1-2 shifting delay

[GatorDog72]

I have a TH400 with a reverse manual valve body on it. When I launch the car hard and grab second, there's a pretty good delay before it actually shifts. By the time it shifts, I'm bouncing off the rev limiter. Is there a way to get rid of this annoying delay, or should I just be shifting it sooner?

[Sam (Bones)]

I don't know much about auto trannys, but when I gang second in my 400, it hits hard and fast, but I had it professionally built for racing 

[cny first gen 71]

Does it have a vacuum modulator? is it adjustable? is there vacuum to it?

[GatorDog72]

I don't know much about auto trannys, but when I gang second in my 400, it hits hard and fast, but I had it professionally built for racing 

That's how I thought it should shift. Maybe I broke something. I will have to check it out I guess. It only shifts late when I really launch the car hard and shift into second at full throttle. I'm shifting it at 6800-7000 rpm and the rev limiter is set at 7500. It bangs off the limiter for a couple seconds, then slams into gear and blows the tires off.  The 2-3 shift is perfect, it shifts instantly. Part throttle launches work okay too. If I launch it softer, then give it about 2/3 throttle and shift it early into second, there's no delay and no slam shift.

 

 

Does it have a vacuum modulator? is it adjustable? is there vacuum to it?

Not sure my transmission has a modulator any more. I don't know much about automatics, I will have to investigate.