Results from the Dyno Today!

[Lum]

Went along to a Dyno shootout today at castle coombe with a local jap car club. Was a good day and as the only rotary in attendance i managed to show all those "boingers" a thing or two.
Made the second highest power of the day (got done by a woman in a R33 GTR:Grrr )
Managed  370BHP at the wheels at just under 1 bar :chat
and         322.4 lbft
It was a brand new Dastek dyno & i don\'t think the operator was fully up on how it works as the correction for RWBHP to FWBHP seems a bit out??
370 ATW
413 ATFW
After every run he was putting the car in neutral and allowing it to coast down to a standstill?
Anybody know if this is right? I thought you were supposed to allow it to slow down in the same gear that the run was performed in, to measure the drag through the entire transmission?

[lee mills]

good results FWHP seems a bit low though.
Thanks
Lee

[Lum]

Yeah thats what i thought, i don\'t think there corrections figures are right.
I\'m sure they\'re supposed to let the car run down in gear?? I think they use the rolling resistance to measure torque too, as quite alot of peoples torque was lower than expected/previous results.
Here\'s the graph if anyones interested

[lee mills]

if power is 370 rwhp fwhp should be approx 440 judging by my results from reworx dyno
Thanks
Lee

[Lum]

Yeah that seems more like it, cheers mate!

[Kash_]

Nice result dude!

[Carl]

The coast down procedure is right,so the figures are pretty accurate,you certainly don\'t have a 70 hp drivetrain loss,43hp loss is about right.
I have used that Dyno with RX7\'s and it is very good,it ought to be since it cost £70,000 which 3 times as much as alot of other Dyno\'s.
Regards
Carl

[lee mills]

The coast down procedure is right,so the figures are pretty accurate,you certainly don\'t have a 70 hp drivetrain loss,43hp loss is about right.
I have used that Dyno with RX7\'s and it is very good,it ought to be since it cost £70,000 which 3 times as much as alot of other Dyno\'s.
Regards
Carl

Hi Carl does this mean that reworx Dyno is inaccurate then as i made 390.7 rwhp and 469.2fwhp. Im just interested as this was my first experience of a dyno
Thanks
Lee

[Carl]

Hi Lee,
You will have to ask ReWorx about that.
Dyno\'s are only a tool to tune a car safely,hp figures to an extent can be a bit taken with a pinch of salt,what matters most is how the car performs,if it feels and drives great then that is the main thing.
Regards
Carl

[Carl]

The operator of that dyno is a pretty decent chap.
We used the Dyno a few times last year,it has been in what must be nearly a year.
Regards
Carl

[Lum]

Thanks for that carl
Just seemed that my conversion from WHP to FWHP has lost me more BHP than others.
Here\'s an example-
Made 1 more BHP than me at the wheels but 20 more at the fly??




As you said, the bloke is a top chap and couldn\'t have been more helpfull throughout the day.

[Ed_RX7]

but wgt do it from the hub not the wheel right or am i wrong??

[arrouk]

as do reworx i think, you would have slightley more drive train loss if this is at the wheels rather than at the hubs.  could the extra losses also be due to a worn gearbox and or diff?

matt

[lee mills]

reworx do it at the wheel not the hub

[arrouk]

is reworx not a  dynamics, same as thor and wgt?

http://www.mazdarotaryclub.com/forums/attachment.php?attachmentid=30873&d=1179853981

borrowed this from a post from warthog, i believe he has his car tuned there.

matt