356 Handling Aids

[S.J.Szabo]

[Meissen540]

It's a scientific fact: all metals fatigue with use. Be it a 356 torsion bar, or the wings on an airplane. The million $$ question is: with a given amount of stress, what's it life span?
Lockheed and Boeing spend millions to understand this. Who recalls the book "Airframe" ?
If you think you can benefit from new torsion bars, go for it. Like Bruce said, it's cheap, and potentially great bang for the buck.

Tom

My Speedster sounds better than Bruce's

[bbspdstr]

It's a scientific fact: all metals fatigue with use. Be it a 356 torsion bar, or the wings on an airplane. The million $$ question is: with a given amount of stress, what's it life span?
Lockheed and Boeing spend millions to understand this. Who recalls the book "Airframe" ?
If you think you can benefit from new torsion bars, go for it. Like Bruce said, it's cheap, and potentially great bang for the buck.

Tom

My Speedster sounds better than Bruce's

After 50 years of continuous Speedster ownership of one or another or a few at a time, Bruce no longer has a Speedster but my last one sounds great with a Bursch!. Weaning myself of a Speedster prepared me for letting my involvement with the Registry lapse....but the end for both were for very different reasons. I could afford the Registry but I can't fix it....I can't afford another Speedster but I can fix them.

Speaking of airframes, that is of interest as of this last Tuesday. Martha was returning from Chicago and her flight was first delayed by a crew shortage. It then taxied out and eventually returned to a gate with an announced air-conditioning problem. Another plane was boarded and taxied out, only to return to disembark due to, get this, faulty windshield wipers. I waited over 5 hours at PHL for the third plane to get her there. Who did the pre-flights? Who verified the maintenance logs on an old airframe with bad A/C or wipers? Flying is getting more than just no fun anymore, it's getting scary!

-Bruce

[Trevor]

After 50 years of continuous Speedster ownership of one or another or a few at a time, Bruce no longer has a Speedster but my last one sounds great with a Bursch!. Weaning myself of a Speedster prepared me for letting my involvement with the Registry lapse....but the end for both were for very different reasons. I could afford the Registry but I can't fix it....I can't afford another Speedster but I can fix them.

-Bruce

That's F'n gold!

[AMP]

FV racers abandoned the Z bar many years ago and went with what is called a zero roll rear. The two rear wheels are connected by two links attached to each end of a single coil over assembly which is free to pivot via rockers at attachment points over the transaxle. If the car is on jack stands you can lift one rear wheel up to its max travel with no resistance as the other wheel goes down - zero roll resistance. You can google "zero roll FV" for pictures and explanations. I have a friend with a V and have looked at this first hand. The rear axle is like a balanced beam where it takes little or no effort to lift one end.

I don't think this would be good or practicle for a street car. But apparently it's the best solution for FV where about everything has been tried within their rules.

I wanted to fit a Z bar to my car but did not like the H&H version for the reasons already stated. I did not want to modify the body by welding or drilling holes. I did come up with a Z bar that used a longitudinal mounted bar with arms running out to the wheels. It was complicated but would have mounted without modifying the car. The easiest solution was Vic's camber regulator. It doesn't add very much if any to rear roll stiffness. The attachment point in the center of the car makes it act like a see-saw. The way I have mine installed it is free to pivot at the center attachment point. To take it a step further the center attachment could be via a bearing - but I think for this purpose that would be like trying to pick the fly $hit out of the pepper.

I like the change to my cars handling with that spring. But I equally don't like the added spring rate on a bumpy road. Eventually I want to try a softer camber regulator spring. Bump stiffness of the shocks could be a factor too. Softer torsion bars also would help. I don't know the spring rate of the single leaf camber regulator spring nor have i looked into how soft it can be and still be effective.

My front sway bar is roughly twice the stiffness of the factory 16mm bar.

Another source for torsion bars and sway bars is Schroeder Steering in Burbank CA. They have been in business for a long time supplying professional racing and make some very nice bars. I know they produce 911 torsion bars and pretty sure they have 356 bars of any size. My front sway bar is a Schroeder. Nice people too. Shameless plug for a friend, Gary Schroeder.

[S.J.Szabo]

[JTR70]

It's a scientific fact: all metals fatigue with use. Be it a 356 torsion bar, or the wings on an airplane. The million $$ question is: with a given amount of stress, what's it life span?
Lockheed and Boeing spend millions to understand this. Who recalls the book "Airframe" ?
If you think you can benefit from new torsion bars, go for it. Like Bruce said, it's cheap, and potentially great bang for the buck.

Tom

My Speedster sounds better than Bruce's

Fantastic tips you guys, thank you for sharing this info!

Tom's post reminded me of an old story that a tank mechanic told me many years ago. During war games and also just sitting idle out in open desert storage rows and rows of tanks would be parked side by side. As the calm and quite dusk turned into evening a shot would ring out...BANG! then another, then another...Though it sounded like a gunshot it wasn't; it was the torsion bars in the tanks snapping. He said this was a nightly thing happing in multiples. Needles to say he was kept busy with torsion bar replacement.

BTW: I had been told to keep track of which side my old rear torsion bars came off of. The reason being that the bar through the years gets comfortable being twisted and loaded in one direction and if you mount it later loading it the other way it invites failure. Any truth to that?
Thanks again guys!
Justin

[AMP]

It's a scientific fact: all metals fatigue with use. Be it a 356 torsion bar, or the wings on an airplane. The million $$ question is: with a given amount of stress, what's it life span?
Lockheed and Boeing spend millions to understand this. Who recalls the book "Airframe" ?
If you think you can benefit from new torsion bars, go for it. Like Bruce said, it's cheap, and potentially great bang for the buck.

Tom

My Speedster sounds better than Bruce's

Fantastic tips you guys, thank you for sharing this info!

Tom's post reminded me of an old story that a tank mechanic told me many years ago. During war games and also just sitting idle out in open desert storage rows and rows of tanks would be parked side by side. As the calm and quite dusk turned into evening a shot would ring out...BANG! then another, then another...Though it sounded like a gunshot it wasn't; it was the torsion bars in the tanks snapping. He said this was a nightly thing happing in multiples. Needles to say he was kept busy with torsion bar replacement.

BTW: I had been told to keep track of which side my old rear torsion bars came off of. The reason being that the bar through the years gets comfortable being twisted and loaded in one direction and if you mount it later loading it the other way it invites failure. Any truth to that?
Thanks again guys!
Justin

Yes there is truth to that. But the less power you put through them and the more old lady like you drive the less of a twist it will put in them. I think the rear ones are marked left and right from the factory.

I don't believe the front one is marked but maybe being in the form of a flat spring makes the front ones less vulnerable. Don't know the answer to that.

[AMP]

If I may, I would suggest that a softer cross spring would only lessen its benefits. It would be more to the point to go with softer bars and a stiffer cross spring to lessen the roll couple.

Probably true but that cross spring is a lot easier to change which is why I had it first. Need to figure out the min weight cross spring needed to do the job on the street. Maybe that is already done and that spring is the minimum spring needed - At this point I don't know the answer.