6800rpm limit?

[Camerooon]

How do?
I have recently bought myself an 03 172 Cup and noticed for the first time on Friday when it was on the rollers that it has a 6.8k rev limit.
With this being my third 1*2 Im fully aware that its supposed to rev to 7200 once fully warmed up but it never goes above the 6800 mark.

The search function tells me that it's the thermostat but I just wanted one final check before I go ahead and get it done.
Is the stat likely to be the problem? There are no other heating issues i.e overheating/underheating and the car warms up fairly quickly the same as the cabin heater.

Any help is appreciated.
Ta.

 

[Tiger260]

I always thought the limiter cut in at 6750.

 

[James105]

I could be wrong and I will try and find the other thread on this, but I think the water temp sensor located under/ behind the airbox can cause this problem as well.

 

[172Ben]

are you looking at the dial when checking what its revving to?

 

[Camerooon]

Ok thanks.

Up until today I hadnt. I thought it was abit strange when the chap at the RR said it was redlining at that and today on the way home from work I had a look and it wasn't even touching 7k.
Like I say, I've had a 182 cup and a normal 182 and they both go to 7.2k.

Its not just a 172 thing is it?
Does anyone know from knowledge or experience what they usually rev to?

 

[Addicted]

Pretty sure 7.2k is RS Tuner standard, not actual standard?

 

[sbridgey]

mine goes to 7200 once fully warmed up

 

[Camerooon]

Not known to me personally but I've always heard/read that the RS Tuner put the redline at 7800.
Neither of my 182s had been messed with. :S

 

[Steven103]

Think this needs a bit of clarification, in bold For ALL PHASE 2 (F4R 738 engine)

* Standard map: 6800 RPM when cold. When warm it's 7250 RPM in 1st, 2nd and 3rd. 7000 RPM in 4th and 5th.
* Renault Group N map (standard on Renault Group N ECUs): 7400 RPM in all gears.
* Most/all RS Tuner maps & lots of specialist maps: 7800 RPM

 

[MartinR]

^^^^Spot on

 

[Camerooon]

Now we've got that settled ...is it likely that the issue is down to the thermostat?

 

[The Fatty]

How can you check if yo have a Group N ECU?

 

[MartinR]

Now we've got that settled ...is it likely that the issue is down to the thermostat?

Or incorrect timing

 

[Chip-mk1]

Now we've got that settled ...is it likely that the issue is down to the thermostat?

Yes, if its allowing water to flow through it too soon then the car doesnt get properly upto temperature.
Trouble is the gauge sits in the middle position for quite a wide range of temperatures, so it will look like its warm enough when its not really.
So at this time of year, it can take ages of driving the car hard before they go onto the hot limiter.

 

[Camerooon]

Roger that! Thanks for the help.

 

[bmh.01]

Probably the CTS rather than the thermostat. Where does the temp gauge settle when its warm?

 

[Goodj]

using decent fuel?

 

[MarkCup]

Think this needs a bit of clarification, in bold For ALL PHASE 2 (F4R 738 engine)

* Renault Group N map (standard on Renault Group N ECUs): 7400 RPM in all gears.

Not sure this is 100%.

Mine revs out to 7,750 rpm (indicated) in all gears...well, as far as 4th gear anyway.

 

[Steven103]

Not sure this is 100%.

Mine revs out to 7,750 rpm (indicated) in all gears...well, as far as 4th gear anyway.

I got my info from here (not saying you're lying or that I'm right, just saying it apparantly came direct from Renaultsport):

"HANSEN Lionel" lionel.hansen@renault.com

Dear mister (Simon),

The FIA rule demand to keep the sensors of series present on the engine.It is possible to modify the connctions of cablage as well as to change the ECU Box.Concerning the characteristics of the modifications in to the Renault Sport ECU Box

The series engine speed is supposed to be 7250 rpm for 1 to 3 and 7000 rpm after. The Groupe N box is always to 7400 rpm limited 1 to 5.

Power + 8 Hp. (with the exaust system)
Torque + 1,7 Mkg.

Let me know if you need anymore information.

Lionel Hansen
Renault Sport Technologies
Direction Competition

Which can be found here: http://www.cliosport.net/forum/show...u-email-from-renaultsport&highlight=group+ecu

 

[MarkCup]

The ECU I have I understood to be a Renault Group N, but from what you're saying above...maybe it's not. Regardless, it definitely revs out to 7,750...

 

[Cup_Phil]

^^^ I wouldn't be doing that much without uprating the rod bolts LOL

 

[Chip-mk1]

^^^ I wouldn't be doing that much without uprating the rod bolts LOL

Agreed, big risk once you get past 7500rpm IMHO, poorly specced long stroke engines like the F4R mean big strain on the rod bolts.

 

[MarkCup]

Pah. 130k on mine, never missed a beat. I'm sure it'll go eventually, but it's been like this from 2.5k.

 

[Cup_Phil]

I'll stick to 7400rpm on mine. Pointless revving past that as you've gone past peak power anyway!

 

[_Tom]

Mine was doing this. New CTS and 5 minute change and all was good again.

 

[Chip-mk1]

I'll stick to 7400rpm on mine. Pointless revving past that as you've gone past peak power anyway!

Depends on the engine, with an RS2 for example, its still make really strong power at those sort of RPMs, in fact in a lot of cases that is peak power.

On the restrictive standard inlet though, I agree totally they are packed up and gone home way before then.

 

[MarkCup]

Agreed...it's pretty much useless beyond 6.5k...but it does help save the odd pointless gearchange here and there on track.

 

[Chip-mk1]

Agreed...it's pretty much useless beyond 6.5k...but it does help save the odd pointless gearchange here and there on track.

Its not such a problem having a higher limiter if you are only ever there occaisonally, the problem is when you have power up there too so you use the big RPMs a lot, probably why yours has survived so long on a high limiter if its rarely there.

 

[warwickstingray]

Had this problem. Didn't ***** around and got thermostat and cts changed. Problem gone.