Before i get started, I will put up my anti-flame sheild and say that I only do this at a track.

Some debate has been waged as to when I should shift my S/C tC when getting myself down the quarter mile. I started by going almost to redline (~6k) on every shift. Then someone mentioned that i should be shifting around 5500-5800, since there is a power dropoff from the S/C at higher RPMs. I tried it, and actually was slower by a few tenths. Chalking that up to not being used to it, i tried a few more times, and was consistently slower. I went back to my almost redline shifting, and I was immediately faster. The guy who suggested that I shift earlier seemed to think I just needed more practice.

So, thats the debate. I have looked at some S/C dyno curves, and there is a small dropoff as you get past 5800. When i shift around that point, though, it drops the RPMs into a range where the power that is lower than keeping it at redline. Because of that, I am sticking with the idea that taking it to 6k RPMs before shifting (when dragging) is the best idea.

Please, tell me if I am wrong

 

shift at 6k, the SC builds more boost as it builds RPMs, and since the redline is actually 6250, by time you react, youll probably be exactly at redline. The best range of power of the SC is closest to redline, so the closer you can keep the RPMs there, the better.

 

Well, so far I'm right! I like hearing that

 

Also when you shift you don't want to be stuck at 3k rpm, thats why you should shift at redline to stay in the power band

 

x2, I don't have my supercharger on yet, but this is how i drive my tC at the drag track.

 

x3 on that one



I dont have the SC but, on an N/a motor you have to shift at 55-58k otherwise you bog

 

you shouldn't bog at 5500 to 5800 rpms. i never drag, but when i'm accelerating hard, i take it up to about 6000 rpms.

as for when the best time to shift is, yeah you want to shift just about right at redline because you want your rpms to be as high as possible for the next gear. with the supercharger, it means you have that much more boost in the next gear.

even if the power starts to drop alittle past a certain rpm before redline, unless it starts dropping off rapidly, and makes less power there than it would be at the rpm you'll beat when you shift, which is pretty unlikely.

but you don't want to bouce off the rev limitor, because that will kill your times.

 

I never understood the whole arguement about shifting earlier because power drops off. Those revs equate into acceleration, and time not shifting, despite "power dropoff", even without the supercharger.

 

people think that just by looking at charts, if you go up to redline you will getting less power cause you get peak power at around 5800 rpm; and after that power drops off slightly
but what about the rpms dropping lower? when you switch at 5800, your rpms drop lower than if you switched at redline
people who switch at 5800.....
maybe theyre scared of hitting the redline and "damaging" their engine...

 

its not so much that we are scared of redlining, its just that RPMs build in this car because the gears are very close together. I personally will hold out to as close to 6K as possible to even begin to shift, because i know that by the time i react and do whatever i gotta do, i will be as close to redline as possible. Bogging really does hurt, and will hurt you shift terribly.

Its kinda like drag racing at the track. They tell you to get on it as soon as the 3rd yellow light falls. It takes time for your body and the car to react.

 

this is pretty much a two part answer. As far as shifting before red line if you know that you are producing your max output from xxxx rpm to xxxx rpm then after you pass that top line the amount of power you are making starts to drop of. if you can shift at a point that you are making close to or exactly at your max power input and shift into the next gear and still be in the meat of the power band you will accel. quicker even though you are in a higher gear.


As for the shifting at redline in a tc I have never had any luck with it at the track. In all my previous cars I could power shift and hook up with no issues, but in the tc if I slam it with a power shift at redline.. or even at 6k unless I lift off the gas it always bogs, and I have found better ets with shifting at 56-58k

just my $.02 perhaps that will change after I get my flywheel, clutch and lsd

 

uuuummmmmmmm that ^^^^^^^ up there was supposed to be from me.. my gf was on here last night.. didnt see that she had logged me out

 

hahaha, silly girls

and i assume you mean 5600-5800, not 56000-58000. That would be a hell of an engine

 

this is gonna be OT
but is yoru gf korean? haha