SmurfLSX

iTrader: (9)

Just curious how many of yall launch of the brake as high as it goes? Should my heads cam 346 be able too hook from a trans brake launch at lets say 4500rpm ? I only have front QA1

Villain281H

iTrader: (5)

Launching as high as you can puts a bunch of strain on your converter as opposed to launching off a 2-step set lower than your stall. 4500 without a good suspension set-up will be violent and likely spinning.

Derek

Dave J

iTrader: (2)

I launch at 5200 on the brake(off converter) but I need it cause I dont have much hp(LT1 )
I dont see how it is all that violent cause I use only a 26 inch et drag and I have never spun on the line even once(100 runs or so) 60fts are usually 1.43-1.45

NHRAFORMULA00

iTrader: (2)

I see you are running an ATI converter,Get a copy of ATI latest catalogue,it will explain to you why the recomend launching at no higher than 2000 off the TB.

Dave J

iTrader: (2)

with a 5200 8 inch race converter? wow I hope this is not the case would be such a waste plus a huge mismatch for my cam and intake combo

camaroboy869592

iTrader: (42)

its all in the setup and just spend the money to get a good converter but i would run a 2 step so the converter would flash

SmurfLSX

iTrader: (9)

i have a synergy 2-step . I have never head launching over 2000 rpms is bad for the converter ? I have laucnhed as high as 3500 and it hooks 1.4x 60

NHRAFORMULA00

iTrader: (2)

Taken word for word out of the ATI 2009 catalogue.
The transbrakes main function is to unload the chassie while staging to make the car shock the suspension and hook consistently.The brake will accomplish this at a mere 1000 RPM.Going higher on the brake only serves to SUPER HEAT the oil in the converter and makes for inconsistent launches.
You should find an RPM that your engine is comfortable with(no stumble or hesitation) hopefully well below 4000RPM. Then the only reason for you to go higher on the brake DELAY is if you are late on the light.Going higher on the brake will ONLY reduce the reaction time of the car, automatically putting you closer to the light.If you run a delay box,be sure to remove the time delay before testing.Many people have over a second in the delay box and stage the car at 5500+ RPM.
The lower the RPM at which you launch the car (relative to the stall speed of the converter),the more free energy the converter gives you.That's a PLUS and your converter and transmission will live longer without the excessive heat.Many large, long stroke engines will run fastwer from a very low stage RPM.
Many of our 350 cubic inch Super Stockers run the quickest from 1800RPM.The converter will flash to its stall speed no matter at what RPM you stage it provided the engine will respond properly to that RPM.
TRUE STALL SPEED occurs when TWO THINGS are present at the same time.They are
1- The maximum amount of torque is input to the converter.
2- The maximum amount of load is present for the converter to accomplish.
When checking stall speed using a transbrake,it MUST be checked on the STARTING LINE. Stage the car ,deck the throtle, look at the stall speed,then RELEASE THE BRAKE and let the car leave. Most converter damage is caused by lifting the throttle from stall speed. WIDE OPEN THROTTLE ON THE BRAKE IS EXTREMELY DETRIMENTAL TO THE HEALTH OF YOUR CONVERTER.

I hope this clears up any misconseptions on how high a TB should be operated from.

SmurfLSX

iTrader: (9)

Could you please explain to me why i went from a 1.6x 60ft time at around 2,000 rpm and then at 3500 i cut a 1.40 lifting the wheels ? Based on that quote its basically the totally opposite ? Not trying to start anything i would just like a better understanding?

Dave J

iTrader: (2)

same with me also
if I leave at 2800 off the 2 step and brake I get 1.55 and if I leave off the converter I get 1.43
I can see it heating things up if you sit on the brake for like 10-15 seconds but I am never on it over 3 and rarely over 2

Rock_Daddy

iTrader: (8)

I understand some of these points by my Vega drag car has no real power uner 4000 RPM's I have launched at 3000 and the car doesnt really go and 20 feet out its like a light switch and it goes. I assume it really depends on the power band as a 2G launch makes my car about as fast as I could move on foot in the first 10 feet. lol

NHRAFORMULA00

iTrader: (2)

1-877-298-5040 ATI toll free, call and talk to a tech they can explain it better for your application.FREE ADVICE!! I was simply posting information from there catalogue.

SmurfLSX

iTrader: (9)

relax it was just a question, based on my results it doesnt add up to there catalog lol

TwoFast4Lv

iTrader: (8)

Guys The MAIN reason they want you to do this is to stop beating the Sprag out of the converter

The reason you do not lift is it also slams the sprag in the converter. same reason you ride the burn out and lift softly coming out of the box.


My car hits really soft from a 2,500 two step and is a monster from 3,800-4,100



BTW Same princple why you should start your burn out in 2nd with a THxxx Transmission

Villain281H

iTrader: (5)

I'll leave that one alone....

SmurfLSX

iTrader: (9)

lol ive never heard of that ? 2nd gear burnout ?

TwoFast4Lv

iTrader: (8)

LOL I guess it is a sensitive subject for some. I do seem to remember a huge argument about it now.

Basicly starting out in second keeps from shocking the hell out of the sprag on the one two shift in the box. Seems most times that(in the box) is where they get broke

Villain281H

iTrader: (5)

Don't forget you can build them better to help in that. Putting a lot of strain trying to spin the tires on a lower # gear ratio can't be good sometimes either, but plenty of power can help in spinning the tires in even high gear

SmurfLSX

iTrader: (9)

whats the difference from shifting the 1-2 off of the light? you still put stress on it but its built for that. right?

Skippy SS

Yep, always go 2-3 with my 400.