i have a car that runs mid to high 5.70's. small block with a BLP 750 alcohol carb. i have a #1 stop under carb stop, air on air off.

my other car has same stop using a 900 quick fuel gas carb. i pull it back to 4300 on stop and shift while on the stop. it is really good and the graph looks perfect.

question is. i have never really had much luck getting an alcohol carb to repeat well on the stop. i basically have tried to run the alcohol the same way as gas as far as rpm and stop timers. for those who t-stop alcohol where should i start.

on gas i go out .20 shift .70 on for around 2.5 to 3.0 seconds. i could buy a gas carb to put on when i throttle stop this car but would like to make the alcohol work. it is really good bracket racing but to be honest i have not tried to throttle stop it yet. would like a good starting point.

ep-thanks

I've only ever run a stop with alcohol, and I run the stop RPM very similar to you. I use an electric stop, and my car is slow so all of the throttle stop events happen in Low gear and I shift downtrack on RPM. Also because the car is slow, I go out 0.500 before the stop comes on, and it's usually on the stop for 1.8-2.2 seconds.

I don't notice the car to be less consistent on the stop than when I'm bracket racing wide open. It's always been great.

Thanks Tony

The biggest thing I found throttle stopping alcohol was the float level. Most builders ship them with the floats as high as possible for volume. I feel like the carb was getting upset and sloshing when dropping out of the wheelie. I lowered might three flats and things got much better.

quote:

Originally posted by SP 124X:
The biggest thing I found throttle stopping alcohol was the float level. Most builders ship them with the floats as high as possible for volume. I feel like the carb was getting upset and sloshing when dropping out of the wheelie. I lowered might three flats and things got much better.

Bogacki had a recent video about troubleshooting via datalogger. The car was going fat after landing from the wheelie, and lowering the floats a bit solved it. Was pretty interesting.

quote:

The car was going fat after landing from the wheelie, and lowering the floats a bit solved it.

The above is an issue. Also many guys that T-stopped alky carbs over the years have cut a slot in the stop butterflies because of the volume of alky flowing through the carb and wanting to puddle on the stop butterflies when it's shut down. This fixes that. Hope this helps.

SL...

What does the car weigh and how much power?

Weighs in at 2350 race ready. 4:86 gear and probably 550 or so hp. Runs mid to high 570s 1/8 mile @ 118

ep

You may need to raise the stop RPM. How big is the engine?