Porsche 944T brakes on VW 1303S

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H2OSB
Posts: 672
Joined: Mon Aug 21, 2000 2:01 am

Re: Porsche 944T brakes on VW 1303S

Post by H2OSB » Fri Nov 29, 2019 1:56 pm

Your last statement is correct. The original adjust-a-strut as well as the subsequent Topline Maxx strut were literally Mk1 length, and Mk1 inserts were used.

As an interesting side note, my second 1303 has coilovers based around Porsche 944 strut housings. It wasn't until after I pursched the Porsche struts and had them in hand that I realized 944 strut are IDENTICAL to 1303 with the exception of the brake hose tab location and the 944 strut has a slotted top hole for camber adjustment. I went ahead and used the 944 housings since I'm currently also using 944 spindles(I may swap back to 1303 spindles and a set of Lanner Khan front disc brakes), and wanted as much camber adjustment as possible.

In a recent effort to eliminate an oddly random Super shimmy on my '73, I replaced the urethane inner control arm bushing with a set of the extra eccentric bushings from Topline. Somehow my first attempt at adjustment yielded some very strange results. The absolutely steller front handling was replaced by very light and squirrelly handling. Since the lowered suspension already had far more camber than needed, I dialed out as much as I could and raised the coilovers up by about an inch. I actually rotated the eccentrics so the inner end of the control arms were at their highest position relative to the outer end, thinking I may have been experiencing bump steer(trying to rid myself of the parallel to the ground control arm angle). I probably should have only done one thing at a time, however, because I did correct the light, twitchy steering, but now the front is higher than I prefer. I suspect my control arm adjustments probably solved the issue.

Ugh, we should probably start our own thread.
H2OSB

TZepeSH
Posts: 303
Joined: Wed Nov 03, 2004 1:55 am

Re: Porsche 944T brakes on VW 1303S

Post by TZepeSH » Thu Dec 19, 2019 2:00 am

Coming back to my question, what is the stock angle of the struts?

TZepeSH
Posts: 303
Joined: Wed Nov 03, 2004 1:55 am

Re: Porsche 944T brakes on VW 1303S

Post by TZepeSH » Tue Jan 14, 2020 5:23 am

I found this topic on the other site, with very nice 3D models of Bug vs 944 spindles. I think I can get all the info that I need from there. It appears (as suspected) that with my current setup I have massive positive steering radius... And I now understand that I was not looking for the strut angle, but for the steering axis inclination, which goes through the strut top flange and the center of the ball joint.
https://www.thesamba.com/vw/forum/viewt ... sc&start=0

H2OSB
Posts: 672
Joined: Mon Aug 21, 2000 2:01 am

Re: Porsche 944T brakes on VW 1303S

Post by H2OSB » Tue Jan 14, 2020 8:40 am

Yeah that was a neat set of renderings. Explained exactly how you could modify 944T spindles to work on a 1303.

H2OSB

TZepeSH
Posts: 303
Joined: Wed Nov 03, 2004 1:55 am

Re: Porsche 944T brakes on VW 1303S

Post by TZepeSH » Wed Jan 15, 2020 6:13 am

Personally, I wouldn't modify the 944T spindles that way. Welding and drilling on a spindle is risky from my point of view. I would expect that it is not just plain steel, but it is heat treated for added strength. If the welding adding material is softer, that might be bad news. You can find the results of poor design of suspension parts in many news; one good example is the Audi Q7 which had major problems at the beginning with spindles that simply broke off... Much easier (although not cheaper) to use dedicated struts for the conversion: I have Kerscher, another friend had a pair done in the UK (I think). And when you go to such a modification, I think money is not necessarily the blocking point.
Anyway, back to the topic: to have the correct scrub radius, I would need wheels with ET51. But none of the 15" 51ET wheels fit over the Brembos. All following calculation are relative to stock sports wheels, 5.5J ET26. So the closest I can get would be with 951 15" Phone Dials which place me at ~17mm positive. I think I can live with that. The current setup with Cookie Cutters and 21mm spacers place the wheels at ~38mm positive... If I am to reference to stock 4.5J ET41, numbers are even worse.

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