How bad is it to redshift?

So Im gettin more and more into racing, and slowly learning technique and the technical aspects of racing. (finding the apex, hitting the apex, breaking, cornering, controlling the drift on off camber turns) yada yada yada.

this dude I know that used to race motorcycles and the like, and is incredibly knowledgeable about just about any kind of car (he's an engineer but being a mechanic put him thruogh school). introduced me to redshifting recently, and I kinda like it.
floor it, up to the redline, keep your foot on the gas, push the clutch in and shift. all without letting up on the gas. gotta shift right quick though, or well...you can imagine.

I went out to the country this last weekend for some QT time with my car, and tried the redshifting from 1st to 2nd, and from 2nd to 3rd. I must say, it does help to accellerate the car faster than normal shifting. and whereas I am aware of the obvious potential damage, shot rod, burned sinchros, fried alternator, and transmission FUBAR, why is this a bad idea for racing? is it?

anyone have any experiences with redshifting, good or bad? whatcha think? I see its advantages, and so far, I haven't noticed any damage to outweigh the advantages when done conservatively for racing. I wouldnt recomend daily driving, not enough road anyway, but....

anyway, Ill shut up...feedback?

I can't see it being any good to a street car.

You let your foot off the gas when you shift for a reason; so you can let the rpms lower to what the tranny is gonna run the engine at in the beginning of the next gear.

If you just keep your foot on the gas when you let the clutch out in the next gear youll either; just have a clutch that is slipping and not transfering power 100% becuase its speed doesn't match the flywheel, or you make the engine go through an instant dive of a few thousand rpm.

That's the dumbest thing I ever heard of. So it's basically power shifting at the redline? I say if you're dumb enough to try it then keep at it. I can't list all of the shit you'll end up braking.

Originally posted by B16EJ1
That's the dumbest thing I ever heard of.

LOL

Well which is it, the imbred ninja lepercaun fuel system cleaner or this?

J/K...no, seriously........

lets also not forget about the fact that in most cases by the time you hot the red line your power curve has fallen off tremendously... so you are taking a roisk of hurting the engine all the while it is not even making a whole lot of power

Thats not a good idea . . .What happens when you miss a shift or hit the wrong gear??

If you were to get proper driving instruction, they dont teach you to leave your foot jammed on the gas while shifting. Most likely you would learn proper clutch usage & how to shift with out the clutch. Both ways do not involve leaving you foot on the floor.

If you like your car, drive it like its meant to. It aint no race car made for abuse.

even race cars made to take the abuse break quickly when driven like that. i NEVER do that in my scca car, all there is to it is to figure out where your power output peaks and figure out how high past that you have to rev to enter the bottom of the power band in the next gear... in the miata the red line is like 7,200-7,500 but running it past 6,750 is not going to make you any gains. when you hit the proper rpm you go for a nice firm but quick shift, LET OFF THE GAS, at least enough to keep the engine reasonably close to the rpm it will be at when you let the clutch out. that is of course unless you like crunching gears and wearing out clutches

getting the wrong gear in a power shift alone should be enough of a reason to forget the idea. imagine you are reaching for 4th and in the process you catch 2nd... BOOM!

The only vehicle that I have ever seen do it(Not let off the gas when an Upshift occurs) are race cars with sequentials that require no clutching to upshift and have an ignition interupt when the shift occurs.

do it for awhile and you'll find out why its a bad idea. But start saving up now for your new... everything.

I agree that is really stupid. Not only will your transmission fall out, but your engine, motor mounts and other "engine" parts do not like that.

Plus you might only gain 1/10th to 2/10ths by doing that but in the long run it will cost you more money.

I'm an instructor for SCCA and I never ever tell someone to do what he told you to do. Proper driving comes from seat time driving CORRECTLY without damaging your car.

That is a really dumb idea UNLESS. With hondata systems. Hondatas ecu have a setting where you can adjust and it will allow you to shift without letting off the gas. That same system also has setting for launching where you can pick a point for launching and completly mash the gas but it wont allow the rpms to pass the point you choose, it has many other features but the quick shift as they call it is just one and thats the only way taht I would even consider shifting like that.

Now see, everything you all have said, is more or less what I told the guy when he told me to do it. I've done it, and it worked out ok, so far.... but yeah, you miss a shift and yer fooked. If it's not quick, the synchros wont allow it.

so as I figured, hence the thread, it aint worth it. I knew the potential for some serious damage was great, just wasnt sure how much, cause shifting like that seemed to work.

89B18C1CRX, what's this hondata stuff you speak of? interesting.
and cause Im a lazy bastard and runnin out the door to work, what's the/a URL for a racing association site? (SCCA?) I'm really gettin into the idea of autoX, so much more fun lookin for the right gear and steering for the right apex, and, and .... oh man is it fun - way better than a straight line. So I think some instruction from a certified instructor on a legal track (not route 9) would be good.

thanks all.
-wheel

www.scca.org

for real when I was at the track I shift like that a few time to see the the differents to see if it really helped


Just shifting fast I ran 17.2 and when I did what you called redshifting I ran 17.0

you can take the way you want to take it maybe I just shift slow when I come off the gas


but now I only do it when I race and go from 1st to 2nd the speed shift to 3rd unless it is neck and neck then I do it to 3rd too

its a waste of a car.

no offense, but neither of u have cars that are truly all out drag-cars that really need to be doing this. is it really worth the chance of blowing ur motor so u can beat that other stock civic dx? or run a 16.9 instead of 17.0?

by NO MEANS am i sayng my car is fast enough either (my car is slow as well), simply trying to make my point.

don't ruin ur car because u want to run 16's....

it's not a "bad" thing it is a unwise thing. when i frist started drags with my car i whould put my feet down and don't let off till the end of the 1/4 run...
yes you run abit faster itz fun, but your hurting your Clutch.
this is what i think you what.
frist dyno the car, and see where your torque and HP start droping, where they start to drop, that is your shift point, so get a tach with a shift light.
BTW, when your launching your car, you want to find the rpm that you get the least wheel spin with the least rpm drop off, for me it is 4200rpm, when i drop in the clutch, rmp drops to 4100 or 3900.
back to shifting,
when shifting you don't what to drop out of Vtec, and when you put the clutch back in you don't want rmp drop off, find that sweet spot for your motor.
What you can do, is run up you gears, shift as fast as you can, and see where the rmp drops to when you put in the next gear,(foot off the gas when shifting for this) this will give ah idea of where the sweet spot is.
So go out, make some passes and take notes, and have fun most of all...
kester

miataracer, thanks for the link.

as far as any shifting goes, I think it has been well stated (to the point of redundancy) that to "red shift" is simply not worth the actual and potential damage done to a/the car of any kind for any reason.

thank you all for the replies...and remember keep it, and leave it, on the track.

PEACE!
-wheel

Originally posted by wheel1856
How bad is to red shift?

you should throw the trans in reverse while your at it. 75-80mph should be good:sly: