Redline-Motorsports

iTrader: (3)

Building a Twin Turbo 62' Chevy Two Nova Pro Touring car that I am using a T56 6 speed in. I have an opportunity to grab a complete Viper T56 tranny for a GREAT deal.

My understanding is that the basic physical size of the Viper unit is about the same. Also the LS1 bellhousing will bolt to the input side of the case. True??

I am not to concerned about overall length as the whole project is custom. I know that the input shaft also has the same amount of splines as the F-body.

Internally I also know that it uses steel shift forks and wider gears.

Anyone else have any experience with the Viper unit as a conversion from an LS1 unit?

wrencher

iTrader: (2)

This site gives you the rundown;
www.ttcautomotive.com/English/products/t-56.asp
www.ddperformance.com
I dont think you can use the viper trans???

Redline-Motorsports

iTrader: (3)

Appreciate the links but could not fully determine the differences between the two units.

Bugsquawsher

iTrader: (1)

I'm not real sure , but I thinks its got different Gearr Ratios.
Seems like I read that somewhere.
But I'm bettin that they are more or less the same.
But dont' take My word for it on this one, I have only rebuilt the LS1 and LT1 T56s.

Looking at the chart and My trannys part number is 1386 020 D
I used the chart number 1386 000 020
It give me this

Weight is 115-129/ 52.2-58.5
Max Torque load is 450/610
GVW is 3,327/1,509 I'm not sure about this one
1st gear 2.66
2nd gear 1.78
3rd gear 1.3
4th gear 1.00
5th gear 0.74
6th gear 0.5
reverse gear 2.9
Look at or ask him to give you the numbers off the little tag on the tranny.
look for one that starts with 1386 then look it up and compair.
Tom

Redline-Motorsports

iTrader: (3)

Found out the difference between the two units;

The Viper transmission has a 31 splne output shaft vs. a 28 spline
The Viper transmission has carbon fiber synchros vs. paper
The Viper transmission has a steel 3-4 shift fork.
The Viper transmission is short from the bellhousing to the centerline of the shifter
To use a Viper tranny in a LS1 car, the input shaft needs to be swapped with an LS1 unit. The LS1 bellhousing will bolt to the front cover of the Viper trans.

NOTE: Early year Viper T-56's did NOT use a steel 3-4 shift fork!

Mike 01WS6

About a 500-600 hp difference.

The F-bodies have been blowing up trannies w/ a stock 346 cube motor. Some live at higher power but have been up graded accordingly (600-700rwhp), these generally do not last too long before waving the white flag.

I have seen Viper T-56's handle over 1000rwhp no problem, on slicks.

There is a difference. As you can see.

Bugsquawsher

iTrader: (1)

wait a minute
if the output shaft is a 31 sline and ours is a 28

WHy do you have to swap out the input shaft to make it work on our cars?

With a standard rebuild you put in the steel 3-4 shift fork for 50 bucks and the new blocker rings (part of the synchros) are Carbon fiber
Tom

Redline-Motorsports

iTrader: (3)

The input shaft on a Viper is longer then the input shaft on the LS1. We are talking about the clutch side not the driveshaft side.

Because my application is custom the overall length and drive shaft yoke don't matter, I am leaving the rear of the tranny as is.

My research has indicated that the output shaft where the strength is. The gears in the all units are the same. I believe that with the larger output shaft that the bearings may also be larger in that area.

Bugsquawsher

iTrader: (1)

So you are sayin that the input and output shaft are different?

gen 3 bu

iTrader: (2)

any new info on this one?

69firebird

iTrader: (14)

the input shaft on a viper tranny will not work on a ls1, I had one here at the house and tried it. for something custom you could make it work.

I have a line on a viper trany if you are interetsed, its pretty chap for one
thanks
ed
firebird455@onebox.com

dennis68

The Viper transmission can be made to replace the LS1 trans by having the input and output shafts replaced, internally they are virtually the same. A stronger trans would be to have the input replaced and replace the front yoke on the driveshaft to use the larger output shaft. There are several vendors offering the T56 in just about any configuration you need.

calhoon

iTrader: (6)

There is much mis-information on the true differences in a Viper over an Fcar T56. Most of what is out there is for "Viperized" units . That is, units converted with a hybrid content. There are several facts one should know if they are doing there own F-car install of a Viper T56:
-The output spline of the Viper is 30T(not the Ford 31T that is out there)
-The input spline of a Viper is the same 26T but the overall length and pilot dia. make it difficult to use in an F-car. However the Fcar input will install -directly in a Viper T56.
-The bolt pattern for the slave is different on the front adapter - again, the front adapters can be swapped directly.
-The iron Fork and carbon-lined rings that come in Viper units can be retrofit into the Fcar unit( its been done for years)
-The gear ratios are identical .The gears are also identical EXCEPT the new '03 and newer Viper box.
-The shifter position and the overall length is different- requiring rework of the car or the trans( rework of the trans is best). Conversion is extensive.
- Speed sensor of a Viper is halleffect(3 wire / powered) VS a sinusoidal-output Fcar sensor.
-The rear mount location & spacing is different and there is no provision on the Viper unit to mount the Fcar torque arm.
The strongest T56 set up available will actually include the SRT-10 Ram truck gearset( same ratios but different gears).

Hope this helps .You can Email me if you want more detail.