PDA

View Full Version : How to obtain fastest acceleration?



Soyabean
04-26-2010, 01:02 AM
So i dunno if there is a thread like this, but i didnt really find one like this one.

So anyways, i have a 5sp GT.

I'm wondering, what is the optimum shift at each gear and at what rpm to launch in 1st?

Like from dynos and stuff, i see that we obtain our peak power at 5500rpm. Now does revving over the 5500 say to 6000rpm allow for a higher rpm at the next gear and thus reach peak quicker at that gear?

Also, when launching from 1st, i think most people rev to 3k then just pop the clutch. I know this isnt good but is this the best method to achieve the quickest acceleration in our cars?

Furthermore, as for the gas pedal, i assume we just floor it at every gear? or gradually at low rpms?

Unoriginalusername
04-26-2010, 07:19 AM
The fastest launch is a balance between not bogging and hazing the tires... it may seem faster to have a squeling smoke show but in reality you're better off easing of the clutch a bit more gradually than just dumping it that will get you a launch just clawing at the tires.

Flat footing it will also get you the best time, but that is the most abusive on your car. it's cheaper to go to canada's wonderland for some thrills than it is abusing your car over the long run

Donutz
04-26-2010, 09:37 AM
Mods also come into play (motor mounts, swaybars, LCA bushings, springs/struts/coils and others). The key is to practice your launch in the manner that UOU described. Try to put down as much power as possible without, or very minimal, wheel spin while engaging the clutch as quickly as possible while balancing smoothness and acceleration.

Soyabean
04-26-2010, 10:50 AM
The fastest launch is a balance between not bogging and hazing the tires... it may seem faster to have a squeling smoke show but in reality you're better off easing of the clutch a bit more gradually than just dumping it that will get you a launch just clawing at the tires.

Flat footing it will also get you the best time, but that is the most abusive on your car. it's cheaper to go to canada's wonderland for some thrills than it is abusing your car over the long run


The fastest launch is a balance between not bogging and hazing the tires... it may seem faster to have a squeling smoke show but in reality you're better off easing of the clutch a bit more gradually than just dumping it that will get you a launch just clawing at the tires.

Flat footing it will also get you the best time, but that is the most abusive on your car. it's cheaper to go to canada's wonderland for some thrills than it is abusing your car over the long run

Flat flooting is when you step on the accelerator all the way? How is that abusive and how does it damage the car?



Mods also come into play (motor mounts, swaybars, LCA bushings, springs/struts/coils and others). The key is to practice your launch in the manner that UOU described. Try to put down as much power as possible without, or very minimal, wheel spin while engaging the clutch as quickly as possible while balancing smoothness and acceleration.

Furthermore, what is the optimal rpm to shift at?

Donutz
04-26-2010, 11:14 AM
Good question! I've never timed myself, so I can't say if how I like to shift vs winding out to the redline is faster. I shift so when I catch the next gear I'm in the 3800 to 4200 RPM range. According to my dyno sheet I'm making max tq around 4200 RPM. I suspect I'm shifting around high 5000 to low 6000 RPM when I merge onto the highway. I've wound it out to the redline, but I don't feel that I'm going any faster than if I were to shift.

Soyabean
04-26-2010, 11:43 AM
Yea, i normally shift after 6k. But i guess i just have to experiment to find out. I just thought that there were enthusiasts who drag their cars on our forum who already found the optimal shifts to obtain maximum acceleration.

BlackIce
04-27-2010, 01:06 AM
with the least amount of bogging and most of amount of traction will give you the best take off! for ever car its different. if you have nearly fresh tires, i would suggest reving around 6,500 rpms let go of the gas, depress the clutch, shift into gear, and then floor it! (make sure you do it really quick or you will lose your high rpms. either do this or burn your clutch!) this is for take offs. you may get some wheel hop depending on the road, but since your tires are already spinning, you will have a better launch once your tires get traction! never failed me.

Shift up around 6,500-7,000 RPMs, that is just before the limiter kicks in and it will keep your RPMs high for the next gear! remember that you need to let go of the clutch at the right time wen you shift up! if you let go too early, your engine will bog/bounce cuz the RPMs are too high for the speed the car is actually moving at. if you let go too late, your car will slow down for a bit then bog cuz it will try to match the RPMs with the cars speed. mazda 3s have very good syncs so it should be fairly easy to do this.

good luck and remember to not race on the streets. if you dont care about your life, fine, but dont do it for the sake of everyone else on the road who dont want to get hurt or killed from someone elses mistake!

BlackIce
04-27-2010, 01:14 AM
Mods also come into play (motor mounts, swaybars, LCA bushings, springs/struts/coils and others). The key is to practice your launch in the manner that UOU described. Try to put down as much power as possible without, or very minimal, wheel spin while engaging the clutch as quickly as possible while balancing smoothness and acceleration.

it is important to get as much traction as possible, but on a RWD or FWD car, you can just floor it like on an AWD car! if your rev at the right spot and get a little bit of wheel spin, means that your wheels are already in sync with the engine and they are already spinning at like 40kph so once you get traction, you will fly off the line! you shouldnt have more then 2 seconds of wheel spin, if you do, then you need to get newer tires for the race.

Unoriginalusername
04-27-2010, 07:15 AM
Flat flooting is when you step on the accelerator all the way? How is that abusive and how does it damage the car?

Flat footing it is when you don't let of the gas between shifts. you hold the pedal to the metal and shift quick enough the tach doesn't over rev... this assumes you can shift quick enough and have no regard for your drivetrains well being

Gizzmo_jr
04-27-2010, 08:54 AM
Unsprung weight from standing stop.

BMWWW
04-27-2010, 09:23 AM
A few feet of roll-out will always be quicker.

Nick
04-28-2010, 02:53 PM
i shift right before 7000rpm, i find that's the only way i can chirp into 2nd =]

Donutz
04-28-2010, 03:06 PM
I can shift at 5500 from 1st to 2nd and spin the tires!

1flycdnM3
04-29-2010, 08:18 PM
Flat footing it is when you don't let of the gas between shifts. you hold the pedal to the metal and shift quick enough the tach doesn't over rev... this assumes you can shift quick enough and have no regard for your drivetrains well being

I did this constantly at the track with my stage 2+ Exedy clutch on my old Honda, but I wouldn't DREAM of doing it on the 3! Why?? Maybe I respect cars more, maybe I enjoy not breaking things, maybe I feel it can't handle it..... whatever the case may be I do NOT recommend doing this, I have "maybe" once or twice done this from 3rd to 4th, but still do not recommend it. Find the optimal shift points/launch point (I will figure this out on the track this summer most likely) and go from there. I notice on the streets (not racing, just practicing) that 4200-5200ish seems the "hot spot" so trying to keep first gear near 5000RPM should enable you to stay in that "hot spot" for 2nd gear and so on.....