When using a hypertech to adjust shift points on an auto, what have you guys found to be the best settings with 2.73 gears on a basically stock car?

 

My suggestion would be to dyno the car to find the highest Horsepower and RPMs point, then find the RPMs drop between gears....lets say you loose 1000rpms in the shift..... then allow the car go past half that RPM range above peak horsepower....

example... peak horse power at 4500 RPMS then RPMs drop diferential from gears is 1000 RPMs then set the shift point at 5000RPms... The point here is to keep the engine reving in the max horsepower range for the longest time.

Thats my logic by the way...

Marvin

 

With a stop watch and a flat road you can determine what your car likes. No theory involved, just measurements:

1. Pick a speed 10 or 15 mph below stock shift point for 1-2 shift, say 30 mph. Pick a speed 10-15 mph above, like 60 mph.

2 Full throttle accelerate from 20 or so mph and start watch at 30 (low point), let trans shift then stop watch at high point (60).

3. Repeat on same stretch of road 5 times. Throw out high and low reading, and average the middle 3.

4. Increase shift speed 2-3 mph with HPP and repeat test. Should be same road, and as soon after first test as possible.

5. If average time is quicker, increase shift point more until average time starts climbing. Pick the best point.

6. Repeat for 2-3 shift. You probably won't want to do 3-4 shift point unless you do lots of top end runs. Use a helper to time the high speed stuff.

7. If you reset shift firmness, do that before you pick shift points. Don't make more than one change at a time. Do each gearchange separately.

FWIW, a vehicle accelerates best when torque at the wheels is maximum.....at any speed. Not everyone believes that.

 

I believe it..... dont forget... max torque at max rpms in that torque band....


If I have max torque at 600 rpms I am not going to acelerate much faster than max torque at 6000rpms... or if you look at it from a diff angle... what gives me more speed... in one second of time having hmmm lets say 300cylinders produce each one 600lbs of trust.... or in the same second of time have 3000 cylinders produce each one 600lbs of trust.


Only because at 6000 rmps I will have more cylinders firing at max torque in the same amount of TIME than at 600rpms...


Dang! I feel like a woman now..... I have had to have the last word..... I think I am going mental.... lol

 

or..... if you look at it from this angle.... Max amount of torque in the least amout of time... Called max Horsepower isnt it?

Oh I really hope I didnt start some S.H.%.T long thread again...


I better shutt-up =X