Saabscene Saab Forum - Saab Technical Information Resource banner
1 - 4 of 4 Posts

·
Registered
Joined
·
3,892 Posts
Discussion Starter · #1 ·
I've just noticed flicking through a copy of an old 9000 spec sheet (for 1996 model year), and it quotes the 2.3 FPT as being 200 hp, 323Nm at 1800rpm torque with a max boost pressure at 1.00 bar, this spec for the manual gearbox.
For the same engine with the auto box the figures quoted are 294Nm at 1800 torque with a max boost pressure at 0.81 bar, but still quoting 200 hp..?
If these auto spec. engines are only boosting at 0.81 bar max with a lower torque figure, then surely the hp output would be correspondingly lower, and not 200hp????
Any theories from the more knowledgable and wise???
And if so, then auto Aero owners really got a bum deal......
 

·
Registered
Joined
·
2,599 Posts
Power = Torque * engine speed. Hence the auto box has limited torque at say 3000rpm max torque point(lower boost)compared to the manual hence at this engine speed lower power. But at say 5000rpm (guessing the value) were max power is developed the torque for both manual and auto will be the same (same boost but lower than peak boost at the max torque point) hence power the same. The torque at the max power point is lower than the max torque point (boost taper). This is the case for all engines, at the higher speed less time to extract all the energy from the fuel.
 

·
Registered
Joined
·
208 Posts
so auto aero owners really have got a bum deal! They have less gears and less gear control so they really need a better torque range where in fact they have a worse one.
Shame everyone concentrates on peak power when this is actually one of the least useful bits of data for your average driver!
 

·
Registered
Joined
·
3,892 Posts
Discussion Starter · #4 ·
Absolutley, but then it's the same as 'Joe Public' having this ridiculous fixation with 0-60 times and top speed...both of which are virtually irrelevant to daily driving, and have never really been a true indication of performance anyway.
I'd much rather know about the 30-50, 50-70, 70-90 splits and maybe 0-100-0 as a test of acceleration and brakes combined.

Thanks Adrian for the technical explanation, even though I did get a tad lost half way through..!!

Graham
 
1 - 4 of 4 Posts
Top