Autocross V Drag

[Southpaw]

In Autocross and using a Standard Bug wheel base , Does or would a shorten wheel base like on a Tub Buggy give the driver an advantage ? And could you take that same Tub and put it on the strip ? Same motor & tranny or is there two different animals ? I was think a custom frame slammed to the ground less body roll and cage with a light Tub body .

[dansam]

Well actually suspension setup is very different for auto x vrs drag. But the same susp can be tuned for both depending on usage for the day. For drag, a softer rear suspension is preferable. FOr auto x the stiffer the better. Ive also found that with the bug during auto x a wider tire in the front can have diminishing returns. much over 215 width causes massive understeer/hop. I recommend almost stock sized tires for auto x. bigger the rear for drag the better. Camber compensator is a big help on auto x if it is a swing axle machine. On drag you want to strip anything off you can.

I like auto x more than drag but Ive done both. nothin like auto x.

[vw1s]

The short wheelbase will give you an advantage in autocross, but, may make the drag car a little squirrly. Guys drag tubs all the time though, so, I can't believe it would be too bad until you got up into the higher speeds.
Optimum setup for drag, transfer as much weight as possible to the rear tires on launch, then let it settle down slowly as speed increases, the reason for 90/10 type shocks on the front.
Autocross on the other hand, you want to remain as balanced as possible, keeping equal weight on all four tires.
Can you tune the suspension to work for either? In short, yes, but, you are not going to achieve the numbers you would with a "purpose built" machine.
In addition, (some will disagree with this) in drag racing, I would run a stock weight flywheel and launch at a higher RPM. The heavy flywheel will keep the car from bogging and help hold the RPM's off the line.
In autocross, I would run the lightest flywheel I could find, (like the 6 lb Scheiffer in Blu) this will allow you to pick up, and drop RPM's quickly, very helpful with engine braking for corners.
I would also run the shortest tires possible on the smallest diameter wheels I could find, depending on what you are running for brakes. My 14" Spectres almost hit the calipers on all four corners, a 13" wheel would not fit. I would then calculate my stock "contact patch" and find an appropriate width tire to match the stock "contact patch", (possibly even smaller if you have lightened the car, as you reduce the PSI on the contact patch). This achieves two things, lowers the gearing, and acts similar to a lightened flywheel. A smaller diameter circle is easier to get spinning than a larger circle.
I would lighten the car as much as possible for either, less weight=more HP!
Every 10 pounds off = 1 HP

[dubfreak1]

A tub buggy would be great for autox. I don't know enough about set-up for drag racing to know if a buggy set-up for autocross would be compromised on the strip. It would seem to me that you'd have to get to upper horsepower levels before it would become much of a factor. The most important thing in autox is the driver, but tires rate a close second. Tires probably would have to be different to get the maximum potential on either type of course. If you're going to build a custom frame anyways, would it still be rear engined?

[Southpaw]

Well that's cool . I'm not looking to go PRO but if I could build one and play on more than one track that a plus . Thanks .

[81pumagtc]

Glenn:

Personally, I think a short tub buggy would be a real handful autox. I suspect that you could get a reasonably good time fairly quickly, but without exceptional smoothness and it would be difficult to lower your times. If you went with a custom frame, you could do a lot of very cool stuff, fast buggy rack and pinion, A-arms, much lighter, and even mid-engine, which brings it's own unique driving style.

The short wheelbase does make the car rotate very quickly, and 14 inch wheels and tires will make the car turn in even faster, much like a motorcycle with but a moderately high-horsepower motor acceleration and deceleration does wicked things with weight transfer. Combine it with a rear-engine and slow steering, and it would be fun, but I think quick, rather than fast.

I also think it would be all wrong for drag racing, but that would be my opinion, with nothing to back it up.

Last time I was at a drag strip was a photo-op at Stanton on my Klein mountain bike. (Great picture, but perhaps the slowest E.T. in recorded history...I would have been beat by a diesel Westy in the 1/4 mile. Sad...)


Dave

[bren]

Check these out:

www.thesamba.com/vw/classifieds/detail.php?id=802351

www.thesamba.com/vw/classifieds/detail.php?id=823859

[ghiastein]

That is too cool
I bet it's a blast to drive
100+ hp on a go-cart

[Ruffuss]

Yeah!! I'd probaly get spun-out and hit head-on. That would really hurt! How about the club building one of these? Looks like a basic design. and I agree would be a HOOT!! to drive.

[81pumagtc]

Oh my!

THAT makes me HOT! I'll bet it's a hoot to drive, and with the basic chassis, not too bad to build. Kind of a cross between a Formula V and a rail.

Dave Riedle

[vw1s]

I have the tubing bender that I got from Dan, pretty basic, but it works, unless someone has a better one...
I may be able to free up some time to do some welding, if I can't, I'd bet another club member could do it.
It would definitely be a fun ride, and a fun project!

How 'bout this one?
www.thesamba.com/vw/classifieds/detail.php?id=825950
A little more purpose built, but...

[dubfreak1]

I think you guys should check out our Classified section ;D ;D ;D

[Ruffuss]

OK!! Dustin, free up some club cash and give it to Rudy! So we can get started. Later Kenn

[Dustin]

Haha if only we had that much club money.