What rpm do you prefer to shift when racing? (12a engine)
 

I know I ask a lot of stupid questions, but I have noticed watching a few videos on youtube that many people wont shift until after the buzzer goes off and they are close to 8000 rpm. I never bothered to look to see if they have modifications or anything and I am sure at some point there would be a drop off somewhere where you lose most of your acceleration. I usually shift right before red line in all of the cars I have driven. But anyway I am asking everyone else on around about where they prefer to shift to get the max power out of each gear. Do you wait until after the buzzer goes off telling you to shift or do you shift before 7000?

It depends on few diffrent things. Power curve, gear ratios and where your at on the track are the main ones, for me anyways.

You would want to shift at peak power. If your trans is set up for a 1000 or 1500 rpm drop in every gear. This would keep you in the power band all the time. But if you have a stock trans, and have some gears that have a 2000 or 3000rpm drop. You may want to over rev and go an extra 1000 or 1500 rpm to get the rpm's up into the power band after the shift.

What I mean is. If your power starts a 5500rpm and ends at 7000 rpm. As you shift from 2nd gear at 7000 to 3ed. You may end up at 3500rpm by the time you let out the clutch. So over reving would help.

Also it takes time to shift. About 1 sec or so. So if your close to the next turn it may not be enough time to shift before you have to down shift or brake.

Then there is the heat of the battle where you just forget to shift. Or if you do shift the other guy will get the advantage of you loss in power as you shift.

There is so much more, but thats a few reasons that I know of.

So, to add on to this, what is the best rpm to take off at? Obviously you don't want to smoke the tires, that is a waste. But then, you want to shift in an area where you have some power. Would you want to take off right at the beginning of the powerband? This is something I have always been curious about.

It can also depend on the motor tuning and weather. there are times where my spec7 will pull strong upto 8000 and others it wount it just come down to listen and get a feel for what mood the car is in.

Too many variables. Way too many.

i shift at 7k if im driving hard, the only engine mod i have is a cat delete. ive gone to 8k once by mistake (i dont have a rev buzzer)

So really it mainly is determined by where you feel is the best. I just don't want to go shifting too high and risk putting more damage to the engine than it would already do racing it. Once you hit red line with all my other cars it just doesn't go any farther. This one will just keep going so I wasn't so sure about how far to actually go with it before it will be considered unsafe for the car.

For maximum acceleration from a stock port engine shift at redline (7,000rpm)

Yes. It's redline. It's redline because the torque produced at the road (by the engine torque multiplied by the ratios of the transmission and final drive and the overall wheel diameter, in addition to friction and inertial effects) is always higher in a lower gear than the next highest one. This is not always true for every car, but it is true when looking at the factors in a 12a Rx-7.

https://www.rx7club.com/showthread.p...oints+purple82

Try to shift somewhere between BEEEEEP and BOOOM.

the maximum power output on a stock 12A is at 6000rpm.... revving past 7000rpm and you not only lose power but you run the risk of apex seal chatter, ruined housings and possible stationary gear failure. the stock 12A wasn't meant to rev past 7000rpm on a regular basis. a few hundred rpm over redline is fine but revving to 8000rpm can put some serious wear on the engine.

Sounds good so I will just shift at the times I do with all my other cars. Right now I am kind of disappointed at this car right now though lol.

Pretty much. Sounds like your street driving, not racing on a track. Two diffrent worlds and real race cars (that I know of) don't have buzzers...lol. Shift lights maybe. But I know I have my shift light come on 500rpm under red line to give me time to shift.
All in all it comes down to Feel and lap times.

This is the only car I have had with a buzzer lol. I got this car for mainly autocross racing, but if I can get it all in good shape, I will also be wanting it for just a nice car to drive around on the sunny days.