What are the average transmission loss on a 2wd saff?

Why would u run a car in 5th gear?

Thanks

Paul

 

You dont run it in 5th gear because its an over drive gear (because of the gearing)

 

normally see about 50hp loss, run in 5th gear to prevent wheelspin

 

I had just over a 55 bhp difference between the wheel and flywheel figure. That was not in 5th gear.

Steve.

 

This could affect power figure???

reason i ask is mine was 114 bhp wheel drag

 

4X4 cosworths are normally about 100bhp loss

 

http://www.pumaracing.co.uk/coastdwn.htm

have read of this, quite an interesting read

 

mine is 2wd

 

17% on a rwd, 22% on a 4x4.

Its hard to select 5th on a Dyno cos no gearbox is connected..

 

What dyno was this run on?

 

 

This thread shouldn't have any replies to it yet as I don't see no 'experts'

 

You're here, so everything is OK now.

 

I see you moaning on Rod's thread about it turning to shit and then what do you do on this thread - post a sarky comment that will indeed turn this thread to shit.

 

It depends entirely on the RR used, Powerstation for instance use a RR that shows very high losses, yet the Power figures are very accurate indeed.

More info needed i think, a graph would be nice too! lol

 

Hey, there's no need to take my comment personally. I just think people use the term 'expert' a little too often these days. Someone owning a tool and understanding how to use it doesn't make that person an expert.

 

i own a 10mm spanner, does this mean i would not be an expert in undoing a 10mm nut? or would it also need to include how to tighten it up as well?

but then i'd need a torque wench

which is another tool

so i suspect that what you are trying to say here is that just because you have a tool box, doens't mean to say you can use everything in it, in the same way as just because you have a pen and paper doesn't make you the next michaelangelo, just because you have a ktichen doesn't turn you into delia smith, etc, yes?

 

I think i'll withdraw my comment after reading the definition of expert in the dictionary

 

expert
Noun
a person who has extensive skill or knowledge in a particular field
Adjective
1. skilful or knowledgeable
2. of, involving, or done by an expert [Latin expertus known by experience]

 

He cold mean someone who is no longer a pert so is an ex-pert

pert (pűrt)
adj. pertˇer, pertˇest 1. Trim and stylish in appearance; jaunty: a pert hat.
2. High-spirited; vivacious.
3. Impudently bold; saucy.

 

lol; this thread has gone awol!

i think Paul is speaking about the RR at interpro as that's where his 2wd saff went last Saturday for a power run.......(unless i'm completley mistaken)

 

Yes you are right Matt

Thanks Rod a sensible answer

I was unsure why i lost 112bhp transmission loss as its 2wd
it made a good power figure of 331bhp and 328lb ft not bad fro a 109k engine imo

will post graph later

Paul

 

 

Why do people insist on taking flywheel figures from rolling roads?? ATW is the way to go!

 

Are you not going to bother with engine dynos anymore then Martin?

 

True Martin would like a atw figure just wondered why losses was high.would be nice to get it on a up to date set of rollers

Paul

 

Yes of course and when I give figures off one I won't try and make them into ATW figures!

 

Could your rear brakes be binding Paul ?????????????

Thats 100bhp down on my atw figure

Steve

 

lol Steve i guess there not as my mates car had nearly the same losses

Don't get me wrong it goes really well on the road

Paul

 

Isn't that what where it counts?

 

HERE HERE

 

funny how now Martin says thats the way to do it that everyone on here will agree, yet AVA have only EVER gave wheel figs and lots of folks think they are being short changed

 

oh yes but don't get behind when i boot it



you won't be able to see

 

Funny how now? Not at all I'm not interested in bullshit, never have been! If AVA go by ATW figures then fair play

 

Im not having a go at you mate.

I know people that dont want to put their cars on AVA's rollers cos they cant give you a fly fig beleieve it or not.

 

All i'd want from a dyno sesh is the ATW figure (no possibility of a mistake being made, or over correction) and to know that the car is running ok

And...... new sig \/ \/ \/ \/

 

right then back to original post

Martin Why?

was mine run in 5th?
and why do u think the losses are so high?

Thanks
Paul

 

Cool, no problems I can give a flywheel figure but I tell all my customers to ignore it and use the ATW figure for comparison.

 

Could the operator not explain this to you?

If it was me I would want cash back and I would go elsewhere.

 

its true
and to be honest i'm 100% guilty of this
when my saph was on at ava i got the wheel figure and straight away asked
whats that at flywheel
alan didn't even bother to tell me, just said its impossible to work out accurately
i now understand how it works and agree
but as long as people keep talking about flywheel figures the atw figure will never sound as good
when we realy all know that how much power makes it to the tarmac is what counts