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124.2 bhp @ the wheels - Any good



_Tom

ClioSport Club Member


Where you from cliosportcraig? I wanna get mine done soon too and where valverodeath got his done is just down the road! I live in clevedon near Bristol.
 


RRs are useless at measuring absolute power. they are good for setting up engines and for checking differences, rolling before and after a mod

flywheel power is at best a guess and 90% of the times overstated, and that can be easily spotted looking at the left side of the graph.....
Quote: Originally posted by ValveroDeath on 26 February 2004
Its pretty standard really! Air filter, full exhaust with de-cat and a PBV (Not that it actually does much till i get cams and headwork!)
 


Last time I had mine done it made 122bhp at the wheels (heavy 17 inch ones!!); my mods are chip, exhaust, de-cat, PBV. 1991 car, J-plate.

So looks pretty consistent with previous posts in this thread.
 


different wheel size wont change power and torque figures.


Quote: Originally posted by steve.stapleton on 26 February 2004
Last time I had mine done it made 122bhp at the wheels (heavy 17 inch ones!!); my mods are chip, exhaust, de-cat, PBV. 1991 car, J-plate.So looks pretty consistent with previous posts in this thread.
 


Quote: Originally posted by crono33 on 26 February 2004

different wheel size wont change power figures.


Well yes they will actually.

The flywheel reading will be the same but the wheels reading will be generally lower with bigger wheels as the transmission loss is greater......
 


I had my valver done a few months back and only got 111BHP at the wheels which I was really miffed about. My only mod is a CAT back Magnex, 111BHP works out at less than the standard 137BHP! I cant work this out as I can keep with my brothers Cooper S from 0 to 90 no problem and my car seems to do well against other valvers??

Id take the figures with a pinch of salt.......but I would say that!

Incidently, I had a K&N induction kit on at the time. The car feels a tad quicker without it so it would be interesting to see if it made any difference to the BHP.
 


Quote: Originally posted by paul1178 on 26 February 2004

Incidently, I had a K&N induction kit on at the time. The car feels a tad quicker without it so it would be interesting to see if it made any difference to the BHP.
Thatd be the reason. A standard airbox imo will give the best power gains on a rr, even against a viper.

The heat generated under the bonnet, and even with a big fan blowing cold air in, the inlet temps are a fair bit higher on a rr than on the road......
 


what i wanta know is how much is the torque at 2000 rpm


Quote: Originally posted by ValveroDeath on 27 February 2004
The graph reads 117lbs/ft @ 5500rpm. Is that alright?
 


why?
they are less. less tyre deformation

Quote: Originally posted by Tom_16v on 26 February 2004
Quote: Originally posted by crono33 on 26 February 2004different wheel size wont change power figures.
[/QUOTE]<!-- ZoneLabs Popup Blocking Insertion --><SCRIPT language=javascript></SCRIPT>Well yes they will actually.The flywheel reading will be the same but the wheels reading will be generally lower with bigger wheels as the transmission loss is greater......
 


Quote: Originally posted by crono33 on 26 February 2004



different wheel size wont change power and torque figures.




Quote: Originally posted by steve.stapleton on 26 February 2004


Last time I had mine done it made 122bhp at the wheels (heavy 17 inch ones!!); my mods are chip, exhaust, de-cat, PBV. 1991 car, J-plate.

So looks pretty consistent with previous posts in this thread.
I does if it changes your rolling radius (gearing).
 


As far as i understand a dyno actually measures thrust at the wheels. By knowing the cars total gear ratio/reduction torque can be calculated. Power is then a product or torque and revs. Flywheel figures are totally estimated by a percentage increase of whats at the wheel compensating for transmission losses.

If a bigger wheel changes the overall gearing then the dyno will under read.

Heavier wheels however will make the dyno over read due to the wheels extra inertia.
 


Quote: Originally posted by ValveroDeath on 27 February 2004

The graph reads 117lbs/ft @ 5500rpm. Is that alright?


Standard is 119lb/ft @ 4500rpm iirc.

I wouldnt worry about it peaking later (probably does this because its tuned), but it sounds about right......
 
  (ex-2.0 Hybrid)CorradoVR6


Thats fine, torque will peak later because of your mods. Scan your graphs in and post them up.
 


Ill try and post em up yeah. Just got to work out how use my scanner first! So are these figures healthy takin in mind its slight mods and 94k its travelled?
 
  300bhp MR2 Turbo


Quote: Originally posted by crono33 on 26 February 2004

RRs are useless at measuring absolute power. they are good for setting up engines and for checking differences, rolling before and after a mod

flywheel power is at best a guess and 90% of the times overstated, and that can be easily spotted looking at the left side of the graph.....

Quote: Originally posted by ValveroDeath on 26 February 2004

Its pretty standard really! Air filter, full exhaust with de-cat and a PBV (Not that it actually does much till i get cams and headwork!)


Got mine R/Rd @ BB tuning - 136.5 bhp at the fly (mines done 104k) so I think (hope) thats very accurate!
 


decent rolling roads have no excuse not to correctly state a flywheel figure, as when the dyno run finishes and runs down, it will measure the loss through driveline which can then be used to get an accurate flywheel figure. This is all assuming RR is calibrated correctly, which they should be. Anybody know what Renault states as an at the wheels figure for a standard valver, or do they only state the 137bhp flywheel figure, i.e what is standard loss through transmission
 


Manufacturers will only ever give a flywheel reading.....

That dont want to advertise the fact power is lost through the transmission, and obviously how much their cars lose against competitors etc.
 


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