haha ...just set your vtec point to 5500.....

 

... and lose power?

 

depend on your mods...

 

To stay in VTEC on the next up shift. Also, "it is better to make torque higher rather than lower because you can take advantage of gearing"

Even though we don't make any more power past 8,400 RPM, we still make very good power all the way to redline, more than you would by shifting right at 8,400 RPM.

 

If you're wanting to accelerate as fast as possible, you should always shift at redline. Whether the VTEC solenoid switches you back or not doesn't really matter. Neither does how fast you are with the clutch. What does matter is that your engine is not producing near as much power at 5700 RPM's as it is at 9000. Shifting at peak HP is not the fastest way to accelerate in this car. Look at any S2000 dyno and you'll see that the engine is producing about 60-70 more HP at the wheels at 9000 RPM than it is at 5500-6000 RPM. There's no way you'll accelerate faster in a higher gear putting down less power than if you kept it in the lower gear and put out more power. The numbers don't lie.

 

yeah thats what i was thinking. Wouldnt you want to shift at that point?

 

[QUOTE]Originally posted by ROLLININMYS2000
[B]

yeah thats what i was thinking.

 

because peak hp is nothing more than a general number that can give you an idea about how fast you can accelerate in a car. Torque at the wheels determines where you should shift.

generally, unless torque is falling off dramatically, you should not upshift b/c the higher numerical gear ratios (or lower gears, however you want to look at it) are multiplying you're torque more than a lower numerical value would.

example...on a S2k, peak torque is at 7500 rpms, we'll say it makes around 125 ft/lbs of torque at the WHEELS at this point and that it drops to 115 by redline and 120 at the peak hp at 8300. estimate that 1st is a 3:1 ratio and 2nd is a 2:1 ratio (ignoring final drive ratio which is how 4.44 gears help, but they have nothing to do with determining where to shift).

3 x 115= 345 to 6k in second
3 x 120= 360 to 5500 in second
3 x 125= 375 to 5000 in second

the amount that the revs drop is an estimation, but you'll see the point. Assume at 6k, its making 115 ft/lbs of tq and at 5.5k, its making 110 and its making 110 at 5k as well.

2 x 115 = 230
2 x 110 = 220
2 x 110 = 220

ALL THESE VALUES ARE SMALLER THAN WHEN IN FIRST GEAR! So technically, even if torque kept falling after 9k, we would want an even higher redline b/c it would allow us to stay in 1st longer. Also, if you notice, if you shift early, after x amount of time passes, a person could have a huge torque difference if someone shifts early. If someone shifts at 8300, then while a person is making 345+ lbs of tq at the wheels, the person who shifted early, is only making 220ish.

So, fuel/cut is best in 1st to 2nd in this case, even if torque and hp are falling. This is why for racing, having torque up high is more affective for acceleration than lots of torque down low b/c gearing can help you out more.

However, say the numerical difference in gearing between 3rd and 4th is less than .5. That might change where you shift. In many cars where torque falls off significantly, 1st to 2nd will be at redline and 2nd to 3rd might but by 3rd to 4th, you will be better off shifting earlier.
BUT the S2k is not one of these cars, it is best to shift at redline, pretty much every gear.