Coil Over Conversion legality?

Hi everyone,

I've seen a few coil over conversions come on the market for VW's over the years. Basically, these do away with your torsion bars/leaves and replace them with some form of arm retainment and a coilover set-up.

I have started a thread regarding the type 3 items over on thesamba: http://www.thesamba.com/vw/forum/viewtopic.php?t=300455 there are also links to items from Remmele Motorsport for the type 1 conversion.

I know a fair few of you guys have had extensive dealings with Engineer Certificates over the years and would like to know (from your experienes) if such a set-up (front or rear) would stand a chance of getting passed on our shores?

Cheers,
Cam

many of the coil-over conversions use the OE shock absorber bolts/mounts. That's a no-no as it puts load into the chassis where it is not designed to take it

From what I can see with air-bag conversions they use a similar mounting system and since they govern ride height must also be load bearing, is this correct? Could following the same design/strengthening principles when planning a coil over conversion be the way to go?

Hi there,
I have also heard that the cast (forged?) shock-absorber top points on the rear are not designed to be load bearing, however I tend to disagree with that sentiment to some degree.
As the whole chassis is not so rigid in stock form anyway - if you are looking at coil-overs you would by matter of course also be looking at increasing rigidity in the whole chassis.
Therefore, you would likely be also looking at making use of the rear 3 bar brace type that is available from manufacturers such as CSP or Remmele. There would be no problems using coilovers if you also used such a design.

Still does not answer the thread question - In ACT I have heard that coil-overs are now not legal. Likely to be similar in other states. This is a typical government reaction - and in essence it solves nothing. When was the last time you saw an accident that was caused solely by the fact that the car was lowered?

I have never seen a standard vw top mount bent by ANY means other than a crash or severe missuse. they were made with longengivity well in mind just ask any offroader. however the aim of the game is more to put weight in the centre of the car so a pushrod style setup would be more advantagious.

The Stump wrote:Hi there,
I have also heard that the cast (forged?) shock-absorber top points on the rear are not designed to be load bearing, however I tend to disagree with that sentiment to some degree.
As the whole chassis is not so rigid in stock form anyway - if you are looking at coil-overs you would by matter of course also be looking at increasing rigidity in the whole chassis.
Therefore, you would likely be also looking at making use of the rear 3 bar brace type that is available from manufacturers such as CSP or Remmele. There would be no problems using coilovers if you also used such a design.

I agree, that would certainly be the way to go. I'm sure if Remmele's item is TUV approved and you bought a complete set-up including bracing then it would make engineering locally a hell of alot easier!

I agree, Mac. They are strong as f*&%!!!
I see where you're coming from with the pushrod idea, but aren't these more popular on openwheelers due to wind resistance issues? Probably overkill on a hardcore streetcar.

I was thinking about VWCOOL's point again and recalled that on the K&L front ends the bump stop's are mounted onto the sides of the beam and operate seperately from the shock absorbing system. Whereas, the BJ has a bump stop within the actual shock absorber, hence the total redesign of the shock tower to more of a pseudo strut tower design?
This should surely mean that the shock mounting points were designed with the intent of taking a load (that of the car crashing down beyond the travel of the leaves & shocks) far beyond what the suspension could handle to stop the chassis/body coming into contact with the road, well beyond what could be considered load bearing?

I'm in no way an engineer, nor pretend to know about suspension design, so tell me if I'm heading down the wrong track with this theory (constant loads vs shock loads, et...)

I keep thinken about this i will ask a mate if he will certify a BJ front end with coilovers anyone got an idea of thespring rate poundage needed for a serious street beetle?

it seems like a good upgrade... No idea on the spring rates, maybe he can tell you what the safe/acceptable limits would be?

On the front?
I would have no hesitations on putting coil-overs on - and in fact I am planning that myself.
As for appropriate springs to use, that is something I have yet to find out.
A good start would be to perhaps buy the GAZ coil-over shocks from UK. As they are designed for the very purpose. From there you should be able to take the springs into a suspension specialist and get them rated on a spring gauge. From there you can decide if you feel you want something a little firmer or softer.
The only other thing I would consider is adding some additional bracing to (and probably seam welding) the front ball-joint beam. Seam welding will ensure that the pressings do not come apart under any flexing (more reliable than just the spot welds). Bracing will likewise reduce flexing and provide a more positive steering and cornering response.