dyno your car and find out.

 

With a record like the one I see in your sig.. I would say you are talking about proven results. Good advice Justin, I also agree with him based on my own experiences.

 

Dyno your car. Ask them for a plot of wheel torque in each gear (like first to redline, second to redline etc). If the graphs cross, then that's your shift point, if not, shift at redline.

 

Most of these posts deal with peak horsepower which is not the point. Whether or not the car is creating less power after 7,000 RPM is not important. You should shift at an RPM that drops the engine to the torque peak upon release of the clutch in the next higher gear. Look at your dyno pull and work backwards from the peak torque.

 

1 7200
2 7200
3 7200
4 hitting rev limit

 

You're not interested in engine torque, you're looking at wheel torque. Once you shift into a higher gear, you loose the mechanical advantage of the lower gear. Basically that means that your engine might be making less torque at higher RPM's, but the tranny is "changing" RPM's for more torque at the wheels. When you shift into a higher gear, you loose some of that advantage. So to shift before redline, you need to be making enough engine torque to overcome the torque lost from the shift.

If you check or calculate wheel torque vs speed from a dyno plot, if/when the lines cross, those are your shift points. If they don't cross, shift at redline.

 

I shift at 8k.

 

I shift at about 7800 RPM right before fuel cut.

 

I shift at 6500 on my race gas map, as you can see the turbo doesn't hold for s%!t up above that... now on my pump gas map, it is nice and flat with good HP at 7000

 

You would be faster shifting around 7400. Notice how the trq drops off... also..


If you go from 7800 back 2000 rpms youre right after that big hump of hp. If you shift a little earlier getting back on the gas youll be right at your peak power with more trq to keep you flying =-)

Cheers!

 

7100-7200 would be the optimal time to shift your car based on your mods, assuming its matchs up with most cars with your same exact mods.

Cheers!

 

I'll give it a shot, thanks man.

 

Good info. Thanks guys!

 

It's torque at the wheels that accelerates the car. When you shift, you change the gear ratio and so a given amount of engine torque results in less torque at the wheels. So its a balance between engine torque dropping at higher revs and wheel torque dropping due to shifting to a higher gear. Given torque curves and knowing the gear ratios, you can calculate for yourself where the best shift point is.

 

Anytime!