Are 131 front brakes same as X1/9?

lookforjoe

True Classic
I'm considering getting a big brake kit (6 piston calipers, 304mm rotor) from the company I got my Volvo BBK from, CEIKA. I'm not confident the brakes I have will be sufficient with twice the HP.

They make them to fit anything, but it's always easier to not be the guinea pig.

They already have a listing for 74-84 Fiat 131 fronts. The question is, is the rotor hub offset and caliper the same as our X1/9? I can't find anything online that helps me figure that out.

Any one have any info on the 131 that would help?
 

carl

True Classic
I want to say the front brakes (131 rears are drums) are the same as 124s and thus the same as Xs. Check MWB catalog, calipers, rotors should be the same for all three vehicles. Been too long since I had one.
 

lanciahf

True Classic
On a side note, a couple of years ago I sent a X1/9 front spindle and 284mm vented disc to Todd at TCE Brakes. He made me a 4 wheel disc brake system that was wonderful on my old Scorpion.

Two years ago I sent him a Fiat 500 pop front vented rotor and fiat 124 spindle. I chose the pop rotor because I wanted to keep the 14"turbo wheels. Todd made a neat mount using radius mount calipers.

I would not hesitate to use him again.

https://www.tceperformanceproducts.com/
 

lookforjoe

True Classic
I want to say the front brakes (131 rears are drums) are the same as 124s and thus the same as Xs. Check MWB catalog, calipers, rotors should be the same for all three vehicles. Been too long since I had one.
Thanks Carl. I found old listings online that show the caliper & rotor being the same. Can't find anything on the slider / carrier bracket to confirm spindle ear mount is the same dimension. The carrier listed on MWB doesn't include 131 in the application I don't see any reason why Fiat would make extra parts where they don't need to, however, I'm not going to make assumptions :D
 

Dr.Jeff

True Classic
Are the 124 and X1/9 carrier/bracket the same? I didn't think so but not sure. The calipers/rotors are, but as Huss says I wouldn't assume anything - the mounting tabs on the spindle/hub/uprights may be a different configuration. But I seem to recall seeing huge brake kits available for the 124, which would be more common than the 131. However as I said, I'm pretty sure the 124 stuff will work on the X.

I'm wondering if the X's significantly lower weight (compared to your Volvo) would require the same BBK as the Volvo did, despite the high performance capability of the new engine? Please don't get me wrong, I'm not questioning the desire to have 6-pot calipers and big rotors - frankly I hate when someone comes up and says "why do you want to do that" - what's it matter why? My question is more for my benefit. I seem to recall you had 6-pot Porsche calipers on your X at one point? How did that feel relative to the car's weight (albeit a much lower performance level than your new swap will be)? As you well know there are some existing bolt-on 4-pot setups (e.g. Wilwood) available for the X. Do you think that would suffice, or does the performance level in your case exceed that? As I said, just for my benefit - not questioning your plans at all.

I remember Ian's TCE set up, nicely built. Not sure how it would compare to what CEIKA offers. Also look at what Tarox offers for the X, I believe they have some BBK's for it.
 

lookforjoe

True Classic
Are the 124 and X1/9 carrier/bracket the same? I didn't think so but not sure. The calipers/rotors are, but as Huss says I wouldn't assume anything - the mounting tabs on the spindle/hub/uprights may be a different configuration. But I seem to recall seeing huge brake kits available for the 124, which would be more common than the 131. However as I said, I'm pretty sure the 124 stuff will work on the X.

I'm wondering if the X's significantly lower weight (compared to your Volvo) would require the same BBK as the Volvo did, despite the high performance capability of the new engine? Please don't get me wrong, I'm not questioning the desire to have 6-pot calipers and big rotors - frankly I hate when someone comes up and says "why do you want to do that" - what's it matter why? My question is more for my benefit. I seem to recall you had 6-pot Porsche calipers on your X at one point? How did that feel relative to the car's weight (albeit a much lower performance level than your new swap will be)? As you well know there are some existing bolt-on 4-pot setups (e.g. Wilwood) available for the X. Do you think that would suffice, or does the performance level in your case exceed that? As I said, just for my benefit - not questioning your plans at all.

I remember Ian's TCE set up, nicely built. Not sure how it would compare to what CEIKA offers. Also look at what Tarox offers for the X, I believe they have some BBK's for it.
You're confusing me (se above) :D

I already have the Vic "BBK", and that, while better than stock for sure, still felt at it's limits with the 1600 motor. I had Porche/Brembos on my Volvo, never made a set fit the X1/9. The CIEKA brakes just work so well. The rotors are much lighter than their comparable sized solids. I don't like Wilwood brakes. If you look at the swept area they cover, it's not great (compared to Brembo / CEIKA / StopTech), in any of their offerings.

I just want to know I can stop without drama when driving aggressively, which is absolutely going to happen with the new setup :D.
 

Dr.Jeff

True Classic
You're confusing me
Sorry, that was a typo - should have read "I'm pretty sure the 124 stuff will NOT work on the X".

Sounds good. Like I said I really do not have a good feel how the various upgraded brake components compare on the X. There really aren't enough out there to get good feedback on.
 

carl

True Classic
The calipers, rotors and pads are the same for 124s and Xs. The carrier brackets that mount the calipers to the hubs are DIFFERENT. The spacing of the bracket mounting holes to the spindles are different. I don't know which brackets the Brava uses or even if they might be a third design. Again, I would defer to the MWB catalog to figure this out.
 

Dr.Jeff

True Classic
The carrier brackets that mount the calipers to the hubs are DIFFERENT
That's what I thought, which means most of the available high end big brake systems will not work on the X. Just a hunch, but I'd suspect the 131 is more likely to be the 124 than the X1/9.
 

carl

True Classic
Not sure as the 131 uses strut front suspension just like the X, 124 uses double A-arm with conventional shocks.
 

Dr.Jeff

True Classic
Oh ya, great point. I've never had a 131 and it's been ages since I had a 124, so my memory has failed me once again. :(
 

Jefco

Daily Driver
FiatPlus has listings for core calipers that are supposed to fit 124, 131, x1/9 (79-88) and Lancia Scorp, and have 48mm piston bores. All the same.
 

Dan Sarandrea (Phila)

Waitin' On Parts...
With your new K setup, your car now has more drivetrain weight, and considering the slight rearward tilt of the K engine, I would suspect that you might be at or beyond 35/65 F/R weight distribution (IIRC stock is 39/61).

If that's the case, then maybe getting the rear brakes to do more work is the way to go....even more so if your are going to do staggered tire sizes.
 

lookforjoe

True Classic
With your new K setup, your car now has more drivetrain weight, and considering the slight rearward tilt of the K engine, I would suspect that you might be at or beyond 35/65 F/R weight distribution (IIRC stock is 39/61).

If that's the case, then maybe getting the rear brakes to do more work is the way to go....even more so if your are going to do staggered tire sizes.
Hey Dan

I already have the larger rear calipers on there - I was considering a 4-wheel set, however dealing with the parking brake is an issue. The kit I have for the Volvo requires a separate cable-actuated piston (mounted behind the caliper) that then acts upon the stock caliper. It works, however it never holds over time, being hydraulic vs. mechanical.
 

Dr.Jeff

True Classic
I've seen some kits that use a separate mechanical parking brake caliper. And some with a traditional 'drum' park brake built into the larger performance rotor. Is it possible the company you are considering can offer something like that instead of the hydraulic set-up?
 

Dr.Jeff

True Classic
That was very common on MANY production cars. But I've also seen it done with some aftermarket high performance brakes. It would depend on the brake kit manufacturer.
 

lookforjoe

True Classic
Yes, very familiar with the Volvo parking brake setup. Every Volvo I ever owned prior to the C30 had it :D

Not going to add that complexity to the rear setup.

This is what the hydraulic mechanism looks like



I made all the measurements for the stock front rotor and hub. They didn't see the 131 rotor as being the same as X1/9



 
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kmead

Old enough to know better
The calipers are identical, the mounting for the caliper is identical but the mount itself is different among the three. I believe the 131 and the 124 are the same mount and the X mount is similar but the caliper lives on the front of the axle so the caliper on the right on an X is the caliper used on the left for the 124 and the 131 as the caliper lives on the back side of the axle.

From the 131 factory manual:
2F920C4B-7533-401E-9F61-53E7087B6CA1.jpeg
294F3B18-E9C5-4DBF-A1AB-6760F123B286.jpeg

From Haynes 124
115132D0-85E3-489C-92A2-46E12938A7A1.jpeg


6B8B5698-0CE4-478C-B9E7-ADE223E4EE50.jpeg


From the X factory manual
28D7BE9A-2CA4-4FBC-8EB1-A0D3D6DDC3E5.jpeg
E06AF8A5-D67F-40FD-952F-652CBD0DF9C5.jpeg
 
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