transmission question ???
Thread Starter
Drifting
Joined: May 2001
Posts: 1,392
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From: Wabash,IN
CI 7-8-9-10 Veteran
St. Jude Donor '08
transmission question ???
would a th350 or 400 fit into my 85 vette ?? if so let me know! im not worring about OD. Would i need a longer drive shaft ? thanks jay
Instructor
Joined: Dec 2002
Posts: 116
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From: San Jose CA
Re: transmission question ??? (flyinace2000)
I'd say there are no advantages over the 700 except toughness. The TH400 is a very beefy transmission. But it doesn't have as many gears... doesn't have the low first of the 700 (though that also means it doesn't have the wider shift jump there)... and has a good deal more friction (and therefore horsepower loss through the tranny).
They are preferred by drag strip folks with big engines who are pretty much only going to use the car for that purpose. I'd only recommend using one if your engine is putting out more than your 700 can handle though. Or if the big 1st to 2nd gear shift is too much of a jump on your car.
- Skant
[Modified by Skant, 11:13 AM 1/26/2003]
They are preferred by drag strip folks with big engines who are pretty much only going to use the car for that purpose. I'd only recommend using one if your engine is putting out more than your 700 can handle though. Or if the big 1st to 2nd gear shift is too much of a jump on your car.
- Skant
[Modified by Skant, 11:13 AM 1/26/2003]
Race Director
Joined: Sep 2000
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From: The Top of Utah
Re: transmission question ??? (vader86)
I would recommend a TH400, yes theyll fit.
There is a difference between "fit" and bolt-in. Neither of the two trans' you mention have a provision for the "C" beam that bolts to both the trans and the diff. A means to accomodate the "C" beam will have to be fabricated. While almost bulletproof, the TH400 "eats" more horsepower than the other two. The 700R4 is basically a TH350 converted to a 4 speed with OD trans. They have similar torque capacities. The TH350 has been modified longer than the 700R4 and can be more easily built to handle more torque/abuse than the 700R4. The 700R4 is catching up. For a great amount of money, I have a 700R4 that the builder says will take 700 hp or more. Unless you find the gear splits in the 4 speed, intolerable, I would stick with what you already have. I have made note of the modifications in your signature. Good luck, and...
RACE ON!!!
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Re: transmission question ??? (jparr)
TH400 is the tougher transmission, usually used by drag racers along with a Gear Vendors OD. The 1st-2nd gear ratios are preferable to the 700, which has a large drop in the 1-2 shift (not good for ETs).
700r4s just dont force you to run low gears in the rear. TH400 (4L80 if its a new one, and they do now come with a 4th gear) might be better suited to his 383 and 3.73s
700r4s just dont force you to run low gears in the rear. TH400 (4L80 if its a new one, and they do now come with a 4th gear) might be better suited to his 383 and 3.73s
Thread Starter
Drifting
Joined: May 2001
Posts: 1,392
Likes: 0
From: Wabash,IN
CI 7-8-9-10 Veteran
St. Jude Donor '08
Re: transmission question ??? (jparr)
thanks for the advice CFI thats kinda what i was looking for!! I didnt know iif it would bolt or fit I was jus curious i think mine needs rebuilt and i thought it might be cheaper to jus buy a 400/350 and put it in :D thanks again JAY
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Joined: Sep 2000
Posts: 17,298
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From: The Top of Utah
Re: transmission question ??? (vader86)
vader86,
I agree with all the above, except the Gear Vendor part. A drag car doesn't need an OD and is only used by those with a street (/strip) driven car and the willingness to part with an additional $2000.00 for the Gear Vender.
The relationship between the TH350-700R4 is similar to the relationship between the TH400 and the 4L80. Only there never was a 4L80. All the 400 based OD trans' are 4L80E. They REQUIRE a computer or some sort of electronic controller. On the plus side, the first three ratios on the 4L80E are the same as the TH400; 2.48:1 first, 1.48:1 second, and 1:1 in third. The overdrive isn't quite as steep on the 4L80E as the 700R4/4L60, something around .84:1, as opposed to .70:1. As desireable and as new and limited applications as the 4L80E is, the prices are "up there", too. Plus the cost of a controller. Length wise the 4L80E would be preferable. Cost wise, it may be a toss up. Individual circumstances might make one more economical than the other.
Again, anything other than a Corvette 700R4/4L60 will require the adaption of the "C" beam. The Corvette 4L60E has the provisions for the "C" beam, but also requires electronic controls. jparr, how about an Allison? I hope some of this is helpful. Good luck, and...
RACE ON!!!
I agree with all the above, except the Gear Vendor part. A drag car doesn't need an OD and is only used by those with a street (/strip) driven car and the willingness to part with an additional $2000.00 for the Gear Vender.
The relationship between the TH350-700R4 is similar to the relationship between the TH400 and the 4L80. Only there never was a 4L80. All the 400 based OD trans' are 4L80E. They REQUIRE a computer or some sort of electronic controller. On the plus side, the first three ratios on the 4L80E are the same as the TH400; 2.48:1 first, 1.48:1 second, and 1:1 in third. The overdrive isn't quite as steep on the 4L80E as the 700R4/4L60, something around .84:1, as opposed to .70:1. As desireable and as new and limited applications as the 4L80E is, the prices are "up there", too. Plus the cost of a controller. Length wise the 4L80E would be preferable. Cost wise, it may be a toss up. Individual circumstances might make one more economical than the other.
Again, anything other than a Corvette 700R4/4L60 will require the adaption of the "C" beam. The Corvette 4L60E has the provisions for the "C" beam, but also requires electronic controls. jparr, how about an Allison? I hope some of this is helpful. Good luck, and...
RACE ON!!!
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