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Shifting Techniqes...

Sig

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In a racing scenario, could you guys share your shifting techniques? For example, do you keep the gas pedal down while shifting, do you let it up all the way for a split second, etc.. I am also curious to hear about clutch release speed on takeoffs.
 

Number9

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Before you can execute some of the more important shift techniques, you'll need to install some add on bits to get the throttle and brake pedals a bit closer together. I can't even reach the throttle when I'm on the brake (stock pedals), so heel-and-toe (misnomer - foot on brake and roll foot towards throttle to blip) is totally out of the question...

Any good recommendations on pedals or pedal covers?

--twc
 
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Number9, I have Momo pedal covers on my NSX. I picked them up while in Italy last summer. $25 US! They work great, although they're a little slippery on wet days. But the pedal size is perfect, and I was able to position the brake and gas pedals in perfect proximity for "heel-toeing". I don't even have to think about it anymore.
Sig, You cannot put the clutch in to shift without lifting off the throttle. Not only will you run the engine to red-line, you want the revs to drop down to the engine speed of the next gear.
 
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Number9, agree that it is almost impossible to "heel & toe" on the NSX pedals, at least for me. Only casually tried it for amusement value though.

But it appears that Sig's questions are more related to upshifts, which the NSX appears to magically handle with a brief breather of the throttle (at least on the 6 speed).

Curious though (looking to learn here), would you really heel & toe on a car like the NSX? Would you double-clutch as well? If so why?

Thanks for any advice,

Ralph
 
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Power shifts (shifting with out or with little release of the clutch pedal) in the NSX with the stock tranny will lead to premature clutch wear (some care, some don't).

I'd suggest taking a look at a 'Best Motoring' video. These are Japanese videos available from Japanese and Chinese book and video stores here in the U.S. These videos profile mostly sports cars driven by experienced race car drivers. Take a look at their shifting technique.

On the NSX, a tip that seems to be repeated often (and displayed in these videos) is that quick release of the clutch pedal is key. Rather than slowly engaging the clutch between shifts, quickly release the pedal, almost dropping it.

IMO, the clutch on the NSX, especially the double disked 1991-1996's is very weak. Consider an upgrade in the future when it is time to replace the clutch. I wish I did not use a stock clutch in my previous NSX when it was time to change. I'm very happy with my new Comptech PowerGrip 2!

-- Chris

------------------
Chris Willson
www.ScienceofSpeed.com
www.NSXClassifieds.com
 
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Double clutching on the NSX is unnecessary, see FAQ. But heel toeing is important for track work as it matches revs during downshifts. IMO I would never speed shift on an NSX
 
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No Double clutcing needed. Chris is right. speed shift in NSX will result in unneccesary clutch wear.

The key in heel toe-ing in NSX is proper shoe wear. The room down there is pretty tight, that I don't think aftermarket pedal cover makes a difference. With proper driving shoes (sparco), I'm able to heel toe and left foot braking. While If I use my regular tennis shoes, it's really a challenge, especially doing left foot braking.

Be cautious for people that going to try left foot braking for the first time. It is totally different feel than right foot braking. Try it with caution in an empty road, no cars around in either your front or your back!!!
 

Lud

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Sig - What are you trying to do? If you are trying to get the last bit of 1/4 mile time of the the car, power shifting (w/o releasing the throttle) will do it. However, it will wear you clutch and isn't particularly easy on the car. But I do know some owners who do it at the drag strip knowing what it does to the clutch so they can be sure they will take home the trophy.

Release the clutch quickly on take-offs. You should never "slip" it unless you simply like replacing your clutch a lot. I see (and smell!) people slip their clutches all the time at NSX events... it really explains why so many people have to replace them every 30k miles. If you are doing several "takeoffs," let the clutch cool down a bit between them.

Re: Heel-and-toe... it is key to smooth "spirited" driving even on the street and certainly at the track.

Re: Double clutching... it is not necessary on a car like the NSX, though some purists still prefer it. If done correctly and quickly it does make everything nice and smooth and saves some wear on the synchros, but it's also just another place to make a mistake and the measurable benefits (other than fun-factor) are not that great on a well-synchro'd car like an NSX.
 
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Well, my point was that unless one is an old-time purist, I can't envision double clutching or even heel & toe'ing on a modern car like the NSX.

At the track, use the breaks. No need to worry about the synchros either.

Just making sure I wasn't missing some higher meaning.

Thanks,

Ralph

P.s.: FWIW, the misnomer "Heel & Toe" goes all the way back to the early british cars that had the break pedal well below and centered on the floor. Truly heel & toe back then!
 
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Just one last word, www.vtec.net is a great source of in-car video for the NSX. Their drivers, even in the 0-60 sprint, use the clutch as opposed to speed shifting.
Requintro, try heel toeing again in the NSX. It's not just for purists, but it really is a necessity for matching revs during a downshift to keep the car balanced in the corners!
 
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ChopsJazz, really don't want to sound like an a*hole here, truly trying to understand so bear with me pushing the point:

* Lets agree that double-clutching is unnecessary on a car like the NSX.

* Lets agree that H&T is intended to alleviate tranny stress while downshifting under severe circumstances (as in before entering a turn).

Since you talk about keeping the car balanced in the corner, I'm not an expert but I certainly make sure my shifting is all done & happy before *entering* a corner.

Given that breaks are cheap and gears expensive, I use the breaks for what they are worth. If you care to advance a notch in tecnique into trail-braking, well that would still be brake play and not tranny work.

Although perhaps I'm spoiled and never had to deal with a track car where ratios are so wide that one could potentially apex a light turn and found oneself in still too low a gear?

Surely I am missing something here...
 

Number9

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When braking into a turn, you can simultaneously downshift and continue braking without upsetting the balance of the car. The point ISN'T to use your engine/clutch as a brake but rather to ensure that you're in the right gear at all times - then you can hammer on the throttle earlier coming out too.

Of course you can always brake, then downshift as you suggested, but that'll be slower. If you're a computer jockey, think multitasking vs. not...

--twc
 
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Thanks Number9, but I must either be or seem real anal here because I still miss the point.

"breaking into a turn"? Sorry, that just doesn't jive.

You are either done breaking, transitioning off the brake or intentionally trail-braking to help you into the turn, depending on the specific turn and your skill.

Unless you are talking about street "racing" and highway ramps, which I guess is a different story...

Again, just so I can get my basics straight: H&T is to match revs into a lower gear - if I'm in a turn that demands a lower gear then chances are my breaking took care of at least the 1 to 2k RPM needed for a sweet spot in the exit gear.

So without having a concern for the synchros, my only guess is that I'd need to H&T only if my gears were greatly spaced, and then only in some turns.

What am I missing?

[This message has been edited by rquintero (edited 25 February 2001).]
 

Number9

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If you're trail braking and then downshift but don't H/T then you'll likely screw up the balance of the car in the turn due to the incremental braking of the engine and the concomitant, incremental forward weight transfer - but not if you H/T and match revs during the downshift. That's the point.

As an exercise for the reader, what happens if you are trail braking at the limit and you have a sudden forward weight transfer?

--twc
 
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Good discussion!!! When entering a corner, let's say in third gear at 95 mph, you'll want to brake for the turn and get into the next lowest gear for better launch in the exit. In many corners this is best accomplished DURING the braking process by tipping your brake foot over and blipping the throttle to match revs for the downshift. In the 95 mph model, you would brake hard, blip the throttle and slip into second at around 70 mph and 6.5K rpm.
Imagine just dumping the car into second at 70 mph with the revs at, say, 3K rpm because you have failed to rev the engine (we've all done that once or twice). The car lurches down in speed and transfers all it's weight onto the front tires, unweighting the rears. Now imagine disrupting the balance of the car in that way in the middle of a 70 mph corner. Spin time!
If you have successfully matched the rpm of the engine to the transmission, then that disruptive weight transfer and subsequent loss of control won't happen, and you're in the correct gear to launch you out of the corner.
Practice downshifting without matching revs and then with it (without braking) and you'll see how much more the car stays in balance.
I have practiced this on empty roads at slow speeds for some time, and I'm still working on perfecting my technique, both on the street and the track.
Hope I was of some help. A good source is "Going Faster!" by Skip Barber (it's my personal track bible. I bring it to every event to remind me of the important stuff!)
 
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I'm enjoying this thread as well. As an old moto-crosser the difference between a pro and amature is the ability to control a bike using the front and rear brakes independently and the throttle.

As I'm probably the only sportshifter here I've been dealing with this issue without the use of a clutch. So far I've found on a downshift the autotrans let's me blip the throttle a split second after I hit the shifter to match the revs. Before trying this I had some scary moments in some turns with the rear end wanting to brake lose. Ultimately it's made me really concentrate on using my brakes. My advantage is I don't have to h-t as it's more like a go-kart just press the brakes and gas.

------------------
Hal Jones
Lake Oswego, Oregon
95T Blk\Blk SportShift
 
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I'm no track racer... here's my technique that is the most fun for me.

In a high speed, tight or semi-tight sweeper, I'm on the brakes to drop the revs 1-1.5K, then clutch, blip, and release quickly for the next lower gear. I enter the turn, then bring the power up at the mid-way part of the turn. Revs are generally hitting 5.5-6K as the road straightens. Then, I let the beast snarl. There is enough time as the revs rapidly advance to allow me to make a quick check in my mirrors as I merge into the appropriate lane.

I find that I can feel the vehicle better when I'm under power in a turn as opposed to trailing braking. The only time I've spun a a car in a turn was when I was lightly riding the brake on a wet surface. I should have know better... but, then, how to do learn... the hard way?
 
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Hmm - I suppose most of us know the perils of abrupt tranny breaking entering a corner.

But then again I thought the job was to setup the car for the turn *before* entering the turn, and the transition from break to power would occur somewhere between the entry and apex. If I found myself downshifting inside a turn I'd think I'd be doing something terribly wrong.

Although I can also see how practiced bleeping before clutch release inside the turn would contribute to a smoother transition into power.

Thanks,

Ralph

P.s.: been wanting to get that Skip Barber video for a while now...
 
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You're right rquintero, the entry to the corner is where the braking and downshifting takes place, allowing you trail brake through the corner if needed. Hopefully the blipping/heel-toe maneuver was accomplished in a straight line. But turn-in is happening in the next 1/2 second (or less), and this is the perilous part of the turn where balance and weight transfer is paramount. Especially if you are already on the knife-edge of control.
When you get a couple of these right it's really satisfying!
 
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