Veloce Raptor

I dunno...if you're only at 6000 rpm at track out (wheels straight, no need for additional stability) and the car makes real power to 8500, why would you upshift at 6000?

Larry Herman

Que MK in
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4
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PedroNole

Ok guys, I just read every post in this thread.... Lots of good stuff in here! Thanks for doing this!!!

CRex

Gents this is a bona fide question. I know what I don't know, which is why I asked. Do people short shift? Yes. Does that always make sense? Probably not. I trust there are folks who know when to do it and are willing to articulate why. Ain't that the point of this thread?

onefastviking

Either could be faster dependent on track,driver,car,etc, that's why most of us preach the data song.
If you are questioning it I would do segments with data to determine which is faster and why.
I would bet each could be used in different situations in a race to take advantage of racing circumstances. One maybe in a qualifing lap and another for a certain passing opportunity.

Veloce Raptor

I am sorry, my response was bona fide & serious. As Viking indicates, there are times when shifting short of redline (sometimes erroneously called short shifting) is better/faster. The "sometimes" depends on the car, the powertrain, the track & where on it upshifting is required, the weather, etc. Data is the best guide to determining advantages/disadvantages to doing so, as there is no hard & fast rule. Some cars see their power fall off dramatically as their engines approach redline. Those sometimes benefit from upshifting before redline in certain circumstances. This fact, borne out by real empirical data, has caused all sorts of "discussions" here on RennList, hence Larry Herman's humorous allusion above.

IMO, your GT3RS is not one of these. And, if you are at only 6000 rpm at track out, and your wheels are straight, there is no real advantage to upshifting there instead of closer to yoru 8500 rpm redline, all other things being equal.

PedroNole

It's all about keeping the car happy and compliant as much as you can. Are there places you can short shift to help the car/you go faster, yes. One example, turn 2 at Watkins Glen. In my car, I would get a decent amount of push as I was entering the turn and winding out 4th gear and sometimes the shift point would come when I would rather have 100% of my focus on what was going on at 120mph in the turn. If you blow 2, you likely blow three and then your lap is done... So, I would come out of 1 in 4th gear full throttle to about 7,400rpm (my car revs to 8,500) and shift to 5th before setting the car for turn 2. Car was happy, I was happy and we both ended up fast..... That help?

Seth Thomas

In this example here I bet also you found your times were just as fast if not faster than if you shifted later. The reason is because you used your shift to 5th as the lift to help get the car pointed at the bottom of the uphill esses instead of pushing the car wide and being off the 2nd apex. So your full throttle point was 200ft longer than using 4th to redline. Data is the answer for this one though.

As for short shifting in a DE compared to running your car to redline that is up to the owner of the car in my opinion. If you are looking to be easy on the car and not abuse it then fine shift early. If you want to act like your street car is a cup car then run it to redline. Either one works and gets the car around the track. If you find you are shifting at 6K RPMs when the car revs to 8.5K then you are being too easy on the car and should consider shifting higher. There is a point that you can be too easy on the car.

One very important point to consider in all of this is to get a rhythm going in the car. Always shift at the same point on the track at a proper RPM. Don't shift at 7k one lap coming out of T5 and then next lap you shift at 8k out of T5. Be consistent because you want to make shifting one of the processes you don't think about when in the car. It needs to be relatively subliminal, creating a rhythm.

Veloce Raptor

+1

mglobe

+1

The two conditions where I'm most likely to short shift are to either make throttle modulation is easier in a turn, or to set myself up so that I can carry a gear all the way through a sweeper rather than have to shift while the car is still loaded. With respect to the latter circumstance, it's usually a turn where I would hit redline right around track-out. T2-1 at TWS going CW is a perfect example of that.

ProCoach

^^this^^

Like Seth said, your "lift" (any sort of pause in acceleration, be it a shift or hitting a fuel or ignition cutout at redline) should be timed to both insure a steady progression of power without interruption and placed most appropriately in the torque delivery of the engine. Witness shifting up earlier from T1-T2 at WGI or between T14A and T15 and again before T16 at VIR.

Seamless, rhythmic... That's the goal.

You can stretch RPM if you want, but it's a lot more expensive if there's no margin and you happen to screw up!

CRex

Thanks--I realize it's an ill-put question to begin with and the answer varies widely from situation to situation. While I have a camera I should certainly invest in a datalogging component!

My butt-o-meter agrees--in my older car with less torque there's a clear disadvantage to short shifting out of this hairpin. With more torque in the new car it felt like a scratch either way. I asked the question coz one of the coaches (driving a similar car) consistently exits the same corner at ~7k and upshift there. The results are faster... he's obviously better set up from corner entry thru exit. I've got my work cut out

Mucho gracias. Good to think of it your way--setting up for the next corner. Oughtta back off my fixation on power and grip...

Point well taken. Here in HK we don't get as much track time time as we'd like (one track event every other month and that already makes me a "frequent customer" which is a shame). Trying to develop muscle memory and consistency without due practice is a b*tch. Your point on rhythm is particularly true--I watch and rewatch my past vids and the brake & shift points are really varies from one session to another. How does one overcome the animal desire for speed and gain consistency? I've always been lacking in the discipline department

True that the higher gear buys me more rear traction. I generally try to avoid up shifting while the car's loaded (as in a fast 4/5th gear corner) for fear that a missed shift will send me into the armco...

Very sound advice. On throttle modulation, I came across this Aryton Senna vid the other day. It blows my mind to think how quickly he's processing the road feedback if's he blipping/testing the throttle about three times a second throughout the corner... skip ahead to 1:25...

IcemanG17

If your engine makes power until XXXX rpm....then of course you want to shift there, or maybe slightly past it.....about the only scenario I can see where it "might" be better to short shift is say you are going into a sweeper, where you are accelerating and holding until redline would put you shifting while still turning, pulling lots of G....that could upset the car....especially a high power car....

Intentionally short shifting an 8500rpm engine at 6000rpm on a straight is costing lots of power... but it all depends on your goal for that day and that session....is it an all out race or just a DE for fun...you might want to take it easy.....or try the "1" gear theory....where you work on smoothness and carrying momentum and don't shift the whole track..... For example the 1 gear theory in my car is about 3 seconds per lap slower.....but far easier on the car!

Veloce Raptor

This is a great video. The loafers are epic...

Look at how much he trail brakes.

The throttle popping, however, does not show what you think it shows. He is using that technique to help rotate a car that tends to understeer a lot (street car with skinny front tires) and get the rear end rotating faster/more aggressively than it normally would want to.

Land Jet

After a lifetime of shifting gears with my right hand, I would think making the transition to left hand shifting would be difficult and maybe expensive{key synchronizers crunching}.