turbo spooling.. differnce between manual and auto?
I am curious as to the difference between the way the turbo's spool and perform with the different tranny (manual and auto).
in my case, it is a GTO. does the turbo stay in boost easier with one or the other??
can someone tell me the differences?
Manuals don't hold the boost as well between shifts. You can powershift ,keep your foot to the floor to help this out and ball bearing turbos generally stay spooled up better and recover quicker.You can downshift in manuals to get quicker spool up.Of course this don't work going up thru the gears which is when you need the two step or antilag.
Autos will generally build boost quick and quite a bit of it ,depending on stall converter. They will keep boost up between shifts. Autos give a bit more driveline loss than manuals..usually estimated at about 5 per cent diff in our cars.
Manuals don't hold the boost as well between shifts. You can powershift ,keep your foot to the floor to help this out and ball bearing turbos generally stay spooled up better and recover quicker.You can downshift in manuals to get quicker spool up.Of course this don't work going up thru the gears which is when you need the two step or antilag.
Autos will generally build boost quick and quite a bit of it ,depending on stall converter. They will keep boost up between shifts. Autos give a bit more driveline loss than manuals..usually estimated at about 5 per cent diff in our cars.
So do not fear a manual with a turbo. And even with a super a good stall is necessary. Buddy had an ati car with a stock stall and it was a big dog off the line.
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The lpe one is pretty nice, and the easiest to install for sure.
A manual is a manual. A turbo manual will still be bad ***, and a manual Supercharger will still be manual. Auto's are better for drag racing, they can leave harder off the line, and no one can shift as fast as an auto. Manuals are fun
.Chris
thanks alot fellas. much appreciated.
just doesnt happen with an auto that always wants to kickdown and rev the engine.
Autos by nature would be slower to build boost, as they dont load the engine as hard. Most dynos will highlight that.
Turbochargers and manuals work very well. Its just you guys in the US love your autos so much. It isnt the same in most other parts of the world.
But for straight line racing, then an auto will usually always win. You wont see any turbocharged automatic circuit cars, or rally cars though, or any form of racing that involves corners.
You cannot use full throttle in a highish gear on an auto car, to see how it actually spools. You can in a manual.
So other factors come into it with an auto. Not everyone drives their car revving the crap out of it.
But yes, and auto will be faster in a straight line. Nobody denies that. Not everyone restricts themselves to travelling in straight lines though.
Put both on a dyno, go WOT at say 1500rpm in 4th gear. And see which achieves max boost first ?
Or cant an auto do that ?
You cannot use full throttle in a highish gear on an auto car, to see how it actually spools. You can in a manual.
So other factors come into it with an auto. Not everyone drives their car revving the crap out of it.
But yes, and auto will be faster in a straight line. Nobody denies that. Not everyone restricts themselves to travelling in straight lines though.
Put both on a dyno, go WOT at say 1500rpm in 4th gear. And see which achieves max boost first ?
Or cant an auto do that ?
Put an M6 in 4th at 1500rpms, put a stalled TH400 in 3rd at 1500, floor it.........who wins?
just doesnt happen with an auto that always wants to kickdown and rev the engine.
Autos by nature would be slower to build boost, as they dont load the engine as hard. Most dynos will highlight that.
WAT
Lol, where did you get your info? It sounds like you haven't driven or even ridden in a real automatic turbo car. In most auto turbo cars the trans is almost always manually shifted and will NOT shift by iteself. I know in my auto car I can put it in 3rd gear at a light and that's the gear it's going to stay in no matter what I do with the gas peddle, there is no kick down.
Automatic transmissions always spool the turbo faster than the same car with a manual trans since an auto loads the engine much harder than a manual trans can. The converter allows slip to occur and the RPMs to go higher at the same speed and boost to build faster, of course once boost builds the stall goes even higher and boost builds even faster than it was before. It's a positive feed back system.
My car was 6spd before i swapped it to a 3spd auto. The spoolup was so much faster I couldn't believe it. I started kicking my self for being a 6spd nut swinger for all those years. It's almost comical to compare the spoolup of a manual car to an auto because the auto spools so much faster.
If you are interested in road racing (every one says they are but very few ever do it) a manual is the trans you want. I personally find my RMVB Th400 with trans brake WAAAAAAY more fun to drive on the street than the 6spd ever was with the turbo.
That's funny right there lol. Let's see, i'd be at 40mph @ 1500 rpms in 3rd, boost would be full on by 50mph from that speed if it hooked and I wouldn't ever make another shift and would top out at 180+mph. Hard on the trans due to heat though.
Although lots of drag only cars do of course use autos.
And as for Ninetres mentioning stock transmissions on turbo cars. Who asked about race transmissions ?
I didnt see anyone ask about them.
The thread starter wanted to know which trans stays in boost better.....and the easy winner of that contest is an auto.


