79 bhp @ the wheels

[Chief]

Anyone know what power at the fly would be?

 

[iPap]

Less than 110!

 

[Mitchy]

100bhp at the flywheel and 79 @ the wheel would indicate a 21% transmission loss would it not?

FWD cars shouldnt be so high so my reckoning is under 100

 

[DeanRSi]

low 90s mate.

 

[iPap]

I wish I had of had mine there!

Seems like a low reading road to me!

 

[Chief]

Simon (the geeza doing the rolling road thing) said that you lose about 30% on the transmission on the road. So he seemed to think that it would be around the 120bhp mark. I just wanted a more accurate figure

 

[DeanRSi]

iirc correctly mate its usually about the 15% mark. but i could be wrong.

 

[edde]

Bout 95~97hp

30% loss though the drive train is a bit high

Id say times the figure by 1.1 and then add 10hp on always about right that. There is a site on the net which gives a good explaination for why this is right think its Ford one something like Puma racing.

 

[Chief]

Surely if matey says its about 30% then its about 30%. Its his rolling road and thats what he does for a living.

 

[iPap]

Quote: Originally posted by Chief on 20 March 2004


Surely if matey says its about 30% then its about 30%. Its his rolling road and thats what he does for a living.

I thought he picked cornflakes out of his beard and hung around outside schools?!?!?!

 

[Chief]

Anyway, a young chap with an Elise turned up after me and his read at 88 @ the wheels. Using Eddes calculations that works out at 106.8. Surely the road must be reading a bit low then?

 

[BenR]

i wouldnt bother going to that rolling road anymore.

Obviously matey doesnt know what hes doing.

 

[DeanRSi]

yeah, i mean if we go by the 30% loss then my valver is making figures that are a wee bit silly,lol

youll probably find chief on another RR youll get a higher figure. the 172s that went on he was only taking to 6k so their figures were pretty low.theres no way mines only 10 brake or so atw less than a 172/cup.he didnt even take mine up into the revs really

 

[BenR]

IF your box was absorbing 30% of the engine power and converting it to pure friction, parts would break. Thats enough heat energy to heat the average house.

And your using a good few pounds of fuel an hour just to heat the gearbox, very unlikely.

 

[DeanRSi]

lol, yeah, i know the valver lumps get hot but not that hot!

 

[Mitchy]

30% in a FWD car.......Your having a giraffe mate.

What does that make my 4wd scoob?? 50% tx loss??

Like someone has said 15% seems to be the rough estimate with 4wd being around 25%. Nothing like the 30% you are quoting.

Like i said before, your flywheel figure is going to be under 100bhp as there is no way your car is producing more than a 21% transmission loss 100-21=79. I think youve got more like 95bhp @ flywheel.

Whats your car supposed to produce? If higher, then this can be down to a lot of factors including tyre pressures, rolling road, operators experience, car jumping, f**ked engine etc etc.

 

[Rich-D]

Quote: Originally posted by DeanRSi on 20 March 2004


yeah, i mean if we go by the 30% loss then my valver is making figures that are a wee bit silly,lol

Aye, if it were 30% then my Cup would be making 210bhp @ fly with just a Viper... unlikely...

 

[Rich-D]

Generally 15% loss for a fwd car...

So, yours is gonna be >>>

[79bhp / (100% - 15%)] x 100% = 93bhp @ fly