Fitting Porsche Brakes to a 1302

[vujade]

I have a 71 1302 Super. I would like to adapt Porsche Brakes to the front and rear. I know that you can adapt 944 suspension to the rear of any IRS & to the front of a 1303.

So what about the front of a 1302?
What can be done?

I have seen some that adapted a beetle hub to a porsche rotor, is this an option? what is entailed?


Please help....I want to know what my options are!

[Jim Andritsakos]

Hello Vujade

You have mail!

[Supa Ninja]

Thats a good question Joe.

[vujade]

I am currently talking with Jim on a few alternatives for adapting Porsche disc brakes to a 1302 other then upgrading to the later 1303 suspension... I will keep everyone posted

[yetibone]

We are about to try '87 944 hubs, calipers, and rotors on the
front of a "71 SB (after striking out with CB's disk conversion)
I'll let you know how it goes.
Yetibone

[vujade]

please do keep us posted :)

[Pillow]

http://www.kerscher-tuning.de/kaefer/detail.php?id=110

Would that work to mount a Super with 944 spindles?

Sorry I do not know the difference between a 1302 and 1303. Use US terms :) LOL

[Supa Ninja]

Adrian
The 1302 is the flat windowed 71-72 Super and it has a three bolt strut, mid year 73 they went to a two bolt strut which looks amazingly identical to 924/944 struts and it isn't difficult at all to convert to a 944 spindle.

Nick

[yetibone]

I think that the way to get a 1302 ('70 to early'73 SB) to work with 944 spindles is to get a pair of lower control arms from a 1303 (late '73 on up) I just found a set in Durham NC. 1303 control arms have ball joints that press into the control arms from the bottom, and have the ball stud pointing upwards.
944 spindles look much like late SB spindles, except they have provisions for mounting a caliper directly to the steering knuckle instead of to an adapter. I intend to use the 944 struts as well, except with SB springs as the 944 springs are much too stiff for a rear engine car, and with stock 1302 strut crowns.
The problem I am experiencing is the difference in the ball joint ball stud diameter. 944 ball joint ball studs are larger than 1303's.
Same is true with the tie-rod end ball studs. Anybody know what ball joints, and tie-rod ends to use?
yetibone

[Michael Ghia]

Get in touch with CSP. I think they're making balljoints to replace the standard 1303 bottom balljoints but they're the correct size to fit your 944 spindles.
Mike Ghia

[yetibone]

Cool banannas!
Thanks for the reply Michael. How do I contact them? Do they have a website?
Yetibone

[Michael Ghia]

Yeti... I got it wrong... it's Kerscher who make them.
http://www.kerscher-tuning.de/kaefer/detail.php?id=110

MG

[Pillow]

Thanks for the clarification Supa!

[Michael Ghia]

Pillow, sorry mate... didn't see your post for looking... I was too busy flicking through to answer :)
Cheers bud
MG

[yetibone]

Thanks for the link Mike. I've contacted them and just heard back today.
The closest fit I could find for those ball joints are ones for a Dodge Omni (EEK!):toilet:



Oh... yeah, I also found out that the spindles and hubs we are using are from an '86 944, not an '87 like I thought before (I've honestly never dealt with any Porsche parts before other than working on a '76 914 2.0, so I didn't know) The brake rotors bolt on the back of the hubs we are using. I don't think this should cause any problem though.

[piledriver]

Hate to ressurect a long dead thread, but I'm just getting into the upgrade fresh after stumbling onto a dead early 944...

The Omni was just a literally slightly scaled up copy of a VW Golf, so I don't see an issue using teh ball joints if they fit, they likely came from the same factory.
(Many parts are actually interchangeable, the early Omnis even had had 1700cc VW engines in them)

The Mk1 Golf ball joints appear like they could be easily turned on a lathe for a press fit, but if the Omni ones work dimensionally, they may very well be precisely what Kerscher is selling for ~$80 a pop. (For a $12 item available at any FLAPS)
I will be checking them out.

I'm also curious if a Golf strut would work...

The rear Golf springs are about right, and rear Porsche 914 springs as well for use with the 944 struts.

[Bug@5speed(US)]

Pile,

Keep us posted on your Omni excursion.. I may need another set of kersher balljoints and would hate to find out I was paying way too much..

VR
ALex

[piledriver]

Anyone have the OD for the stock 1303 ball joint handy?
(and perhaps the length of the late arm)

The ~1980 version of the Omni BJ looks close... As does a Chrysler minivan.
Same style as the 1303s, but retained with a snap ring.

I'm wondering if I could stick them in some Chromemoly plate and weld to the existing 1302 arm, wrap around style.
Not looking at one at the moment, not sure if that's even practical, but would be able to set the width a little longer to cure any positive camber issue.

A extended/welded early steel (forged?) arm could almost certainly be stronger than the stamped steel 1303 arms, and could be easily designed to take the common Omni or perhaps minivan BJ.

Another possibility is add just a tab of CrMo and bolt on a Golf/944 BJ, seems to be more common and cheaper, same basic concept, depends on dimensions,.
Saves having to buy a late sway bar, too.

The bit of steel I'm visualizing would only cost a few bucks. Have a good welder handy, and the 1302 arms will be no loss if I have to use the 1303s.
Have a spare set anyway...

[evilC]

I changed the bottom arm of my 1303 to a fabricated one with a platform for a standard 944 bottom ball joint that are bolt on not press in (thats a BIG plus in my book). I then was able to use the 944 struts complete with spindle, brakes etc. The advantages of the standard 944 ball joint are that they are off the shelf and are very easy to change.
On reflection I should have used a Heim joint with a fabricated pin to fix into the bottom of the spindle carrier that would have allowed greater camber adjustment. that will now have to wait for the A arms that I intend to fabricate.

evilC

[Simon]

On reflection I should have used a Heim joint with a fabricated pin to fix into the bottom of the spindle carrier that would have allowed greater camber adjustment. that will now have to wait for the A arms that I intend to fabricate.
Interesting point!
Are you sure a heim joint can handle such a large axial load?
Aren't there any high angle ball joints available that would fit?

[piledriver]

Still have the overall dimensions for that fabricated arm?
I'm chafing to get on this.

The high angle ball joints I have seem have a very short service life.

I went up and looked again at the 1302--- I see no reason an extension of the existing arms wouldn't work.

The 944 and a Mk1 Golf use the same ball joint AFAIK. That would be the easiest way.

FWIW---

Found a mid-year 944 yesterday at Pick-N-Pull (or mabe it's U-Pull it...) in Garland, Texas yesterday.

Mid year model, steel brakes, but aluminum rear arms.
Had a small fire under the hood (really), silly thing looks easily repairable at first glance.

Seems essentially complete other than the wheels. Still has 1 phone dial on it.

[evilC]

Interesting point!
Are you sure a heim joint can handle such a large axial load?
Aren't there any high angle ball joints available that would fit?

We are talking normal formula race car detailing here and the loads on a beetle front suspension are infinitely smaller. when was the last time that a beetle managed a 3G lateral load??????

evilC

[evilC]

[QUOTE=piledriver;67321]Still have the overall dimensions for that fabricated arm?
I'm chafing to get on this.

The high angle ball joints I have seem have a very short service life.

..............................QUOTE]

I'll have a look. I was not completely happy with the design as I tried to incorporate a caster adjustment in the bottom ball joint mount - hence my desire to create a compression strut fabricated bottom arm (think of the Japanese Racer with the caster adjusting rod (tension rod) on the cab side of the main track arm.:rolleyes:

I did some very quick calcs on the angles involved and it wasn't that bad especially with a lowered suspension say 40-50mm.

evilC

[piledriver]

Interesting article/pics.
http://www.sportcompactcarweb.com/tech/0508_sccp_making_it_stick_part_3/index.html

Particularly the monoball installed on the Sentra LCA...

Checked out Coleman Racing the other night, good stuff, cheap.

As to the caster, it's too bad the SB sway bar/forward link isn't threaded...

The super long lower arms on the 1302/3 make a great starting point geometry wise.

[evilC]

I don't like the SB AR bar to control the caster as there is too much compliance in the system even with reasonably hard PU bushes. Thats the main reason why I want to use a compression strut to triangulate the TCA that will afford adjustment for caster and locate the bottom strut joint more precisely. Also, the AR Bar mount then is located with double heim joints that will allow adjustment of the fixing location, altering the lever arm on the AR bar itself that means that the roll stiffness can be altered.
Finally, another advantage of dislocating the AR bar from the TCA is that the anti-dive can be dialed in on the inboard 'A' arm mounting points rather than lowering the AR bar with all the compromises that that entails.

evilC

[piledriver]

Locating links w/spherical ends and using a "normal" sway bar sounds better, and shouldn't be too hard to pull off.

Might even be able to improve the geometry at the same time,

Slightly off topic:
Do 944 seats fit easily in a later SB?

[STIDUB]

just a quick question, are the 928 944 968 etc the same for their somewhat bolt on characteristics, or is it just the 944?

[evilC]

Locating links w/spherical ends and using a "normal" sway bar sounds better, and shouldn't be too hard to pull off.

Might even be able to improve the geometry at the same time,

Slightly off topic:
Do 944 seats fit easily in a later SB?

I currently have a new fabricated TCA (50 x 30 x 3.03Kg) with PU bushes for the AR bar and inner pivot; dropped inner pivot point to drop the roll centre; flipped AR bar with PU bushes. The outer ball joint is on an adjustable carrier to set the caster from around 2 deg to 5 deg. It works but as said the A arm/compression strut would have been a better solution. The amount of fabrication just to put the spherical links in with a normal sway bar means that it is but a little step to do a full A arm fabrication that incorporates less adaptation (botches) to acheive a much better result.

evilC

PS I have fitted Alfa 116 GTV seats that are similar to 944 ones - God! the drivers seat is heavy (height adjustable)

[yetibone]

Man, y'all had to blow the dust off this thread! :lmao:

EvilC, I think what I ended up doing with my front end is similar to what you've got planned. I started with late 1303 control arms, and added a triangulating member that connects to the frame head with a 13mm heim joint. The sway-bar is no longer a structural member of the front suspension, so I connected it to the control arms with drop links. By screwing the heim joints deeper into the triangulating arms I fabbed onto the stock control arms, I can increase caster.

pics and such from another thread (http://www.germanlook.com/Forums/showthread.php?t=5536&page=2) Pictures of the completed arms are a couple of posts down the page.

The difference in driving the car is noticable. The steering is much steadier under hard braking.

[evilC]

The way you did goes some way to what I am thinking but there are a few points of difference:
1) The stock TCA will be discarded and a new A arm in CHS will be fabricated with the triangulated link being in compression rather than the tension arrangement you have, the connecting point of the triangulation being closer to the stub axle end. I'm not sure yet whether the inner bush will be retained or bit the bullet and go full heim joint.
2) The ball joint end will have a heim joint to enable the camber to be adjusted.
3) The compression strut of the A arm will have a heim joint at each end to enable the caster to be adjusted in situ.
4) The AR bar will have a separate pair of heim joints as yours but will be solidly located to the A arm and not through the old TCA bush.

I am expecting better control under braking as you experienced as well as better responsiveness in the corners, all of which should aid confidence in the car.

evilC

[Simon]

The way you did goes some way to what I am thinking but there are a few points of difference:
1) The stock TCA will be discarded and a new A arm in CHS will be fabricated with the triangulated link being in compression rather than the tension arrangement you have, the connecting point of the triangulation being closer to the stub axle end. I'm not sure yet whether the inner bush will be retained or bit the bullet and go full heim joint.
2) The ball joint end will have a heim joint to enable the camber to be adjusted.
3) The compression strut of the A arm will have a heim joint at each end to enable the caster to be adjusted in situ.
4) The AR bar will have a separate pair of heim joints as yours but will be solidly located to the A arm and not through the old TCA bush.
Are you planning on doing this?

Just to be sure:
Would you still use the inner mountingpoint of the stock LCA?

I've always wondered why the 935 setup uses a tension arrangement, nice to see you'd use a compression one :)

I know i've said it before, but a heim-joint/rod-end at the outer side of the A-arm isn't really good design. the axial load is OK (though it's made to withstand a much larger radial load), but mainly because of the bending you apply to the shank of the rod-end.
A spherical bearing mounted in the A-arm is a much better design.

And do you think you'll gain a lot with adjustable caster?

[pantswagen]

http://www.kerscher-tuning.de/images/dynpic.php?file=L2thZWZlci9ncmFmaWtlbi8vYnJlbXNlL2 Z1ZWhydW5nc2dlbGVua19ncm9zcy5qcGc=&width=500
http://i10.ebayimg.com/02/i/001/0f/87/122f_1.JPG
http://www.kerscher-tuning.de/images/dynpic.php?file=L2thZWZlci9ncmFmaWtlbi8vYnJlbXNlL2 Z1ZWhydW5nc2dlbGVua19ncm9zcy5qcGc=&width=500
http://i9.ebayimg.com/01/i/001/0b/c2/803a_1.JPG
http://i14.ebayimg.com/07/i/000/d9/01/6ce0_1.JPG
got to be a vag part

[Simon]

got to be a vag part
Why do you think so?

[Axl]

Man , I'm a mechanic , and you guys are into this beyond what even I would have been thinking of . This thread has got me thinking more about what I'm going to do . The one thing I was thinking about when someone had mentioned about the ball joint shaft being too large is that you can get a tapered reamer to enlarge the hole for the joint , if you want to use that spindle .