Quote:
Originally Posted by Vigilante375
So a stock 128i makes 199 (highest on the chart) vs 135i's that make at least 270 (on the same dyno).....so 270-199= 71. I like to see where you get the 30rwhp less from. You're seriously making up some ricer math my friend. If a 128i was only 30rwhp less than a 135i then why buy a 135i then when you could throw a cam/full exhaust and have more power.....
I never really noticed the drive train loss for FI cars but now I see that they do retain a bit less drive train loss than N/A cars. 6spd 04 GTOs make a little under 300rwhp (350 hp stock) while 05-06 6spd GTOs make 330-360 rwhp (400 stock) the autos are generally 10-15 hp lower.
Hell, the new ZL1 is interesting either way but auto ZL1's are making 460-470 rwhp while 6spd ZL1's are making 510rwhp+ and they are 580hp stock.
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It's more a rating thing than actual loss. The drivetrain loss esp static on a dyno is the same no matter what kind of engine you have. meaning turning the gears in the trans, pumps in auto trans and the differential, half shafts etc is what sucks up power. The fact some cars routinely are further from the rated flywheel HP, whether turbo, sc or n/a is not so much that the motor is better, just that flywheel is either optimistic or not.
A great example of a n/a car that had little loss were the ls1s in the camaros.
the 98-00 cars put down 280 on average (305 rating) and many 01s put down 295-300. not surprisingly the 345 hp rated corvette with essentially an identical motor put down essentially identical rwhp ratings (just like the 350hp gto you mention). moral of the story, the camaro was way underrated from factory, corvette/gto probably wasn't.
remember an auto trans pump and converter suck up a fair bit of HP, reason why they have pretty disparate numbers, i'm assuming the zf is just pretty efficient in our cars as numbers aren't as different as say GMs.
it's all semantics but in the end related to the power of the motor, not the induction method.