What % transmission loss?
 

Hi can anyone hazard a guess or know the % of bhp/torque loss due to transmission?

had dyno today and car was producing 211 bhp and 224 torque at the wheels

would like to know fly figures too

many thanks

prob about 260 at crank id say

Realistic transmission loss is between 16-20%

258~261bhp 273~277lb

whose rollers? and what make? and why did they only give you wheel figures?

do you have print out? scan it?

Simon

this is going to be an interesting thread

thanks for the interest hopefully can see what is what

here is the scan:

http://i143.photobucket.com/albums/r...995/BazWRX.jpg

what dose it matter

second run looks like ecu has pulled timing.. what fan did they have.. I would suspect the engine was too hot..

Simon

diffrent dynos calculate losses in diffrently

mmm interesting question......

'Matter' might not be the correct term, I am interested as all the dynos i have done before have been pulley figures:

YouTube - mr2 dyno run

so i have no idea how wbhp relates to pulley hp on an AWD car, also different rollers give different figures, some apparently tweak figures to make things look better.

Also interested to see what the experienced people on here make of the graph as i bet just by looking at it they can tell what is wrong or right, for example the second run was made about a minute after the first one so heatsoak aside why is it 38hp less and 65lbs/ft torque different and finally if there is something wrong then hopefully i will either a) find out what to look at with respect to the car or b) work out why i spent £50 for two runs that weren't correct :) hope that answers you question mate

sorry simon i forgot to say that i went here Janspeed - Home very nice bunch, showed me around the factory etc was good but just wanted to check the figures as i felt something might be wrong, they had one fan in front of the car with the bonnet closed and it was angled slightly down, dont know if that would affect it, does anyone know another RR in somerset/dorset? so i can compare

ahhh.. been there... assuming still the same fan.. deffo not going to give intercooler cooling to a tmic am assuming you are on a tmic..

Simon

16% loss was used on my car when it was tested in a Rototest (units connected directly to the hubs, no wheels on).

Yeah TMIC and one fan at the front with the bonnet closed, would you know any more around the south west at all?

thanks for the replies

Alright mate. I use Surrey Rolling road. Im hoping to get my car mapped on there in Dec/Jan (Got to talk to Simon) Come along for a convoy when i go mate.

Powerstation isnt to far either

yes powerstation mounts fan to tmic..

Surrey Rolling Road use a nice big fan..

Dave,

17th december any good to you my friend?

Simon

As discused me old china plate. :D

praying clutch comes now

according to MRT australia is it about 40% drivetrain loss thru 4wd and front or rear is 20%

thats way too much i thought it was 22% approx

They are full of **** then!

thats way too much i thought it was 22% approx

The % transmission loss is entirely inaccurate IMO.

The adage is that the dyno measures power at the wheels, but having had my car on a few rollers there have been huge differences in the wheel figures but the calculated flywheel figures have been fairly close.

DD tend to show lower wheel figures but use something like 23% to get to a flywheel figure

Dastek seems to show higher wheel figures but calculate losses.

Maha wheel figures were ridiculously low.

Which one is right ?

Those graphs look strange, there is a big drop on the first run at just under 6k like the IAM shot down and reduced boost and timing - then stayed at that level for the second run. This is right at the point where the bhp is still increasing which may explain why the peak torque is higher than the peak bhp.

Unfortunately the AFR graph is meaningless.

I'd take it to a proper set up with proper cooling and decent/useable graphs Baz.