i was just wondering??? many people is been revving their cars up to 9k and such even tho they know their power ends at around 7900 or 8??? does it make any difference on ur 1320?? or do gain any speed the fact that switching ur car on higher rpm's make ur rpm drop on a lil higher rpm's??? because ive noticed that on my car i peak at 7900 and power drops / and also i revved at 8500 and notice cars are gaining on me after the peak rpm...ANY INPUT?? from the all motor guys?? any help or opinions will be appreciated....

 

im guessing that near the end of the quarter mile, they would rather keep pushing and end the quarter in a higher rpm instead of shifting near the end

 

Personally i like to rev up until i stop making power if u make power to 8 shift at 8 but if you can make power till 9000 or 9500 you wanna keep going until u stop making power it also depends on your power band the best way is to get the dyno sheet and see you power band and race off of that from my experience. Just my .02

 

i believe it depends on your powerband, i'm on an f22 and it stops making power about 6000 but i shift about 6100-6200 because it puts me right in the meat of my powerband in the next gear.

 

shift when u stop making power, and if u dont have the parts to be reving that high u'll screw something up.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sedracer &raquo;</TD></TR><TR><TD CLASS="quote">i believe it depends on your powerband, i'm on an f22 and it stops making power about 6000 but i shift about 6100-6200 because it puts me right in the meat of my powerband in the next gear.</TD></TR></TABLE>

... people will often spin their motors a bit higher so that when they shift, they don't fall out of their power bands.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by alfaaay &raquo;</TD></TR><TR><TD CLASS="quote">

... people will often spin their motors a bit higher so that when they shift, they don't fall out of their power bands.</TD></TR></TABLE>

You want to shift at the most optimal point to where you get the MOST AREA under the curve. Because each gear shift brings you at a different RPM the next gear, the most optimal shift theoretically is at a different RPM at each gear.

 

well i got dyno tuned and the power falls at 7900...my tuner said i need bigger injectors to be revving that high...actuall i don't worry about revving a lil bit higher maybe around 8500 since i got my head built on blox b cams...after peak my power drops like crazy....it needs to be retuned as soon as i get a better header and injectors......when u rev ur car after the power dies ..does it helps you when you race or u shift at the right rpm's where u peak at

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by cpforyou &raquo;</TD></TR><TR><TD CLASS="quote">

You want to shift at the most optimal point to where you get the MOST AREA under the curve. Because each gear shift brings you at a different RPM the next gear, the most optimal shift theoretically is at a different RPM at each gear.</TD></TR></TABLE>

Exactly. That could mean shifting right where you power falls off or holding the gear for another 2,000rpms (or more) depending on your area under the curve.

Example: Let's say your car has a very narrow and peaky power band, a good example is if your VTEC engagement point is set horribly wrong/high. If you power suddenly climbs like a rocket (as in your VTEC engaging) to it's power peak then aftewards barely tapers off as the rpms continue to rise you would be a complete idiot to shift exactly at your power peak. That would drop your engine back down into the sharply decending side of the power curve. By holding on to the gear past peak power where the curve still stays relatively flat you can maximize acceleration.

 

Here's the simplest way to look at it. Consider the ratio of the gear ratio after the shift to the gear ratio before the shift. This ratio is also the ratio of your RPM after the shift compared to the RPM before the shift. Ideally, you want to shift at such an RPM that HP is the same after the shift as before in order to realize maximum acceleration. This increases average power. And this necessitates increasing the rev limit on an engine that produces peak HP so close to the rev limit (as is the case with Honda VTEC motors).

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by StorminMatt &raquo;</TD></TR><TR><TD CLASS="quote">Here's the simplest way to look at it. Consider the ratio of the gear ratio after the shift to the gear ratio before the shift. This ratio is also the ratio of your RPM after the shift compared to the RPM before the shift. Ideally, you want to shift at such an RPM that HP is the same after the shift as before in order to realize maximum acceleration. This increases average power. And this necessitates increasing the rev limit on an engine that produces peak HP so close to the rev limit (as is the case with Honda VTEC motors).</TD></TR></TABLE>

 

[QUOTE=ActiveAero]

Exactly. That could mean shifting right where you power falls off or holding the gear for another 2,000rpms (or more) depending on your area under the curve.
can someone explain to me what's the area under curve???..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by cpforyou &raquo;</TD></TR><TR><TD CLASS="quote">You want to shift at the most optimal point to where you get the MOST AREA under the curve. Because each gear shift brings you at a different RPM the next gear, the most optimal shift theoretically is at a different RPM at each gear.</TD></TR></TABLE>

I stand corrected. This is really how you determine where to shift . From what I've seen and experienced though, this is something that you have to consider a lot more when driving non-Hondas. I don't know what it is about Honda motors/trannies (GS-R and ITR trannies at least), but shifting a little above redline seems to work fairly consistently.