Power Graph Thread

[PukkaSilvia]

rpettarfor's s12

[30psi]

Yeah it is...

[adzs12]

random

[Wocketfast]

from the dyno at the JAE 2007, these are wheel power (bolted to hubs) not flywheel as the images state

T25, intercooler, Greddy Profec II boost controller, 2.5" straight through, colder plugs, HKS clone filter, bigger throttlebody

The red line is the first run at 7-8 ish PSI the second is with overtake boost locked on.

They estimate about 20% transmission loss for RWD cars so thats around the 200BHP mark which follows the general thinking on this site for the level of mods.

BOOST


BHP


AFR

Think I might need a new fuel pump, although it didnt actually get anywhere near being lean (16) or even closed loop (14.7)
Strange how they have that blip in the AFR ratio, guess thats the ECU switching to the "eek he's flooered is map" at high RPM/load

[30psi]

Its leanest point is about 12.6:1 with the highest boost setting, which is about perfect for good power. The peak at 4200rpm seems a bit odd on the 2nd run though, but no harm being too rich though

[alundra]

So, can we refer for all dyno that 18% of power is lost to transmission?
Because i have my first dyno tomorrow and i need this spec.

[PukkaSilvia]

You cant find out the true transmission loss just by measuring the power at the wheels.

Although it is not very not accurate,the rolling road machine will calculate losses for you. That is why the operator coasts down the car on the rollers from high rpm in neautral.

People talk about a percentage you can use yourself to work it out. That is just from averages over time. The average rear wheel drive road car with between 100 and 200 bhp loses about 17% of the engine bhp as transmission losses.

Only way to know the true transmission loss is to measure the flywheel power on an engine dyno and the wheel power on a chassis dyno and take one away from the other