I've tried taking it to a track and running the car, but I'm still having trouble finding optimal shift points on this car. btw, this is on an '05 evo, anyone out there have any tips? that is short of taking it out on the road and just going at it over and over again or putting it on a dyno. if those are my only options, i guess i could give it a few more tries... but any advice would be appreciated!

 

What do you mean where's the best shift point?
It's different for every car. The best shift point is right there before where your car starts running pig rich and starts losing power. No point in keep revving it. On a stock car it's maybe around 6000-6500, you can feel it die afterwards and then you shift.

 

There was a long post out there on this subject. Basically, unless your torque curve has a large hump somewher below 4000rpm, never mind, just go to max in every gear. Acceleration is all about torque not HP. Remember that it is multiplied by the final gear ratio so 1st has about a 35% advantage on 2nd therefore unless your torque curve is very pronounce at lower rpms then it is hard to gain 35% by shifting. I know it feels weird because you want to get back in to the heavy part of the torque curve as you seem to be able to feel the kick in the pants, but the truth is you're gong faster to hold the gear. Looked at several stock Dyno runs and the conclusion was the same on all of them when I plotted them out. Don't shift til you run out of rpm's.

Persnonally looking at the burshur type 1 kit and after that mod, still holds true; except even higher 7500rpm (because the chip mod allows it).

 

6900 if you have stock cams and turbo, 7500 with cams and stock turbo, 8000 with a bigger turbo.

 

i have a ralliart and im facing this problem. My torque curve DOES have a large hump below 4krpm (thankyou mivec cam!), but my HP doesnt peak until about 5500. However, my TQ really starts to drop almost exactly where my HP peaks. But, my HP stays high for another 1k RPM. do I want to go for the most HP, most TQ or some ratio of both? When shifting at redline, im about 1/2 a second above where I know the car could be. According to my dyno, where should I be shifting? Im thinking of trying just before 6k next time out. Here is my dyno (4th gear):

 

Fun with mathematics time. Torque is always decreasing at peak power, in fact, dT(R)/dR = -T(R)/R where R is the RPM where you make peak power. It's easy to get confused about the relationship between torque and power and how gear ratios affect things, but a simple thing to keep in mind is that your accelleration at any given speed is proportional to the power delivered to your drive wheels divided by the speed. So as a first cut, you always want to ride the peak drive-wheel horsepower curve. You shift after the horsepower peak so that you drop back to the RPM at which you make the same horsepower you were at, but this time on the way up.

A stock Evo has a pretty flat power curve so shift points aren't as sensitive as something like an S2000, where you probably have to run it up to redline.

Dave H.

 

wow, bravo, great answer! so graphically, if i typically drop 900RPM between shifts, lets say the shift point is R1 and the RPM after reengagement is R2, which would be R1 - 900.

RD = RMP drop
R1 = shift point
R2 = R1 - Rd
my slope is: m = (y(R2) - y(R1)) / (R2 - R1)
and my line is: y = m(x - R1) + y(R1)

So if I graph a line through R1 and R2, I will be optimized when, for a value R1, the area between my line (from R1 to R2) and my power curve is maximized, right? If this is correct, then by eyeballing it, it looks like 5900 RPM is my sweet spot =) IE: 5000 - 5900. So i just graph the following on against my HP:
R1 = 5900
R2 = 5100
m = (150-145) / (5900-5000) = 5/900 = .0055555
y = .0055555(x - 5900) + 145

Integrate between the too, find the max. done.

I am just assuming my speed increase is somewhat proportional to RPMs. is there a good way to log speed at each RPM so I can be more specific? Will a GTECH do it? It would benice if i could get those datapoints /w my HP dyno datapoints.

Can Dynojet export the results to csv or excel? I'll bring a floppy to my next run, import to matlab and simulate. lol! im splitting hairs, but im a geek and i need to find something to keep me busy on my lunch break

 

7300 RPM on full out throttle.

Only way to get back into the Top end RPM range and skip the dreaded stock turbo/engine 5500 RPM power dip.