Datsun Roadster Forum-311s.org

NISSTECH wrote:Just wondering what the ride height is on the cars using these springs? Can anyone using them give a frame to ground measurement? Just wondering if all the sets were made the same.I wasnt expecting to see so much arch.

I guess you're asking about the steel parabolic springs. I'm still putting in taller blocks but when I had the 20mm blocks installed, the frame sat 2.25" higher compared to the height with comp springs. This was measured on the frame directly above the axle centerline.

NISSTECH wrote:Just wondering what the ride height is on the cars using these springs? Can anyone using them give a frame to ground measurement? Just wondering if all the sets were made the same.I wasnt expecting to see so much arch.

The top of my rear wheel arch is 11.5" above the centre of the axle. Check out the photos at the start of this thread - we're using lowering blocks to get the right ride height.

Cheers,
Steve

That is an easy way to measure the height!

My '66 sits at 10 5/8" from axle centre to the lip of the stock arch with the composite springs. No lowering blocks!

The maker in Oz is offering to make the parabolic monoleaf springs with the reverse eyes. Based on his measurements, it seems that it will bring down the ride height to the level of Nissan comp springs and solve my problems with the Panhard rod and my Koni shocks reaching the mounts. But he wants a minimum order of 2 sets to ship to the US. I'm trying to figure out an economic way to ship. But is anyone else interested?

I thought here was a very high failure rate with the springs made this way? Have they found a way to make them work with the reverse eyes?

NISSTECH wrote:I thought here was a very high failure rate with the springs made this way? Have they found a way to make them work with the reverse eyes?

I was told that about half the springs crack when reverse rolling the eyes during the rolling process. If they don't crack during the rolling process, they won't crack later. They are dye penetrant checked after rolling to inspect for cracking. I'm just repeating what I was told.

Wow! A 50% failure rate at production, how can they afford to produce these?!
I can't think of many manufaturers that would put up with that kind of question mark.

notoptoy wrote:Wow! A 50% failure rate at production, how can they afford to produce these?!
I can't think of many manufaturers that would put up with that kind of question mark.

That's the reason for them rolling the eyes upward on most. I suspect the cost for the reversed eyed springs may be higher to cover the cost of the failures.

Daryl Smith wrote:That is an easy way to measure the height!

My '66 sits at 10 5/8" from axle centre to the lip of the stock arch with the composite springs. No lowering blocks!

It's also the most accurate, as wheel size doesn't affect the outcome.

Cheers,
Steve

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So Dean, does this mean you are working on an alternative spring, or reproductions of the early springs as well?

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At this point, there are no aftermarket springs of any design or material available in the US that can replace Nissan comp springs properly. All so far have way too much arch, resulting in a rear ride height at least 2 inches higher than comp springs. Lowering blocks do not solve the problem. Believe me, I've tried.

was this resolved?

My resolution was this: I sold the parabolic monoleaf springs and re-installed my comp springs.