bigcityvette

what is preferred or better for auto crossing? I will assume a stick shift vs an automatic because of the clutch and gear options (vette 6 speeds vs 4 for the auto)

thanks!

xsiveone

Stick! You can choose what gear instead of have the transmission choose for you. Plus, automatic transmissions zap power. It probably wouldn't be a problem on an autox course, but the auto trans will overheat more easily on a road course. I've seen quite a few newbies go out to a road course like Road America or Gingerman with an automatic trans and end up wrecking the trans.

X

VetteDrmr

I'd say stick, as well, but for a different reason. You have much less control over when the auto will shift. I'm sure there are mod kits out there for autos, but I'm assuming you're talking about a stock tranny.

HTH, and have a good one,
Mike

xsiveone

That's what I said, wasn't it?

X

Solofast

Stick for sure.....

Just spent the last couple of years in an automatic.... It's good to be home in Z....

The problem is that the spacing of the gears in any automatics is really wide. But, if the class rules are such that you can get it geared right an auto can be pretty fast. If the class rules let you run any rear gear you can run a really short final drive ratio and that gives you a short first and spend most of your time up in the rev's in second. The problem is with street prepared as defined by the Slow Car Club of America, you have to stick with final drive ratios that came in the car. For that reason you are out of luck, you will be slogging in second for much of the course and won't have any punch coming off of corners.... That is true for Stock and SP classes. Now if you want to go and get into S/M ( no not that kind of S&M (get your mind out of the gutter) I meant Street Modified) you can put in any rear gear and an auto may be able hold it's own. Problem is, in S/M you can do anything with the motor and you can make tons of power, and then just put in a six speed and drive around in second all day....

One of the things about an automatic is that there is slop in the driveline. I like to be able to help point the car in offsets and slaloms with just a bit of a lift, and it is harder to do that with a automatic until the car is winding up pretty tight. There just isn't enough engine braking when you aren't up in the rev range....

Some folks can do it, but I like the stick...

xsiveone

It would be much better if the Corvette had a 6 or 7 speed manumatic transmission, but since it has a old school 4 speed auto with overdrive, it's really not a very good transmission for doing anything with corners.

X

Solofast

That could cure it for sure, but they would have to put the rear end ratio and gear spacing pretty close to match the six speed. That is kinda unlikely since that would make the automatic seem like it was hunting a lot in everyday driving. Remember that most of the folks buying automatics aren't racing them....

Bill Dearborn

I have met many very competitive drivers who prefer an automatic. They use left foot braking and keep their foot on the throttle to keep the engine on the power curve. Watching them launch off a corner is amazing. I know one guy who runs a modified 66 with a loose converter, two speed power glide and 4:56 gears. With fresh tires his times around a course are close to or better than a large number of the SCCA single seat Mod cars. I have been to many events where he was FTD over these cars.
Bill

xsiveone

That's why people love the new Sequential Manual Transmissions. Best of both worlds.

You'll also have to remember that autox isn't like running road courses. Autox is much lower speeds. There's no way that you could run a two speed power glide at a road course.

X

Allthrottleandsomebottle

Guess you have never heard of Circlemaster transmissions..........

xsiveone

That's for a circle track, isn't it?

X

Allthrottleandsomebottle

Or other as you want built...........I like a challenge, with the right gearing for the right course

Skant

For drag racing, automatics are generally preferred.

For road racing and autocross, manuals are strongly preferred.

You can always find exceptions. But the vast majority will appreciate a manual tranny over the automatic for racing with twisties.

- Skant

USAsOnlyWay

I don't know how to explain this exactly, but the other advantage to a Manual in auto-x. Is you can, especially with a torquey V8 of a Vette, throw it in second and for most courses be done with it. This constitutes 1 gear change for the whole course.

Now of course an auto can get held in 1st. No gear changes, assuming you have the rpm capability for that course, but so can the manual as well. (Though I believe manuals are geared a little bit more for acceleration than auto's so you won't be able to go as deep with a 1st in a manual commonly than with a 1st in an auto)

But here is the final point, say you want to do without shifting as mentioned before, and you manually keep your auto in 1st gear. (Here's where I can't explain why right now, I can't remember it enough but I am sure someone else here can) With your manual in 2nd gear you are applying the torque with a much lesser multiplication factor (gears) so that it is much easier to control the car especially on exit of turns.
Ok so someone explained that to me once and I can't explain it now, but there ya go. More reasons for a manual.
(Somebody clean up this mess I made...)

Skant

I think what USAsOnlyWay is trying to say is that with a manual tranny, you can select a higher gear in order to limit the amount of torque you're putting down and help provide a smooth application of power so you don't jerk the tires free. Whereas an automatic will always downshift if it can when you go to full throttle.

This isn't just something you do to make the car easier to drive. If you're negotiating a turn where the higher gear already gives you as much torque as you need, then you're eliminating the need to upshift later on. And eliminating unnecessary shifts is beneficial to your lap times.

Whether manual or automatic, shifting will always upset the car to some degree. And on an autocross, you're usually turning almost the entire time. So you often have to deal with shifting while turning. You can't upset the car while it's at full cornering force (unless you like spinning), so you have to back off a little bit for the shift. Naturally, this hurts your time.

This is why lots of folks just stay in 2nd gear the entire time. You never have to shift, and the torque coming out of turns is tamed, so it promotes an ultra smooth style.

Personally, I shift between 1st and 2nd throughout the track and use fine control of my throttle foot. But there are places where I'll get it up into 2nd early so I don't have to shift at an awkward spot.

- Skant

USAsOnlyWay

Thank you Skank!

USAsOnlyWay

Thank you Skant!

vms4evr

OK I'll throw in my lot on this one. This is just from autocross perspective. I've autocrossed a 92 coupe with A/4 for the last 2 years.

I love left foot braking. With the 92/A4 I could keep both feet on the pedals and just modulate. Depending on the start of the course would determine when I got out of 1st into 2nd. I would manually shift it. Since the 700R4 has a big jump from 1st to 2nd you never upshift in any kind of turn. It's worse than the 6sp. With the 3.07 rear axle you'll be low in the power band on tight courses in 2nd. You might be able to hold 1st longer but it'll be wound pretty tight. On more open courses it works fine. You can drag the brake pedal a little and trail brake easily too. The other place it gets tough is a turn around. You come in hot in 2nd gear. Brake like mad and then downshift manually to 1st. That same big spacing on 1st-2nd hits you on the downshift. Better have the car pointing in a straight line before you do it. I actually learned to rev match the 2nd-1st shift while left foot braking. Sometimes the torque converter can be your friend...

The biggest advantage to the manual isn't the clutch or the macho thing about having a manual. I took a lot of crap when people found out my car was an auto. I have my fair share of wins in that car with base FE1 suspension (mostly).

The biggest advantage is simply the gear range. On a C4. 4 speeds and rear axle for A4 is 2.59 and 3.07. Manual has 6 speeds and rear axle is 3.45. Much better gear combinations. The clutch is the next peice. You choose the release of the clutch vs the torque converter chooses the engagement time. It might not coincide with exactly when you want it to happen. Surprise!

Long term a 6sp with D44 axle will take much more beating than an A4 with D36 axle. So longevity goes to the manual package.

This year I've swapped over to an 02 Z06 so now I get to try my hand with a manual. I just finished my 1st autox with it. I like the gear range for sure. But I can't get at the brake pedal with my left foot. I'm gonna miss that a lot. In fact I did on my 1st run. Came in hot and heavy into a tough turn. Tried to left foot brake, car wouldn't slow down, realized that was the clutch, there goes a wall of cones This is what happens when you haven't driven a manual in 10 years! Now I have to learn all over again...

Graham

mvitacco

Gram makes some good points. G.H.Sharp wone FSP in an
automatic LE1 Z28 Camaro (automatic) though it must be said that
package was available with a 3:73 rear. IMHO you certainly can autocross an automatic where you would not want to road race or do HPDE type events with one in theory.

Since autocross is just a short increment before track events (where
you'll probably eventually end up eventually) why not start out with
the 6sp and keep the same car for both?

No one metioned the most obvious reason: The ZF 6speed or Tremec
is just a plain blast to drive anytime anywhere! The sounds comming of of the ZF is worth the price of admission alone. If anyone can
remember the M22 Muncie they will know what I mean.

Allthrottleandsomebottle

Had one.....in a 64' El Camino