power shifting

[racingbeat]

is anyone can talks more about power shifting for MP3H
which is the best rpm to shift for every gearH

 

[changedman]

well, depends on what you feel is a good rpm to shift at. also depends where you are driving.

 

[Yello-MP3]

If u are talking about racing and u care not for life of ur tranny then from the line rev ur engine to about 2000 rpms and when the light turns green drop ur clutch and let ur wheels spin it will only spin for maybe 5 feet or so but i have found this is the best way to jump off the line. (Still in first gear) When ur rpms hit about 6000 leave ur gas to the floor and shift to second as fast as u can. Do the same for the flollowing gears.

 

[nocar]

i tried that once and it shifted really fast but i heard a really bad sound. i dont think its worth to do that? or did i do it wrong

 

[Yello-MP3]

Hey nocar...

did ur gear grind???? If not u heard ur rev limiter. That means u just need to shift faster. Try again and shift right at 6000 and ur rpms shouldnt reach ur rev limiter.
Peace
Zane

 

[turboge]

I can see the bits and pieces of tranny on the ground already...

 

[TXMazdaSpeeder]

when i race i shift at redline and i launch at just below 2k let out then get back on it after a couple of feet, eliminates the wheels spin but it doens't bog off the start, i dont power shift either and with just a short shifter i run a 10.8 at 67 int he 1/8th mile (very few 1/4 miles in dallas)

 

[Stealth5]

hell man, rev it up to about 6500rpms and just flat dump the clutch....youll be off in no time

 

[Equinox]

hell man, rev it up to about 6500rpms and just flat dump the clutch....youll be off in no time

you are the smartest man ever.


powershift at 4500, drop the clutch from stops at just about 2k, because really you'll end up hitting 3 or 4 by the time the clutch engages

 

[RX-KEVIN]

7 1/4

 

[Ryan]

i tried that once and it shifted really fast but i heard a really bad sound. i dont think its worth to do that? or did i do it wrong

thats becuz you engaged the clutch with the pedal to the metal, i dont advise holding the gas down liek this, not completely down anyways, try 1/4 - half throttle and then punch it as your releasing the clutch.

 

[LinuxRacr]

If you are refering to true powershiftin, you will phuck your Tranny (that sounds bad).

 

[Ryan]

i know... i personally never powershift. I did in my old car, but nah not in my new car no way.

 

[nocar]

yea i powershifted once in a race, good results but i lost my tranny that week.

 

[DBR]

which is the best rpm to shift for every gearH

there's several factors involved but i'd guess the best shift point is redline in each gear, because even though the torque curve is falling off, there's still more torque than if you shift to the next higher gear, where you may have more engine torque but less torque at the wheels (because there's less torque multiplcation thru the tranny after the shift).

here's the mp3 torque curve (blue line):

http://www.flyinmiata.com/protege/tech/dyno_runs/MP3_ecu_comparison.pdf

and this article explains about torque multiplication thru the gearbox, and how to pick the best shift point (which in practice is often the redline):

http://www.allpar.com/eek/hp-vs-torque.html

oh yeah, and here's the gear ratios if anyone wants to do the math:

M/T
1st: 3.307 (13.575)
2nd: 1.842 (7.561)
3rd: 1.310 (5.378)
4th: 0.970 (3.982)
5th: 0.755 (3.099)
Reverse: 3.166
Final Drive: 4.105

(got them off the mazdausa site for a 2003 p5.)