simons2k

Thanks for the responses! Shifting at 9k to keep it in higher rpm/vtec for the next gear makes sense.

As for the fellow enthusiast, he was one of those annoying "know it all" types. Maybe he was trying to win a race by giving me those "shift tips". He did sorta challenged me. He drives a Mitsubishi 4dr compact with no badges other than "O.Z. rally edition" in the rear. Kinda looks like an Evo but it certainly wasn't.

s2knikko

if you know how to shift right you can keep your power up enuf to stay in vtec or maybe one rpm under so it hits it directly.... i get more power to the wheels when i shift at 8300... if you are holding to 9k rpm then you are running for 700 rpm without building horsepower... shift as soon as you are in your peak hp range (8300) and you will be right back to making hp... make since guys?

jguerdat

While this isn't the post I alluded to earlier, this thread may be of interest...

cdelena

What you are really interested in is the force applied at the driving wheels, so gearing must be considered in order to know how to maximize acceleration. That chart has been posted and explained more than once, but the bottom line is that shifting at the redline in the first four gears is most effective.

Gregg Lee

[QUOTE]Originally posted by jguerdat
[B]Someone quite a while ago had charts showing torque vs. RPM in each gear.

Gernby

After thinking about it, I think cdelena's suggestion is best. Even if power drops off significantly, the lower gear ratio will provide more acceleration than the next gear, even if there is more power.

My car dyno'ed at 136 ft-lbs at 6K RPMs, and 115 ft-lbs at 9K RPMs.

In 1st gear that would be multiplied by the total 14.9:1 gearing ratio: 2026 ft-lbs at 6K and 1713 ft-lbs at 9K

In 2nd gear it would be multiplied by the total 9.7:1 gearing ratio: 1319 ft-lbs at 6K and 1115 ft-lbs at 9K

In 3rd gear it would be multiplied by the total 7.0:1 gearing ratio: 952 ft-lbs at 6K and 805 ft-lbs at 9K

Johnny--2K

i agree with S2Knikko....if shifted fast enough, you can keep the revs in the vtec range. Its all a matter of timing!!!

Gernby

It doesn't matter how quickly you shift. If you shift from 1st to 2nd at 8300 RPMs you will be at 5500 RPMs or less in 2nd gear.

PedalFaster

The ratio between the gears is fixed; shifting faster or slower doesn't change it. If you're shifting at a point below that which should put you in VTEC in the next gear, but miraculously find yourself in VTEC in the next gear anyway, your "timing" is really you slipping the clutch and adding more revs while shifting. Those revs would be more usefully added with the clutch fully engaged (i.e. before the shift).

Realize that many of the people you're arguing with actually participate in sanctioned racing and know what they're talking about.

Steve

jeffbrig

[QUOTE]Originally posted by gernby
[B]After thinking about it, I think cdelena's suggestion is best.