Wheelbase dilemma

Yep, I've another question,
I've just been noticing how wierd the car looks while sitting, and believe that my front wheels are too far back in the wells. I didn't do the pan-shortening job, but the wheels measure to the best of my ability, "on-spec" with the plans. I searched the forum, but didn't hit any thread directly on-subject.
The question is, can the wheelbase be lengthened by shimming the torsion tubes from the frame, and how far can you go?? My guess is I'm about ~1" too short. Steering is o.k. to move forward by that amount, if the job is do-able. Recommendations??
-Tim

so you did not shorten the pan the wahtever your kit called for 10 - 11" or so? how did you shorten it?

I had a similar problem with my used CMC flare. The body was not square to the pan. Take some measurements from the fender to the tire . I had a 2" difference which made one side look like it was an inch shorter. I had cut all the adhesive and bolts and slide it forward. Had to redrill new holes to square it properly. It looked great until the motor went south which started the completed overhaul.
Joe S

Tim,

Don't shim the front end for any reason! I don't even want to mention it, but he only shimming that can be tolerated at all is a thin caster shim on the lower tube if drop spindles are used. Even this is only used to correct a defect in the way drop spindles work, it will restore high speed stability, but NO SHIMMING THE FRONT END to achieve a lenghtened wheel base!

There are WAY to may forces at work to risk everything on four bolts!

Be careful and safe,

TC

I

O.K., maybe som more info. would help precipitate a suggestion. I did not shorten the pan. I bought the car from a guy who had already done that, but not much more. Initial measurements confirmed the spec. in the book was acheived (whatever it was).
The measurements from the front tires to fenders were made and are within 1/8" of each other (some 'noise' in the measures is expected, based on wheel alignment). 2-1/2" drop spindles are used, and maybe place the car a bit lower than desired, so caster shims would both raise the front and lengthen the wheelbase a 'bit', but not enough. The rear wheels are fine, and centered in the wells. Curious, but it's like the body is just too long!! Any further thoughts???
-Tim

Tim,
I used to wonder about the front wheel position as well, then I looked more closely at original A type cars and noticed they appear to have the front wheel not centered in the opening too. Check out profile photos on a site like www.europeancollectables.com under the type A cars in their inventory and see if your car is not that much different in front wheel location.
Rick

Tim , The caster shims are about 1/4 " thick. The purpose is not to lengthen the frame, but to readjust the caster angle. Think of a motorcycle , if the forks were perfectly verticle.....thats a bad thing, but by moving the front axle out, so that the fork now "angles" forward of the bike, you now have increase the stability at higher speeds. Most dropped spindles are about 1 1/2 inch drop. With the spindles that you have it is a must to use caster shims, they can be bought from CB performance, online. I guess you could say it keeps the double tube perpendicular from the ground, rather than angled back at the bottom.



Gclarke "The Vacaville Guy"

Tim ,

Post a few Pics here, also reconfirm you have the correct 82 3/4" wheel base i.e. a center hub to hub measurment (+ - 1/4" is OK.)
Also take a look at the front "arch" that lays over the forward tunnel section ..is it laying square to the chassis and not back or forward an 1/2" to 3/4" or so ?

I just went out to the shop to check a CMC I have with the body laying in the proper position on the chassis and the front wheels are centered within the front wheel well openings.

Alan

Guys,
I have checked a few things; the wheelbase is ~83-1/8" crest to crest between the tires on either side. I checked this with the plans before mounting the body, and thought it would be long enough. There may have been more error in the measurement than I thought, though. The Arch is square to the eye; a significant amount like 1/2-3/4" would be noticeable without measurement. I'll try some photo's of the car for you guys next...
I took the it for a spin last night and noticed that the wheels rub the wells around corners and over bumps, so I know something has to be fixed. The min. clearance is about 1/4" between the tire and fender well behind the tire when turning the wheel, and 2-1/2" in front of the tire. mods are required; what should they (the safe ones) be??
I thought about fab.-ing a "spacer" to go between the torsion tubes and frame, rigid enough to handle the loads. Also, modifying or making new spindles, with the axles in the 'right' place. All are difficult, so recommendations are accepted.
-Tim

Tim.....One size smaller tires?????

Gclarke

Gary,
I'll file that one with the "jig-saw to fiberglass" proposal
-Tim

This thread hasn't seen action in a while, but I thought I'd update it; there's still a big problem with my wheelbase!!
I ordered some more caster shims and installed them. There are now three sets on the bottom torsion bar! The net effect was as expected; they raised the front a bit and moved the wheels forward a bit, but only a bit. The wheels don't rub the wells around corners now, but the asthetics suck!! It looks like a hack job - not exactly the desired effect. The car is short enough, and this makes it intolerable. Anyone have any further suggestions or experience??
Thanks.

Tim

Can you post or email me a good pic or two?

Alan

Alan, and others interested...
Here's a couple of pictures; don't laugh! It's a pretty dorky look. Anyway, what you're seeing is with 3 caster shims in place, so it used to be worse. That was when the wheels screetched against teh wells around every corner. At least now I don't "hear" the problem!
Some sort of macro-solution must be involved, since there's been a distinct lack of "I've been there before" responses. I find it hard to believe though that no one has ever come up short on the pan shortening effort! Anyway...as previously stated, the measurements are right on, so I'm at a loss to explain, but the views say it all
-Tim

A quick fix would be "Vehicular Viagra"

The caster shims are not an answer as it throws the geometry out of wack big time .A solution to your problem (other than pulling the speedster apart and redoing the chassis) might very well be an extension of the frame head.....Don't balk at this idea .......yet! If welded professionly, this would surely be a safe alternative and pass any DMV certification .
I did a Jag SS 100 build 8 or 9 years ago and that had a frame head extension of 14" to increase the car's wheel base and is super strong.
It was constructed similar to the inside verticle demensions of the axle beam,( looked like a basic box kite configuration) The replica manufacture indicated bolting the extension to the exsisting frame head as an axle beam is done using the original axle beam bolts.(I had this professional welded also) then, the axle beam was bolted and also welded to the frame head extension.

So what you need to come up with is the exact measurment and then go from there
Alan

Since everything as far as the suspension geomerty is part of the front axle , you would not have a problem extending the front end. It looks like you need to move the axle up 2inches towards the front. Two 2" .120 wall square tubing tack welded vertically over the original axle mount for fit up. Use a tubing cutter to notch out the square tubing for the new axle saddle mount. With a little pounding bend .120" around the axle to replicate the diameter. Weld the saddle in the cutout. Center drill the new mounting bolt holes. Added thread tube stock to the existing mounting location. Complete final welds. Piece of cake. When you bringing it over?

Joe S

. . . I'll be there Tuesday, (2007!) Your responses confirm my train of thought to this point; custom fix. No problem, just need to get those measurements and some steel on order. Might also have a fab shop do it. Right now, the engine is missing its alternator and shroud; finally adding the tins. Thanks for the feedback! I'm going to send the pics to the "builder" and ask him what happened, just for amusement!
-Tim

Tim
Find yourself a good dirt track car fabricator, these guys are creative.....with the punishment that their cars take it would be a good choice.

Tim:

Check out the pic posted by Mike Cochrane of his car, in the v.s.clearcoat thread in the General (non-technical) Forum. (post #2)

His front wheel placement doesn't look that much different than yours?

May have to look into the the long tie rod issue, it may hit the top of the fabricated extension, also the steering column shaft length (another extension piece here) extending the brake lines etc. But anything can be done.

I think the illusion is the RED underneath. Change that to black and you will see a marked difference.

Also you think the flares caused a problem?

Now I can't sleep....

Tim, Take a look to see if the front pan head was replaced. The weld will be just on the cockpit side near the brake pedal. If it was replaced it may have not been fitted up properly. Or the pan was originally set up for a dune buggy. I have a buggy in my garage right now that has an 80" wheel base. A frabricator might have to trim your old axle mount a bit. You won't have to change the tie rod geometry. Though you will have to extend the steering shaft. You may want to lift the body off the chassis to perform the fabbing. Fabbing with the body is no fun. Paint under side with a Bedlliner paint.....it will give you some protection again underside rock dings (Nasty!!!) and it will make it more kitless looking.
Good Luck
Joe