Matt's Stock NB8B, Low power?

matt9111 · Postby **matt9111** » Sat Oct 25, 2008 3:26 pm

Stock NB8B, just after major service has been done.

Stock except for K&N Pod on standard piping, only made 61.3rwkw?

Sound to low?

Postby **mx52nv** » Sat Oct 25, 2008 8:04 pm

Were you running on a chassis dyno?
And if so was it a Dyno Dynamics or another brand?
If it was a Dyno Dynamics (in shoot out mode) then we can compare it to our club's dyno day results.

Also, what gear did you run in?
1:1 is 4th gear for the 5 speed gearbox and 5th gear for the 6 speed gearbox.
Running in other gears will mean lower or higher results (for comparative purposes).

On our last Club Dyno Day most of the normally aspirated NB8s were making between 72 to 82 rwkw (depending on modifications).
So YES, 61.3 rwkw does sound a little low (if the circumstances indicated above are similar).

matt9111 · Postby **matt9111** » Sun Oct 26, 2008 1:31 pm

Yep, I was running on a chassis dyno....I think (the one where they jack the car up, take the wheels off and attach your hubs to two rotating dynos?)

It's a 6 speed, the run was done in 5th because apparently that's a 1:1 ratio....

I don't think its the dyno, because my mate in a VT S-pack Commodore with a cat-back exhaust did 103.8rwkw, im pretty sure they're around 90rwkw from factory.

So what do you guys think it could be?

Postby **mx52nv** » Sun Oct 26, 2008 1:51 pm

Matt9111,
What you described is a hub dyno which traditionally reads a little higher as there is less transfer loss (no wheels and tyres).
I am not sure if there are correction factors that are used

Basically, if you are reading 63 hub kw then it should be less on a 'rolling road' dynometer.

In order to be sure you are really losing power, we need to compare apples to apples

Does your hub dyno operator have past results of other NB8s?
Are there any other forum members with NB8 dyno results on a hub dyno?

Once we determine that it really is reading low then we can start looking at causes/reasons :mrgreen: