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View Full Version : Help - Brake or Not?????


YDLUZ
10-06-2005, 11:35 PM
okay, re-cap:
I have a 3,500 lb (w/drv) '71 Camaro street car, ran 9.61 @ 137.6 back in May, 65 degree day and no humidity. Pulled a strong 1.33 60' in a 75' wheelie and the pass before 1.31 60' spinning hard because I forgot to let air out of the slicks. Ran 3.87 330' and 6.06 @ 111.5 1/8. This was on a .087 nos / .091fuel (around a 235 hp shot) big shot plate, 6 psi fuel pres, 1,000 bottle pres, 434 sbc. Launch rpm was way high, footbraking left at about 6,000 rpm when I floored it on a mtr that I shift at 6,800 rpm. I was in high gear before the 330' mark and pulling over 7,500 rpm through the traps. Conclusion - blowing through the N/A converter!!!

Last night:
Same as above with new 9.5" tight nitrous converter, set up for 350 shot tune-up and ran more spray - .098 nos / .096 fuel (around a 280 hp shot). Planned to go up to the 350 tune-up and lean it out but got stopped because no license. Would only 60' a 1.420 leaving on the bottle - no tire spin at all and very low rpm launch-will only foot brake 1,800 rpm. Ran a 6.098 @ 115.03. So, gained 3.51 mph there but lost e.t. because the bad 60'. Ran 9.525 @ 142.91 1/4. So, gain of 5.31 mph & .085 in e.t. So, made up the loss in 60' plus overcame the terrible heat / humidity to gain 5.31 mph. Trapped 7,000 rpm.

So...
The converter is putting more pwr to the wheels + some more pwr in N20.
But....the 60' time is almost a 10th slower - ouch!!!!!

QUESTION:
How about a trans brake?????????? The car will hold the pwr easy, hell I bet it will hold a 1.20 60' time. Yank Racing (the torque converter co) thinks this is the best option. AND-go to more pwr on launch with the 350 shot. How would this work, can I floor it against the brake on the bottle??? I've nvr had a brake so I'm clueless? Is this the right move??? They said if I loosen the converter up I'm gonna have problems on the big end again. Especially on the 350 shot.

Thank You for any help!!!

Hutch
10-07-2005, 03:23 AM
A transbrake will allow you to leave at a higher rpm for sure. As far as leaving with the nitrous activated on the transbrake ,I would not suggest it but it has been done and apparently worked well for that application.
I would have the nitrous come on the instant the transbrake is released via a relay setup, examples are found in the knowledgebase forum http://yellowbullet.com/v-web/bulletin/bb/viewtopic.php?t=260.

Keep working with the new converter and altering the nitrous tune to accept the new load on the motor.

Take care ,Hutch

YDLUZ
10-07-2005, 06:04 PM
A transbrake will allow you to leave at a higher rpm for sure. As far as leaving with the nitrous activated on the transbrake ,I would not suggest it but it has been done and apparently worked well for that application.
I would have the nitrous come on the instant the transbrake is released via a relay setup, examples are found in the knowledgebase forum http://yellowbullet.com/v-web/bulletin/bb/viewtopic.php?t=260.

Keep working with the new converter and altering the nitrous tune to accept the new load on the motor.

Take care ,Hutch

Thanks - would you buy / install a brake or work with the big 350 shot tune-up first??? Anything I do to put more pwr to the launch now is a direct gain in 60' due to no tire spin. What do you think?

Hutch
10-08-2005, 01:51 AM
Work with the tuneup first,when you have exhausted that, go for the transbrake.

Take care ,Hutch