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how much HP does an auto use
Posted: Wed Mar 29, 2006 8:58 pm
by frp88
Ive got an a440f behide my 13BT i just would like to know how much my auto suck to a manual.I not sure but i think turbo 400 and 350 are about 20 to 25 ponys and manuals are 5 to 10 so can any off you tranny guys help with my question . thanks mike
Posted: Thu Mar 30, 2006 5:40 pm
by sudso
I thought most autos suck less power than a manual but the T350's and 400's are one of the worst HP robbers for an auto.
You can get smaller tricked up convertors for them which rob way less HP.
Posted: Thu Mar 30, 2006 5:58 pm
by roverlux
i was told that a th400r4 (i think thats it) out of a chev corvette is the absolute bees knees. thicker bands better servos and clutch packs and internals. and to mee seems ok. my vette hauls with this manulized box!
Joe.
Posted: Thu Mar 30, 2006 8:40 pm
by turps
Havent been in a std Patrol Petrol 5spd, but the Nissan auto suxs power big time.
Posted: Fri Mar 31, 2006 7:18 am
by RN
Auto's have always tended to use more fuel than manual cars because the engine has to run the transmission ie torque convertor and internal hydraulic pumps. Therefore a portion of your available power is syphoned off .
The auto's have become a lot more efficient especially with lock up overdrives, but generally not as good as a manual.
Posted: Mon Apr 03, 2006 8:33 pm
by frp88
so i gess no off you auto boys know the correct no's maybe i off you could confirm if my no. are close to the mark
Posted: Mon Apr 03, 2006 8:54 pm
by -Scott-
RoadNazi wrote:Auto's have always tended to use more fuel than manual cars because the engine has to run the transmission ie torque convertor and internal hydraulic pumps. Therefore a portion of your available power is syphoned off .
The auto's have become a lot more efficient especially with lock up overdrives, but generally not as good as a manual.
Yes!
Between auto and manual, both will have frictional losses in the gears themselves. The number and size of gears each is spinning will affect the efficiency, but I don't believe the difference is significant from a fuel economy viewpoint.
The biggest loss in an auto is the "pumping" of hydraulic fluid in the torque converter. The fluid heats because it's gaining energy - the rate at which that energy is lost is a measure of the transmission's power loss.
More efficient torque converters, and lock-up converters, reduce these losses. The more time an auto can spend in lock-up, the better for economy.
From an economy viewpoint, autos are getting closer to manuals, but the manufacturer's are cheating a little. They take advantage of the torque multiplication in the converter, to run taller diff ratios and/or taller overdrives, so autos will often have lower rpm for a given cruise speed. Once the vehicle is up to speed, and the converter locks, the vehicle can be more efficient. It's the overall vehicle which is gaining efficiency, not the auto trans by itself. So a vehicle which WON'T lock it's torque converter at highway speeds
is a right royal PITA!
Cheers,
Scott