June 21, 2011 at 2:37 pm #233529
I haven’t seen mention of sway bars. When I was making life miserable for MGAs and TR3s with a Super Beetle I ran a sway bar on the rear suspension. It turned oversteer into mild understeer. We were pretty even until bumps in a turn started bouncing their live rear axles around and I was gone. Sway bars front and rear would make a VW based TD handle more like a front engined TD.
This isn’t the only company that sells sway bars for classic bugs. It will give you an idea of pricing. VW changed from swing axles to full IRS in 1969. A Camber Stop will stop tuck in on swing axle cars.June 21, 2011 at 4:08 pm #245256edward ericsonParticipant
Sure you had oversteer in your Beetle before the rear sway bar, BD?
Other than that, I concur. It is probably a good idea to do a rear swaybar install on the IRS TD, since we’ve modded the VW to place even more weight rearward while unloading the front suspension, which tends in both cases to promote understeer.
With the adjustable front beam lightened by 12 small leaf springs, plus new tires inflated to 15 lbs in front, 22 in the rear, I’ve got Bridget so she’s no longer plowing and squealing though every easy turn in second gear. Still much room for improvement though, and this IS a safety issue, not just an embarrass-rival-drivers issue.
Thanks for the link.June 21, 2011 at 4:55 pm #245257newkitmanParticipant
Doesn’t your VW based TD have the sway bar underneath the front beam? I was under the impression they were standard equipment on air cooled VWs from 70 on. I’ve been wondering about rear sway bars on our TDs. You answered one of my questions. Thanks.
VW based 53MGTD - "MoneyPenny"
"If one thing matters, everything matters" - from the book The ShackJune 21, 2011 at 6:06 pm #245258
Yup. Oversteer. I’m talking about a stock Bug. The VW TDs may have unloaded the front end so that there isn’t enough traction to induce oversteer at road speeds. That may be why there isn’t a thread on sway bars. The front end plows before the rear end jacks up.
Suspension geometry can do a lot to minimize oversteer at low speed. But there will always be more weight on the rear axle. At some point in a turn the rear end will have less lateral traction than the front and will swing out. That usually happens when the rear end jacks up. It comes as a big surprise to drivers who aren’t expecting it.
The post swing axle cars are pretty civilized at around town speeds. But even they will tuck the inside rear wheel in a fast turn, albeit at a higher speed and not as severely as in a swing axle car. The rebound geometry of the rear end causes it to steer wider than the front end. The driver steers into the perceived “skid” and finds himself going the wrong way in the opposite lane. That’s what gave rise to Ralph Nader’s assassination of the Corvair, “Unsafe at any speed”. I had a 60 Corvair. Once I learned to tighten the turn and ignore the body angle it was a fun car in the twisty bits, especially with 80 hp and a two speed Powerglide. I was never in the right gear. There weren’t enough of them. But that’s another story. The transition from mild understeer to oversteer is what catches drivers by surprise. The rear sway bar keeps the rear end flat.
Safer and Funner.
Ed raised a point I had not thought of. Plowing and squealing through easy turns in 2d gear? That sounds light. Has anyone weighed their car for weight distribution? Is there a recommended minimum weight for the front axle? Perhaps we should be talking about ballast instead of sway bars.June 21, 2011 at 7:12 pm #245259Paul MossbergKeymaster
For what it’s worth…
Classic Roadsters Ltd. recommended adding weight to the front end.
Behind the grill, there is a fiberglass box that the builder fills with 140 pounds of sand, then seals the top. It is all under the carpeting when the trunk is finished.
They also recommended adding more ballast on the floor pan under the trunk floor, in front of the driver. The gas tank is on the floor pan on the passenger side.
The car still rides a little stiff. But the handling is fine for streets and for some enthusiastic “back road” driving.
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)June 21, 2011 at 8:58 pm #245260
This is a safety question.
Do all VW based kit manufacturers specify weight and location of ballast?
Does everyone have the appropriate amount of ballast in their cars?June 21, 2011 at 9:55 pm #245261edward ericsonParticipant
To NewKit: Yes. Stock front sway bar. ’69 pan.
There is no provision or recommendation for ballast in the BCW car. I believe the thread(s) about the adjustable beam address the ballast question in the negative. Or at least Mark (PinkMG) does.
Bridget’s troubles were related to the over-stiff front sprong rate and the ancient tires, both cured now. She handles all right (at around town speeds) and even seems stable on the highway, but I am not about to mistake her for a performance car, the way some of the Speedster guys insist on doing.
I will be curious to run some skidpad tests on Bridget this summer and see where her limits are. Haven’t had the time yet. Will report.June 21, 2011 at 10:16 pm #245262newkitmanParticipant
Just to pass along the FiberFab and CMC FiberFab kit info. Neither kit mentions anything about adding ballast. Both however do talk cutting the front beam, turn it and re-weld it. Removing the large and small springs is way easier.
VW based 53MGTD - "MoneyPenny"
"If one thing matters, everything matters" - from the book The ShackJune 22, 2011 at 12:31 am #245263Will BurgeParticipant
I removed the small leaves and cut the beam and welded in adjusters top and bottom. This not only softened up the ride but lowered the front closing the gap between the fenders and tires. I like a slight rake downward in the front.
- You must be logged in to reply to this topic.