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Going very fast in a straight, salty line.
modulus - February 8th, 2004 at 12:00 AM

Since about 1991, the "Dry Lakes Racers Australia" has been running land speed trials at Lake Gairdner. The web site is below, and class rules are available there.
http://www.dlra.org.au/ 
Last year a stock-bodied FJ Holden with a grey motor managed 107 mph.

Out of idle curiosity, I'm interested in trying to work out what sort of VW might make a good candidate within the rules/class structure thet they run, and what aspects would be important in the engine design etc.

For example, a chopped-top, cleaned-up fibreglass Karmann Ghia might look the go, but would a stock-bodied early beetle be more competitive in the right class, bearing in mind that within its capacity class, it will be up against the most recent high-tech multi-valve, variable timing Japanese designs?

Some questions come to mind:
- does anyone have accurate drag coefficient factors for the various Beetles and the two KGs?
- what sort of maximum RPM can a Type I motor be spun at? What sort of bottom end modifications are needed to sustain this?
- what power can be pulled out of a Type I motor with single-port heads? Ditto with twin port?
- what sort of tall final drive ratios are available consistent with the power and RPM guesses?
- is the air-cooled design too over-the-hill to ever be competitive, or would it be better to roll out a New Beetle?
- what is a good class and capacity to compete in?

Over to you good folk,


Oasis - February 8th, 2004 at 12:11 AM

I was talking to Stan pobjoy yesterday about a car that he made to compete in a land speed record (on salt). It never happened and ended up being raced in the conventional sense. As for your questions, NFI... but it was an interesting conversation none the less. I'd ask him though.


56astro - February 8th, 2004 at 10:10 AM

Stan's open-wheeler spins to 8000-9000 rpm, his motors in hill climb cars do 7000-8000 consistently.

If Craig reads this I'm sure he'll comment.


Cam - February 8th, 2004 at 05:21 PM

The biggest problem with the beetle is the flat windscreen and big airdam underneath the car at the rear (above the gearbox).
I think going over 107MPH is do-able in a standard bodied beetle tho. However the US salt flat boys have found that 150MPH is where you run into "an invisible wall".
Perhaps a streamlined 1303. Shave off the gutters, build full underbody aerodynamics and venturies at the rear.
How about a waterboxer as the powerplant, from a mid to late 80's kombi?


Peter Leonard - February 9th, 2004 at 01:40 AM

i did 100 mph with a fully laden superbeetle and a passenger a few years ago south of darwin... but let's face facts... bugs push a hell of a lot of air...


Cam - February 9th, 2004 at 07:41 AM

They do, it's even worsened on salt for some reason. Not sure exactly why this is, but it's apparently so. So expect your salt speeds to be abit slower than what you can do on a normal road.


VWCOOL - February 9th, 2004 at 06:21 PM

Might get Craig T to put his engine in a stripped Oval shell - the most aerodynamic, believe it or not! Hmmm... H:bouncee used to pull 200+ in road Beetles...


modulus - February 10th, 2004 at 10:54 AM

Quote:
Originally posted by VWCOOL
used to pull 200+ in road Beetles...


I mentioned the 107 mph FJ Holden on purpose. I think that any survey of hot FJ Holden owners will find that they've all easily exceeded 100 mph at some time. Strange, then, that a very well prepped, single purpose example can only average 107 mph over two runs....

I guess 200 kph in a Beetle on the salt (averaged 2 ways) would be a remarkable result and would require well over 100 HP....but I'm guessing as I don't have Cd figures or reliable results to compare...


whatnow - February 10th, 2004 at 04:24 PM

the thing is that i don't think that many hotted up FJ's would be running grey motors.

VWCOOL unfortunately after reading the rules it isn't quite as simple as just fitting an engine.... there are serious rules regarding safety, inc. serious roll cage, seat mounting and harness type/mount rules, all cars in the record classes must be fitted with an inbuild fire extinguisher system (or in the case of a vw with it's fuel tank in stock position 2 systems), flywheel scatter shields etc etc.

as for the types of car to use, seeing as the beetle is known for it's bad high speed aerodynamic behavior i would count them out straight off.

to me it seems that the best engine break to run in would be CLass G 1.51 - 2.00 L (where i think a VW motor would be most competitive).

for cost/availabillity/class regs i would see the following as a few options:

a late T3 in Production Coupe and Sedan... G PRO record 117.527mph

an early single port car (prob T3) with mod'd DP motor or a sub 2L T4 motor and an air dam, in Gas Coupe. G/GC record 57.280mph

once you get above these catagories you the rules change in suce a way that the vw looses the advantage of having a nice flat floorpan.

another idea is a finding a long wheelbase (for stabillity) manx style shell (as long as you can prove there were more than 50 of that style body shells made) with a lowered nose, air dam, side skirts, rear spoiler (not a wing), no windscreen, no front lights, a partially covered cockpit area, a belly pan, etc. running in Modified Sports. no record.

still having F-ALT written on the window really appeals to me

just a few ideas.

h.