what rpm should i shift at to get the best performance (best acceleration) in each gear?

my engine is entirely stock.

 

About 500rpm before redline.

 

Really? I would say redline; While you start to lose a little bit of power after 6500 (7500 on an s5 n/a), I believe it is still beneficial to stay in a gear a liiiittle bit longer, so that you don't lose MORE power on the downshift. I've also wondered this myself, though. I can't imagine that 7k is the perfect place to shift all of the time, though I feel that at least through first and second, it's preferable to shift at 7k than 6500.

Any of the more experienced guys have an answer?

 

Redline is fine too. I'm giving a rough number, really. Heck, I dunno, maybe 7500 would be slightly better. But I'm betting power doesn't increase much as you get up high.

 

No, power actually DOES start to drop off at 6500, EricGrau. You are absolutely right on that point. I see it this way, tho:
(all numbers are arbitrary; just to look at it from a theoretical standpoint)
If you make let's say 150hp at 6500, and that drops to 145 by redline
Say you make 110 at 4k, and 120 at 4500.

Shifting 6.5k->4k keeps you between 110hp and 150hp. then you shift out at peak power

Let's say, though, that you go up to 7k, leaving one gear at 145hp, entering the next gear at 120hp. NOW you are putting down at least 120hp, instead of 110, at worst. You are staying closer to peak power for more time, so that should be beneficial. My guess is that the perfect shift point is a little over 7k in first, right on 7k in second, and slightly below for subsequent gears.

That is just my theory, though. Flame away

 

thanks for responding. that was about what i thought but i just recently bought the car and due winter coming it is being stored already. and sometimes cars get their peak power at a different rpm in every gear.

now i have another question tho.
my car makes an annoying beeping sound when i push it too close to redline, anyone know how to disconnect it?

 

I believe that is the "up shift buzzer" that is supposed to tell you the correct time to shift for maximum gas mileage. . .its a stock feature that I'm looking to aswell

 

DUDE why the hell are you gonna disconnect the warning buzzer? That's retarded.

The warning buzzer warns of low coolant, and other things, in addition to telling you to shift at 6500, so your incompetent self doesn't destroy your engine. Anyways, you shouldn't be spending THAT much time between 6500 and 7000 RPMs anyways, so just ignore it when you are up there.

I will laugh my *** off when you disconnect the buzzer, end up low on coolant a week later, and blow your engine 'cuz of overheating. I don't want to see a 7 die, but I WILL laugh at you.

 

^^ ok thats a lil extreme but i know what point your makin...he might not.

the shift buzzer and low coolant/ low oil are all on the same buzzer/speaker. there is no way to remove just the shift buzzer(i dont think anyway...never looked into it) unless you take the speaker out which you loose the low coolant and low oil as well. obviously you are going to need those 2 things.

 

there is a way to Adjust the Buzzer though.so that the Buzzer goes off Later than 7,000 rpm..I think either IceMark or Hailers...One of the Big Wigs on forum has Posted up How to do it..so..Cough...Search!.

 

There is a little variable resister pot on the back of the tack you can adjust.

 

here is the link on HOW TO ADJUST THE REDLINE BUZZER. http://www.jimrothe.com/mazda/overrev.html hope that helps you..Just Don't Disable the Buzzer..or you may find your Car ..Disabled..(Damn!. I'm good at this Search Stuff!..)

 

Wow! People that know how to use the forum, like Misterstyx?!?! OMGWTFBBQ??!!?!?!!!!!!111one

 

thanks to those of you who helped with the disconnection of the buzzer. and those of you who actually need a buzzer to let you know something is low in your car are the reason that new cars don't have guages anymore and now have dummy lights...hence the name, dummy. Try checking your car once in a while and possibly just take note of your guages. i have two vehicles and i have never used dummy lights to realize something is wrong.

Also i don't spend a whole lot of time in the 6500-7000 range except when racing and everyone here knows rx-7s are fast.

 

The shift point for best acceleration will be different in every gear. Usually its real close to redline in first, then it drops from there. You can find a gear calculation program out on the web, if I can find mine buried on my laptop that I never use I'll post it up.

 

Practically speaking, just shift right before the buzzer. Or after the buzzer if you forget; that's what the buzzer is for.. Maybe, for each gear, you can find the optimum balance between dropoff past 6500rpm and the gains from being in a higher rpm after the shift, yada, yada. But it probably isn't enough to be worth the trouble.

 

Take a dyno plot and scale the X axis to be speed and scale the Y axis to be power to the ground (power times gear ratio). If the power curve in one gear crosses over the one in the next gear then that's your shift point. Power does start to drop off towards redline, but it also drops off before the power peak and that's where you'll end up after the shift. That combined with a reduced torque multiplication will usually mean that the optimum is redline unless your power drops off quite substantially and/or your gearbox has fairly close ratios.

 

wow... maybe i should downgrade my exhaust so i can HEAR my buzzer..... dont want anything bad to happen hahaha

 

anyways... A good driver should be able to notice when the power is going dull in the higher rpms. Once you figure this out you will know when to throw the next gear.

But personally. I have an 88TII and i do 7,500 in first gear only nd 7,000 on the rest. Only when dragracing though. I pretty much never see past 7,000 since i rarely drag race.

 

Way to get all butthurt and be a complete ***** when we try to help you. You're worthless. Sell your 7 and buy a car that deserves to be hacked up, like a Nissan 240SX.

The buzzer is a safety measure; unless you are building a dedicated track car, and need to remove weight, there is no need to remove it.

 

The buzzer is adjustable, so it's not necessarily consistent from car to car. This makes it a less than suitable gauge for a car that you're unfamiliar with. I stand by my original hypothesis of 7.2k in 1st, and 7k in each subsequent gear.

 

The thing is that power falling off in gear doesn't mean you'll have more power TO THE GROUND in the next gear. The only way to know for sure is to do the dyno plot scaling and see for yourself.