TH350 max HP
10-04-2017, 06:54 PM
#2
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St. Jude Donor '05
Had stock ones with a simple shift kit + trans cooler (2800 stall) hold up to 430hp for yrs. Maybe confab can pipe in and give more info
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caryb78 (10-05-2017)
10-04-2017, 07:01 PM
#3
Le Mans Master
I built one for a guy running a 455 in a 67 GTO. Raced every week on slicks for a long time. (4 or 5 seasons) He wasn't super fast, but he ran hard and was consistent.
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caryb78 (10-05-2017)
10-04-2017, 07:05 PM
#4
Le Mans Master
Yeah any T350 with even a basic rebuild and good Transgo shift kit will hold 450-500hp for quite a while......Just use good stuff for the rebuild....(clutches, bands, sprag etc)...
A T350 can be built to go 8s if you have the loot....
A T350 can be built to go 8s if you have the loot....
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caryb78 (10-05-2017)
10-06-2017, 01:35 PM
#6
Safety Car
The weakest part of a TH350 is the intermediate sprag/roller clutch.
You have to be really careful with shift kits and other mods (ie removing the accumulator spring) to make them shift harder... it will bust that sprag on the gear change. In a TH350 you want a quick but firm shift.... tire barking shifts are going to be death to a TH350 if you have any power once you get some traction.
They make a hardened/heat treated outer race for the stock intermediate sprag/roller clutch that is sold as an "upgrade" but in reality it is no better than the stock sprag.... I honestly think it grenades easier than the stock race....
The only real "affordable" upgrades are the machined direct drums with the bigger 32 element sprags from ATI or the new style mechanical diodes that CK Performance sells. Those run about $300-$400 but are worth every penny if you are near or over 500HP.
I ran a TH350 in my 84 for a long time..... Started out at 10.50's@124MPH and a few years later it was running 8.50's@155MPH. I blew up a bunch of TH350's before I got hooked up with a trans builder that really knew his stuff.....
I used an ATI 32 element sprag/direct drum. Trans Go FWD pattern manual VB. Raybestos Blue Plate Clutches. 4L60 low sprag/roller clutch (wider and stronger than stock and is a direct fit). 5 clutches in the direct, 5 clutches in the forward, 3 clutches in the intermediate and 5 clutches in the Low/Reverse.
I never hurt it after it was built this way and ran it 2 seasons with an inspection at the end of every season. I swapped to a Powerglide and sold the TH350 few years ago to a guy over in the C4 section who wanted to do a TH350 swap to his 10 sec C4.
Will
You have to be really careful with shift kits and other mods (ie removing the accumulator spring) to make them shift harder... it will bust that sprag on the gear change. In a TH350 you want a quick but firm shift.... tire barking shifts are going to be death to a TH350 if you have any power once you get some traction.
They make a hardened/heat treated outer race for the stock intermediate sprag/roller clutch that is sold as an "upgrade" but in reality it is no better than the stock sprag.... I honestly think it grenades easier than the stock race....
The only real "affordable" upgrades are the machined direct drums with the bigger 32 element sprags from ATI or the new style mechanical diodes that CK Performance sells. Those run about $300-$400 but are worth every penny if you are near or over 500HP.
I ran a TH350 in my 84 for a long time..... Started out at 10.50's@124MPH and a few years later it was running 8.50's@155MPH. I blew up a bunch of TH350's before I got hooked up with a trans builder that really knew his stuff.....
I used an ATI 32 element sprag/direct drum. Trans Go FWD pattern manual VB. Raybestos Blue Plate Clutches. 4L60 low sprag/roller clutch (wider and stronger than stock and is a direct fit). 5 clutches in the direct, 5 clutches in the forward, 3 clutches in the intermediate and 5 clutches in the Low/Reverse.
I never hurt it after it was built this way and ran it 2 seasons with an inspection at the end of every season. I swapped to a Powerglide and sold the TH350 few years ago to a guy over in the C4 section who wanted to do a TH350 swap to his 10 sec C4.
Will
Last edited by rklessdriver; 10-06-2017 at 01:35 PM.
10-06-2017, 02:07 PM
#7
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St. Jude Donor '05
always wondered about that.....2nd to 3rd would be firm but not out of control. 1-2 would bark them at anything over part throttle.