black_list_typhoon
New member
I just recently smoked my second stock 700r4 and am in the process of building a full race turbo 350 to put in the hole. just wondering if anyone has done this to there sy/ty and if u have any tips on what not to do.
Turbo 350
- Thread starter black_list_typhoon
- Start date
'JustDreamin'
Dream: 6LV8 Turbo Bravada
Re: Turbo 350
Either a TH350 or TH400 would be acceptable transmissions, but they're only 3 speeds, so no overdrive. If you're willing to give up overdrive, run with it.
Also, both of those 3 speeds have a shallower 1st gear (700R4 is 3.06:1, TH350 is 2.52:1, TH400 is 2.48:1) so it does load the motor harder (spends more time in 1st)
I'm no expert, but I expect the TH350 is the least expensive (no 27spline conversion shaft needed), followed by the TH400. 400 is certainly capable of more power, but depending upon your needs may be overkill. I think the TH350 is significantly stronger than the 700R4.
4L80E is a good choice if you want overdrive in a trans that you won't break in most applications. It basically is a TH400 with a .75:1 (that's an oversimplification, but basically true). It's not bulletproof (you can certainly still break a 4L80E, just it takes alot more abuse to break it). Problem is the 80E conversion is complicated and expensive.
'JustDreamin'
The TH350 and 700R4 are completely unrelated. Not even close.TYTILIDIE said:
Either a TH350 or TH400 would be acceptable transmissions, but they're only 3 speeds, so no overdrive. If you're willing to give up overdrive, run with it.
Also, both of those 3 speeds have a shallower 1st gear (700R4 is 3.06:1, TH350 is 2.52:1, TH400 is 2.48:1) so it does load the motor harder (spends more time in 1st)
I'm no expert, but I expect the TH350 is the least expensive (no 27spline conversion shaft needed), followed by the TH400. 400 is certainly capable of more power, but depending upon your needs may be overkill. I think the TH350 is significantly stronger than the 700R4.
4L80E is a good choice if you want overdrive in a trans that you won't break in most applications. It basically is a TH400 with a .75:1 (that's an oversimplification, but basically true). It's not bulletproof (you can certainly still break a 4L80E, just it takes alot more abuse to break it). Problem is the 80E conversion is complicated and expensive.
'JustDreamin'
black_list_typhoon
New member
Re: Turbo 350
i chose the turbo 350 for the bang for ur buck factor. its cheap to build and they are very very strong. only tranny that i have built that was stronger is a powerglide but it only has two gears (high and low speed). the turbo 350 is also lighter than both the 700r4 and the turbo 400. i was just seeing if anyone had already done this conversion and what there outcome was. but thank u for ur input.
i chose the turbo 350 for the bang for ur buck factor. its cheap to build and they are very very strong. only tranny that i have built that was stronger is a powerglide but it only has two gears (high and low speed). the turbo 350 is also lighter than both the 700r4 and the turbo 400. i was just seeing if anyone had already done this conversion and what there outcome was. but thank u for ur input.
fivetodrive
CRISPY
Re: Turbo 350
The twin turbo v8 Carbed Syclone ran a Turbo 350 and was into the 9's
http://www.syty.net/forums/showthread.php?t=21595&highlight=twin+turbo+syclone
The twin turbo v8 Carbed Syclone ran a Turbo 350 and was into the 9's
http://www.syty.net/forums/showthread.php?t=21595&highlight=twin+turbo+syclone
George Blake
DONATING MEMBER
Re: Turbo 350
It's too late now but a TH400 has better gear spacing than the 350 and they take much more punishment. Next time you want to do a little something more, get a 400.
It's too late now but a TH400 has better gear spacing than the 350 and they take much more punishment. Next time you want to do a little something more, get a 400.
'JustDreamin'
Dream: 6LV8 Turbo Bravada
Re: Turbo 350
But the stock gear ratios in those two transmissions is nearly identical.
TH350:
1st: 2.52:1
2nd: 1.52:1
3rd: 1:1
TH400
1st: 2.48:1
2nd: 1.48:1
3rd: 1:1
Or where you thinking of an aftermarket ratio set, like the 2.75:1 1st / 1.57:1 2nd gearsets that area available for the TH400?
'JustDreamin'
I won't argue the 2nd part of that, the 400 will take more abuse, and as such is probably a better choice for a strip only truck (like Ed Hess' truck).George Blake said:
But the stock gear ratios in those two transmissions is nearly identical.
TH350:
1st: 2.52:1
2nd: 1.52:1
3rd: 1:1
TH400
1st: 2.48:1
2nd: 1.48:1
3rd: 1:1
Or where you thinking of an aftermarket ratio set, like the 2.75:1 1st / 1.57:1 2nd gearsets that area available for the TH400?
'JustDreamin'
George Blake
DONATING MEMBER
Re: Turbo 350
They are nearly identical but the TH400's swapped into identical vehicles that had TH350's consistently run quicker. I attribute it to the gear spacing. The manner in which they shift is different but it's hard to believe the shift characteristic would make the 400 that much quicker.
Take care.
They are nearly identical but the TH400's swapped into identical vehicles that had TH350's consistently run quicker. I attribute it to the gear spacing. The manner in which they shift is different but it's hard to believe the shift characteristic would make the 400 that much quicker.
Take care.
black_list_typhoon
New member
Re: Turbo 350
the turbo 350 is lighter than the 400 so i went with it. My dad has been building race tranny's for 18 years now and he said that right now the 400 would be overkill and not worth the extra weight.
the turbo 350 is lighter than the 400 so i went with it. My dad has been building race tranny's for 18 years now and he said that right now the 400 would be overkill and not worth the extra weight.
George Blake
DONATING MEMBER
Re: Turbo 350
We've already killed the "extra weight" bunk about the 4L80
Trucks that have changed ONLY the trans from a 4L60 to a 4L80 ran .2 quicker in the quarter.
Just FYI.
We've already killed the "extra weight" bunk about the 4L80
Trucks that have changed ONLY the trans from a 4L60 to a 4L80 ran .2 quicker in the quarter.
Just FYI.