Starting line RPM with brake

Trying to get a feel for what starting line stall speed with a trans brake - new car and sorting it out.

Ballpark combo -

451 SixPack SS package
3400# on the starting line.
Over 700hp at 7500
Over 650 lbs. with a pretty flat torque curve
15W tires

Anyone have something close to this that can chime in on their starting line rpm on the brake ?

I was about300 lbs lighter, I had about 30 more hp. I had 32- 17.5- 15 tire, l was leaving at 3600. Tried 3800, it gave me my best 60’. Didn’t try any higher. This was a 440 sb.

Just keep turning the RPM up until - it slows down, it won't hook, or it goes too high. Of course, getting after it, it may want to have some suspension/shock adjustments to take full advantage of it.

Our pro tree car had no chip in the low side, went 5800 on the mat and liked it.

Super Stock car I help with we tried some stuff in the past. Went higher and faster every time we turned it up. I think he has it at 3600 now. We did some up grades and I think it could stand some more. But it's consistent, hooks, has a good 60' and not violent, so he hasn't fooled with it.

Your going to have to test different RPM to find what your parts want, some cars like different RPM for different tracks
tire pressure, track prep, HP, converter and chassis all come into play

That’s what we will be doing but the car had to be raced before we ran shift rpm and starting line stall speed loops.

With peak HP at 7500, I wouldn't hesitate to have a converter that flashes at 67-6800. Especially with a flat torque curve, get the flash closer to the hp peak versus peak torque. RPM on the brake, start at 4000-4500. Work it from there.

Closer to peak torque the better, as long as it hooks. Like Steff said upper high 6000's range on the stall.

I haven’t seen RPM at launch make much( if any difference) in 60 foot or ET, footbraking or using a brake.
Talking a 9 sec 3350 pound car.
Just have to experiment with rpm to where the car consistently hooks and works the best. I would probably start out somewhere around 3600-3800 and see how it likes it. And adjust from there.
Mine liked around 4100 best.
On the same night, racing two classes, one on a 400 pro tree with brake, other class footbraking, car would ET the same off the foot leaving at 2000 as off the brake at 4100, 60 foots were typically pretty much identical as well.
Moving the RPM around most definitely will effect reaction time though, lower the launch rpm, the “ slower” your reaction time will be, higher, “ quicker” reaction time.
Just what I have seen
I am not a proponent of the common belief a car is faster off the brake, because I have never seen it myself. I think it also has a lot to do with the convertor well sorted to the combo too.

If bracket racing, whatever gets you .00x or .01x lights. Fill the tires to where they should be, get it to leave clean, and let it eat. Adjust as needed for the lights.

1000 rpm below what the convertor flashes at

I didnt use any starting line chip..I left at 6200 RPMS
on all passes.. I would go WOT then either use the delay or let go of the button...
I normally had .010 to , .020 lights and had a pile of .000 lights(and also reds).. car weight was 2400 lbs at
the line... you just have to play around to see what it likes... my 60' time was always 1.19(every time)

Combination and driver dependent. If you cant hit the tree you will need more RPM, so if you cant at 3000 go up. If the car has a way tight converter go up, etc etc. Lots of variables. In theory IF the driver can hit the tree it is usually best to leave as low as the combination will tolerate. And that varies greatly from car to car and driver to driver.

Al, hopefully a test day is close in the future to try stuff out. Play back tach didn’t, track was not optimal, found a bald spot, blah, blah, blah. Lowering the engine speed made it quicker but I think because the track was not any good. It got on the bars after lowering the engine speed 600. Driver can hit the tree.

In theory I thought the use of a brake approximated a manual trans. If that is true then doesn’t leaving at a higher engine speed mean a better 60’ as long as the car hooks ?

my
Higher rpm faster sixty , traction dependent .
With 6000 stall I lam leaving @ 4000 at the moment with nearly 3800lbs , have used 4500 . I am bottom bulb racing .
Sixty will be 1.45s give or take . Best of 1.42
With footbrake and a little tighter , 5000 stall , vert i was leaving @ 1350 for 1.49-1.52 sixty best of 1.46 . Leaving just after the 2nd bulb is on .
Car will run about a 1/10 quicker et and a hair more mph off the brake . BUT i have run similar PB et of 10.25s
I race on radial slicks .
So normally quicker sixty = quicker et .
My reactions off the brake are normally a tighter grouping average than footbrake .
We do not get the track time like in USA .

Tex

My old S/P car left between 5600 and 5800 RPM at WOT off of the trans brake, 1.23 60 ft times, 5.50 at 125.+ MPH in the 1/8 mile
I never tried anything lower
Still didn't win any races with that car

You know what Scotty says, "rev up your engines!"

Here is a couple examples for you all to chew on. The heads up car we leave to 38-4400rpm on the brake. It is adjusted to make up for driver reaction time, he dont race much. Car has been 1.09 60' converter stalls at 9200 rpm! Higher has done nothing for anything but reaction time on a .400 pro tree. I found the same results with our dragster and the Stratus, 1.02 and 1.00 60'. Since we both leave off the top bulb on a full .500 tree we are both at 4000rpm. Nothing found going higher in RPM on either car other than more delay. But as I said t is very combination dependent. HP has a roll to play here as well. FWIW both the latter cars have converters that stall at 65 and 6700. My 64 we leave at 3900coverter stalls at 6600 and the 60' SUCKS but we are pulling alot fo timing and they click the 60' clock with the back tires...But it helps me with the bottom bulb for sure.