Axle Weight Distribution VW based TDs

[Brian]

The following axle weight distribution from my rear engine

BCW MGTD replica, I hope will be of use in suspension

discussions.

Vehicle Weight (no passengers) 1720 lbs

Front Axle Weight 600 lbs

Rear Axle Weight 1120 lbs

Passenger weight transfers to the axles in approximately the

same proportion, 35% to the front axle and 65% to the rear.

(Weights measured on truck scale.)

Brian

[Mark Hendrickson]

Great info Brian. When I scaled the VW based Pink MG the percentages were nearly the same, only mine was about 200 lbs. lighter.

A stock VW is just over 2,000 lbs. so you can see the need for spring rate (torsion bar/leaves) rate reductions. In addition, a stock VW had a larger amount of front end weight, but surprisingly nearly the same rear weight.

These MGTD kits are bascially WAY lighter in the nose than a stock VW. I always believed that the driver and passenger weights in a VW kept the nose planted on the pavement anyway. So, I scaled my MGTD with and without my 260 lbs. sitting in the driver’s seat. It was nearly 20% of the weight while driving, a very important detail that should not be overlooked. Handling doesn’t count sitting still, you’ve got to be in the car.

[Roy Carroll]

I used two  1″ thick steel plates about 18″ square to add more weight to the front end.  I bolted them under the pan, right behind the front beam.  Plenty of weight to keep the front end down at high speeds. I also plan to fabricate two roll bars (one behind each seat) for added protection in case of a roll over.  Beetlone.

[B Harrington]

We made up a weight box using old connecting rods to mount it to the front axle beams. Fabricated the box from aluminum plate it sits way far forward and below the center of the front axle. added 150 lbs and it solves the whole weight issue. Classic Roadsters used a similar solution I believe. The trick is as low and far forward as possible

[Paul Mossberg]

Brian is close regarding Classic Roadsters’ solution.

The provided a fiberglass weight box which holds 150 pounds of sand. It is mounted directly behind the grill shell. Top of the box is even with the top of the body side panels. It is trapezoid shaped to fit the body as it angles in towards the grill shell. It’s about a foot and a half deep and a foot long (front to back).

The weight helps, but the ride is still pretty stiff unless you soften the front end.

Pual Mossberg

 

Paul Mossberg
Former Owner of a 1981 Classic Roadsters Ltd. Duchess (VW)
2005 Intermeccanica Roadster

If you own a TDr and are not in the Registry, please go to https://tdreplica.com/forums/topic/mg-td-replica-registry/ and register (you need to copy and paste the link)

[Mark Hendrickson]

Adding ballast is NOT the way to make your kit car ride and handle correctly. The one and only way is to lower the the spring rates to fit the weight and weight distribution of the car.

When racers dial in their cars, they don’t add weight to the front or rear of the car to get the thing right. True, they may add weight in a particular spot (usually a frame rail) to make minimum weight requirements and affect weight distribution, but this doesn’t even compare to what is being done to these VW kit cars.

Ferdinand Porsche designed the twin beam front end on these cars to be spring rate (torsion leaves) adjustable by adding or removing torsion leaves. There are 10 in each tube. Four leaves in each tube are wide and are required to stay. Six leaves in each tube are narrow and up to all six can be removed from each tube.

So, I do not understand why the manufacturers and builders use the “Add 4 tons of dead weight to get it right theory”. It took me an after noon to remove the torsion leaves and correct the ride on the Pink MG (now Angelica).

Please note that adding a large amount of dead weight to these cars is also unsafe. the weight becomes a projectile in even a small wreck if not fastened properly. I have a friend who added weight to a racing car improperly and suffered a crushed left tibia as a result.

I know I hammer all the VW kit builders on this, but taking the time to do it it renders your ride a pleasure to drive and makes it safer too. Plus, it’s free! I hammered so much about this that two Speedster owners in my club did it and can’t believe they are driving the same cars! They are both using only the 4 wide leaves and none of the narrow ones in each tube.

No offense meant by my stance on this subject. It’s just the right way to do it.

 

[B Harrington]

100% correct concerning spring rates and ride. Never understood why CMC told you to cut a coil out of the front springs on the Ford and Chev TD kits. Cutting a coil increases the spring rate.

However, my point with the VW TD is very simple and has nothing to do with the spring rate.The  car is too light in the front period. The weight bias is much different than a stock VW – thats why the front suspension ends up being to stiff and the rear too soft.

[Jeff Troy]

Hello,

I have a complete and unbuilt Fiberfab TD kit for VW, and have already cut and rewelded the upper front end beam as shown in the manual. This procedure drops the front end a bit, approximately one inch.

I realize that weight distribution (center of gravity) and incidence and not the same, and I’m guessing that the front end drop (incidence) is suggested to prevent the VW pan from going airborne at highway speeds. However, is making the drop enough of a step to retain decent handling, or should one or more leaves be removed from the tubes as well?

My original owner/builder 1976 Bradley GT has recently crossed the 575 thousand mile mark, and it weighs approximately 1600 pounds. It handles beautifully, but the seating area is a lot farther forward than the MG’s.

Thank you and warmest regards…

Jeff Troy
759 New Holland Ave.
Lancaster PA 17602
717-917-3670
jefftroy@aol.com
www.bandmix.com/jefftroy

[Mark Hendrickson]

The only way to correct the ride and handling is to correct the spring rates.

That’s why we don’t use Peterbuilt leaf springs on the rear of Chevy S-10 pickups.

The procedure you performed only adjusts the way the car sits. The suspension and handling will be horrible…every drive a brick?

I described how to correctly do a VW front end in one of these cars in a previous post. Until you do this the car will never ride or handle properly…in fact, I feel they are actually dangerous.

[Frank]

Pink MG wrote:

I described how to correctly do a VW front end in one of these cars in a previous post. Until you do this the car will never ride or handle properly…in fact, I feel they are actually dangerous.

I made the posting that Pink is referring too a Sticky topic so that it will always stay on the top of this section.

I will make a sticky out of any posting that is a regular problem. If someone likes the info in a posting and thinks it should be nominated for Sticky status… PM me or just post in the thread your nomination and I’ll make it so. This is one of the big reasons I wanted to start these Forums based web. The topics are far easier to follow and stay on subject and it makes finding information of new members far easier and prevents a lot of repeat questions and answers.

 

[Mark Hendrickson]

Jeff, I am only 120 miles from the PA Turnpike exit for Lancaster via US 222. Maybe we can hook up some time?

Sounds like you are VW saavy. I bought a bare adjustable beam and used the parts from the previoulsy cut beam that came with my car. I also “scaled” the car on 4 wheel electronic race car sales that a buddy let me use. After I got it riding correctly I adjusted the beam for ride height and nearly equal suspension up/down travel.

I also removed the rear torsion bars and turned .100″ off each one. The car rode and handled superbly with no added ballast. Bill Collins now calls the car Angleica on this web site.

[Author]

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