How much gain in ET from transbrake?

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How much gain in ET from transbrake?

Postby 357Bronco » Fri Sep 13, 2013 7:01 pm

My Bronco runs 5.3's at 65mph, leaving off the foot brake at 950 RPM in gear. Has anyone added a brake to a full bodied truck and seen the difference in 60' and et? I'm only around 400HP and weigh 3500lbs,and was thinking of launching 2-3 thousand RPM. Would like to know if it would be worth the investment. Only looking into it to try something different, and maybe get a little better at the tree with my reaction. I'm bracket racing and don't really need to go any faster, just more consistent, thanks Scott.
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Re: How much gain in ET from transbrake?

Postby Durango Kid » Mon Jun 09, 2014 1:28 pm

I can only relate my quarter mile bracket racing experience, so don't take it as the gospel. Some even heavy door cars can pick up a few tenths with a brake and others go the other way. If the power range, gears, and converter aren't an optimal match the cars can pick up, and If the footbrake setup and technique are good, there's not much to be gained. By the same token, the launches can become overly aggressive in some cases and the loss of traction can hurt 60' and thus et. The biggest advantage I think with a 2 step & brake is being able to hold the car more efficiently in the beams, and hit the tree more consistently. Sorry I couldn't be of more help, and good luck!
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Re: How much gain in ET from transbrake?

Postby chainreaction » Tue Jun 10, 2014 4:46 pm

Scott, When I added the trans-brake on my old jeep funny car "Kamikazi" I was at 2200# with driver and roughly 425 hp. Without changing anything else, I picked up a tenth and a half. But the big gain was consistency. I had a 4200 stall converter and was leaving at around 3800 rpm's. You are quite a bit heavier so i would figure you'd gain closer to a tenth, unless you factor in the ford power plant then I'd guess more like 1/2 tenth....
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Re: How much gain in ET from transbrake?

Postby 357Bronco » Wed Jun 11, 2014 12:25 pm

My 60' seems soft, was 2.0, and the last couple races 2.1, and haven't made any changes. Our track prep and grooming has been great, and there seems to be plenty of bite. Maybe I'll change some air pressure, and adjust my bars in the back to see if I'm missing something as far as ET. I really need more work on being consistant at the tree, can be frustrating at times giveing away rounds because I'm slow at the tree or alittle too good :roll: And Darryl, I know you secretly love my Ford.
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Re: How much gain in ET from transbrake?

Postby sandguy356 » Sun Jun 15, 2014 10:11 pm

Scott,
with my little bronco going from the foot brake to the T brake resulted in about .3 improvement in ET, with most of it coming in the 60ft. That was running 20.00s on the back with 12.00s up front, 4.11 gears.
I had a set of 5.13s but never got to try them out, I figured an improvement with those also.
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Re: How much gain in ET from transbrake?

Postby Straight Shooter » Fri Feb 06, 2015 10:47 pm

On my 3.5 second rear engine car that stalls at 7300 it runs real close to the same stalling 4500 on the footbrake and leaving at 7300 on the trans brake. Probably 4-5 hundredths in this application. I have Wilwood drag racing disk brakes on it so I can hold it pretty good. I would think a tighter converter would make even less difference as log as the converter is loose enough to allow the engine to be in the power at stall speed. The biggest ET robber with an automatic is too tight of converters. You loose a lot of ET by having to struggle up to power and then when shifting it has to struggle again to get to power again.
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