[88stangGT]

i want a c4 trans for my soon to be turbo 89 GT. now some people where saying i would need to make a certain amount of horsepower to leave off the transbrake with such low of a gear (3.27). is this correct and if so why? my car will be making around 400-450hp. should i get the transbrake. or should i get one without and leave off foot brake. 3000 stall convertor... please give me your opnions..

[trueblue01]

I don't see any great advantage for you to spend the extra money on the trans brake. With that gear and stall, foot braking will work better.

[1slo5.0]

Originally Posted by 88stangGT i want a c4 trans for my soon to be turbo 89 GT. now some people where saying i would need to make a certain amount of horsepower to leave off the transbrake with such low of a gear (3.27). is this correct and if so why? my car will be making around 400-450hp. should i get the transbrake. or should i get one without and leave off foot brake. 3000 stall convertor... please give me your opnions..

Why such a tight gear? A transbrake will work fine but with that low of horsepower and that tight of a gear the car is going to be a turd off the line whether you have a transbrake or not.

[88stangGT]

the car is going to have a turbo... alot of people with them have 355 in the rear and are running out be4 the 1320. with a 327 you will have enough room. and you can also drive it on the streets alot easier and the highway.. not really looking for a dedicated 1/4 mile car. still drive it around all the time.

[1slo5.0]

Originally Posted by 88stangGT the car is going to have a turbo... alot of people with them have 355 in the rear and are running out be4 the 1320. with a 327 you will have enough room. and you can also drive it on the streets alot easier and the highway.. not really looking for a dedicated 1/4 mile car. still drive it around all the time.

Having a turbo doesn't matter. The rpm range and mph at the end of the track is what is going to dictate what gear you need. Assuming you will really make 400-450hp and your car is average weight (3200 pounds with you in it) it should run in the 11.80 area at around 118 mph. Assuming a 26 inch tall tire, with a 3.27 gear that is about 5000 rpm at the end of the track. With a 3.73 gear it will be around 5700 rpm at the end of the track. With a 4.10 gear it will be around 6300 at the end of the track. I seriously doubt your engine will be out of steam by 5000 rpm if it makes the horsepower you are looking for. Street driving won't be any worse with more gear but highway driving will be noisier with no overdrive and deeper gears. 3.27s will put you around 2600rpm at 60mph and 3.73s will put you around 2900rpm.

Have you considered an AOD and a deeper gear? That will give you the best of both worlds.

[JBIGBOOTSY]

Originally Posted by Darrell Having a turbo doesn't matter. The rpm range and mph at the end of the track is what is going to dictate what gear you need. Assuming you will really make 400-450hp and your car is average weight (3200 pounds with you in it) it should run in the 11.80 area at around 118 mph. Assuming a 26 inch tall tire, with a 3.27 gear that is about 5000 rpm at the end of the track. With a 3.73 gear it will be around 5700 rpm at the end of the track. With a 4.10 gear it will be around 6300 at the end of the track. I seriously doubt your engine will be out of steam by 5000 rpm if it makes the horsepower you are looking for. Street driving won't be any worse with more gear but highway driving will be noisier with no overdrive and deeper gears. 3.27s will put you around 2600rpm at 60mph and 3.73s will put you around 2900rpm. Have you considered an AOD and a deeper gear? That will give you the best of both worlds.

You are right Darrell, but some turbo guys praise, and swear by the taller gears.

[86_Notch]

if it's not a dedicated drag car then i don't see a need to spend the money on a brake, after all using one on the street will only result in massive wheelspin, so i say practice footbraking

[GoodOleBoyzRacin]

footbrake will be fine fer you. you just wont get the full advertised flash on the stall it will be prolly more around 2850-2900. dont know much about transbrakes. never worried with them

[88stangGT]

im not really looking for a all out 1/4 mile car i want to go to the track run it see wat it does and then just drive it around.. drove my friends car tonite c4 355 gears supercharged on the highway wasn't bad at all......

[1slo5.0]

Originally Posted by GoodOleBoyzRacin footbrake will be fine fer you. you just wont get the full advertised flash on the stall it will be prolly more around 2850-2900. dont know much about transbrakes. never worried with them

If the converter does 3000 on the transbrake it will probably only see 2000-2200 on the foot brake. I agree that he doesn't need one, especially after he made it sound like he isn't going to race much and it is going to be more of a driver than anything. Transbrakes are useless on the street.

[88stangGT]

well its gunna b a street car.. drive it around mess around with other cars.. all in all it should be ok...

[1slo5.0]

Originally Posted by 88stangGT well its gunna b a street car.. drive it around mess around with other cars.. all in all it should be ok...

Skip the transbrake and put that money somewhere else then. I'd strongly consider a well built AOD and a little bit deeper gear for a street car. It will give you better acceleration and also the overdrive gear for low rpm cruising speeds. Just something to consider.

[88stangGT]

the money for a c4 and a good aod is alot diffrent...

[1slo5.0]

Originally Posted by 88stangGT the money for a c4 and a good aod is alot diffrent...

I guess it depends on what you consider alot. The difference between an AOD and C4 from PA is $350. I'm sure if you found a good local transmission shop that has experience with AOD transmissions you could save a few more dollars.

[88stangGT]

im gettin a c4 built to handle 600hp for less then 1g. thats fresh rebuild with kevlar bands, reverse manul valve body and 300m input shaft...