Rev Limiter

[SWEET172CUP]

Today I decided to see if the gear change light worked for the first time on my cup so I floored it in second. The revs just kept on going over 7500 and almost to 8000 before I changed up. The gear change light never came on but the over rev light came on around 7500.

Am I right in thinking the gear change light should be a green light in the position of that red light that goes out just before you start the engine?

Can anyone help!

 

[admob]

yes it is the green light! whats the over rev light?????

 

[SWEET172CUP]

The over revving light is green and looks like a gear stick according to the renault manual.

Suerly my car which is standard shouldnt be able to rev this high. Should I be concerned?

 

[wackojacko]

NO!!!

The "over rev light" is your shift light. This thing in the middle has nothing to do with the shift light.

and i doubt VERY much that you managed to get 2 8000k (unless of course you have had it chipped )

 

[McBunny]

hehe who told people it was a shift light everyone seems to think this lol

 

[SWEET172CUP]

I didnt get to 8000. I backed off at approx. 7650-7750 because I was concerned. Should it go this far? Or is there a problem???

 

[McBunny]

it shouldnt go that far at all unless its been chipped and had the limit raised or removed

 

[viceroy]

Quote: Originally posted by dogmaul on 12 February 2004

hehe who told people it was a shift light everyone seems to think this lol

Well it is in a way...If you dont shift, youre going to hurt the engine

 

[CUP80Y]

Its descibed on the original marketing of the Cup as a Shift Light, after all it is a track orientated car. Does the 172 have one?

Renault handbooks etc call it an over-rev light - (they dont want people with blown engines / problems all quoting the official handbook as stating its the optimum ideal time to shift do they? LOL)

Is it not the optimum time to change then?? Ive always found I get a bit more from the engine at the very top end, then the light comes on. In fact I use the light many many times a day.

Sweet Cup - did you buy it second hand - could it have been chipped? If not - sounds like they missed putting the limiter on!!!!

 

[McBunny]

no no no the cup isnt a track orientated car now thats more balls than the light been a shift light

yes the 172 has the ouch ouch your hurting me light.

its not the optimum shift moint either a few 100 rpm less usually

 

[Moby]

^^^^^

agree there, it gives you a few moments to change before the rev limiter kicks in.

 

[CUP80Y]

Ok...so the optimum change point is more like 7,000 rpm is it?? Or is it even lower ??

 

[McBunny]

its about 6850 lol where my max power was

 

[Rich-D]

A standard Cup or 172 should hit the limiter at 7250rpm in 1st, 2nd & 3rd and at 7000rpm in 4th & 5th when fully warmed up!

Now summat aint right with yours...



As for the green light, its just there to warn you before the limiter kicks in, nothing else.

 

[CUP80Y]

Ill do a bit of earlier shifting then!! But I am only quoting what I was told by the Specialists at Renault land, and the useless bumf they handed me.

 

[Roamer]

Has anyone hit the limiter in 5th in a 172/cup? and did they gps the speed?

 

[McBunny]

erm nope lol never hit the limiter in 5th but was doing 140+

 

[MAC30L]

limiter and shift light in 5th. Speedo was about 145 reading. Cup.

 

[Rich-D]

Quote: Originally posted by Roamer on 12 February 2004



Has anyone hit the limiter in 5th in a 172/cup? and did they gps the speed?

According to the gearing a Cup or mk2 172 will do 142.8mph @ 7000rpm in 5th, so will read slightly higher on the speedo due to error.

 

[Chris n nic]

It does sound like it has been chipped...if so the power is held quite well all the way to the limiter which is just short of 8k

Chris

 

[philip]

cupboy, a standard cup will give you maximum power around 6k revs and maximum torque before that. shifting at 5.5-6k revs is prob your best bet. On mine its about 5.7k and Ive got another thread going on how best to install a proper shift light.

re the cup being a track day special, I am not aware of any production cars being track day specials, maybe barring a few extreme caterhams. Even Nobles need a fair amount of tweeking to get best performance on track. Nowdays all production cars are compromised for comfort, safety etc that you dont necessarily need on track. I think a more appropriate way to describe a cup is that its a good BASIS to start from for a track car, and its lighter/cheaper than the 172 and has no ABS which youd need to ditch for a track car.

 

[Chris n nic]

Ive never done a track day (yet!) but I would have thought there would be some benefit to reving the engine higher as when changing up your revs will drop staight back on cam. Dont flame me as Im not mechanic but it just seems logical to me

Chris

 

[RPM]

The Mk1 seems to have the limiter at 7000 rpm from 3rd gear. At least mine.

 

[Andyman]

Quote: Originally posted by Roamer on 12 February 2004

Has anyone hit the limiter in 5th in a 172/cup? and did they gps the speed?

I ve seen 139 in the mk1.....it was shaking like leaf [ and so was I ] so I backed off.

 

[rich[182]]

I thought a std 172/cup reached max bhp @ 6500rpm and max torque @ 5500rpm - forgive me if im talking crap but based on the above why is it even worth ever going above 6500rpm when youve gone above the max bhp and torque anyway

Ive found it all too easy to loose track of rpm in 2nd gear and on two occasions have hit the engine cutoff presumably at 7250rpm

Should I be going into 3rd @ 6500rpm ?

 

[172cliocup]

172 Cup nearly revs to 8000 rpm standard. Its a track car, so renault remapped the Cup especially for this.

 

[Rich-D]

Quote: Originally posted by rich172 on 12 February 2004


I thought a std 172/cup reached max bhp @ 6500rpm and max torque @ 5500rpm - forgive me if im talking crap but based on the above why is it even worth ever going above 6500rpm when youve gone above the max bhp and torque anyway

True the "peak" power figure is achieved at around 6500rpm, however the power does not suddenly drop away and slow you down, it levels and gradually tails off.

If you were to short shift at 6500rpm then especially in 1st & 2nd youd drop out of the power band and it would actually slow you down...

 

[Rich-D]

Quote: Originally posted by 172cliocup on 12 February 2004

172 Cup nearly revs to 8000 rpm standard. Its a track car, so renault remapped the Cup especially for this.

[sighs]

The Cup and mk2 172 both have the SAME engine, gearbox and rev limit...

As I said earlier, a standard car will hit the limiter at 7250rpm in 1st, 2nd & 3rd and at 7000rpm in 4th & 5th

 

[JAY172]

a cup/172 shouldnt rev to 8000rpm on a standard ecu.the gearstick light was intially there to show the driver the best gearchange point but its a bit of a gimmick.the rev limiter does cut in slightly earlier in 4th and 5th.

 

[Neil82]

Is it a new Cup or second hand?

 

[SideShowBob]

You really want to shift at least a few hundred RPM above your max power, as max power should be in the middle of your range.

In other words, say you shift at 6500RPM, then youll drop too low, and end up going slower, whereas if you shift above the max power, youll drop just below it again, and keep within the highest power ranges.

Easiest to see if you look at a typical power graph, you dont want to shift at max power, you want to shift after that so you stay at the top of the power graph, rather than dropping low on it.

Sorry, ive just finished 12 hours night shift, Im not sure Im making any sense...

 

[SWEET172CUP]

The car was new and so must be standard. This has only happened to me once but Ill see if it happens again when I get free from rush hour traffic (wishful thinking!)

 

[Essex_lads_bro]

Ive hit the limit in 5th @ 149mph...

 

[Rich-D]

Quote: Originally posted by Essex_lads_bro on 13 February 2004

Ive hit the limit in 5th @ 149mph...

Your speedo is over-reading then!

 

[Essex_lads_bro]

I dont think it was because, the alfa 147 gta i was racing said he was doing 158 and he wasnt to far in front! and the nissan skyline said he was doing 167 which i can believe as he was quite a way in front lol!

 

[Rich-D]

So how many revs were you doing at this alleged 149mph then?!

 

[Essex_lads_bro]

are you coming to southend on the 21st?

As my friend who was with me at the time has pics on his camera phone!

Was over 7000 i know that much lol, and the green gear change light had come on sometime beforehand!

 

[cupsportmad]

How do you get over 140. Mr car starts to feel unsafe after 130. Scared of getting that "oh sh*t" feeling of impeding doom.

 

[McBunny]

mine felt fine at that speed and we were doing it for about 15 miles

 

[Essex_lads_bro]

Oh i was certainly gettin some vibrations thats for sure lol!

It was just the adrenaline tho, i just had to keep going to find out how fast I could go! Plus had to try and keep up with the other 2 lol!

Was the most scared both my friend and I have ever been while driving but exciting at the same time.