How are you figuring you shift point from your dyno sheet. Thanks

Your gonna have to play with that but its usually just above the
max torque point but it varies

I shift at my max HP.
NOT your torque.
You'll be shifting way too early going by peak torque.

I use to think that a engine dyno sheet would really help me to start with a shift RPM at or near peak HP RPM, NOT SO on every motor is what I found out
You can try shifting at peak HP RPM for several passes and then try short shifting it by 200 to 500 RPM below that, if it goes slower try 200 to 500 RPM above the peak HP RPM and it goes quicker and faster keep testing until you find out what your car really likes
The converter and several other things determine what shift points will work the best for each car
Most theory on drag racing are just that, theories

The accepted start point is to have the engine pull down to peak torque after the shift. If this is a typical Mopar with a big, straight, bada$$ torque line, the car may like high gear ASAP.

I shift when it feels right. Ron

and it will be different 1-2 from 2-3

That's the beauty of drag racing...there are no canned answers. Performance is elusive you have to work for it!

Time slips don't lie.

When people ask me where I shift, I ask them: which gear change? People are usually astonished where I shift at. But I think my stuff is so fundamentally different than what the race guys do, there is no point in comparing. The world of 106° LSAs with 102° ICL is sooo different than 112° + LSAs and >112° ICLs, not to mention a converter that is tight at 2200 rpm.

I went racing this week and I can tell you I did not look at the tach at all going down the track and never do. I just shift when I feel it peaking. I ran 10.76 three passes in a row a few years ago so I must be getting the shift points pretty close. And I almost always run within a few hundredths all day unless something goes wrong. I know using the tach can keep you consisdent but I always shift any car I drive by when I feel the eng is peaking and I have always been as fast or faster in any car I have raced then anyone else who drives them. Ron

I like this starting point. And it reflects what Cab said about the converter effect on shift point.
My converter guy said the converter should pull the engine down to max torque at the shift, assuming a certain RPM drop.

A few things I've learned. Shifting earlier than needed on a high torque engine seldom bothers ET much. Shifting late will slow you down. 727 trans takes a few hundred RPM to complete the shift. In testing Turbo Action valvebodys in my stuff it can be 300-600 RPM depending on if its 1/2 or 2/3. The RPM doesn't fall as far on the 2/3 as it does on 1/2. Therefore the 2/3 can be later. If you want to be consistent the shift needs to be close to correct every time. Not using a tach isn't going to get it. We try to predict runs within .005 or closer. Ultimately the quickest acceleration will be measured by highest average G force. For those of you that are running data loggers and that fancy stuff. Read here:

https://www.racepagesdigital.com/tech-why-the-g-meter-is-the-most-important-sensor-for-going-fast/

Doug

Yep, been doing it that way for 25 years give or take a couple. Data is your friend... not your butt.

Data Recorder

My Go Pro showed me I short shift when I leave first and bounce off the rev limiter when I'm chasing.
Probably a hold over from my motocross days, but I don't see the shift light even though it's in my face.

Anyway....Hello Shifnoid.

The way I look at it is....... it comes down to the interaction between the motor and converter.

Swapping from a 2800 stall converter to a 4800 stall converter will almost certainly require a different shift point for best ET’s.

You just need to experiment some and see what works best in your combo.