Tranny Brakes

[oldskool]

I see that tranny brakes are legal in Super Stock. Does anybody remember exactly what year they were made legal ? Do all SS cars now run a brake ?

We've always run footbrakers, stock and bracket. So I have absolutely no experience with a brake at all.

So is there a rule of thumb as to aprox how much your ET can be lowered by using a brake ?

Now let me narrow it down a bit. I realize that a 283 sbc needs all the help they can get because of low torque. But I'm talkin about a 400+ cube motor which makes 500+ ft lbs of torque below 4000 rpm. Can a brake lower ET by as much as 2 tenths or more ?

Hey, I know these are dummy questions. But if you've never done something, and know nothing about it, how you gonna learn without either asking about it or trying it for yourself ?

Also, with a high torque engine, would it be best to use a Glide, TH350 or TH400 ? I assume the Glide would be slightly slower, but by aprox how much ?

[jmcarter]

Don't recall when brakes were legalized for Super Stock but it's been that way for several years (another forum member will probably pipe in) but the vast majority of the cars have brakes. However, you still see several racers who compete very well foot braking, presumably because they feel more consistent doing it that way. It's all about what you're most comfortable with. One plus to brakes is that you may find your spot on the tree a bit easier simply by adjusting button travel as opposed to changing tire pressure, stall RPM, etc.


Based on my experience you won't get much ET reduction using a brake (~.02-.1) because of the different dynamics when shocking the chassis with a brake (if you've never used one, your back may feel it the next day and definitely have your helmet planted to the headrest when it releases). Also likely that several chassis adjustments will be required. If your car hooks well now and you have a lot of front end travel best tie it down before releasing the button or you may find yourself pointed to the sky (experience speaking). IC and shock adjustments are likely in order. As for which trans is quickest it depends not so much on power as the weight of the car since you don't have the gear multiplication of a 3 speed. 3100-3200 pounds is the traditional rule of thumb 'brake point' for a PG but if you have a very narrow torque band then a PG may drop you too far out of the sweet spot at the 1-2 shift.


And make sure your converter is built to handle a brake and if you have a borderline rear gear setup then be prepared to upgrade there or you will regret it.

[oldskool]

Thanks for the info Jim ! I was expecting at least .2 better ET. If it's only worth a tenth or less, then it's probably not worth the expense for the brake and necessary drive train and suspension upgrade, at least not for a barely under build.

[Ed Wright]

I still adjust tire pressure and RPM. Bob Cruzen, Gary Emmons and Pete Perry all coached me a lot about them when I first tried doing this again.

[Travis Miller]

Originally Posted by oldskool

I see that tranny brakes are legal in Super Stock. Does anybody remember exactly what year they were made legal ?

The 1978 NHRA rulebook is the first year that states "TRANSMISSION BRAKE: Allowed " in S/S.

At the 1977 Indianapolis Nationals, 17 S/S cars were discovered with (at the time) illegal trans brakes. The following year trans brakes were allowed in S/S.

[oldskool]

Originally Posted by Travis Miller

The 1978 NHRA rulebook is the first year that states "TRANSMISSION BRAKE: Allowed " in S/S.

At the 1977 Indianapolis Nationals, 17 S/S cars were discovered with (at the time) illegal trans brakes. The following year trans brakes were allowed in S/S.

Hey, that's some cool info. THANKS for posting it !

Maybe you also know how to look up the national records for different classes beginning back in the mid '70's ? I'd like to trace the records thru the years and what cars held them, if such info is still available.

[Mike Pearson]

Originally Posted by oldskool

Thanks for the info Jim ! I was expecting at least .2 better ET. If it's only worth a tenth or less, then it's probably not worth the expense for the brake and necessary drive train and suspension upgrade, at least not for a barely under build.

Sounds like your car might benefit from the trans brake. My car did pick up when the brake was installed. That was years back and I was barely running the index at the time. It made my car easier to drive and more consistent on the tree.