Front brake option

Just for fun I pulled out a spare set of front and rear disk brakes from a water cooled VW (Mk2-Mk4 era) and tried them on the X.

The front calipers can easily be adapted to the X with a simple adapter bracket (took me less than a hour to measure, design and build a set of test brackets...really don't see what all the fuss is about).

Pics would be great. I need images to assimilate data, the old xWeb threads are horrible like that, pages of text with no images to aid understanding. Are the VW radial or axial mount calipers? You have access to CNC machinery or a mill? Hard to visualize a safe adapter bracket that was banged out in 1/2hr or so, unless you have access to the appropriate machinery :D
 
Yes, I am just finishing up an adapter plate for the rears and am about to shoot a video showing how to swap the parking brake mechanism side to side. A bonus is that I acquired some 14" wheels and they appear to clear the larger brakes front and rear.
 
Pics would be great
I agree completely. I had a few spare minutes and was just playing around with it so unfortunately I did not take pictures. Frankly it was really not that impressive, very similar to one of the kits offered by a well known vendor here, only a slightly different caliper. The brackets are simple to make; basically a plate with 4 holes cut to a shape to clear things. If better ideas do not materialize then I will re-visit this option.

Yes, I am just finishing up an adapter plate for the rears and am about to shoot a video showing how to swap the parking brake mechanism side to side.
Awesome! I still think the New 500 components is the way to go. Very anxious to see your results and the related specs. Thanks.
 
My Vick Prima didn't fit in my 13 inch wheels, just a slight rubbing in my CD31 and CD39 wheels. I took it off and went back to stock brakes. I might put it back on and grind the edge of the calipers down a little, it wouldn't take much grinding for it to work, just a little bit off would do it.
The Vick Primas do not fit under the CD30s either as the spokes are too thick where they connect to the rim. The do clear the CD91s with no problem. I have the Allison kit that uses the 500 rotors and they are a direct bolt on but they will not fit under a 13" rim.
 
The Vick Primas do not fit under the CD30s either as the spokes are too thick where they connect to the rim.

Actually, our kit will fit under SOME of the CD30's. I tried a set personally. I assume this is just like with the CD16's in that the wheels are not all the same. Quality control must have been lax.
 
Actually, our kit will fit under SOME of the CD30's. I tried a set personally. I assume this is just like with the CD16's in that the wheels are not all the same. Quality control must have been lax.
Anything is possible. Maybe the aluminum replicas will clear. My CD30s are the original magnesium purchased in 1981 from a Fiat dealer when I was stationed in Germany.
 
Regarding the application of "New 500" brakes to the X1/9 (and Scorpion), MotoTrooper has done excellent work with documentation. You can review his thread from the X1/20 forum here:
https://xwebforums.com/forum/index....new-scorpion-owner-1553-restomod.28514/page-3

Huge thanks to him for doing this!

Something that came up in this referenced discussion is the weight of components. That is something we should consider as a criteria for component selection. The next time I have my X1/9 and VW brake calipers and rotors out I will weight them. The VW calipers I have are the early (Mk1-2) type and are heavier than the all-alloy later VW ones (Mk4). Perhaps others can get similar information for the options such as New 500 and VW Mk4 parts?
 
I moved some info from over there to here.

I found a spreadsheet on one of the 'Locost' web sites for figuring the desired components and balance of a braking system.
Start here:
http://www.stoptech.com/technical-support/technical-white-papers/proportioning-valves

The attached zip file is an Excel spreadsheet which has multiple sheets/tabs. You will need to gather some info about your car which is likely something you already know or can find in Road and Track or similar.

It is from a the Locost forum prepared by Mike Polan and based on a book about brakes by Herb Adams. It should give you a starting point which will need to be verified with testing of course.It is an Excel file, which many other programs can open. I use Apple's Numbers but you should also be able to open it with Google Sheets. https://www.google.com/sheets/about/ This runs in your browser, you will likely need to create an account with Google if you don't have one.

I have fiddled with it for an X1/9 and find that you want larger rear calipers with the existing diameter front calipers to get to a desired "perfect" balance.

Here is a link to my file, you should be able to open it directly. You will want to go to the Analyze tab at the the bottom to see the base X (you can fiddle with the caliper diameter (convert mm to decimal inches) to see the effect. Then go to the Design tab.

You will see that the existing 48mm front and a 38mm rear will get you very close to the ideal. 40mm rear will get you almost exactly what you want which is 50/50 but that would be for ideal conditions, dry roads etc.

Going with the 500 brakes 54/34 nets you a front biased solution, which is no surprise.

Anyway play around with it. I have a copy of the unsullied file on my computer so no worries about changing anything.

https://docs.google.com/spreadsheets/d/1SkTjBOwib11g8a5kXB312f4Rgtu8cBJ-JuRK39CBumc/edit?usp=sharing
 

Attachments

  • AdamsBrakes.zip
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Reviving this thread.

In another recent discussion about brake upgrades, there was reference to a shop that specializes in custom Wilwood product applications (TCE Performance Products in Arizona). The have done a couple of Fiat projects that will allow Wilwood calipers to be used on the X with different rotors. One used a larger 284mm rotor from some Euro spec Fiat (not specified what model). The other used New 500 rotors, but for Fiat 124 mounts. So they could easily make them with the 500 rotors for the X application. The site includes the listing for the larger rotor package, less the rotors themselves (customer supplied).

Here is the other thread, page 3: https://xwebforums.com/forum/index.php?threads/time-to-replace-brakes-upgrade.35480/page-3
And here is the TCE link: http://www.tceperformanceproducts.com/

This is just something to add to the whole topic for consideration. I have not had a chance to get back to any of my brake upgrade projects, so no new development for the previous thoughts/concept ideas. But want to keep this discussion going.
 
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Reviving this thread.

In another recent discussion about brake upgrades, there was reference to a shop that specializes in custom Wilwood product applications (TCE Performance Products in Arizona). The have done a couple of Fiat projects that will allow Wilwood calipers to be used on the X with different rotors. One used a larger 284mm rotor from some Euro spec Fiat (not specified what model). The other used New 500 rotors, but for Fiat 124 mounts. So they could easily make them with the 500 rotors for the X application. The site includes the listing for the larger rotor package, less the rotors themselves (customer supplied).

Here is the other thread, page 3: https://xwebforums.com/forum/index.php?threads/time-to-replace-brakes-upgrade.35480/page-3
And here is the TCE link: http://www.tceperformanceproducts.com/

This is just something to add to the whole topic for consideration. I have not had a chance to get back to any of my brake upgrade projects, so no new development for the previous thoughts/concept ideas. But want to keep this discussion going.


Looking into this a bit from Rock Auto Spec's.

The Fiat 500 Pop front rotors are about the same but the height is different between that and the Abarth. Cost is less than $50. Next week when I am in the City I will stop in at Car Quest and pick up a rotor and do a rough fit. If it looks plausible I will drill out the mounting holes on the X1/9 strut and see how it bolts up to the knuckle. One other thing I was thinking is that the backing plates will have to be changed for the larger diameter rotors. Looking at Rock Auto again the backing plates are $6. Jeff what are you planning for the vacuum source on your car, does it have a vacuum pump driven from the engine like the Fiat?

Here is some information for comparison. Sorry about the metric for one and imperial measurements for the Pop. Bob Martin wants me to look into this and I have all of the parts at home, I have a spare 2013 Fiat Abarth running for parts in the barn and to play with.

TonyK.

Grimsby Ontario Canada.


Rotor casting type
Vented

Rotor Inner Diameter (IN)
6.102

Rotor Outer Diameter (IN)
10.126

Discard Thickness (IN)
0.795

Nominal Thickness (in)
0.866

Rotor Type
Conventional

Overall Height (in)
1.594

Surface Finish
Plain

Wheel Bolt Circle Diameter (MM)
98.000

Number of Bolt Holes
4
Pop 2013 260MM Height 40MM thickness 22MM





Rotor Casting Type
Vented

Rotor Inner Diameter (MM)
171.700

Rotor Outer Diameter (MM)
282.990

Discard Thickness (MM)
20.200

Nominal Thickness (mm)
22.000

Rotor Type
Conventional

Overall Height (MM)
43.640

Surface Finish
Coated

Wheel Bolt Circle Diameter (MM)
98.000

Number of Bolt Holes
4

Abarth 2013
 
Looking into this a bit
Tony, let's continue this topic here instead of hijacking Pete's discussion about master cylinders. However I hope something comes of that thread because it could work well together with whatever we find here.

I thought I saw listings for both the Abarth edition and the 'regular' 500 with the same diameter rotor (257mm/10.126"). I'd have to go back and review everything I researched previously, I just don't recall the details. But I think you said the rotors from your Abarth donor car had 282mm (as in the specs above). And if that is the case, then maybe the 'small' 500 rotors (257) will clear the 500 calipers on the X knuckle? That would be nice. It's great that you already have some Abarth spares to play with. Honestly that is what prevented me from taking this plan any further, not wanting to buy a whole bunch of parts for testing the theory.


Jeff what are you planning for the vacuum source on your car
Tony, I assume you are referring to vacuum use with a brake booster? My intent was not to use a booster, so no need for a vacuum source. I would like to find a larger master cylinder that can somehow be mounted on the X's pedal box. That will allow the use of larger calpers without the need for a booster...assuming the new master is the appropriate size to balance with the larger calipers. That is why I'm so interested in what becomes of Pete's thread about larger masters.

Please let us know what turns up with the Abarth parts experiment. If they can be fitted, I believe the calipers for all models of 500's (including Abarths) are interchangable (fitment wise). So a complete set of normal 500 brakes (rotors and calipers) would work and will be a bit more affordable. MotoTrooper was able to get pretty far with it on his Scorpion. But I sort of lost track of that project too. I need to get back up to speed, just too many projects going on at once.
 
Although the Fiat line is an excellent source of parts there are some other companies which may have parts we might consider.

I will pick on VW as I am somewhat familiar with thier products as I have been driving them as long as I have been driving Fiats.

The first US market GTI’s used a vented rotor 239 x 20, which was then carried over to the A2 bodied Golf and Jetta. Admittedly they have a 100mm bolt circle which would need to adjusted. This rotor is much closer to the diameter of an X rotor. Unknowns are the distance from the back face of the rotor hat to the disk face relative to the Fiat part. These are low cost and easily bought. You might consider picking up one of these as an alternative to a Fiat part.
 
The first US market GTI’s used a vented rotor 239 x 20, which was then carried over to the A2 bodied Golf and Jetta. Admittedly they have a 100mm bolt circle which would need to adjusted. This rotor is much closer to the diameter of an X rotor. Unknowns are the distance from the back face of the rotor hat to the disk face relative to the Fiat part. These are low cost and easily bought. You might consider picking up one of these as an alternative to a Fiat part.
Special K, scroll back up this thread (post #40). I've already mounted a VW Mk2 caliper and GTI rotor onto X uprights. The carrier bracket "adapter" I made was merely a prototype for fitment testing purposes, and not intended to be a final product. It showed the calipers can be adapted to the X, but they do require a custom adapter. And the bolt pattern issue was not addressed beyond some discussion. Personally I think the better solution for that would be to have the Fiat hubs redrilled/threaded to 100mm and choose from the vast selection of 4X100 wheels. Then rotors could easily be replaced in the future.
However it was about that same time that MotoTrooper announced he had mounted 500 brakes on his Scorpion project. So after considering the VW components, I decided it would be a better choice (to me anyway) to use calipers and rotors that are a direct fit to the X's suspension (ie. 500 brakes). That may change again depending on what develops.
 
Drilling and tapping to 100MM bolt circle is a challenge as there is little material on the hub face to do so. Take a look at the 2 knuckles in the picture. On the left the Abarth hub on the Right the X hub. Just to let you know the wheel bearings are the same size, just the Abarth has tone rings for the ABS system. If you look at where the bolt hole are there is little left to drill and thread to 100MM bolt circle.

TonyK.

Grimsby Ontario Canada
SAM_5104.JPG
 
Sorry Tony, I meant to redrill the discs for 98 rather than change the hub on an X. I have looked at the 100mm issue and prefer wobble nuts or bolts.

The disc doesn’t care where its holes are or that it has obround holes (its a Steelcase engineering term).

My VWs never ate discs, I got 100k out of my last Golf’s discs so having to replace the discs won’t be a regular occurrence. Perhaps I am just easy on brakes.

I have been looking to get a set of front calipers from an Audi A2/VW Lupo as they are aluminum and have 48mm pistons which are more appropriate to an X.
 
Funny how my perception didn't see that, drill the rotors. I am loosing it. Why didn't I think of that?

Thanks for the explanation and tolerance.

TonyK.

Grimsby Ontario Canada.
 
I was the one suggesting to redrill the hubs to 100mm, so you can have more wheel options. But I hadn't looked at the hubs to realize the lack of material to do that - thanks for pointing it out.

Agree VW rotors last a long time and they could be redrilled to 98mm. Also agree the later aluminum calipers would be preferred, my VW calipers are the heavy iron ones (like the stock X's).

Overall my thought was to see how fitting Fiat 500 calipers compared to making VW calipers fit (custom mount/carrier adapters and drilled rotors).
 
Looking into this further I purchased a front vented rotor from a 500 POP. ( $ 51CND) Car Quest says that it is 257MM diameter and the hat is slightly lower by 3MM which shifts the disk out board and in the direction needed. I drilled the holes out on the knuckle with a 31/64th drill bit which is about .004" larger than 12 MM. No further modification was done. I then proceeded to bolt up the rotor, brake pad carrier and finally install the brake pads ( used ) and the caliper. If you are paying attention you will see that the caliper should be from the other side as the brake hose points down instead of up. I think we have a winner here. Please look at the pictures and post any comments and questions.

TonyK.

Grimsby Ontario Canada.
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Tony -

Maybe I missed it in an earlier post, are the calipers, pads and pad holders all from the 500Pop as well?

Thanks for the intell.


Looking into this further I purchased a front vented rotor from a 500 POP. ( $ 51CND) Car Quest says that it is 257MM diameter and the hat is slightly lower by 3MM which shifts the disk out board and in the direction needed. I drilled the holes out on the knuckle with a 31/64th drill bit which is about .004" larger than 12 MM. No further modification was done. I then proceeded to bolt up the rotor, brake pad carrier and finally install the brake pads ( used ) and the caliper. If you are paying attention you will see that the caliper should be from the other side as the brake hose points down instead of up. I think we have a winner here. Please look at the pictures and post any comments and questions.

TonyK.

Grimsby Ontario Canada.
 
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