shocks mount options on T1 with 944 arms

[zen]

here are some options i am aware of:

1. reducing stud 14mm -> 12mm for the arm to shock respectively.
2. drill the bottom shock bushing sleeve to 14mm (not a very safe option though)
3. replace the bottom shock bushing and sleeve with a 14mm (no kit known of by me at this time)
4. sleeve the top bushing of a 14mm shock down to 12mm with a 2mm thick sleeve.
5. use a threaded insert in the trailing arm to knock it down from 14mm to 12mm.

has anyone ever drilled the top shock mount hole from 12mm to 14mm and run a shock with 14mm over 14mm? thoughts on this? i assume stock 944 shocks would work.

what about making a bolt for the top mount by turning down a 14mm bolt at the end and thread for 12mm? go through the shock then into the mount and nut it appropriately. should be easier to get ahold of the right size donor for that than option 1. thoughts?

[boygenius]

Do the porsche shocks have a 14mm top opening. why not use a metal sleave that is 12mm I.D. and 14mm O.D. to take up the the extra space. They would be the cheapest option to manufacter and would work on the greatest number of applications.

[zen]

doh, forgot to mention that one. also was thinking about that solution for the trailing arm. just use a threaded insert. i will update the options list above to have these.

[boygenius]

Originally Posted by zen

doh, forgot to mention that one. also was thinking about that solution for the trailing arm. just use a threaded insert. i will update the options list above to have these.

Like a timesert???

[MattKab]

I recall the 944T rear shock being much thicker, and much longer than a T1 piece.

The bush in a shock mounting eye is bonded into the rubber. Yes they can be pressed out. I considered this option, drilling the rubber out to say 17mm and then pressing the 944 bush into the drilled out rubber. This would obviously require a thick washer each side to keep the bush secure in the rubber.

Another option would be to cut the lower mounting eye off the chs T1 shock and weld the 944 eye/rubber/bush to the bottom. But welding a shock absorber that is already charged is borderline ridiculous IMO.

The problem I see is being able to torque the M14 thread up enough so that it stays tight. Which is the downside of drilling out the 12mm bush.

My T1 arms/yellow Koni's have been 14mm at the bottom for nearly 2 years now. Used daily too. I use locknuts on the lower bolts.

A die-cut 12mm thread on an 8.8 M14 will not be as strong as the original rolled M12.

Have you noticed the ball-ended coil-overs that seem favoured when using 951 arms on an IRS T1?

When the ali arm is fitted to the chassis, the M14 lower bolt (Porsche) and the top M12 bolt (VW) are not paralell. Look at the $75 adapters, notice how the shock will be spaced away from the arm? These 'look' made for fitting 951 arms to an NA 944. Which will surely have the same indifference as the T1?

Matt

[zen]

Originally Posted by MattKab

Have you noticed the ball-ended coil-overs that seem favoured when using 951 arms on an IRS T1?

When the ali arm is fitted to the chassis, the M14 lower bolt (Porsche) and the top M12 bolt (VW) are not paralell. Look at the $75 adapters, notice how the shock will be spaced away from the arm? These 'look' made for fitting 951 arms to an NA 944. Which will surely have the same indifference as the T1?

Matt

i haven't see these. do you recall where you saw this?

[MattKab]

Originally Posted by zen

i haven't see these. do you recall where you saw this?

I first saw this when I mock-fitted a 951 arm up to my car.

I've just checked the gallery to no avail. I have a great picture of Stuarts '79 with Remmele coil-overs and 951 arms that clearly shows the alignment correction only offered by spherical bearings.

The rubber in the mountings will just about deflect enough to get the 2nd bolt in, but when you see this, you too will lose all faith in such a mis-fit. The strain will cause premature failure of the rubber as you'd guess.

I'd like to see how the shock is mounted at the top on a 924/944 and a 951 side by side.

Matt

Here's Stuart's top and bottom bolts:

[Maynard]

You can get replacement rubber at most auto supply stores. I found some Energy Suspension urethane bushings at one store. I ended up drilling out the original sleeve, but I don't like the results. It is not perfect and I think it may be too weak (part of the reason I went with urethane). If you have some used 944 shocks and can press out the sleeve successfully, you could probably use it with the aftermarket bushing. I will probably have a machine shop make new sleeves for me.

[zen]

maynard, are you seeing the same shock alignment issue mentioned above? did you space out either end of the shock?

[boygenius]

I used some rounded chrome washers to space my shocks out from the trailing arm. I will try to post some pics later.

[Maynard]

Originally Posted by zen

maynard, are you seeing the same shock alignment issue mentioned above? did you space out either end of the shock?

I did have some mis-alignment, but it seemed minimal in my case. I had no problems at all installing the bolts and did not add spacers (although I did consider it for the top). Maybe it could potentially cause some premature wear in the bushings, but now that I found replacements I wasn't as worried about it.

[Xellex]

Sorry to dig up this old thread, but what's everybody using nowadays for this bolt issue?
At the moment I'm using the 944 original shocks with their respective bolts, mostly as a mock-up because I'm not driving it.
I want to get Koni shocks but that will bring up the bolt problem.
Are you guys modifying the bushings or using reducing bolts? And if so, where from? I've sent a mail to MBT but they are not responding.
Any1 know who made these? Lanner maybe?

[evilC]

I have 924S (944) alloy arms with spax PSX kit dampers on the rear of an '03 bug. The set up is use the standard 12mm top bolt and ream the bottom bush to 14mm. The amount of metal left is acceptable in the metal bush especially as the damper is not under load unless you use a coilover. If you are using coilovers then its a different ball game in anycase and certainly the 12mm top mount is not sufficient to tat the loadings of anything more than a helper spring.

evilC

[jmd]

I am about to install 87' (wide) 944T Trailing arms, spring plates and Torsion bars on a 69 Chassis.

In doing so I am considering the suspension and am wondering about a coil-over setup versus some more traditional Koni type deal. I am running an STI engine and Porsche 901 Trans so that brings additional weight to the chassis... I am also putting a cage on the chassis (a bit of a cage anyway) The fuel tank will stay in the front as well as the radiator and fans.

I am expecting my 'bare running chassis' to weight in about 2-400lbs more then stock...

So is there anyone running 87 wide-arms and torsion bars if so what is your suspension choice?

anyone else have thoughts on how to overcome clearance issues?

[evilC]

i assume the torsion bars are the 25mm ones? If so, the increase in spring rate will probably be about right for a quick street machine with the extra rear end weight. If you want to be more precise in the adjustment you could reduce the torsion bar to the N/A one 23mm (a Type 3 ones the same) and add a light coil over so that you can select the correct overall spring rate for your application/preference.

With that extra weight bouncing up and down on the rear a six point kafer cup brace would be a worthy investment as it stiffens up the frame horns as well as the damper mounting point and providing substantial lateral stiffness.

evilC