Question between 1/4 mile/autocross/road racing

[The Blue Pilot]

My question has to deal purely with acceleration.

1/4 mile races are all about acceleration. When you start off a road course, assuming the road is straight for at least 1/4 of a mile, acceleration should be about the same, correct? Same with an autocross course, except imagine that acceleration to be between 1-2 maybe 3rd gear only.

With that in mind...what's the best way, non-dependent on the type of race it is, to accelerate with the 2005 wrx' stock gearbox, assuming near stock HP?

Double clutch up? Power shift into gears? Which is it?

Any videos would be informative and appreciated. Thanks..

(I find when I shift too fast up gears my car bogs.)

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[Draken]

You almost had me? You never had me - you never had your car... Granny shiftin' not double clutchin' like you should. You're lucky that hundred shot of NOS didn't blow the welds on the intake! You almost had me?

[vinceGC8]

^^ i was thinking the samething when i read it.

[The Blue Pilot]

Is there a better way of asking? Cause I checked and I'm sure this isn't OT.

[Howl]

Just leave it in D.









Seriously, the answer is whatever works best for you and your setup. One drivers in one car may go faster using one method and another driver in another car may go faster using another method. If you're asking what the method the "pro's" use I'm sure you'll get some answers, but their method may not help or even be applicable to your situation.

[REX8]

Why in gods name would you double clutch an upshift?

[mla163]

Apparently nobody can say "double clutch" without a F&F reference coming up.

[KC]

With that in mind...what's the best way, non-dependent on the type of race it is, to accelerate with the 2005 wrx' stock gearbox, assuming near stock HP?

Double clutch up? Power shift into gears? Which is it?

If you think shifting is the same across all three disciplines, you have a bit of more learning to be done.

The answer is rather simple tho... in practical application, if you can afford to replace parts, powershift. If you can't, take your time (but shift quickly). Every fast (non-powershift) 1-2 upshift is a 2/10th to 3/10th second loss (datalogged) and proven fact on most cars. After that, it comes down to gearing, course, speed being carried, etc...

Your car bogs because the gearing has the shift points below boost... which is why modified cars have something like their gearing modified to always be 'in boost' after the shift or an anti-lag so the turbo doens't spool down and is always spinning.

There's your free pass. "What's best" questions are always met with sarcasm and off-color posts because they're stupid and show a total lack of effort on the behalf of the poster to have actually researched before actually asking the question.

"What's best? Blue or VCR? They're two totally different things, but becuase there's blue DVD players or VCR's that may not be blue, they're related, so there has to be an answer!"



--kC

[REX8]

Originally Posted by mla163

Apparently nobody can say "double clutch" without a F&F reference coming up.

Only when in reference to an upshift

[bluescoobywagon]

Road racing is more about smooth shifts then fast shifts. You may want fast shifts on the straights, but you always want smooth shifts in corners. Also, rarely will you have a standing start road race as an amatuer. Drag racing requires the best launch and fastest shifts you can manage without borking your transmission. Autocross is sort of a combo as you usually need a good launch, but depending on course design, you may want fast shifts or smooth shifts. Doubleclutching (downshifts) is pretty common in autocross and road course racing.

As for a good AWD launch technique for noobs, the most recommended method is to hold the car at 5000 rpm then smoothly but quickly let the clutch out as you smoothly floor the accellerator. Done properly, you might get a little wheelspin, but the car doesn't bog and the clutch doesn't stink up the car. A little smell is normal, but a lot means you let the clutch out too slowly. If the car jerks or makes loud banging noises, you weren't smooth enough. Done properly your passengers will emit cuss words and think about buying a Subaru...

[leecea]

Originally Posted by bluescoobywagon

Doubleclutching (downshifts) is pretty common in autocross and road course racing.

Why? It seems to offer no benefit with most gearboxes.

[Fish]

Do what I read on a Nissan forum..
clutch before shift.. rev the piss out of the motor... shift.. and then drop the clutch with the motor still rev'd the piss out of.. it.

the poster was sure of his logic at least.

[generalee69]

Originally Posted by bluescoobywagon

Road racing is more about smooth shifts then fast shifts. You may want fast shifts on the straights, but you always want smooth shifts in corners. Also, rarely will you have a standing start road race as an amatuer. Drag racing requires the best launch and fastest shifts you can manage without borking your transmission. Autocross is sort of a combo as you usually need a good launch, but depending on course design, you may want fast shifts or smooth shifts. Doubleclutching (downshifts) is pretty common in autocross and road course racing.

I agree with almost everything you say, except as bolded above. Smooth is the word.

The key to downshifting on a road course is rev matching. You don't want to compression brake a lot. A little is ok, a lot will make things go boom.

Whether it is common or not... I dunno.. but I don't do it.

[mug23]

Most of the time the only reason why you want to double clutch is to safe the transmission. If your syncros are gone or about to go, double clutching will help you get through the race then you can do the repair after the race. Otherwise, most of the time, you use heel and toe downshifting.

[The Blue Pilot]

Thanks for replies..


I was only asking this because, as mentioned in the first post, I bog the car alot, whether I'm downshifting or up, and I'm trying to figure out what's going on. I'm trying to maximize my performance but minimize the damage that could be done, both to the clutch (not as much), the engine, and most importantly the transmission.

[The Blue Pilot]

Originally Posted by mug23

Most of the time the only reason why you want to double clutch is to safe the transmission. If your syncros are gone or about to go, double clutching will help you get through the race then you can do the repair after the race. Otherwise, most of the time, you use heel and toe downshifting.

Either I Have big feet..or heel and toe is RIDICUlously hard for me to do. I can and have done it, and my brain understands how it works...but I guess with the pedals being the way they are it's really hard for me..

[pieces]

Originally Posted by The Blue Pilot

Either I Have big feet..or heel and toe is RIDICUlously hard for me to do. I can and have done it, and my brain understands how it works...but I guess with the pedals being the way they are it's really hard for me..

Keep practicing. It isn't easy (or at least it wasn't for me). You'll feel like you have clown shoes on for awhile.

[generalee69]

Originally Posted by The Blue Pilot

Either I Have big feet..or heel and toe is RIDICUlously hard for me to do. I can and have done it, and my brain understands how it works...but I guess with the pedals being the way they are it's really hard for me..

There are different methods of heel/toe. Road racing I use the ball of my foot on the brake pedal and the rotate my foot around the edge of the pedal to touch the gas pedal.

There is a real danger of slipping off the brake pedal when doing it this way, so I probably wouldn't recommend it. My legs are too long to keep my foot fully engaged in the brake and rotate my heel over to the throttle.

Autocrossing -- With my long geared Mustang was easy, becuase I didn't have to shift (just left it in first gear and go)... so I learned to left foot brake. With the STI... Does it matter I'm a ****ty autocrosser

You're not trying to heel/toe during the 1/4 mile are? j/k

[bluescoobywagon]

Originally Posted by leecea

Why? It seems to offer no benefit with most gearboxes.

I guess it isn't all that common in road racing, but it tends to be the only way to get a Subaru 5MT (not like most gearboxes) to drop into 1st smoothly at an autocross.

[The Blue Pilot]

Originally Posted by bluescoobywagon

I guess it isn't all that common in road racing, but it tends to be the only way to get a Subaru 5MT (not like most gearboxes) to drop into 1st smoothly at an autocross.

Exactly...

I'm having troubles with the gearbox, and it's been almost 5 years I've owned the car...

I guess I just have to do a lil more searching and a whole lot more practicing.

[generalee69]

... go faster so you don't have to downshift to 1st....

[bluescoobywagon]

I got a 6MT instead, and don't have to downshift out of 2nd when the 5MT guys do anymore...

[schnellgti]

Originally Posted by bluescoobywagon

I guess it isn't all that common in road racing, but it tends to be the only way to get a Subaru 5MT (not like most gearboxes) to drop into 1st smoothly at an autocross.

Right there is your problem. Solution: Buy a cheap car < $1000, then you don't have to worry about the tranny

Dropping it into first while keeping the right foot mashed seems to work quite well durring rallyx's (well the clutch disagrees of course ). Also you cant hear the horrible noises over the rocks hitting the skidplate

[leecea]

I've always heard there is no benefit to changing down into 1st at an autox.

[fliz]

Originally Posted by leecea

I've always heard there is no benefit to changing down into 1st at an autox.

If you can widen the corner there isn't. Of course, it takes some practice to come up with a second gear line on a single cone turnaround. I could never do it, but I watched FTD do it on multiple occasions.