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-   -   CNC made aluminum Uniball rear suspension system (https://www.germanlook.net/forums/showthread.php?t=11413)

Wally June 18th 2012 05:36

I think what Turbonutta wanted to know is what is it that fysically limits travel eventually.
My guess is its the end/limit on the damper itself that limits downward travel.

owdlvr June 18th 2012 13:53

Quote:

Originally Posted by Wally (Post 84078)
I think what Turbonutta wanted to know is what is it that fysically limits travel eventually.
My guess is its the end/limit on the damper itself that limits downward travel.

If this is the case...its going to void the warranty on any commercially produced damper out there. I'm not aware of any company that doesn't require external limits for both upwards and downward travel.

For my car, to keep the QA1 warranty I have the stock bumpstops in place for upward travel, and installed limiting straps for downward travel. I'll try and snag some photos of my setup the next time it's up on stands. The limiting straps for suspension drop were a fairly significant puzzle to sort out!

Anyone looking at uniball setups should be aware that the car doesn't need to take air for full droop to occur, and with it possible damage to the damper. This is an issue for _all_ uniball options, since the stock downward limiter is eliminated.

-Dave

Turbonutta June 18th 2012 14:21

yes wally you are correct i wanted to no what limited the downward travel, maybe a limiting strap or simular could work, is the shock strong enough to limit travel, i know its only going to its limit when on a jack or going over a hump

im still trying to decide if i want/need a set of these as im still fitting my alloy arms

-Alex- June 20th 2012 07:31

Yeah, shock limits the downtravel first probably. After it, the uniball joint hits to housing parts. Max safe angle is 65 degrees for joint.


http://img839.imageshack.us/img839/60/maxtravel.jpg

Wally June 20th 2012 07:53

That doesn't look like a problem at all: the front Mc Pherson struts are limited also by the shock's max downward travel. All other OEM cars also I think? Only inward travel needs an external limit as the whole car then needs to be slowed down. Full downward travel just needs to slow down the weight of the wheel and suspension. The down travel being dampenend by the shock's action anyways, so the 'bump' will be minimal I would think.
Why you think thats a problem or voids warrenties Turbonutta?

Limit straps originated from swing axle gearboxes imo where you didn;t want the suspension going extremely positive on camber ('tucking under the car') which caused lot of accidents back in the days iirc. If the shock isn't overly long, your CV's will cope and there is no problem. Or am I missing s/th?

owdlvr June 21st 2012 00:51

Quote:

Originally Posted by Wally (Post 84093)
That doesn't look like a problem at all: the front Mc Pherson struts are limited also by the shock's max downward travel. All other OEM cars also I think? Only inward travel needs an external limit as the whole car then needs to be slowed down. Full downward travel just needs to slow down the weight of the wheel and suspension. The down travel being dampenend by the shock's action anyways, so the 'bump' will be minimal I would think.
Why you think thats a problem or voids warrenties Turbonutta?

Front struts as used in MacPherson strut assemblies are designed with an internal bump stop as part of the strut. This is not the case with all shocks out there, and it's far more likely the rear coil-over shocks used by most GL folks do not have internal bumpstops. I don't have the QA1 documentation handy, but it specifically mentioned installing suspension limiters for both upwards and downwards movement to protect the piston and valve assembly from possibly topping or bottoming out. The documentation was clear about how not having limiters (in both directions) would void the warranty.

Every shock is different, and since they're typically not used in the intended application people should be checking. For my QA1's, I had to install limiting straps to ensure the shock doesn't top out. Anyone who's running these shocks without, is running without a warranty and potentially damaging the valving.

-Dave

Wally June 21st 2012 03:09

Quote:

Originally Posted by owdlvr (Post 84102)
Front struts as used in MacPherson strut assemblies are designed with an internal bump stop as part of the strut.

Where in a Mc Pherson strut is the rebound limiting?

Inbound is clear with the rubber boot thingy in there, but what is there for full extension?

Seriously, I really wouldn't know.

owdlvr June 21st 2012 11:54

A strut cartridge designed for a macpherson strut front suspension will have an internal rubber (or similar) disc which keeps the valves from contacting the shock body on full extension. This is also found inside the mono-tube style shocks used on the torsion bar front suspension in a beetle. I can't say for sure if it's found in the design of the rear monotubes (stock style shocks), but it doesn't matter as the stock spring plates keep the suspension from fully extending the shock.

Universal coil-over shocks are designed without any internal protection, and its accepted practice in dirt-track racing that limiters are designed in the suspension linkage for both bottom out and top out. The only shocks I can't confirm are the Fox shocks, as there is nothing online about the requirements. This isn't too surprising though, as there was nothing online about the QA1's...it's only because I read the materials in the box that I realized.

I will get photos of my limiting straps up soon.

-Dave

-Alex- July 3rd 2012 17:07

Here is a second version which i have designed. The housing is one piece desgin and also uses M20 joint instead of smaller joint what MBT and Remmele are using.. Goes down under :)


http://img684.imageshack.us/img684/9...ll944aluar.jpg

http://img405.imageshack.us/img405/9...ll944aluar.jpg

Wally July 3rd 2012 17:32

Like!
I hope I can afford a set one day.

-Alex- July 4th 2012 03:22

I am not sure that can i get done these single piece uniball housings at locally. For this i need quite big block of aluminum and also needs time at lathe, if nice looks at outer surface is needed.


I have to ask if someone wants this style.

kendy August 2nd 2012 08:09

Hi

But what about absorbers? What will fit for this system?

Regards
Kamil

-Alex- August 3rd 2012 15:13

Remmele sells coilovers what will fit well to rear. Also here at the forum is more info about rear coilovers. QA1, Koni and AVO are quite popular.

kendy August 4th 2012 04:09

but i cant find fx QA1 dealer in Europe :( Only Kerscher - 880 E/pair - what about remmele price? Do u know?

-Alex- August 4th 2012 06:50

Does it matter really? I bought QA1 coilovers from autofabcart, not so expensive. Shipping was $72.

Remmele shocks are also expensive, around 850€ about 200€ more than QA1.

http://remmelemotorsport.com/fahrwerk.html


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