Dyno And Compression Question

[SLYDA]

Hey,

Just had a quick retune on my car, last time it made 353.8HP, this time it made like 320HP however i have upgraded a few things, new coils, fixed a blown out turbo to manifold gasket and installed a thermo fan. The car now feels faster however its less power than before? now when he showed me with air temp correction on it showed 449HP which is closer to what i would believe it to make based on everyone else that has the same mods? im running 1.45BAR and hits full boost around 3800RMP this time it was about 10 - 15 degrees hotter than last time though however. It was done on a dynapac hub dyno.

Also are peoples cars normally dyno'd on a power run with air temp correction on or off? also does the shootout mode make a big difference?

I have PFC with Boost Control kit

HKS 3037 Pro S 0.68 rear

740CC injectors

Splitfire coils

Full exhuast.

Bla Bla Bla who cares right?

and a fully stock motor.

Thanks for your help guys.

[JMW]

The old "seat of the pants" rule is the best. If it feels faster, then generally it is!

Temperature does play a bit role whether its hub or roller dyno.

The thermo will have removed alot of paracitic drag from the motor.

Shoot out mode always reads higher because of the ramp rate the dyno runs at, hence some exagerated dyno figures but no proof on the track!

Slower ramp rate (more load on the cell) = more exact power figure

Edited December 23, 2008 by Jamesrb25

[Rolls]

Are those figures from the same dyno? if not then don't worry about it.

[raZ1911]

"The old "seat of the pants" rule is the best. If it feels faster, then generally it is! "

Thats not true, if cars are set up differently less laggyer but maybe a bit less power, different turbo setups etc some may feel faster but loose top end depending on tune etc.

Post up dyno sheet.

[SLYDA]

i noticed the thermo fan straight away, car was less rough and went to redline heaps quicker. And it was the same dyno. Checked the compression before the run and changed coils was between 148 and 151 across all cylinders and dont think i had any vac leaks.