Uno Turbo Front Caliper Install

[Rupunzell]

These Uno Turbo calipers have been ready for years to be installed. Finally decided to spend about 1.5 hours to get this done.

Inside of the Uno Turbo caliper. Powder coated, new seals and all.

UT calipers open, pads, M12x1.25, 20mm long, grade 12.9 cap screws, SAE hardened washers. Loctite 242 applied to the screw threads.

Stock exxe rotors and Uno Turbo rotors 240mm OD, 20mm thick, 46mm tall.

UT rotor on exxe upright.

UT rotor and caliper installed on exxe upright with caliper open.

Pads in place.

UT caliper with pads closed. The Goodridge hose is visible in the back ground.

Torque caliper screws to caliper bracket floating pins. 15mm hex on the pins.

UT caliper install done.

Back side of the UT caliper.

Rather uneventful conversion. Stock Fiat bits essentially with a simple remove and replace. Next up is to bed in the pads.

Rear calipers were converted to 38mm diameter pistons variety. I'll post that project later.



Bernice

 

[kmead]

Bernice:

Thank you for posting this install. A few questions if you will.

So this doesn't require any sort of intermediary bracket to install from what I can see here, is that correct?

In regards to the hoses, are those also stock items or?

Looks like all the things one might want. So theses are for an Uno turbo, do you know if there are additional models from the European line that these also were used on?

Many thanks in advance and looking forward to seeing the next installment.

Karl

 

[Sandgroper]

:clap:

Great to see another UnoT front brake setup Bernice. I'd be interested in how you assess the change in rears to 38mm diameter pistons affect the brake pedal feel / ballance. Like Karl I look forward to your next well documented installment

Been using these for a VERY long time and they are FAB, a freak of the Fiat parts bin that needs no adapter bracket Karl.

The best part of this install is the vented disk and the extra endurance before brake pad fade comes into play. EBC pads Green and Yellow both tried, both have + & - points.

Sad thing for you folks is that unless I am wrong again these never made it to the Continental USA ( please point me in the right direction if I'm mistaken ). So the UK is probably where you will find them. The first series Punto that succeeded the Uno had vented disks on some up spec models but wobbly grey matter recalls they don't fit, hat height or something. Will have to check archive.

I run these exact hoses and they have been good for 6/7 years, they are aftermarket Karl I got mine from a UK vendor.

I just left the 'Island' watching Marc Marquez falling off again racing himself, will be 'home soon' some catching up to do on here. I found the images of Steve C's Uno Turbo running around Bathurst from many years ago, I just might get around to uploading it Bernice.

Keep the siny side up.

Sandy

 

[dragonsgate]

Do the brakes fit in 13" rims?

 

[Dan Sarandrea (Phila)]

I have been able to acquire the caliper brackets but so far no dice on the calipers themselves or the discs.

 

[motoTrooper]

Nice installation

Hey Bernice, are these the same size piston calipers as the Fiat Abarth ones I have? You mentioned that a larger master cylinder was required to get best performance. Have you done this also?
Best regards,
Christopher

 

[Niklas Andersson]

Mine almost did fit.

After a minor grinding operation on the brakes it works though.

Not the wheels you see in the pic, I need to use my originals for the safety inspections and I'm not shifting brakes for that.

 

[Rupunzell]

The Uno Turbo front caliper set up is a direct install, no changes to any of the bits involved. This has been a known exxe front brake up grade for a while now.

Primary reason why this is a near ideal upgrade for the exxe:

*Caliper piston diameter is the same, 48mm. The current Fiat 500 offerings in the US have larger diameter pistons about 54mm. This affects braking system bias, pedal travel and pedal feel. Four pot brake calipers can have similar equivalent piston area, the volume of brake fluid required to move all four pistons to press the pads to the rotor can be quite different resulting in longer pedal travel for the same master cylinder diameter. The pedal mechanical ratio (pedal force required to produce xxxx psi fluid pressure) is also affected with a change in master cylinder diameter.

*** The exxe already has too much brake bias in the front which is the cause of cooked front brakes and front brake lock-up. Increasing the caliper piston diameter to larger makes the front brake lock up problem worst. To cure this means increasing the front master cylinder diameter to a larger diameter to match the caliper piston diameter to be used. This will affect the rear brake master cylinder and brake caliper piston diameter relative to overall brake system balance. Gets complex pretty fast to achieve proper good overall brake system performance. ***

*Rotor diameter is 240mm which is slightly larger than stock solid rotors. Trade off is added weight over the stock solid rotor. As the rotors go up in size the sprung weight increases which is NOT good for suspension performance. Bigger is not better.

*Floating pin calipers used on the UT calipers are a significant advantage over the Fiat sliding wedge design.

*The UT calipers are cast iron, stock Fiat are aluminum alloy. This is another trade off adding sprung weight to the suspension.

In the overall system, the added sprung weight -vs- gaining vented slightly larger rotors with the same single piston diameter is a good one. This adds significant heat capacity into the front brake system, more consistent pedal feel due to the floating pin caliper design, higher caliper rigidity due to cast iron at the expense of weight.


IMO, this is the near ideal front brake upgrade for the exxe to be used as a performance road car.


Given up on 13" wheels due to performance tire availably in the US. With exceptions of R compound or real race tires, performance street tires choices are nil. The current wheels are 14"x6" Biturbo wheels, in this wheel size performance tire choices are almost as poor as 13". This mandates an up grade to 15" wheels in the not too distant future due to tires.


Problem today, finding UT caliper brackets appear to be a serious problem. Rebuilt calipers, caliper rebuild parts, rotors, pads are not difficult. EBC offers complete brake kits with greed or yellow pads and choice of rotors. These need to be imported from the UK or EU as the Fiat Turbo Uno was never sold in the US.

http://brakeparts.co.uk/#!/shop/fiat/uno/83-94/UNO TURBO/Front - Brake Calipers and Wheel cylinders


https://www.dcperformance.co.uk/improve/performance-brakes.html

Goodridge brake hoses are also available from UK or EU suppliers. Not checked US suppliers. At the time when the brake hoses were purchased, there was no USA offering for them.

Overall this was not an low cost project. The use calipers set was imported from a UK ebay seller years ago, cleaned up, powdered coated, rebuild kits and replacement parts came from New Zealand, rotors and pads were imported from the UK. Not a project for those in the USA who are cost sensitive.


Bernice

 

[lookforjoe]

Very nice work.

Calipers are identical design to Bendix brakes used on Volvo 850/S/V70 series, I wonder if the rear caliper bracket offset is similar....

EDIT: Looking again at the slider bracket install - the bracket is not evenly spaced on the rotor hat. Assuming the hat is firmly secured, the bracket needs to be a few mm further outward to center on the rotor hat, unless it's just camera angle?

 

[fiatfactory]

Similar upgrade can be had by using regata / ritmo 105 series front brakes. 257mm diameter 12mm thick solids, so not as sexy as a vented rotor, but the extra diameter really adds significant extra brake torque to the package. Regata / ritmo front hubs are actually the same item as late X19 front hubs (as in identical down to the part number) so everything simply bolts right up. Same 2 pin sliding design, same larger pad area.

Kind of reminiscent of the PBS use of Lancia beta discs and calipers / caliper carriers, but with no mods/welding required.

SteveC

 

[x19dave]

Steve I went down the 257mm dia disc route but I used Punto GT brakes and discs which are vented so still look sexy and have a 53.9mm piston.

Not sure if you guys had the Punto GT.

I also went down the larger rear piston route I think they might be 131 rear callipers but not sure, to try and keep the front to rear balance.
Not sure how well it will work as not had the car back on the road yet lots of other stuff to do before then and now the bad weather is coming and no garage looks like it might have to stop until next year

Dave

 

[x19dave]

uno turbo calliper discs

Dan
if you are looking for uno turbo callipers and discs Not too hard to get hold of over here in the UK if you are willing to pay postage, think I have a set myself.
Dave

 

[Sandgroper]

Where do ya get ehm!

Hi Bernice


Thank you for the details on F/R bias much food for thought on improving the brake system in these wee beasties. I'd be interested in your apraisal of these in a track focused car.

I had promised these images to you some time ago now, for the rest of you eye candy loving folks, this is a rather famous Fiat Uno Turbo in Western Australia. This is the vehicle model that is the source of these calipers. I have only ever seen three 'Down under' Frank has two, as these were never sold new in Australia, and I saw one in NZ when I was thinking of buying the whole car for just the powertrain. It was too good to break up so I didn't.

Last I time I saw Frank C's ( Steve C's papa ) race car it was in the showroom in Perth.

When you concider how much of a 'pest' this little Italian was and how it got in the face of the big V8's on the track during the Group C years it was plainly a pretty potent machine. NOT a standard powertrain, its turbo is huge. For those that know the legendary number 05 yes that was Peter Brock.

My setup with stock Fiat friction pads. I have tried Yellow but settled on Green EBCs.
Edit: 15's fit fine 13's won't without a massage of components with a grinder.

https://s18.postimg.org/vts8081p5/Uno_Calipers_15_s.jpg

I don't feel the added weight up front is a noticable issue, I'm sure it is there but for a warmed over X19 the benifits outweigh the extra mass IMHO. My coilovers have a lower spring rate than most recomend run on the board as I prefer a more comfortable ride than a slalom monster would require.


IF you can find some old UnoT calipers in Europe it's a no brainer, freight cost will determin if you pull the trigger and ship them to the US.

Steve, Perhaps you an tell us more about those years?

Best regards
Sandy

 

[Rupunzell]

Thanks Sandy for those great pix of Steve's Uno Turbo.
Question for Steve, what ever happened to this Uno Turbo?

The LeMons racer has a different brake set up with four pot Wilwood calipers on larger vented disc in front and stock diameter rotor in the rear with 48mm front calipers. Every bit of heat capability makes a difference for these endurance racers. Over the years, there is a collection of "well done" brakes from LeMons. Ranging from a simple running the pads well into the backing plated to toasted calipers to the steel pad backing getting so HOT the pad backing and brake caliper has become a solidified unit. If time and motivation allow, I'll see if some of these brake flab eau images can be found and posted.

So far so good, on the UT front brake conversion with 38mm rears. Pads are still seating. At this moment, the exxe behaves much nicer when braking for corner entry, does more of a squat (improved corner entry) than a nose dive compared to the stock brake system. There is an option to apply the limiter valve to the front brakes if needed.

This is IMO a very worth while project and make a significant difference in braking performance, heat capacity and chassis behavior.

Front pads are Ferodo FDB370A with Green stuff in the rear. At some point I'll order up a UT EBC brake kit with Green pads.



Bernice

 

[fiatfactory]

Uno race car is still around, just retired from active duty. RHD road car is registered and used by dad as a daily driver from time to time.

Two series 1 Turbos (one LHD and one RHD) were bought to Australia by the Australasian distributor as test and evaluation vehicles is early 1987... they were about to be shipped offshore again (to some pacific island country for resale) but before they were packed up the then State manager asked my dad if he was interested in them both... a deal was done.

Sandy's pictures are actually of both cars... the one sitting in the race track paddock is the RHD vehicle, we took it to Bathurst as a spares vehicle, as there were no spare parts available for this model...

The second picture (following Peter Brock) is the LHD vehicle in it's Group A trim, still standard bodywork and basically standard engine / transmission (locked differential) but with huge AP racing four piston calipers and 300mm ventilated discs up front. Car classed as a finisher in 1987 Hardie 1000km race at Mt Panorama. Lost laps due to heat transfer from the front brakes melting the CV joint grease and the CV's siezing (one at a time) and the replacement parts were hastily removed and transferred from the RHD spares car to the LHD race car. Still completed 113 laps of the 163 total, which is the minimum to be classed as a finisher... percentage of people who finish this race on their first attempt is under 5%. Only problems all race week was the clutch disintegrating under power (replaced with an AP racing unit machined up in the paddock) due to sticky tyres and additional boost... a strange misfire problem which was traced to the wire ignition leads we had installed causing some sort of RF interference with the ECU brain... swapped the leads back to the OEM suppressed items and the problem went away...and the CV failures during the race.

Third picture is the cars last guise, as a 'street car' class racer... all steel body panels, 90% of the curb weight in race trim, R spec radial tyres, but car used lancia Beta 2000 8valve engine with a huge turbocharger, Lancia transmission with Bacci&Romano LSD unit, pushing almost two bar of boost it was up around 350hp and under 750kg...often beat large V8 6.0 litre cars and won several state championships in the class, won the local 300km endurance race twice. The original 1.3 turbo engine and trans are still sitting in the corner of the workshop... only done about 2000km.

UnoT sits on the back of a Fiat 241, which used to be a covered wagon and was originally used to sell fruit door to door in the early 1970's... bought from the original owner, the chassis was lengthened and it was converted to a race car carrier in the mid 1980's... I drove it across Australia with the racecar on the back and towing a trailer with the spares vehicle behind, and tools/spares/rims and tyres.... 1438cc pushrod powered...so not fast. 5000km each way, and coming down out of the Blue Mountains towards Sydney on the OLD Hume Highway was 'interesting' with the brakes not really performing too well with that sort of weight pushing it along...

SteveC

 

[PaulD]

So far so good, on the UT front brake conversion with 38mm rears. Pads are still seating. At this moment, the exxe behaves much nicer when braking for corner entry, does more of a squat (improved corner entry) than a nose dive compared to the stock brake system. There is an option to apply the limiter valve to the front brakes if needed.


Bernice

I am setting up to do this conversion. Now that you have had some driving time, I am wondering about how you experience your brake balance. Do you ever use the brake limiter valve for the fronts? Have you had moments where you wish you were limiting the rears instead?

Paul

 

[Rupunzell]

Upgrade works well. The exxe does more of a squat under braking than a front nose dive typical of the stock brake set-up. Stopping distances are definitely shorter, but have not way of measuring them with any significant accuracy. This is based on feel of deceleration under braking. Heat capacity is definitely improved and by no small margin. Since this is a street driven road exxe, there has not been a need to adjust the front brake pressure limiter yet. No problems with rear brake lock-up even when the roads are wet, so far. Pedal feel is excellent with minimal alteration in pedal travel.


Bernice

I am setting up to do this conversion. Now that you have had some driving time, I am wondering about how you experience your brake balance. Do you ever use the brake limiter valve for the fronts? Have you had moments where you wish you were limiting the rears instead?

Paul

 

[TonyK]

Upgrade works well. The exxe does more of a squat under braking than a front nose dive typical of the stock brake set-up. Stopping distances are definitely shorter, but have not way of measuring them with any significant accuracy. This is based on feel of deceleration under braking. Heat capacity is definitely improved and by no small margin. Since this is a street driven road exxe, there has not been a need to adjust the front brake pressure limiter yet. No problems with rear brake lock-up even when the roads are wet, so far. Pedal feel is excellent with minimal alteration in pedal travel.


Bernice

I went down this route for my Abarth Powered X1/9

Uno Turbo front calipers as delivered from the UK. The set came with 2 used brake rotors that I had turned. Every thing was rusty. I sand blasted and powder coated the calipers using Eastwoods Home powder coating system. The pad carriers were epoxy primered and painted black. In an attempt to lower the cost of the upgrade I chose to use the same X1/9 stock brake hoses. I pulled a used front caliper from my parts bin and was sure that the hose fitting was 10 MM x1.0 mm thread, that is an error pointed out by Bernice as it should be 3/8" x 24 TPI. Anyway the banjo bolt was bottoming out so I set the caliper in my milling machine and drilled the hole .500" deeper and tapped with a 10x1 mm tap. To correct my error I just purchased 10 x 1.0 MM banjo bolts, the hose fitting will accept the 10 MM banjo bolt without modification.

While the caliper was in the Mill I also face the metal at the hole location, but I think it is possible to just file it. I also drilled and tapped a hole for the X anti rotation retainer and installed it as well.

Here are a few pictures with the new brakes on the car.

Now there was a question will stock 13" rims still fit. Yes if you use another 5MM spacer. The black carrier makes contact with the inner hub of the rim without it. The rim that I tried this on was the 87 phone dial cast rim. I did not try the steel rims from my 79 for clearance.


TonyK.

Grimsby Ontario Canada.

 

[kmead]

Nice machine with nice tools you have there to make minor modifications. Or major ones if the desire strikes

Thanks for the write up.

 

[TonyK]

Well I have been at this for a while and still something isn't quite right.

Installed the brake upgrade but found that the pedal travel was a bit mushy and decided to also install Stainless Steel Brake lines. Ordered from the UK and was sent a set of 911 brake lines. After arguing with the vendor for weeks sending emails and pictures he finally conceded that I had the wrong lines. Those were sent back and weeks latter the correct lines came in. The timing was all wrong for me as I was working on my wife's cousin's X and that tied up my shop. Anyway last week that car was finished and I moved it out an brought the Abarth X back into the shop to change the lines. Once done I proceeded to do the bleeding of all 4 corners and just for information I have always used silicone Dot 5 brake fluid on these cars due to the fact that they sit for great periods of time and go from 0 degrees F to 95 degrees F with 100% humidity. The Dot 4 brake fluid absorbs moisture and presents a corrosion problem. With the bleeding all done I started to putting away my tools and about 30 minutes latter I was ready to move the car. I put my foot on the brake pedal and it was mushy. I pressed a bit harder and the pedal went to the floor. It appears that the 30 year old master cylinder gave up and I was presented to change it. Since I had a new spare in the basement I installed it. Of course I had to remove the pedal box and go through the process of brake and clutch line bleeding. Once done I took the car for a drive and pedal travel is noticeably longer/greater. It does not have the hard feel like before the upgrade. Just to let you know the Green Stuff pads are new, the rotors turned and the rear brake pads are also new. I only drove the car 5 KM running it up to about 60 miles an hour then braking hard. I took the car back to the shop and bled all four corners again and got one small bubble from the RR corner. I have not had the chance to drive it again today.

I am hoping that 1 the pads need more time to bed, possibly there is air in the system still. I know silicone oil is a bit compressive but I was running that before and didn't notice it.
In my mind I wonder if the 2 cross over tubes above the Master cylinder are bled of all air or if this could be a problem.

Not totally happy with where I am with this. The car runs well and it is fast, stopping was a bit of a problem before, hence the upgrade. Currently the situation is worst as the pedal goes nearly all the way to the floor in hard braking.

Comments most welcome.

TonyK.

Grimsby Ontario Canada.