2003 Z4 2.5i A/T chasis dynamometer result

[melbs]

zeddy is completely stock with 107s

its only at 166.9 hp at the wheel :?

wondering who else had their zed dyno'd? curious to see the result of a pre face lift 2.5i M/T

 

[EdButler]

That sounds perfectly fine to me; dont forget that published figures from BMW (in europe at least) are at the flywheel. Dyno's however, must to be taken with one huge pinch of salt in my experience!!

Typical RWD cars loose around 17% power through transmission losses at the top end. Therefore:

BMW's Flywheel Figure: 192BHP
166.9 + 17% = 195.2BHP

 

[melbs]

That sounds perfectly fine to me; dont forget that published figures from BMW (in europe at least) are at the flywheel. Dyno's however, must to be taken with one huge pinch of salt in my experience!!

Typical RWD cars loose around 17% power through transmission losses at the top end. Therefore:

BMW's Flywheel Figure: 192BHP
166.9 + 17% = 195.2BHP

yup, the rating by bmw is at the flywheel.

so i guess mine is within the acceptable range.

just wondering if other 2.5i 2003 zeds have theirs rated same as mine because a fellow club member had his e46 325i smg rated at 182 whp. we both used the same tires(borrowed his) as mine kept slipping

in your experience, are the dyno ratings over or understated?

thanks

 

[EdButler]

Well an auto is bound to loose some through further transmission losses... The SMG is basically a Manual so a slight increase over yours is reasonable. There are many other variables however like cooling, which petrol you both had etc.

As with Dyno accuracy, every single one is different. Especially 'Dyno Dynamics' that somehow calculate the flywheel figure without run-down losses!? Basically i stay away from getting opinions from the 'peak' numbers and concentrate more on the power/torque/AFR lines and if they look correct (no flat spots, 12.8:1 AFR etc)!!