SouthFL

Funny thing happened this weekend.

I was lapping at Homestead and ran into someone I knew from my Skip Barber class who was instructing that day.
I asked him if I could ride passenger with him as a refresher, since I've been lapping solo for half a year now and I'm no longer getting any feedback. I really feel that I'm pretty much stuck on doing the same things over and over and am not progressing much at this point.

So, we hop in to his S2000 and get on the track. He's pretty much hitting the same line as I, with a few areas where he can apex a little earlier than I due to his skill and car setup. Riding in the S2000 was very similar to the 8 both in powerband and feel. But, the one thing I did notice was that in the brake zones, his rev matching was much quicker than mine - the sound of the blip and exhaust was noticeably different.

So, after a few laps, we go back to the paddocks and hop into my 8 for a few laps with me driving.
At the 1st brake zone, I'm doing my thing- double clutch rev match braking, which was taught to me at Skip and he says- why are you double clutching? I ask- what do you mean? He explained that he wasn't double clutching, just simply rev matching in the brake zones- much quicker and more applicable to a sprint race in a car with synchros (which I had known technically, but never witnessed knowingly). I laughed and explained that I thought he had extremely fast footwork based on the sounds I was hearing from his car- which sounded very similar to lots of ontrack vid footage I've watched. I had always wondered why my footwork sounded different in the blip and exhaust note.

Lol. So, long story short. My feet aren't so slow afterall.

'ringmeister

interesting, although matching revs/heel-toe without double clutching is a lazy, short-cut method. proper double-clutching in combo with matching revs is MUCH easier on the synchros. you are essentially doing the synchros job for them, and it is soo satisfying when done correctly. the shifter drops into the lower gear like butter, no resistance. with practice you can do it very quickly. at the pocono long course, at the end of the banking to re-enter the north course, i go from 5th down to 2nd (no skipped gears) in my evo. the secret is that after double-clutching & revmatching and you have selected the next lowest gear....as you bring the clutch pedal up to complete that shift, just bring it up to the engagement point, the point it "bites". don't come all the way up through the travel of the clutch pedal. as soon as you reach the engagement point, depress the clutch again to begin the next downshift. i is only a small amount of time saved but if you are rapid enough with all your movements you can run down through the 'box quite quickly.

SouthFL

I agree. I'm all for double clutching (for all of the inherent benefits in tranny life and vehicle stability it offers). In my street car, at lapping days, I will no doubt do the full process of gowing down every gear (4-3-2) with blipping in neutral. I do it rather quickly- as quick as one can, and smoothly, but it's still not as quick as a rev match downshift. I can see how in a sprint race, one would forego the double clutch, while double clutching in an endurance race makes sense (for drivetrain life). The guy I was in the car with has had some competitive race time in one of the Barber series, and acknowledges that all though double clutching is taught at the Skippy school (and enforced by the instructors), in sprint races, people do what's quickest, and sometimes forego going down every gear in the heat of battle.

I guess knowing how to do the whole process is good practice, but one must also know when the full process is unecessary. What I found out yesterday was that there was something between double clutching and simply throwing the lever in gear without any blipping, which is essentially single clutch rev match downshifting in the brake zones.

SouthFL

Also. In particlar, I've run into a lot of racers out there who don't double clutch, claiming it's a waste of time. But when I ask them if they know how to double clutch downshift in brake zones, they respond, "no." Some also think going through each gear is a waste of time.

This instructor is a guy who knows how to do the process well, and is foregoing the process in favor of a single rev match while going down each gear. He isn't overlooking going through the gears. I wonder how much added wear he's putting on his gearbox as a result.

John V

iTrader: (1)

Double clutching a synchro box is a waste of time. I learned how to do it on an '87 Turbo RX-7 because the synchros in that box were toast after 140,000 miles of hard use (i.e. rushed shifts).

The synchros will last a very long time when used properly. There is absolutely no need to double clutch one. You'll go faster without wasting the time.

SouthFL

I just corresponded with the instructor and he's gotten 70,000 miles out of his gearbox while single clutching. He does change his tranny fluid after every event.

altiain

iTrader: (3)

I had 110,000 miles on my '99 Miata's tranny when I sold it with plenty of single clutched, rev matching downshifts. While I can and occasionally do double clutch just for giggles, I rev matched every downshift ever needed at autocrosses and track days, and 98% of my street downshifts as well. I agree with John V that double clutching is unecessary with a modern synchro box.

CosmosMpower

I frequently drive a S2000 as well as my RX-8 and the S is much easier to rev match downshift as far as the pedal placement goes. I actually have to shift my feet a bit on the brake pedal to get to the gas with the side/ball of my foot but not so much on the S. I still can't do it fast or smooth enough consistently like Altian though.

Winning 8

double clutch is a fast and safe way to change gear, but rev match is a lot faster.
what skip teach is basic tech, but when you are racing that is another story.

alnielsen

iTrader: (4)

I went to Skip Barber class a while ago and trained in a Formula Ford. We had to double clutch because of the straight cut gears and lack of syncros in the Hewland gear box. I have been double clutching the RX8 because I am not racing and time hasn't been important. When I begin TT, that will change.

guy321

I love homestead, very good course for brakes.. I wasn't in a car though. I was going 130ish down the front straight into turn 1 then braking/downshifting 2 gears to go into turn 2/3.. yummm

SouthFL

We had rain in the morning sessions. Made things very interesting along with the 55 degree weather which made for reduced grip once the course dried for the afternoon sessions. I was basically wearing diapers in the morning sessions- first rain event under my belt.
I like Homestead also. Great facilities besides the track itself.

Thanks for the feedback all. Makes the whole shifting style/process much clearer.

guy321

How good do turns 3 and 8 feel in the 8? What kinds of speeds are you doing there?

SouthFL

3 is a compromise for 4. I find it very slow- very late apex setup for the bowl at 4.
I typically don't look at the speedo when lapping yet- just focused on the tach, line, traffic, corner workers and brake zones still, so I haven't a clue as to my mph speeds at turns. Haven't developed that much awareness yet. I'm definately entering 3 at the top of 2nd/ sometimes bottom of 3rd (with a downshift back to 2nd in turn 3's brake zone), depending on how well I do turn 2.
I'm still doing 1 and 10 less than 100mph at part throttle 4th gear.

8 is straightforward. Still a late apex for me.

I can compare the stock 8 versus a Stage II, suspension modded WRX Wagon, and one definately needs to modulate throttle much more in the 8 (obviously due to the RWD vs AWD) than in the WRX. It's a bit tricky, as the 8's throttle is pretty acute, so smooth on/off increments need some practice. Car is definately steerable with the throttle in general. The mental string connecting the pedals to the steering wheel really applies on the 8. I've pretty much dialed out any push with the mild alignment of -1.2f/-1.4r setup, 34psi all around.

guy321

I know that map I crashed in 6. SOunds good though, got any video?

I don't know about in a car, but I was definitely doing turn 1 over 100mph.. it's deceptive, but technically still a "straight"

SouthFL

Lol. Just put it up for reference. Sorry about the incident.

guy321

THis isn't me.. but my Homestead experience was alot liek this! Ahh brings back memories.

http://www.youtube.com/watch?v=eE6rko4GDBA

timaf

used to race Formula Fords with straight cut non syn Hewland trans. All you needed to to was blip the throttle, no need to let the clutch back out. Even with the clutch in, you will speed up the lower gear to match.

ZoomZoomH

iTrader: (1)

so how do you double clutch rev match while braking for a corner? i've only done it on the street where i'm braking slowly or need to downshift for faster acceleration, on the track i only do single rev match/heel-toe downshift

SouthFL

It's the same. For the most part, you do most of your braking in a straight line. By the time you're tuning in and if you have any residual trail braking to dail out, you're already in the gear you want to be in. So, coming down the straight into your threashold brake zone, shifting 4th-3rd-2nd, you're committed to turn-in in 2nd gear (if it's a 2 gear turn). Whether you're double clutching or single clutching, your brake zone doesn't really change in theory, just the amount of steps involved is what changes. While racing, you want to keep it simple and efficient while fending off the guy behind.

SouthFL

How does the input shaft spin with the clutch engaged? I thought that was the hole purpose of blipping while in neutral with the clutch not engaged.

SouthFL

Youtube blocked at work. I'll check out the vid this evening.

timaf

There is still enough friction even with the clutch engaged to turn the input shaft. we've just exhausted my gear box knowledge. all i know is nobody i know double clutches. Just blip the throttle as you change gears. With a tranny w/o syncro's, it takes a little getting used to but it is not difficult. With syncro's, not really neccesary but certainly doesn't hurt.

TeamRX8

iTrader: (25)

guy321

i used to double clutch to rev match, een heel toe.. it ay be slower but it's more smooth