Rev Limiter

[Rich-D]

Quote: Originally posted by Essex_lads_bro on 13 February 2004


are you coming to southend on the 21st?

Nope... I live way up North, so wont be there.

Quote: Originally posted by Essex_lads_bro on 13 February 2004


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!

The limiter "should" have come in at 7000rpm in 5th (or so we are told), but if yours went past then in theory yes it could do that speed!

However going off my Cup, Ive never gone past 130mph as it just starts to suddenly stop accelerating at this point and I didnt wanna hold it at that speed. It gets there very quickly then just kinda dies off...

 

[Essex_lads_bro]

mine honestly pulls really really hard past 130 upto about 140 thats when it backs off and speed builds up rather alot slower...

 

[Rich-D]

Quote: Originally posted by Essex_lads_bro on 13 February 2004

mine honestly pulls really really hard past 130 upto about 140 thats when it backs off and speed builds up rather alot slower...

Its quite wierd in mine as it pulls strong & hard up to about 130 then just kinda hits a wall and stops!

Not tried for a long time though and it was still quite new then, so probably just a tight engine holding me back. How many miles yours done?!

 

[Essex_lads_bro]

done 5100 miles now...

am just thinking tho, my car was very much warmed up before this occurance and the outside temperature was around 0.

My car is definitly gettin better the more miles i do!!!

 

[Rich-D]

Might have to give it another go now... just coming up to 6k miles...

 

[Essex_lads_bro]

Go for it mate!

Just out of interest... did u run ur car in properly or bend the rules/recomendations a little bit, as i must admit im guilty of the latter...

Do u use ur for commuting etc or just for fun?

As the only time i use mine is to go out for a drive really, would say ive done about 1500 motorway miles in total, the rest are fun miles lol!

 

[Rich-D]

Mine was run in properly, so will obviosuly take longer to loosen up than one that was hammered from new...

Only had about 4k miles on the clock when I tried it though, and only did it twice (same night), but it wasnt keen on going much over 130 at that time!

I use mine for both commuting and fun, so most of the time its being driven to work & back and not thrashed, so hasnt had a hard life so far.

Was on the rollers at the end of last year though and its making good power & torque now, in fact it was really strong mid-range, but seems tight at the top and still needs to free up, even the RR operator said it.

 

[Bryan]

rich - generally renaults final gears seem longer than they should be, the williams and 16v revved further in 5th, the lower spec mk2 models rev to 6750rpm as opposed to 6250rpm in 5th, i can only assume that the 172/cup gearing is based on similar lines, if this is so, then expect the limiter in 5th to be nearer 8000rpm

find a nice quiet motorway in the early hours of the morning (or a good straight trunk road) and go for it, see what you can get

 

[Rich-D]

Quote: Originally posted by bambam on 13 February 2004


rich - generally renaults final gears seem longer than they should be, the williams and 16v revved further in 5th, the lower spec mk2 models rev to 6750rpm as opposed to 6250rpm in 5th, i can only assume that the 172/cup gearing is based on similar lines, if this is so, then expect the limiter in 5th to be nearer 8000rpm

find a nice quiet motorway in the early hours of the morning (or a good straight trunk road) and go for it, see what you can get

Well I cant even get to 7000rpm in 5th, let alone 8000rpm, but I very much doubt theyd go that high...

Its definately limited to 7250rpm in 1st, 2nd & 3rd then in 4th the limiter is set earlier and kicks in at 7000rpm, I am also lead to believe that its the same in 5th, but this has yet to be confirmed.

 

[Essex_lads_bro]

didnt thrash mine from new, did about 100 miles of below 4000rpm, then up to about 400 stuck under 6000rpm, and then after that opened it up a bit.

Always warm my car up properly tho, keep it topped up with oil (topped it up once so far), only use bp ultimate or optimax, and check tyre pressures regularly etc.

Is loosening up now which is good...

 

[Rich-D]

Quote: Originally posted by Essex_lads_bro on 13 February 2004


Is loosening up now which is good...

Mines getting better by the day too!

Took my mates mk1 172 a long time to get up to full performance though, it was really tight from new...

 

[Essex_lads_bro]

yea just give it time, itll get there...

where abouts r u anyhow mate?

 

[Rich-D]

Quote: Originally posted by Essex_lads_bro on 13 February 2004


where abouts r u anyhow mate?

Lancashire...

 

[BenS]

Ive got the ECU from Rsport and done 22,000 miles and mine goes like a rocket uptp 140. I can sit at 130 put my foot down and it picks up the same as if I did it at 100. Not gone passed 140 yet so will have to find quite road for testing.

You will find the more miles u pile on the better the engine will perform.

I dont bother taking the revs over 7200 that often as i find all the torque is around 4-6000rpm and that gives me good performance when blasting on b-roads against other cars. Power doesnt drop off after 7000 but trails off at 7500rpms.

 

[Neil82]

Quote: Originally posted by BenS on 13 February 2004


Ive got the ECU from Rsport and done 22,000 miles and mine goes like a rocket uptp 140. I can sit at 130 put my foot down and it picks up the same as if I did it at 100. Not gone passed 140 yet so will have to find quite road for testing.

You will find the more miles u pile on the better the engine will perform.

I dont bother taking the revs over 7200 that often as i find all the torque is around 4-6000rpm and that gives me good performance when blasting on b-roads against other cars. Power doesnt drop off after 7000 but trails off at 7500rpms.





I am sorry but a Cup/172/182 will never accelerate over the last 10 mph of its speed range the same as it will from 100.

 

[Lagerlout]

Nope, nowhere near.

 

[MAC30L]

I have the Ktec system on my Cup, and I think Neil has proven that both the ECU and the ktec system give about the same gains on the road.

But as for goes like a rocket uptp 140 - I find mine starts to pull up at around 125. Thats when a CTR goes past me anyway. The Cup will crack 140 fairly easy, but not as described above.

 

[Homer]

Quote: Originally posted by Rich-D on 13 February 2004

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...

the ideal time to change is at the point where the power available in the lower gear dorps below the amount that the engine would produce when you change to a higher gear. Obviously some engines you will hit the limiter before this point in which case you rev to the limiter and others you wont.

Obviously you have other variables like being on cam and torque etc, but in essense thats the basics !

 

[CUP80Y]

I drive trying to keep revs above 5k in each gear as much as possible - seems to do the trick - M3s, porsches etc... no chance.