In a message dated 03/17/2001 6:07:12 AM Pacific Standard Time,
Want1937hd@aol.com writes:
<< I'm still in the early planning stages of a LSR car, and have a wheelbase
question. The rules say you can modify the wheelbase up to 130 inches, I
understand that this makes things more stable, at what point do you deside
what is right? For example, a 1932 Ford roadster has been going well over
200MPH for years now. If you stretched the chass is to 130 WB would it go
any
faster? I'd like to hear from those that have been there and done that. I'll
admit that aesthetics is the main reason for asking this question. Bob in
snow covered Connecticut
>>
Bob,
You'll find that in the Hiboy Roadster classes there are other rule
constraints that will also limit the wheelbase. I'm no expert, but these are
my observations from building and sompeting with a Street Roadster and a
Modified Roadster.
For instance, there are rules that:
1. "Bodies must be mounted in the conventional manner" (this precludes
mounting the rear end anywhere but near the stock location).
2 "The driver must sit ahead of the differential and behind te firewall"
(this precludes rear-engine roadsters or "slingshots").
3. Engine setback is limited to 15% on Street Roadsters, 25% on Gas & Fuel
Roadsters, and 50% on Modified Roadsters (to get the driver ahead of the
differential and behind the firewall on a MR it's tough to get much more than
50% setback unless you offset the engine or run at the max 190"wb).
4. Street Roadsters must run rear fenders and can only lengthen the hood 3"
(this dictates a max wheelbase of about 110").
5. Engine setback limits prevent setting the body aft on a long wb chassis.
6. "Grill shells must be mounted in the same vertical position as original"
(this seems to prevent what is mentioned in (5) above).
7. There is a maximum overall length from the front of the grille shell to
the back of the body of 143" on 28-32 roadsters and 152" on 32 & later
roadsters.
Regards Modified Sports classes, the requirement that the driver sit in
the stock position, behind the engine and ahead of the differential, along
with the 130"wb maximum pretty much dictates engine setback maximum unless
the engine is offset. In that case the rule regards body modification,
changes in width and/or contour aft of the cowl would limit most engine
offsets.
These limits, when applied together, pretty much limit the maximum wb for
hiboy roadsters. On Modified Roadsters, a 190"wb car could in theory get the
engine 50% back if the front sparkplug was 95" aft of the front spindle. That
would give the chassis builder 95" for the engine, tranny, and the drivers
legs.
As a final note, there is a prohibition in ALL CLASSES regards placing
the rear of the flywheel housing at or aft of the drivers knees. By the time
you combine the approximately 30" measurement from the front sparkplug to the
aft of the bellhousing (on a full-sized V8), add another 30" from the drivers
knees to the differential centerline, you have used up 60" of the maximum
130" allowable wheelbase. On a modern V8 engine in a Modified Sports I think
you'd be "hard-pressed" to locate the gas, brake, and clutch pedals ahead of
the firewall.
If you don't already have one, get the SCTA Rulebook. It's the best
document that ANY LSR enthusiast can purchase............Ardun Doug King
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