Shocks and sway bars for MG TD replica

[Ol'fogasaurus]

... However, your MG can be made to handle well if you'll begin with the "thru-bar" replacing one whole torsion leaves stack, and (at first) no front sway bar of any kind. All of this is reversible. You can put the leaves back in later if it comes to that.

FJC

I have a lot of respect for FJ's opinion: the part about being reversible is worth considering. My point was meant to go the other way feeling that taking stuff out (to me) is easier than putting it back in but it also may be a wash either way.

My opinion is also based on other's opinions that were fed to me many years ago before I knew of FJ but since FJ does have a background in this I would defer to his ideas.

I already had said my opinion was worth what you paid for it... and that was zilch .

Lee

[KentT]

FJC,

Thanks for the response. If I understand correctly, you're suggesting that I begin with a through-bolt on the top beam, and the full stack of leaves in the bottom beam, with no sway bar at all.

I assume that it is safe to prep the beam with adjusters, top and bottom, should I need to re-install leaves in the top beam at some later point. Is that a safe assumption?

What orientation should I place the adjusters in, with an end goal of reducing the ride height about 2" from stock front height -- in addition to lowering the spring rates (of course) for this lighter front end?

Can I do that with stock height spindles, since I've already ordered the appropriate bolt-on disc brake conversion kit for them? Or, will lowered spindles be required for this method to work?

Should I plan for installing rear plate adjusters now? I think mine has been adjusted to lower the rear one notch -- assuming the builder followed the build manual procedures.

Thanks,
Kent

[Steve Arndt]

What do you think about this:

Instead of the through rod in the top, how about leaving the stock spring pack in and just leave the center grub screw out? You could test it quick and easy that way. This is assuming you have adjusters in each beam tube.

The through rods would be better in the end though since you can tighten them to give a touch of preload. The stock springs and grub screws don't always hold the arms up against the beam tightly. For a quick test though you could try my idea I think.

[Ol'fogasaurus]

I got thinking about this again and the whole topic kind of opens up a whole bunch of additional questions/debate for me . Unless Kent is in a big hurry (to spend money and time) I think there are some more questions and ancillary things that could be discussed here.

Kent, what a fun build and fun topic you have opened up. Give me a chance to learn more too.

Lee

[Steve Arndt]

Our shop works on an MG TD replica car. It is such a good kit that for a day of only glancing at it I didn't notice it was a VW. Then I looked under the front area and noticed the beam sticking out the sides past the hood. Dead give away.

This one had all the "right stuff". Special rear view mirrors, vintage luggage on the back (even more rear weight!), leather straps holding the bonnet down, wire wheels, British gauges, etc. A pretty cool car.

One totally funky thing on it is the body work over the rear torsions. He wanted us to do torsion bar spring plate bushings but the body work was blocking access completely.

[KentT]

One totally funky thing on it is the body work over the rear torsions. He wanted us to do torsion bar spring plate bushings but the body work was blocking access completely.

Yes, one brand of these kits (Daytona, maybe) moved the body tub back even farther. Then, they had to put a hump in the rear of the running boards to clear the rear torsion beam. You'd need to remove the body to access those, I think.

Luckily, I don't have that issue -- I can access mine under the rear fenders, similar to a Bug.

I don't have adjusters in my beam yet -- I'm prepping a new (used) beam to use. Mine has had the centers cut and rotated to lower the car...

[FJCamper]

Hi KentT,

Steve's suggestion about loosening the center grub screw for springing tests is workable to a degree. The leaves are still within a square-cut housing and will try to rotate but can catch. You can test this if you ever have the leaves exposed (no trailing arms installed & removed center grub screw) by trying to rotate the leaves with a Vise-Grip.

Don't drive a beam axle VW with the center grubs removed. The center grub screw is the only thing holding the leaves in place. And the trailing arm grub screws are the only things holding the trailing arms to the torsion leaves! With no center grub screw, the torsion leaf stack can shift side to side and finally one trailing arm or the other is pounded off.

Anyway, on the issue of lowering, the dropped spindles are the best for maintaining geometry, but lock you into a permanent drop. Adjustable front axle beams are okay IF (in caps) the adjustment goes from stock ride heigth to two inches or more lowered. Thru-bars work on adj beams just like stock beams.

For the rear, you should run adjustable spring plates. These give you quick and efficient ride height ajuustment, and are the major start in tuning for predictable and controlled tire adhesion breakaways. Raise the rear, you tend toward oversteer. Lower it and you tend toward understeer.

Now, neither raising or lowering affect rear torsion bar spring rate.

If the car is too hard and bouncy at the rear, which feels firm at first, but bouncy tends to break tire adhesion, you might go to a coil-over rear shock and replace your rear torsion bars with a dune buggy type swivel joint.

Again, we're running ahead of ourselves, but tire-tuning and brake balancing are next.

FJC

[KentT]

Thanks FJC, for your time and patience. It's great to interact with someone who's really "been there - done that." I'll proceed with putting the adjusters in, top and bottom, once they arrive. Here in the hills, everything is mail order...

Speaking of which, is a 1/2" through rod sufficient, or do I need something stronger? I understand that I want Grade 8 stuff and not Home Depot...

This place sells the pieces/parts individually, so I can do only one beam, rather than the kit for both top and bottom: http://www.pacificcustoms.com/ac401030.html

So, it's:

Thru rod (sized TDB, awaiting your response)
2 pinch nuts
2 nylock nuts
2 teflon washers

Correct?

[petew]

Hi all, been a while since I was on here... for those who don't know me, I went through all these dramas trying to get a LWB dunebuggy/subaru engine to handle for dirt autocross.

I have read the whole thread and FJ is totally on the money IMHO.

I'd just add these points...
1. Every ounce you can take away from the rear end/move to the front of the car will help you...
So break out the drills & hole saws and cut holes where ever you can. Cut off any unneeded brackets. Use zip ties. Replace metal with plastic/ali where possible. Shorten your exhaust if possible. Move your seats forward as far as is possible. Replace them with lightweight seats if you can. Use lightweight wheels and tyres on the back. Use thin wall tube for the rear bumper. Move the fuel tank further forward. Get the battery AHEAD of the front axle line if possible.
All of this will make a noticable difference.
2. Your tyre pressures/sizes will vary wildly from front to back.
I autocrossed a stock beetle today and had 30 psi in the front and 40 in the rear. My old buggy used to run 18psi in the front and 38 in the rear!

P.s. love to see some pics of the car.

[KentT]

It is truly a "barn find" -- it was last registered and on the road in 1998, and been in a barn until I got it. Here's what it looked like the day I towed it home:

Dsc06021_sm.jpg

And more or less what the exterior looks like now:

vw4me-640.jpg

This winter weather has really slowed progress, because that is also the only place I have to work on it, unless I tow it to a friend's garage...

I was able to borrow his garage for my recent engine build, but I still don't have it installed. And now, I'm working on the suspension and brakes.

I have a new top, carpet and interior for it -- but I'm focusing on getting it road-worthy first. As best I can tell, it has 53,000 miles on the running gear -- it was a numbers-matching, tired 1500 SP, and they used the donor's speedometer which shows that mileage. Because the shocks and steering stabilizer were original, I don't believe it had "turned over" and had 153,000 miles on it...

[petew]

Looks very cool. I reckon you want some real skinny tyres on the front end, like say 145s.

[KentT]

Looks very cool. I reckon you want some real skinny tyres on the front end, like say 145s.

Most likely. These are 185x65s all around that match the original height, but are a bit wide for the front...

[petew]

I'd say 185s are overkill for a stock beetle... although some might disagree. Certainly they're way too wide for what you want. I think 145s might suit the looks of the car better too.

[KentT]

Yep. My tire choices locally were very limited, and I was lucky to make it home, towing it, with the dry-rotted tires that were on it. If they hadn't been steel-belted Falkens, I likely wouldn't have...

I just wanted to get "new rubber" on it for initial road-testing....

[KentT]

Well, I have all the needed parts on hand -- finally -- Snowmaggedon sure delayed things in the Southeast, it seems. Also found an experienced VW shop abotu 50 miles away to weld in the SAW adjusters. I was going to attempt myself with with my nephew doing the welding, but decided to pay a pro who's done this many times before. That's cheaper than screwing up the front beam, and I don't want to be removing the beam again to cut them out and redo them should we put them in incorrectly. I'll acknowledge my limits rather than taking lessons from the school of hard knocks...

Also stumbled across a pair of NOS Spax adjustable shocks for the front on FleaBay -- the last pair the guy had -- at what I thought was a great price -- $89.96 for the pair, plus shipping, Buy-It-Now price. After some hasty research, since they're supposed to be about the same as stock Boge shocks on their softest setting, and damping/rebound adjusts stiffer from there, I thought they should be a fairly safe experiment, so I jumped on them before someone else did...

They arrived this afternoon, and they appear to be truly "old-stock" based on the box they came in (both shocks as a pair in a single factory box) and the fact that they adjust via a set-screw not a knob like the newer ones. I think they have fewer adjustment settings also. They're also a medium gray/blue in color instead of yellow like all the pics I saw when researching Spax. My first reaction is "I'm impressed" -- this is the first gas shock I've ever seen that does NOT try to extend and consequently would tend to raise the already very light front end... They stay where you release them!

We'll see if they're still too stiff on their softest setting, but I thought adjustability was better than continually swapping shocks to find what would work best. I'd already tried cheap Empi gas shocks for a lowered beam on my cut/rotated beam and they were too short (in addition to being VERY stiff) -- so I'm hoping these will work to replace the totally worn out original Boges, and allow me to "dial in" a usable setting.


Too bad I couldn't score a pair for the rear at that price!

EDIT: I just checked this morning, and the shocks are still in the partially compressed position that I had left them in, after sitting in the box all night. As I said, I've never before seen gas-charged shocks that did not want to extend to their full length. These do not... they stay where they were last left.