just had a rolling road-figures down?

[jmsonline]

Just had a rolling road done and got less than i expected with a dip in the torque aswell between 4.5k and 5.5k and 2 peaks at 4.5k and 5.5k. Anyone else got the same mods/figures?!

clio 172
full cat back s/s exhaust
decat
air filter
group n ecu remap

rolling road: 163bhp @ 6531rpm, 145lbft @ 5624rpm

any help/advice much appriciated
thanks

 

[Ads_172]

Rolling roads are generally only reliable for 'before and after' figures mate, the actual readings are often pretty unreliable. Also, Renault's power figures for the 172ps engine are also pretty unreliable!

 

[GordonD]

Renault's figures are for power at the flywheel.

Chassis dynos measure power at the wheels.

Any chassis dyno that quotes power and torque figures that are anywhere near Renault's figures is simply lying. Its inflating the numbers to stroke the egos of its customers.

The dyno mine was done on says my car produces about 120 bhp. That's an honest figure. And that's in a car that does 15.0 quarter miles with a fat driver. So there's nothing wrong with its power.

The trouble with dynos is you can't compare what one dyno gets with another because customers like you complain they're "only" getting 163 bhp after they've modified a car the manufacturer says produces 171 bhp, so they come up with these phone baloney pretexts for inflating their numbers. You can only compare before and after on the same dyno. Dyno the car before and after its modified.

The dyno graph for my car shows a dip about there too. And the dip was actually larger with the Viper system on it than the standard air cleaner. After I saw how little difference the Viper made, compared to how much noisier it was, I went back to the standard air filter.

 

[ChrisR]

And that's in a car that does 15.0 quarter miles with a fat driver.

lol made me chuckle

 

[stan*]

Renaults figures are indeed at the fly...and his figure is an estimated flywheel figure.

All Renaults are down on factory figures...some more than others. Youve just got to live with it and not get upset when u go on the dyno!

 

[Adey.]

And that's in a car that does 15.0 quarter miles with a fat driver.

lol made me chuckle

the quarter mile time doesnt really prove how much power the car ruffley has, u need to look at the terminal speed. how fast was it crossing the line?

 

[stan*]

Neither does terminal speed lol!

 

[Andyman]

What your car does on a rolling road has no relevance what so ever to a quarter mile time.

 

[ja.jack]

GordonD's clio seems a bit down on power. Did'nt Fred or someone say they usually saw 140-145bhp at the wheels?

 

[ChrisR]

lol made me chuckle

the quarter mile time doesnt really prove how much power the car ruffley has, u need to look at the terminal speed. how fast was it crossing the line?

was the with a fat driver comment that made me laugh, not the time

 

[jmsonline]

cheers for the comments, i know factory figures mean crap but i would expect 164bhp on a standard 172 with no mods?!

 

[stan*]

my mates 182 made 167bhp when it was 12months old...go figure!

 

[jmsonline]

Will inlet manifold matching help out much?

 

[stan*]

Certainly will. £180 drive in/drive out from me. Or £150 on exchange basis.

 

[ja.jack]

Save up all your spare cash and put the motor in the capable hands of BenR for his new hi-torque cams.

He might even throw in a manifold job.

 

[E-ray_172]

im sure people on here with standard 172's have got a avg of 166bhp, but as said before if your happy with the peformance on road u shoundnt worry.

 

[jph172]

jmsonline- is there any way you can post up your graph?
Where was it done?

 

[jmsonline]

heres the torque graph:

http://public.fotki.com/jmsonline/clio/dscf0790.html


done in northampton

 

[ant]

i blame the front spoiler

 

[ja.jack]

Just noticed that. Looks a bit naff.

 

[jmsonline]

i blame the front spoiler

aint got that bumper on there anyway

 

[Adey.]

Neither does terminal speed lol!

terminal speed has a direct relevance to the power the car produces. terminal times can go up and down quite a bit due to traction and such like. have a proper look into it get 2 diff cars with rufley the same power and ull get rufley the same terminal speed one can be rwd and one fwd, the rwd might get a quicker time but the speeds will be very close

 

[stan*]

There may be a vague, in-direct relationship...but its not close enough to be used as a quantifiable measure.

Too many variables...gear ratio, drag, frontal area, etc etc etc to make it anything close to definate.

 

[jmsonline]

back to the post.....is my graph cause to be worried or are those spikes normal?

 

[Ali]

Mine ran 171 std and 148ft/lb.

 

[Ex-User (19928)]

There may be a vague, in-direct relationship...but its not close enough to be used as a quantifiable measure.

Too many variables...gear ratio, drag, frontal area, etc etc etc to make it anything close to definate.

Power to weight and quarter mile times usually compare pretty well.

 

[MATT BLACK]

Did you let the car cool down before it was rr'd - if not add 10hp onto those figures. A warm engine will suffer from power loss

 

[jmsonline]

Did you let the car cool down before it was rr'd - if not add 10hp onto those figures. A warm engine will suffer from power loss

nope wasnt cooled down. cheers for the info!

 

[portal172]

Erm, don't let it cool down too much, it won't rev out...

 

[E-ray_172]

dont they usually put a fan at the front so you get cool air into your air intake anyway.