Here’s a sbc converter that has a 6600 stall (no chip matted on brake) launching at 3700, in 1500’ DA, using a 5.14 diff with a 7.20 SLR (as SLR increases, flash stall decreases). The cursors are set to flash and fall back. Paying attention to the “fall back” number is something to also consider imho.

I stand by the last paragraph in my prior posting, and the OP recent advice confirms this….
{{{“I can almost guarantee you that when you give a converter builder all your sbc engine information and ask their advice it’ll end up at a 5XXX rpm window (pick a # between 5001 – 5999). And they’ll tell you that’s what you need and want. I’ve seen it, I’ve experienced it, and I get it”}}}…..

To me, the wise (and least expensive) choice would be installing what one has now (it’s in an acceptable rpm window) to achieve the actual baseline, and then determine what, if any, changes would be desired.

I think you be very happy if u just install as it is now, the 60ft may not be what u want but when it gets to the 330' you'll like the # from there on out, Do you have a race pack or play back tach?

Okay one more question, I promise I'm not Columbo. When I spoke to Brandon he asked what my shift rpm and finish line rpm was. It's 7000 shift and around 7200 at the finish line. Does this play into him saying I need to change the converter stall fron 6500 ish? TY

You have a converter in the car now. Can you share what rpm it flashes to leaving the starting line? If you don’t know or are not sure, could you do a converter stall test to see what you presently have?

It would be helpful to know what flash stall you are starting from as I believe you’re trying to improve the launch based on what you posted in an initial thread.

https://drr.infopop.cc/eve/for...912/m/7047042386/p/4

Larry Woodfin wrote "posted January 12, 2023 09:18 PM
The converter is fresh from Ultimate [Lenny did it before he sold out] and is a proven spec for the combination."

This message has been edited. Last edited by: markemark,

quote:

Originally posted by Bucky:

quote:

Originally posted by Lenny5160:
Are you going to try it first? I would.

Geeze heck yes. I would. If one is ever to error on one side it's best in a bracket car to error on the loose side. Too loose for some is just right for a bracket car.

100% this. I would run what you have first and see if it tells you it needs to be changed.

Run it, what do have to loose other than an hr to change convertors ?

quote:

Okay one more question, I promise I'm not Columbo. When I spoke to Brandon he asked what my shift rpm and finish line rpm was. It's 7000 shift and around 7200 at the finish line. Does this play into him saying I need to change the converter stall fron 6500 ish? TY

you may need to raise the shift some but that really wont hurt anything from where you are at .these motors are built to stand it

I vote for run it and see what you have that way if it does need to be adjusted you will have accurate info to work from instead of an educated guess

2500lb, 4.56, 424sbc
I have the Abruzzi M3WAT and a BTE 38050. Your BTE would be looser, but I don't know about 6600 stall loose. I'd have just thrown it in there too see where you were. Hopefully it works for you.

Just for reference:

The Abruzzi is much looser at 6100 stall. I shift 6800, trying to shift as much as 7200 made no difference. Launch at 4200 top bulb, 3200 footbrake. .012 difference between classes. 1.052 in delay box generally.

The BTE stalls at 5600, I shifted it at 6500. It has a much more aggressive stator than the Abruzzi and thus the hit is very hard, essentially, it's too much for the 160 degree track temps we see in the summer during the day. Launch at 3800 top bulb, 2500 footbrake. 1.108 in delay box generally.

ET Wise: 5.92 with the Abruzzi, 5.83 with the BTE same track similar weather this past season. I am running the Abruzzi simply because it is extremely consistent, the BTE is very good, except when the track is too hot or too cold.

^^^^^^ Good info. Are your converters Sprag, Spragless or Diode?

When I write stall rpm, it’s what the converter is supposedly rated out of the box. When I write about on the track, I write “Flashes” to leaving the starting line. The difference between the two can be 200 -300 rpm less for Flash. Keeping Stall separated from Flash can be misleading.