BHP whats your's??
Discussion
I took my car for a rolling road session, not quite what I'd hoped for but pretty good..........
Really good garage and a genuine nice guy, Kevin from the scooby clinic at Wingerworth Nr Chesterfield Tel:01246590807/591664
Don't be put off by the name, this was one of the only garages that could do a 4 wheel drive rear engined car!
Really good garage and a genuine nice guy, Kevin from the scooby clinic at Wingerworth Nr Chesterfield Tel:01246590807/591664
Don't be put off by the name, this was one of the only garages that could do a 4 wheel drive rear engined car!
splashback said:
damianc4s said:
So did he disconnect the propshaft to the front?
No why it's a brand new rolling road so i presume it must sort that out (you have worried me a little now)
If it's a Dyno Dynamics rolling road, the propshaft should have been disconnected to get a proper reading (and save your viscous 4wd coupling). All post-964 4wd systems use a viscous coupling that can vary between 5-40+% of the drive to the front axle. If the car ecu detects slip on the rear wheels it will send part of the power to the front wheels. As a result, the rolling road doesn't get proper readings as it doesn't know exactly how much power is being shuffled between the front and rear axles. The 964 4wd used a fixed 50/50 split with no power shuffling.
splashback said:
fergus said:
I presume that's a corrected 'at the flywheel' figure? If it's not... 
Nice peak torque reading though....
Nice peak torque reading though....
Yes at the flywheel
Only running 1 bar of boost though so there's room for improvment he's looking into it for meSo what was the at the wheels reading ? do you have that graph ?
A flywheel reading is only a guesstimate depending on what % loss the dyno operator programs into the dyno .
polarexpress said:
splashback said:
damianc4s said:
So did he disconnect the propshaft to the front?
No why it's a brand new rolling road so i presume it must sort that out (you have worried me a little now)
If it's a Dyno Dynamics rolling road, the propshaft should have been disconnected to get a proper reading (and save your viscous 4wd coupling). All post-964 4wd systems use a viscous coupling that can vary between 5-40+% of the drive to the front axle. If the car ecu detects slip on the rear wheels it will send part of the power to the front wheels. As a result, the rolling road doesn't get proper readings as it doesn't know exactly how much power is being shuffled between the front and rear axles. The 964 4wd used a fixed 50/50 split with no power shuffling.
You can run a DD rolling road in 4wd mode but there is a limit of 400bhp on them (Allan@Weltmeister might be along to confirm this). A Porsche is just too damn intelligent and 'rocks' itself on the dyno, transferring power from front to back to front etc etc causing damage as Ade says to the viscous coupling if you continue for too long.
You can run a 996 TT with the prop connected if the dyno is taken out of "togetherness mode" we choose not to do this as it puts our very expensive and complicated machine at risk and could potentially damage your transmission. Not a risk we would take for a £65 power test.
BTW the results are sadly vaueless as you had an IT of more than 5 degrees above the AT which means it will have massive corrections built in along with the fact that the huge temps seen by the IT [inlet temp] probe would suggest horrifically high actual charge temps and a serious lack of airflow through the rear decklid. he large charge temp will lead to boost reduction, fences of their actionsuel enrichment and ignition reduction by the cars ECU resulting in reduced power.
Your car probably has good power but needs to be tested in an environment designed to accomodate Porsche cars. Sorry for the "outburst" but it saddens me when good people go along to places that imply thatthey know what they are doing, take their money, convince them into upgrades and have no real idea of the potential consequences of their actions.
Car was also run in wrong gear and wrong dyno mode.
Allan
BTW the results are sadly vaueless as you had an IT of more than 5 degrees above the AT which means it will have massive corrections built in along with the fact that the huge temps seen by the IT [inlet temp] probe would suggest horrifically high actual charge temps and a serious lack of airflow through the rear decklid. he large charge temp will lead to boost reduction, fences of their actionsuel enrichment and ignition reduction by the cars ECU resulting in reduced power.
Your car probably has good power but needs to be tested in an environment designed to accomodate Porsche cars. Sorry for the "outburst" but it saddens me when good people go along to places that imply thatthey know what they are doing, take their money, convince them into upgrades and have no real idea of the potential consequences of their actions.
Car was also run in wrong gear and wrong dyno mode.
Allan
Edited by weltmeister on Wednesday 20th December 22:38
To be fair this is a new rolling road recently purchased by a friend and the test was done on my brothers car for free, he certainly wasn't trying to sell any upgrades. The owner would probably be more than happy to take experienced advice such as that offered.
Daves, (Splashbacks), car is an X50 with a DMS upgrade that was promised to take the car to 500 plus bhp at the flywheel, reading the comments above it seems likely that it may achieve this sort of figure under the right test conditions.
Anyway, I'd love to see that dyno chart come off my Cerbera.....(although that said, it's not nearly as fat)!
Daves, (Splashbacks), car is an X50 with a DMS upgrade that was promised to take the car to 500 plus bhp at the flywheel, reading the comments above it seems likely that it may achieve this sort of figure under the right test conditions.
Anyway, I'd love to see that dyno chart come off my Cerbera.....(although that said, it's not nearly as fat)!
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