Does using a clutch pedal make you quicker?

[MatskiMonk]

Put the adjustable transmission in it and the problems are gone (applies for ever manual N-car)

Yeah I could do that, but I prefer to keep things stock, I prefer adapting to the car - rather than adapting the car to me.

As I never actually race anyone, it's not like I'm worried about loosing the time, I'd just prefer to have the option to control it myself rather than wait for the PS4 to complete the slowest shift since the earth's magnetic poles last inverted.

 

[mk1xr2]

@cleanLX much better then watching a boxers foot work, not to keen on the accelerator pedal on the 1st video tho looks uncomfortable

 

[Nuschel01]

you can list all the top sports car drivers of all time... but no one heel-toe'd and left footed like the old school group B gents.

He could even clutch without having his foot on the clutch

 

[cleanLX]

@Nuschel01 wow, never saw that before...

@mk1xr2 pretty common to have the toe brace... throttle return springs are prone to wear/breakage/binding, so, they have the toe brace in order to "lift out" of the throttle... just in case... it gets hung wide open... :ZOINKS:

 

[Nuschel01]

One of my most favourite videos

 

[Vegard]

1. rev matching to aide against synchro wear... ehn...
2. ensure the rev match cancels out/negates any unwanted engine braking... which has a tendency to make the car unstable... to the point of swapping ends

You rev match to save the clutch, to avoid compression lock and to avoid sudden weight transfer.

had a completely different reason to use heel-toe, and other magic. The turbo lag. You were slow if you let the revs go down and lost turbo pressure. They needed engine revs even while decelerating, to maintain revs, thus pressure for the exit and the proper acceleration.

I very much doubt those group B cars produced meaningful boost just from a stab of throttle without any load on the engine.

 

[fastone371]

yep rev's, and like you noted pressure, aka load... which is why you see them on the gas while braking... crazy stuff with those cars back in the day.
With the turbo motor you can have rev's without load, for instance off throttle... and, todays drag race cars on the starting line will have rev's, but need load as well... there is a term for it which escapes me, but watch a turbo car "bump in' to the staging beams and they are under great load (whole car lurches/jumps) to keep that pressure up.


Funny... I still think the RX8's are "new"... .

Turbo drag cars stage with the ignition timing massively retarded and air fuel excessively rich, they found out when it backfires the excess fuel in header tubes is igniting causing the turbos to spool up, it wont really build enough boost with just the load by itself, just not enough RPMs, thats why they all sputter. When they "bump in" the violent cars bump with the trans brake, another option is to run 4 rear calipers, you can build enough brake force to stage with the brake pedal this way instead of the car rocking with the trans brake.

 

[cleanLX]

You rev match to save the clutch, to avoid compression lock and to avoid sudden weight transfer.

Save the clutch? That is the first I've heard of that.
Aide longevity of synchros in a synchro'd trans, sure, to avoid the required time consuming double clutch on a face plated trans, sure... definitely to avoid for the engine braking (never heard it termed compression lock, are we talking about the same thing? The term "lock" makes me wonder, because nothing gets locked... neither the engine of the driven wheels, certainly a speed differential between tire and road, but, not locked... ???) which results in weight transfer/tire/road speed differential and resulting snap spin... agree'd, but I've never heard anyone say it is to save the clutch. I find it especially curious when the heel toe in a typical setup still utilizes the clutch... interesting.
Not picking a fight, would like to learn more.
kinda reminds me of people who believe you down shift to save the brakes... I guess in a race with mega $$ on the line that would factor in but for sportsman type racing brakes are wayyy cheaper than an expired engine... at least that is what they tell you in driving school... brakes are for stopping, rev matching is required for stability (explanations of such noted above) when selecting a lower gear ensuring the correct gear/revs has been selected for corner exit...

So, maybe save the clutch factors in like the brakes... in championship racing... it is so? For us normal folks a $150-$800 clutch makes more sense to replace/damage than a $2000-$4000 trans...

Curious.

 

[MatskiMonk]

Save the clutch? That is the first I've heard of that.
Aide longevity of synchros in a synchro'd trans, sure, to avoid the required time consuming double clutch on a face plated trans, sure... definitely to avoid for the engine braking (never heard it termed compression lock, are we talking about the same thing? The term "lock" makes me wonder, because nothing gets locked... neither the engine of the driven wheels, certainly a speed differential between tire and road, but, not locked... ???) which results in weight transfer/tire/road speed differential and resulting snap spin... agree'd, but I've never heard anyone say it is to save the clutch. I find it especially curious when the heel toe in a typical setup still utilizes the clutch... interesting.
.

In terms of the clutch, I'd imagine the saving comes in from reducing the slip in the plates required if the revs aren't matched. As for Compression lock, I don't think "compression dramatic-under-rotation-of-the-driven-wheels" is quite as catchy.

 

[Stotty]

(never heard it termed compression lock, are we talking about the same thing? The term "lock" makes me wonder, because nothing gets locked... neither the engine of the driven wheels, certainly a speed differential between tire and road, but, not locked... ???) which results in weight transfer/tire/road speed differential and resulting snap spin...

When I was younger, and hadn't learnt any mechanical sympathy, I would regularly shift down to 2nd at 50-60mph, dump the clutch, and 'under rotate' (in F1 speak) the back wheels... worked like pulling the handbrake on, and was a great way to initiate a drift.

 

[cleanLX]

When I was younger, and hadn't learnt any mechanical sympathy, I would regularly shift down to 2nd at 50-60mph and 'under rotate' (in F1 speak) the back wheels... worked like pulling the handbrake on, and was a great way to initiate a drift.

Well, unfortunately, I still do this from time to time when acting like a jackolantern... :shame:

 

[Vegard]

Save the clutch?

If you don't rev match on a downshift the engine is brought up to the right speed by the drivetrain, through the clutch.
This guy explains it pretty well:

never heard it termed compression lock

It's mostly a problem in RWD cars with high compression ratios, on dry tarmac at least. Under heavy braking there's very little weight on the rear tires. If you downshift and dump the clutch without rev matching there's a good chance you momentarily lock up the rear wheels. On loose surfaces or on snow and ice I never downshift without rev matching for fear of locking the driven wheels, even in my FF daily driver.

When I was younger, and hadn't learnt any mechanical sympathy, I would regularly shift down to 2nd at 50-60mph, dump the clutch, and 'under rotate' (in F1 speak) the back wheels... worked like pulling the handbrake on, and was a great way to initiate a drift.

I actually picked up the expression watching Tsuchiya's drift bible.

Edit: he calls the technique Shift Lock but it's the same principle.

 

[Stotty]

Well, unfortunately, I still do this from time to time when acting like a jackolantern... :shame:

I learnt my lesson by destroying a differential... though that was probably mostly down to flat shifting 1-2

Now I T&H religiously.

 

[cleanLX]

with sincerity...
I know what it is, why/how it's done, and am "ok" at it in real life, but, i never heard anyone say it "saves the clutch", especially when the whole point of heel-toe is to fee up the left foot to operate the clutch.
Not questioning the attributes of the action, just the "saves the clutch" portion.

Wait a minute... you were not talking about heel-toe, you were singling out rev matched shiftes w/o the clutch...

Ok.
I've got it now, sorry for the sidetrack... grrr... I was still thinking heel-toe, you had moved on.
We are in complete agreement now.

 

[cleanLX]

I learnt my lesson by destroying a differential... though that was probably mostly down to flat shifting 1-2
Now I T&H religiously.

LOL!
My mustang is built to do just that... flat shift 1-2, 2-3 and 3-4 (absolutely not 4-5 tho... that would be shrapnel-ville).
Showing a friend how it's done in my Wrangler with 35" tires on it...resulted in a trip to the ring and pinion store...
Been there... me too. pocket book... ouch.

 

[Stotty]

Showing a friend how it's done in my Wrangler with 35" tires on it...resulted in a trip to the ring and pinion store...

 

[mk1xr2]

36.2 paddles
36.0 h shift
M3 bb raceway
Wish I got the shifter out sooner now

 

[VeeDoubleU]

36.2 paddles
36.0 h shift
M3 bb raceway
Wish I got the shifter out sooner now

You don't have to change gears at all for M3 at BB Raceway though

 

[mk1xr2]

You don't have to change gears at all for M3 at BB Raceway though

I used 3rd on the 1st corner I run wide if I do it in 4th

 

[VeeDoubleU]

I used 3rd on the 1st corner I run wide if I do it in 4th

Then you aren't slowing down enough

Going into 3rd means you lose time when you upshift into 4th, no matter manual, auto, clutch, no clutch etc, and that momentum matters.

 

[mk1xr2]

That's true I just tested on bb because it' a short track and was braking at the same point for clutch and without. You definitely get a better pull with the h shift from 3rd to 4th which is what I was trying to find out

 

[TamasToth]

I very much doubt those group B cars produced meaningful boost just from a stab of throttle without any load on the engine

Obviously not. I'm not native english and wanted to keep it simple. Sorry if it was confusing. Boost needed, exhaust flow needed, whatever it takes.

 

[Vegard]

Obviously not. I'm not native english and wanted to keep it simple. Sorry if it was confusing. Boost needed, exhaust flow needed, whatever it takes.

I guess group B cars didn't run dump valves so it would make sense if it was done to prevent compressor stall. Is that what you meant?

 

[Lord Protector]

I guess that'll happen soon

I try to maintain it really well though.
2003 is not old

I suppose I should have written cheap instead of old, because it was one of the cheapest cars I was willing to go with for a "race car".

Put the adjustable transmission in it and the problems are gone (applies for ever manual N-car)

I for one cannot stand the whine in an N car

 

[TamasToth]

I guess group B cars didn't run dump valves so it would make sense if it was done to prevent compressor stall. Is that what you meant?

UrQuattros (if we started this offtopic from W. Röhrl) didn't use BOV - as far as I know. However they needed to give throttle to maintain proper boost, to be able to accelerate immediately with proper turbo pressure. But I'm neither a racer from that age, nor had an urquattro. And I'm not an engine expert at all. All I know - as been told and read - is that early turbo engines needed this driving style to play out the bad characteristic of the engine, to avoid lag, to avoid the unwanted effects when the pressure is built up and the turbo kicks in.
My Mazda 323 GT-R is a different type (and streetlegal) but also old enough to have quite a turbo lag. Also, a little later, the Mitsubishi Evos and Imprezas got ALS, either with extra switch (in gr. A) or without a switch, just by ECU program (gr. N) which basically let some extra fuel detonate even when throttle is lifted, to keep the turbo spinning.

 

[Vegard]

My Mazda 323 GT-R is a different type (and streetlegal) but also old enough to have quite a turbo lag

That’s because it runs a homologation turbo with very restrictive intake and exhaust. Just those two things, if replaced by high flow substitutes, can give you 30 hp and much faster spool. But now we’re definitely way off topic.

 

[TamasToth]

That’s because it runs a homologation turbo with very restrictive intake and exhaust. Just those two things, if replaced by high flow substitutes, can give you 30 hp and much faster spool. But now we’re definitely way off topic.

Substituted But you're right, lets get back to topic. So far we've learned that not-sequential, non-racing cars do profit from using clutch in GTS.

 

[fastone371]

36.2 paddles
36.0 h shift
M3 bb raceway
Wish I got the shifter out sooner now

I cant believe it made that much difference on an oval with a single shift.

 

[VeeDoubleU]

I cant believe it made that much difference on an oval with a single shift.

Actually, an oval is the place you'll probably find the biggest advantage with clutch usage, due to the momentum needed. Not using a clutch on a fast oval will mean you lose speed until the next braking zone, which for BB Raceway is 25 seconds away really. Fortunately, BB Raceway + Northern Isle rarely require shifting, or at most, 1 gear

 

[Blacki2k2]

Wut? He shifts from 4th to 3rd and the camera tries to capture the deceleration by going backwards and then forward he also lifts off the brake to hit the corner

Seems legit asian style...

I tried today the clutch pedal while upshifting with the paddels... from third to fourth... landed in N. I was not really fast that way...