what gear for turbos?
Turbos love lower gears and more load since they are exhaust driven. Of course it depends on how fast you plan on going as well. I am currently running 3.42s with 28" tall tires and may even go to a 3.08 just to push the top speed up a bit and make around town a bit better with no overdrive.
On The Tree
Joined: Nov 2004
Posts: 199
Likes: 0
Just like any car, you gear it to hit top rpm at the traps. I wound up with a 3.00 because I'm going 146 mph at 6200 rpm on a 26" tire. It just so happens that turbo cars usually run allot of mph and the engine peaks early, so you wind up with a tall gear. Nothing to do with spool-up.
Mike
Mike
I found an f body gear calculator and crunched some numbers. I now realize with even 3.54 my top speed in the quartermile on tires like my stock nittos might be pretty limited and likely would have to shift to fifth and not sure how much et that would lose?? Any ideas on that? I can of course go to higher tires maybe or up the rpm but not sure what is safe rpm for a 408 with my fairly mellow cam? 6500, 6800,7000. For sure don't want to go over 7000 and somewhere mid 6000 is likely about right. My car is not a race car and the dana 60 I plan on getting only comes in 3.54 lowest choice. Guess just be happy with that. Unless decide to to 9 inch or 12 bolt and then could go lower. But too much lower is not great off boost. I think 3.42 or up is best for off boost on these cars ,especially heavier ones like my ta.
I am curious now to see what JM is running on his aps twin turbo car as he has 4.10 gears in his auto so can't see how he can get much more mph than his current 139. He did say he is going to 3.73 and not sure what size tires he runs. He is running an auto 4l80.
I am curious now to see what JM is running on his aps twin turbo car as he has 4.10 gears in his auto so can't see how he can get much more mph than his current 139. He did say he is going to 3.73 and not sure what size tires he runs. He is running an auto 4l80.
[QUOTE=MY99TAWS6;9087158]might be pretty limited and likely would have to shift to fifth and not sure how much et that would lose?? ta.
QUOTE]
I can tell you, you definatley dont want to be shifting into 5th at the track.
Like said before, you want your setup to be right at your peak power, just as your crossing the traps. If you have to shift into 5th you got too steep of a gear. You could also run taller tires to fix that.
QUOTE]
I can tell you, you definatley dont want to be shifting into 5th at the track.
Like said before, you want your setup to be right at your peak power, just as your crossing the traps. If you have to shift into 5th you got too steep of a gear. You could also run taller tires to fix that.
How tall are et street radials that fit on my 16 inch old camaro z28 rims? I don't think can raise the rev limits much past mid 6000 and feel good about it. And really can't see having to go down to the low 3.0s for off boost around town driving.
But car is not a track car anyway so not a huge deal. If its only a few tenths from going to fifth no biggie.
But car is not a track car anyway so not a huge deal. If its only a few tenths from going to fifth no biggie.
