Best Air Filter, AirBox, Air Intake
07-12-2014, 11:43 PM
#51
The RS4 ran in homogenous mode, ie, injection on intake not compression stroke
Since the fuel os injected under hi pressure as it expands it absorbs heat(cools) the charge
Heat of expansion PV = nRT stuff
The sls makes 25% more hp but only 8% more torque
Primarily by moving the peak down the band
5000 to 4750 or 5% lower
Since T = 5252/rpm x HP
Therefore if you maintain power at a lower rpm you will increase torque
The base c63, pp and 507 have 450/480/507 but essentially the same torque since no cam or intake revisions were made
I won't say it is 'easy' to increase peak power, but it is 'easier' than making torque
Since the fuel os injected under hi pressure as it expands it absorbs heat(cools) the charge
Heat of expansion PV = nRT stuff
The sls makes 25% more hp but only 8% more torque
Primarily by moving the peak down the band
5000 to 4750 or 5% lower
Since T = 5252/rpm x HP
Therefore if you maintain power at a lower rpm you will increase torque
The base c63, pp and 507 have 450/480/507 but essentially the same torque since no cam or intake revisions were made
I won't say it is 'easy' to increase peak power, but it is 'easier' than making torque
07-13-2014, 07:10 AM
#52
Super Member
Header and tune should net 100 wheel hp. Cams with heads should be another 50-70 at the wheels. Are intake manifold is already perfect with nothing much to be improved on it. Pulley should be about 10 wheel but the pulley actually moves the rpm band 300-400 rpms lower... So you get in the power band sooner.
07-13-2014, 11:42 AM
#53
So, to be clear, are you saying a header mod (like long tube) with tune, without modifying the remainder of the exhaust, would provide this sort of yield? I'm sure the #s vary and again I've only started to explore and learn about this subject myself, but I've seen so much about catless and other exhaust mods just wondering if they yield less power and moreso help with sound? thx
07-13-2014, 01:11 PM
#54
When the factory designs an exhaust ( actually they work with a supplier) they put an engine on a dyno with a variable back-pressure test set-up
They can measure pressure and flow before/ after each system component
That way they can optimize power/torque/efficiency/sound
The exhaust is a calibrated system component
It will be hard to improve on without impacting one of the parameters negatively
They can measure pressure and flow before/ after each system component
That way they can optimize power/torque/efficiency/sound
The exhaust is a calibrated system component
It will be hard to improve on without impacting one of the parameters negatively
