th gear

7500 shiftlight
7800 limiter
5th gear

not yet tested
Laurence

 

[Ian P]

Quote: Originally posted by hype on 16 July 2003

Quote: Originally posted by BrynO on 16 July 2003

Is the shift light on all 172s? only had mine a few days but not noticed it yet.

Took me a while to notice mine - its green, shaped like a gear stick and in the top right (i think) of the dash. Im normally paying more attention to the road than anything else so often miss it.

Its on the second to top left of mine and has never come on, whether at ignition or in anger. Has been in to Renault to be looked at but they said maybe a different dash (wtf?). Craigy172 had the same as me but once it was chipped it started to light up. Not sure what to think really.

 

[hype]

It was bothering me so much I just went outside to check! I was wrong the first time, its on the bottom right in the mk2.

http://members.lycos.co.uk/thehype/greenknoblight.jpg

its the little green one

 

[Matt 172]

I know this is an old topic, but we got over the 7000rpm mark yesterday in 3rd and 4th and no shift light, the car seemed to loose power and the backend of the car seemed to shift for some reason, someone shed some light, Sorry Clio MK2 172 on 53 plate?