Quote:
Originally posted by deathbygaetano
Spyder_Venom: I guess what I don't get is why it's quicker to match the revs than to use the clutch. It seems like it'd take longer for the engine to climb down in rpm than it would to disengage the clutch and do it that way. I used to have a little Alfetta that I shifted without the clutch. Granted, It's not race engine, but it seemd like it took longer to rev-match than to just blast through it with the clutch.
Also, what about open throttle shifting? Would it be more beneficial (not to the clutch i'm sure  ) to shift that way instead of rev-matching? I think they do that in Le Mans. I haven't ever raced on a track so please correct me if I'm mistaken.
|
For down shifting its not a matter of all out speed, and since the motor is already being pulled down by the slowing of the car a quick blip of the throttle (while still hard on the brakes) is all it takes. During down shifting I will sometimes do a cross gate shift from 3-2 but its a little uncomfortable for me, still. While upshifting its very natural. I don't need to make a effort to match revs. All I need to do is back off a hair and it will slide right into the next gear with out missing a beat.
The reason this is faster is 1. you don't loose as many revs while the clutch is out, you also don't get the shock to the drive line when you let the clutch back out. 2 Loosing revs can be kind of kept by blipping the throttle, but as I said, its hard on the drive line - the other major advantage and not to be confused with #1 is gear transfer times, how long it takes you to go from WOT in gear 1-2. If you do it right it will go in to gear just as fast as if you used the clutch but you don't loose the time with engauging and dis-engauging the clutch.
In road racing there is this big deal over if you should heal-toe and use the clutch or use the newer left foot, clutchless shifting technique - personally I use both... it all depends on the track. At BIR (my local track) I have gotten to the point that I will never heal-toe there becuase of its size you never have any 5-1 or 5-2 down shifts. At a track like Pocono I would just throw the damn clutch in after the L O N G strieght going into the tunnel turn (back when they ran it the "normal way" LOL) and throw it into 2.
People talk about using the engine rev's to pull down the speed of a car.. This is dangerous but it does have its plus sides *IF your car is not equiped with a brake bias controller. What engine braking does in a RWD car is slow down the rear wheels in addition to what the brakes are. On most production cars running non stock tires (by that I mean DOT slicks, other high performance tire) the front end will be way out of balance with the rear. Even though your rear brakes do 20-30% of the braking of the car, in some cases they have concluded becuase the car was mis-proportioned it was doing less than 3%. The dynamics of a car will be the ultimate ruler of just how much it can take but still, a differnce of 27% braking capacity is huge. How if you have a bias controller you can adjust that and get it to the treashold of the vechical. The reason I would do this is simple, when downshifting you have a great chance of down shifting too soon and over revving the motor. No rev limiter can prevent this and results are catastrofic. Another reason to have a bias controller is by evenly setting up braking they will run cooler. You will find that brake fade is far less noticalbe when the car is leveled off.
Sorry for the long ramble about this, hopefully some of it made sense. I know a missed a lot but I'm trying to not write a book on the TFP
