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-   Suspension, Brakes, Drivetrain (https://www.miataturbo.net/suspension-brakes-drivetrain-49/)
-   -   Racelands... Help me make this somewhat better (https://www.miataturbo.net/suspension-brakes-drivetrain-49/racelands-help-me-make-somewhat-better-75569/)

buffon01 10-21-2013 10:18 PM


Originally Posted by vehicular (Post 1065377)
Sell the Racelands on craigslist. Buy something that doesn't suck.

I wonder what I could get with $100 that doesn't suck more...


Originally Posted by Slider (Post 1065387)

:dealwithit:

vehicular 10-21-2013 10:39 PM


Originally Posted by buffon01 (Post 1065440)
I wonder what I could get with $100 that doesn't suck more...

Blown factory shocks. 2x4s. Welded chain. Rope soaked in wax. Super bouncy balls in nested PCV pipe. Anything.

buffon01 10-21-2013 11:27 PM


Originally Posted by vehicular (Post 1065451)
Blown factory shocks. 2x4s. Welded chain. Rope soaked in wax. Super bouncy balls in nested PCV pipe. Anything.

My crappy factory suspension was definitely worse than what I have now.

vehicular 10-22-2013 10:33 AM

Interesting. I drove a factory car, my car with shortened/ revalved Konis, and a car with brand new Racelands in the same afternoon a few months ago, and I thought the Raceland car was an underdamped, bouncy, unpredictable mess. While my dad's 91 SE on stock shocks was pleasent in all catagories.

Joe Perez 10-22-2013 10:40 AM


Originally Posted by buffon01 (Post 1065368)
I'm going to get the spacers and add the helper spring, that should help.

Adding spacers and helper springs is functionally equivalent to just raising the position of the existing spring perches.

If raising the perches to the desired ride height puts you into a coilbind situation, then you would have experienced coilbind at precisely the same height by using spacers and helper springs.

vehicular 10-22-2013 12:24 PM


Originally Posted by Joe Perez (Post 1065570)
Adding spacers and helper springs is functionally equivalent to just raising the position of the existing spring perches.

If raising the perches to the desired ride height puts you into a coilbind situation, then you would have experienced coilbind at precisely the same height by using spacers and helper springs.

Not entirely true. He'll gain the compressed length of the helper spring worth of ride height at the same preload level, meaning that he can dial that much preload out to keep the same ride height.

vehicular 10-22-2013 12:25 PM

He will still have to suffer the ridicule of his peers, though.

Joe Perez 10-22-2013 12:44 PM


Originally Posted by vehicular (Post 1065629)
Not entirely true. He'll gain the compressed length of the helper spring worth of ride height at the same preload level, meaning that he can dial that much preload out to keep the same ride height.

No.

Adding a solid mass of metal (a compressed helper spring and spacer) in between the primary spring and the spring perch is functionally identical to raising the level of the spring perch.

Both of these two things will increase the ride height of the car by the same amount. Further, assuming that all four corners are raised up by the same amount, and that the car is not raised up so much that the suspension reaches the droop limit of its travel, the preload on the springs will remain unchanged.

Since the opposing force (the weight of the car) remains the same, for every 1 cm that the lower spring perch is raised up, OR for every 1 cm of "dead" thickness added between the spring and the perch (spacer, fully compressed "helper" spring, etc), the upper perch will rise by 1 cm, taking the car along with it, and the compressed length of the main spring (at rest, with the weight of the car bearing down on it) will remain the same.


If, as you suggest, he adds some amount of thickness of spacer and compressed helper spring, and then "dials out" that same amount of height by lowering the position of the lower spring perches, then nothing at all will have changed, either statically or dynamically, aside from adding a small amount of weight in the vicinity of the upper spring perch, and removing a small amount of weight in the vicinity of the wallet.

Joe Perez 10-22-2013 01:23 PM

2 Attachment(s)

Originally Posted by vehicular (Post 1065629)
Not entirely true. He'll gain the compressed length of the helper spring worth of ride height at the same preload level, meaning that he can dial that much preload out to keep the same ride height.

Following up on my previous, I've drawn a picture to help illustrate the point. In it, I have stripped the problem down to the barest essentials:

https://www.miataturbo.net/attachmen...1&d=1382462609

At the left, we have one spring, resting atop one lower spring perch (red rectangle), with a 500 lb weight sitting atop it which represents the weight of the car on one corner.

In the middle, I have raised up the lower spring perch by one inch. Since the weight atop the spring has not changed, the compression of the spring remains unchanged, and the spring and weight both move upwards by one inch.

At the right, I have left the lower spring perch in its original position, and added one inch worth of "dead space" to the system, the green rectangle representing a fully compressed helper spring and spacer. As before, the weight being exerted on the main spring does not change, so its length remains the same, and the 500 lb weight simply moves up by the same 1 inch. (It would be the same if this were placed below the main spring as above it.)


Does this help?

vehicular 10-22-2013 02:55 PM

You're thinking about this backward. He has already raised the spring perches and is now (possibly) in coil bind. If he adds the spacer that the helper spring becomes when you put weight on the spring package, he can lower the spring perch, and allow himself more spring travel and maintain his current near-stock ride height.

Joe Perez 10-22-2013 05:59 PM


Originally Posted by vehicular (Post 1065688)
You're thinking about this backward. He has already raised the spring perches and is now (possibly) in coil bind. If he adds the spacer that the helper spring becomes when you put weight on the spring package, he can lower the spring perch, and allow himself more spring travel and maintain his current near-stock ride height.

I'm not sure why you think this.

The compressed length of the spring is almost completely independent of ride height. It's a function of the spring rate, the length of the spring, and the weight of the vehicle. So, for a given vehicle weight, spring length and spring rate, the compressed length of the spring will be the same regardless of what the ride height is and how it was achieved. Thus, so will be the amount of free travel available before coil bind occurs.


If his current combination of spring length and ride height (as a function of lower spring perch location) mean that he is in coil bind at full compression at present, then lowering the lower spring perch and adding back in an equal amount of spacer to achieve the equivalent ride height will not fix anything- he will still encounter coil bind at precisely the same point in compression travel. The only ways to fix coil bind are:

1: Shorten the spring (best),

2: Lower the static ride height,

3: Raise the position of the upper spring perch relative to the chassis, or

4: Artificially limit compression travel, such as with bumpstop spacers (not a good thing.)

Braineack 10-22-2013 06:13 PM


Originally Posted by vehicular (Post 1065688)
You're thinking about this backward. He has already raised the spring perches and is now (possibly) in coil bind. If he adds the spacer that the helper spring becomes when you put weight on the spring package, he can lower the spring perch, and allow himself more spring travel and maintain his current near-stock ride height.


okay...

:jerkit:

vehicular 10-22-2013 07:59 PM

1.)

Originally Posted by Joe Perez (Post 1065746)
The compressed length of the spring is almost completely independent of ride height.

The only ways to fix coil bind are:


2: Lower the static ride height,

Wat



2.) I don't understand what the disconnect is here. Racelands are stupid, but they aren't in coil bind all the time.

Joe Perez 10-22-2013 09:32 PM


Originally Posted by vehicular (Post 1065787)
2.) I don't understand what the disconnect is here. Racelands are stupid, but they aren't in coil bind all the time.

Nobody ever said they were.

Discussions of coil bind are completely independent of judgements as to the relative merits of one damper vs. another. The suggestion was put forth that adding spacers between the spring and spring perch was somehow different from adjusting the height of the perch itself, and I am debunking that specific observation.

buffon01 10-24-2013 04:39 PM


Originally Posted by Joe Perez (Post 1065746)
I'm not sure why you think this.

The compressed length of the spring is almost completely independent of ride height. It's a function of the spring rate, the length of the spring, and the weight of the vehicle. So, for a given vehicle weight, spring length and spring rate, the compressed length of the spring will be the same regardless of what the ride height is and how it was achieved. Thus, so will be the amount of free travel available before coil bind occurs.


If his current combination of spring length and ride height (as a function of lower spring perch location) mean that he is in coil bind at full compression at present, then lowering the lower spring perch and adding back in an equal amount of spacer to achieve the equivalent ride height will not fix anything- he will still encounter coil bind at precisely the same point in compression travel. The only ways to fix coil bind are:

1: Shorten the spring (best),

2: Lower the static ride height,

3: Raise the position of the upper spring perch relative to the chassis, or

4: Artificially limit compression travel, such as with bumpstop spacers (not a good thing.)


I was under the impression that instead of getting the spacers I could get a longer spring, but that conflicts with 1 (shorten the spring)... I'm confused.

SK-NZ 10-26-2013 10:35 AM

I'm going to go ahead and take a wild guess that what you need is a spring with larger spacing between each coil(I have no idea for the terminology here) of the spring.

So instead of:
\
\
\

It becomes:
\

\

\

etc

matthewdesigns 10-26-2013 12:32 PM

I'm still using the Racelends that the PO installed on my car, because cheap. I replaced the rear springs with 7"x250# QA1s and still had coil bind. Then I found a set of 8"x250# Eibachs which also have a smaller wire diameter. Now I have no coil bind issues whatsoever, have the height at roughly 4.75" to the weld, and the ride is somewhat less intolerable than before. OP this is probably your best bet for a cheap fix.

Stealth97 10-26-2013 01:24 PM

I feel more dumber after reading this one

buffon01 11-11-2013 01:02 PM

Thanks for the comments. The car seems fine for now. I'll update later if anything changes.


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