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eviloval Samba Member
Joined: May 03, 2003 Posts: 208
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Posted: Wed Dec 28, 2016 10:11 pm Post subject: Re: Porsche 944 Brake conversion on 1303 |
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H20SB check your pm's. In regards to the 944 spindle mod....I just hit it with a die grinder till I got some adjustment out of it (and still had some meat left). Nothing fancy about it. The problem is that everything was maxed out adjustment wise and while my wheels looked like this || I wasn't too thrilled about having nothing left on adjustment. The camber plates would of given me a little more adjustment to make the whole thing work. But, since I was using stock fenders the offset created by using the 944 spindles, hubs and 1303 control arms pushed my wheels even with my fenders. So, either I had to go to stiffer springs, raise the car up further or endure having the fender come down on the tire on hard cornering. And while most of my driving would never encounter this issue its when I wanted to drive the back roads and do some spirited driving I would run into this problem.
I resolved it by going to a 1302 suspension with lanner's custom 944 hubs. The 1302 suspension brings the wheels in 3/8" to 1/2" of an inch. Enough to clear the fenders and allow me to drive it like I stole it (with some mods to the fender of course). Would love to hear more about the 924 spindles since it could be a better alternative than what I'm running. I love the custom hubs, but....if something goes wrong its a custom part. I can't just go on craigslist or partsheaven and pick up another. That has been the draw back to this whole modification....parts that are custom or not something I can pick up at a dealer.
I had gotten to a point where I was looking to remove the strut mount to the spindle and raise that mount as much as a could without touching the control arm. This would make the spindle angle in more creating camber to get my wheels to look like this /\. It wouldn't take too much distance to create the camber I was looking for. The problem was that the spindle would need to be modified slightly since it would pivot more. So, the strut mount would not only need to be moved up but made longer for the bottom bolt to engage. This would also have an added effect of lowering the car further....what ever distance the strut was modified. I even think I talked to Jon at topline about the modifications and I believe he may of been willing to make a special set of struts with this modification. Just, never pulled the trigger and did my homework on what needed to take place. |
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Dodgy Samba Member
Joined: January 30, 2006 Posts: 516 Location: Leicester, UK
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Posted: Thu Dec 29, 2016 12:57 am Post subject: Re: Porsche 944 Brake conversion on 1303 |
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eviloval wrote: |
When I did my conversion I had to grind away part of the meat of the 944's top spindle to allow the spindle and strut to have a camber adjustment. Without grinding the spindle you will have no adjustment short of the crash bolts. |
Yes some material is removed from the upper 'ear' of the 944 spindle
eviloval wrote: |
Interesting idea with moving the top hole of the spindle. I don't know if your car has a rack and pinion vs a steering box... |
As a '75 my car has R&P. I think the original tie rods will be long enough to link to the 944 spindles, but we'll see... I do have 4cm wider wings ready to fit, so am not particularly concerned with tyre clearance here. Anyway, we're at the opposite end to the 'narrow front end' style trend with German Look! _________________ '75 1303 (current project) owned since 1989!
'72 Squareback - full resto completed 2008 - now sold
356 Speedster kit, completed 2005 - now sold |
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H2OSB Samba Member
Joined: April 14, 2013 Posts: 1290 Location: Modesto, CA
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Posted: Thu Dec 29, 2016 8:54 pm Post subject: Re: Porsche 944 Brake conversion on 1303 |
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Both Evil and Dodgy, could I get a bit more detail regarding what material was removed? I've not run into any issue where the amount of camber adjustment seemed to be limited by some part of the spindle.
Dodgy, I'm jealous you have factory R&P. I doubt you'll have an issue with tie rod length but just because careful with it. I'm running 15x5.5 Porsche steels with ET30 and have no issue with rubbing neither inside nor out though my springs are 2.5 inch coil overs.
Evil, unfortunately I've committed to using 1303 parts so going to the 1302 suspension isn't an option but it's not a bad idea. I considered having Lanner makes some hubs for my 1303 spindles but I've done too much with 944 spindles to turn back. I will be using Porsche M calipers for better front rear bias. They not only bolt to the spindles but also are centered over the rotors.
H2OSB |
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Dodgy Samba Member
Joined: January 30, 2006 Posts: 516 Location: Leicester, UK
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Posted: Wed Jan 04, 2017 1:07 am Post subject: Re: Porsche 944 Brake conversion on 1303 |
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H2OSB wrote: |
Dodgy-- Is there any chance you can post a pic of the 944 spindle superimposed over a 1303 spindle to demonstrate exactly what material needs to be removed?
H2OSB |
Here you go...
(1303 axle in blue, 944 in green)
Unmodified 944 stub axle:
After modifications:
The parts are aligned at the lower mounting hole in these images to make the comparison clearer. in practice the 944 stub axle will sit lower as shown in the previous images.
There are other views of the overlay in my gallery. I will post an engineering drawing showing the modifications including dimensions etc once I've proved it fits in the real world in the way that the CAD predicts! _________________ '75 1303 (current project) owned since 1989!
'72 Squareback - full resto completed 2008 - now sold
356 Speedster kit, completed 2005 - now sold |
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H2OSB Samba Member
Joined: April 14, 2013 Posts: 1290 Location: Modesto, CA
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Posted: Wed Jan 04, 2017 7:47 am Post subject: Re: Porsche 944 Brake conversion on 1303 |
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Thank you so much!!
H2OSB |
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Dodgy Samba Member
Joined: January 30, 2006 Posts: 516 Location: Leicester, UK
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Posted: Sun Jan 08, 2017 11:02 am Post subject: Re: Porsche 944 Brake conversion on 1303 |
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Some progress...
944 stub axle welded and holes drilled, 'bump steer' bush fitted (press fit with stering arm heated and bush frozen):
Reshaped:
Fitted to car: (sorry for blurry image...)
My garage floor slopes in all sorts of ways, so I haven't been able to measure camber etc accurately. But initial indications show that about 2 degrees negative camber is achievable within the normal adjustment range of the standard 944 upper eccentric bolt. This is with the inner adjustment of the lower control arm set to mid position.
Looks like the standard R&P tie rods are plenty long enough to accommodate the additional half inch or so required for the straight 944 steering arms.
Will make a more accurate measurement when wheels are on etc. _________________ '75 1303 (current project) owned since 1989!
'72 Squareback - full resto completed 2008 - now sold
356 Speedster kit, completed 2005 - now sold |
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H2OSB Samba Member
Joined: April 14, 2013 Posts: 1290 Location: Modesto, CA
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Posted: Sun Jan 08, 2017 11:14 am Post subject: Re: Porsche 944 Brake conversion on 1303 |
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AHH yes! So good to see. Please, at your earliest possible convenience, PM me the address where you have the drawings with measurements. I'm filled with hope now.
H2OSB |
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Dodgy Samba Member
Joined: January 30, 2006 Posts: 516 Location: Leicester, UK
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Dodgy Samba Member
Joined: January 30, 2006 Posts: 516 Location: Leicester, UK
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Posted: Sat Jan 14, 2017 5:27 am Post subject: Re: Porsche 944 Brake conversion on 1303 |
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Mocked up the front brakes, I'm using the single piston sliding caliper type (ATE). Will be including the back plate / dust shield as per factory.
Shiny new brakes will follow when I'm a lot closer to getting this car on the road!
Photo below shows positive camber, but this is with suspension at full droop. With weight on negative camber looks OK.
One potential issue seems to be that the track rod contacts the bottom of the strut at full steering lock - primarily because the 944 has straight, shorter arms compared to 1303. However I still don't have the spindle bolted securely yet, or the spacer fitted (pry bar is in photo taking up some clearance). Will check this closely once wheels are fitted etc and I can check in 'running' condition.
_________________ '75 1303 (current project) owned since 1989!
'72 Squareback - full resto completed 2008 - now sold
356 Speedster kit, completed 2005 - now sold |
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Dodgy Samba Member
Joined: January 30, 2006 Posts: 516 Location: Leicester, UK
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Posted: Sat Feb 04, 2017 12:39 pm Post subject: Re: Porsche 944 Brake conversion on 1303 |
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So I've now bolted everything together properly and had a chance to try some Porsche rims. There isn't a lot of choice of sizes out there...
First I tried 17x7.5" ET53 (Cayenne) which were just ridiculously wide.
Second I tried 17x6.5" ET55 (Boxster) which fits nicely as shown in the picture below. Today the car sat on wheels for the first time in about 8 months!
Once it was down on the ground I was able to make a better assessment of the camber situation - result! 0deg camber is dead centre of the adjustment range! (I love it when a plan comes together!)
There is almost 3/4" clearance between the spring and rim / tyre - this is with 205/55 tyre and an 8mm spacer behind the rim. Not yet not sure the final tyre size I'll choose, and still working out the best wheel offset. From what I've read, vehicles with ABS are generally configured with zero steering radius, I think that will work out to be a 3mm spacer or thereabouts.
So with the wheel set square, I fitted the front wing (4cm oversize) and I think it looks pretty good!
It looks very W-I-D-E. Converting to the aluminium Porsche trailing arms at the rear is supposed to widen the rear track significantly - I hope so as it looks like it will need it to match the front!
What you can't see in the photo is the ridiculous amount of toe-in. The tie rods may need extending, this is the next thing I have to investigate. Certainly in the factory configuration (one fixed rod) there isn't enough adjustment, whether or not two adjustable rods can be made to work I don't yet know. Extending the tie rods is a pretty simple modification.
The steering range will also need to be reduced slightly to prevent the tyre contacting the inner wing or anti-roll bar on full lock. I believe this is also fairly simple to do, by putting spacers in the ends of the steering rack. Supers (certainly the R&P ones) had a much tighter turning radius at full lock compared to Standard Beetles, so losing a little won't be the end of the world.
It's hard to make a judgement on ride height, the car is mostly at full mass (interior is in, engine is in, but an almost empty fuel tank and missing some panels. I'm not looking at building something particularly low, but maybe the spring cups could come down 10mm or 20mm. Not something to worry about now. _________________ '75 1303 (current project) owned since 1989!
'72 Squareback - full resto completed 2008 - now sold
356 Speedster kit, completed 2005 - now sold |
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Dodgy Samba Member
Joined: January 30, 2006 Posts: 516 Location: Leicester, UK
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Posted: Sun Mar 19, 2017 12:54 pm Post subject: Re: Porsche 944 Brake conversion on 1303 |
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Some progress, finally did a trial fit of the rear suspension arm this weekend...
Went from this...
To this...
The Porsche trailing arm has to be used as the hole pitch to the cast diagonal arm is different to VW, as a bonus this includes a ride height fine adjustment via an eccentric bolt. Swapping the inner bush over from the Porsche (small bore) to VW (large bore) was pretty straightforward.
I found that the heads of the bolts between the two parts of the trailing arm need to be thinned down to about 3mm, otherwise they foul on the strut tower casting. I'd rather not fit a spacer behind the arm to add clearance as it will affect the alignment of the trailing arm and the face it bolts to on the diagonal arm. However I might yet add a spacer behind the cover plate on the outside of the arm, to account for the extra thickness of the Porsche double-plate design (+3mm). The cover plate will fit without a spacer but it is very close to rubbing on the outer face of the arm.
Oh my goodness, the back end looks W-I-D-E. Maybe too wide as the widest wing [fender] available is +6cm and the tyre sticks out beyond the standard wing by 7.5cm... This is with a Boxster front wheel (6.5" ET55), rather than rear (8" ET40), which would project further . I'd prefer to fit the same size rim & tyre to front & back anyway.
Not sure I wanted to go above +6cm wings as they start to look a bit weird. I already have +4cm at the front, which look OK.
I measure the increase in track (to the hub face) at +76mm each side. The rim projection beyond the hub face is actually pretty similar similar between the 4.5" ET 34 Beetle rim (~24mm projection) and the 6.5" ET55 Porsche rim (~27mm projection)
The original VW brake line flexi hose from the floorpan to the suspension arm fits perfectly, I haven't got to the handbrake cables yet but many others have posted solutions for these.
Another problem is the driveshafts, initial measurement looks like the VW driveshafts are around 115mm too short. I think a late 944 driveshaft (531mm) should fit, but unfortunately I don't have the ones from the donor car that supplied the suspension to try them out. The 90mm VW CV joint will fit the Porsche driveshaft at the gearbox end (a 3mm spacer will be required under the circlip).
The VW damper does fit, but the tube in the lower bush needs to be removed to allow it to fit closer to the arm and accommodate the larger lower bolt. It's at a slight angle compared to original installation, but not enough to cause concern.
One step closer... _________________ '75 1303 (current project) owned since 1989!
'72 Squareback - full resto completed 2008 - now sold
356 Speedster kit, completed 2005 - now sold |
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racoguy Samba Member
Joined: May 15, 2010 Posts: 687 Location: new zealand
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Posted: Mon Mar 20, 2017 11:27 am Post subject: Re: Porsche 944 Brake conversion on 1303 |
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There are 2 different width rear hubs on the 944 arms, looks like you have the wide ones hence your wheels stick out so far.
I can't remember what year uses the narrow hubs as I did mine more than 15 years ago. _________________ https://www.facebook.com/pages/West-Worx/460154187360186 |
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Dodgy Samba Member
Joined: January 30, 2006 Posts: 516 Location: Leicester, UK
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racoguy Samba Member
Joined: May 15, 2010 Posts: 687 Location: new zealand
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Posted: Mon Mar 20, 2017 1:51 pm Post subject: Re: Porsche 944 Brake conversion on 1303 |
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Yep from memory the hub and stub axle are different, best to just use the early ali arm if you can then you'll have the corect hubs, stubs and added benefit of a bump stop mounting.
Use early 944 axles as well, beetle cvs for gearbox end can be made to fit the 944 axle with a small mod
You can fit alloy arms and Cup 1 / 2 / 3 wheels under stock guards with the narrow hubs.
The inner bolt in the spring plate needs to be machined thinner and the shock tower clearancing a little. Ghia almost done, runs and drives ill post a pic later _________________ https://www.facebook.com/pages/West-Worx/460154187360186 |
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Dodgy Samba Member
Joined: January 30, 2006 Posts: 516 Location: Leicester, UK
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racoguy Samba Member
Joined: May 15, 2010 Posts: 687 Location: new zealand
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Dodgy Samba Member
Joined: January 30, 2006 Posts: 516 Location: Leicester, UK
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Dodgy Samba Member
Joined: January 30, 2006 Posts: 516 Location: Leicester, UK
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Posted: Wed May 17, 2017 9:44 am Post subject: Re: Porsche 944 Brake conversion on 1303 |
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Well thanks Racoguy for the tip!
Late hub:
Early hub:
Fitting the early hub takes 47mm off the wheel offset on each side, by my measurement. There is no difference to the brakes apart from a different rotor to accommodate the reduced offset.
New wheel projection is ~25mm, will fit under +4cm wings no problem
RH side is done and I have a working solution for the handbrake, simpler than other solutions I've read about. Will post details with measurements when confirmed to work on both sides.
For the driveshaft, late 944 driveshaft (length 531.5mm) fits a treat. The VW CV joints fit at the inner end to connect to the gearbox, they need a ~3mm spacer as they are slightly narrower than the Porsche CVs.
Getting there... _________________ '75 1303 (current project) owned since 1989!
'72 Squareback - full resto completed 2008 - now sold
356 Speedster kit, completed 2005 - now sold |
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Dodgy Samba Member
Joined: January 30, 2006 Posts: 516 Location: Leicester, UK
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Posted: Fri Jun 02, 2017 8:19 am Post subject: Re: Porsche 944 Brake conversion on 1303 |
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More slow progress...
LH side is now assembled, both driveshafts cleaned, painted & rebuilt with VW CVs on inner ends and Porsche CVs on outer ends. Still looking for a small offset 944 hub for the LH side.
Oh, and the trailing arms got sandblasted & cleaned up too!
I worked out a solution for the handbrake that is pretty neat, maybe I'm not the first with this approach but I've not seen it before. Link to drawing with modification notes is here:
Modified VW handbrake cable for 944 brakes (dropbox link)
Photo shows the handbrake linked up, I'll modify the securing plate for the cable later, as I'll add a location for the ABS sensor wire. Also at the top of the photo you can see the VW flexi hydraulic line sits perfectly in the mounting bracket on the 944 arm. Result!
Have started playing with wires on an ABS module... But really I need to get back to making some progress on the bodywork _________________ '75 1303 (current project) owned since 1989!
'72 Squareback - full resto completed 2008 - now sold
356 Speedster kit, completed 2005 - now sold |
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kiwi_obecny Samba Member
Joined: October 23, 2010 Posts: 20 Location: Czech Republic
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