Ok here's the story Since I planned doing an engineswap and suspension refresh I am also looking for better brakes. Looked at the 'popular' swaps and decided I wanted something like the vette C4 swap,...but at the same time I started looking at the offerings of 'old europe' because uhm I live there
Long story short conclusion: need Brembo 4-piston calipers !

Finally last week I scored a set of calipers from a 1999 Porsche 996/911 carrera 2 and additional parts like mounting bolts, pad retainers and a set of used front rotors and pads. The front rotors are just for taking measurements.
Now there is some stuff I need to get figured out to make everything work... here are my findings so far:

Adapters/brackets
These brakes are a popular swap for several VW's, BMW's , Audi's and some others. Some companies are making (certified) brackets for these swaps. There are universal brackets available too (you drill holes for your specific application). If really lucky one of these may already fit...or not. But they should not be too hard to make from scratch...Also the guy I bought the brakes from has a tuning shop and he says he can make brackets.

Rotors
The stock porsche rotors are 32cm / 12.5 inch diameter. My quest is to find 12"or 13" rotors with a 5x100 bolt pattern. Specifically aftermarket rotors for 5x100 cars from VW/Audi/Seat/Subaru...The offset is the next thing to consider, because of the increased size of the calipers at the side of the wheels I want to have the rotor as close to the knuckle as possible, right?

Ebrake
There is no Ebrake provision on the rear calipers so I am thinking about using an extra (Wilwood) spot caliper to make the ebrake functional and legal (=main reason!)

So far this is an experiment and I would appreciate any usuable input to make it reality...
I am new to doing something like this and I dont want to cut corners.

Now some pix


comparison with 84-87 rear rotor


comparison of rear calipers

fronts

wow ..i want..i just got some brackets for the 12 inch vette rotor swap. Couldnt you use the C4 vette rotors and drill the correct 5 x100 pattern or buy a set already pre drilled from West Coast?

quote Originally posted by Erik: wow ..i want..i just got some brackets for the 12 inch vette rotor swap. Couldnt you use the C4 vette rotors and drill the correct 5 x100 pattern or buy a set already pre drilled from West Coast?

Yes that is a possibility, but I am also curious if there is a rotor to find thats bolt-on..

If you go to:
http://www.needforspeed.co....tType=BRE10&User=NFS
You can select different manufacturers and get their brake specs. I tried this ages ago attempting to match the LeBaron rotors..without success. From Memory you're looking at 5 stud VW/Seat/Skoda, some, though not all Audi, New Beetle, New Mini and Toyota Avensis. I'm sure there are a few others but I can't remember them at the moment.

iain

Audi TT uses 5x100 don't they? I think their rotors are pretty big. May want to check those.

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Didn't late 80s to early 90s Toyota Celica Supra's habe 12 or 13 inch front rotors and a 5x100 bolt pattern?

The maximum I found was 312mm, those were Audi TT/ Skoda Octavia/VW Golf

Do not forget about the master cylinder. The pistons look much smaller than the Fiero but what is the total fluid displacement? Perhaps easiest is comparing the bore of the Porsche master cylinder to the bore of the Fiero and looking at how much stroke is provided between the two.

And more kudos on your car again... Especially once you get these on there!!!

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2005 Smart ForTwo CDI
1986 Austin Mini
1986 Fiero GT 5-speed (waiting on a brake upgrade)
2007 Ninja 500

Subaru WRX

Acura Integra

Audi TT

VWs

Celicas

These are just few of the cars that use 5X100 and have a big after market line of products!

JG

Eh rod where did u score those's at?

Thanks for the input guys ! Some options are new to me.
the list so far:

Subaru WRX
Acura Integra
Audi TT
Skoda Octavia
VW Golf
New Beetle
New Mini
Toyota Avensis
Celicas

Apart from determining the offset of the needed rotors another consideration is the size of the center hole that goes on the Fiero hub....anyone have the exact size of the center hole of a fiero rotor ? It would be nice if a custom made centering ring is not required.

Mastercilinder: I may need to upgrade the MC but I am not sure yet. I dont know how to calculate the needed size of the MC....
One thing that I am considering is a proportioning valve to balance the front-rear brakes

I think I saw a setup where it was mounted in the cockpit of the Fiero......would like to see how thats done.

One thing I might use to assist in braking force is this vacuum reservoir (got the idea from FieroX's setup) :

Dont know if it will help but its not expensive to try.

The Wilwood spot calipers I am looking at:

This opposes a new problem...I mean challenge lol..Looks there is a custom bracket needed to fit the fiero ebrake spring to be able to disengage the caliper..

Duc, I found them on marktplaats The whole set was 600 euro's which is a fair deal considering the price they normally go for.

Have you considered going to 2 piece discs? If you used those you wouldn't have any centering problems as you can use the old hubs/discs as hats (centres), provided they were in decent enough condition to turn down and true up.
That method is used quite a lot in motorsport to save cost. Since you'd just need the disc the cost isn't ridiculous and the amount of machining needed is minimal, so that keeps the cost down. The discs are also lighter and better vented than one piece.
One piece discs you're almost certain to have to machine the spigot (disc centre bore) to match the hubs, then sort out some sort of spigot ring to keep the wheels hub centric, especially at the front since the new disc would act as a spacer, as it does in the LeBaron conversion.

Compbrake in the UK do quite a large range of widths/diameters of 2 piece:
http://compbrake.co.uk/Rotors2.htm

as do Rally Design:
http://www.rallydesign.co.uk/catalog/default.php

You do know that spot caliper isn't designed for a vented disc? It'll only accomodate a disc up to 13mm thickness.

Well may you know about movit.de and that they have a conversion kit for the fiero .
And you may saw pics of Jürgens Fiero 1987- white the first Porsche brakes on a Fiero .

I talked with him some years ago on a Fiero meeting in Stuttgart and he said that he would never ever do the conversion again .
These brakes have way to much power for the Fiero .
And that he have problems with overdosing and brake control and this lower control arms and lower ball joint ,he hade to weld them in to
the lower arms because they got lose .

So if you wanna make your self some problems ..................

[This message has been edited by Torch-Red87 (edited 02-07-2007).]

Thanks Iain for your uesefull contributions ! That last one is quite a different approach but very interesting.

Just to get the picture...if I read right.:
Basically you turn down the fiero rotors to lets say 3/4, this is the hub to mount the new 'seperate' rotors on, drill (and tap?) about 12 mounting holes and put them on...I can see some of the benefits
No added trackwidth
No centering rings
Easy replacing
No redrilling
I guess the fiero rotor has to be machined down to a set size so it slots perfectly with the new rotor right ? Or is there some other procedure to get a balanced install ?

quote Originally posted by Iain: You do know that spot caliper isn't designed for a vented disc? It'll only accomodate a disc up to 13mm thickness.

Yes I know but they state spacers can be added to increase the width, however I cant find if there are spacers available..

For what you could sell the Porsche parts for, you could probably buy a well-thought out, developed, bolt-in upgrade from Held, WCF, etc. that would work 100% as well for any purpose the Fiero was put to. I would not try to DIY engineer a one-off deal on something as life or death as brakes. But good luck if you try it.

[QUOTE]Originally posted by Fie Ro:

Thanks Iain for your uesefull contributions ! That last one is quite a different approach but very interesting.

Basically you turn down the fiero rotors to lets say 3/4, this is the hub to mount the new 'seperate' rotors on, drill (and tap?) about 12 mounting holes and put them on...I can see some of the benefits
No added trackwidth
No centering rings
Easy replacing
No redrilling
I guess the fiero rotor has to be machined down to a set size so it slots perfectly with the new rotor right ? Or is there some other procedure to get a balanced install ?
[QUOTE]
Yes, as far as I know that's how it's done, never done one myself yet, though I do have a set of Brembo in the garage, somewhere, (recent house move),.
I'm at the same sort of stage as you, I plan on fitting a Vauxhall/Opel 2.5 V6. That puts out 175hp, 195 with 3.0 inlet cams, 220-225 with a little porting, head skim and larger throttle body and later plenum. It'll be for road use with the odd hillclimb/sprint thrown in. I hillclimbed a 2.5 Iron Duke, even with decent condition brakes and carbon metallic pads the thing just didn't stop. With the decent engine and lighter weight then brakes become the priority. I have been accumulating bits for a possible LeBaron/Cadillac swap but I may just end up engineering something with more accessible parts, the carriage costs to get the Cadillac/LeBaron bits over to Scotland are hilarious, Rock Auto want 4 times the cost of the brakes for carriage.

I have been looking out for 4 pot Brembo from Fiat/Seat on evilbay but they have been selling for way more than I want to pay. I may see if I can get hold of a set of 4 pot Volvo front calipers, those are quite popular here for conversions being cheap and plentiful, rear I'm not sure, the VW type hydramech caliper from Rally Design is proving popular. Whatever I end up with I'd like to keep it compatible with 15" wheels if possible to allow cheaper race rubber for hillclimbs, so I'll probably stick to around 285mm for the fronts.

iain

Thanks Iain, that looks like an interesting project ! I will be doing a modded 3800IIsc swap, ported / Intercooler / MPS / N* TB etc mated to a getrag, this is a good time to redo the suspension too and that also leads to the quest for better brakes to stop the extra power.
I have 17" rims so that should give enough space, if not I have an excuse to get bigger rims

quote Originally posted by schumi: For what you could sell the Porsche parts for, you could probably buy a well-thought out, developed, bolt-in upgrade from Held, WCF, etc. that would work 100% as well for any purpose the Fiero was put to. I would not try to DIY engineer a one-off deal on something as life or death as brakes. But good luck if you try it.

Even if the total cost comes close its still expensive to get a kit shipped. I agree with the safety issue, thats why I said its an experiment untill they prove they work....If not I may easily sell the calipers, take my loss and learn a lesson. I am not scared to learn

Bump.......Interesting set up. I really want to see more of this porsche brake conversion. Keep up the good work and good luck

Have you seen this? It's a kit offered by a company in Germany for 84-87 Fieros. They are located south of Cologne and they claim that they have been legalized in Germany...



http://cgi.ebay.de/Pontiac-...QQrdZ1QQcmdZViewItem

I have an automatic search for fiero on ebay.de and I haven't seen these yet. I have seen some stuff at specpro's site but the conversion rate means that would cost ~$1800 (for me). Their other stuff seems expensive as well but then, I am still thinking of the land of plenty (of Fieros).

If you can find out the size of the master cylinder from porsche, (I do not know the year or stuff or I would try to find it) you can get an idea of if your master cylinder will have to be replaced or if you can get by with the original. Just calculating from the brakes would be difficult (because I am lazy) but if you post the size of the pistons in the porsche calipers, someone may do the math to figure out if there is a very big difference between fluid displacement. I mention these to get you a ball park idea. If it is definitely going to require a larger master cylinder, it could take a little less time to complete the project.

Are you getting snow? I heard a winter storm warning for Benelux area.

Yep the snow has come and it gone the next day it is a high of 5 c now..long live holland and no snow for more then 2 days.

quote Originally posted by yellowstone:

Hmm interesting....by chance I found a thread on fiero.de about using VW Corrado parts, also Timo (fiero1fan) mentioned it too yesterday...maybe this is a set based on the Corrado? Pricey though.

A colleague of mine happens to run the dutch Corrado forum,I'll try to get some info from him. I know Audi TT and Seat cupra (brembo) brakes are a popular swap for them.

midengineracer: I took some rough measurements with a ruler, piston sizes:
front pairs
32mm and 36mm
rear pairs
24mm and 26mm

I found a german document with pattern sizes. Made a compilation of the matching 5x100's :

It is late and I am lazy (I mentioned that already) but I calculated the front as well as I think I can. Calculating the area of the two front pistons and adding them gave me an area of 1822.13 mm. Using the Fiero piston at 2" gave me 2026.83 mm and if it is only 1 15/16" then the area is 1901.17 meaning that in both situations, the Porsche calipers will have less area. If I remember my hydraulics right, that means there will be less clamping force so you would need to boost by going to a smaller mastercylinder or stronger booster (S-10 booster upgrade maybe).

Someone please back up the hydaulics part with a formula... Or show it wrong...

I also do not know how much difference there will actually be in pedal feel but I bet it will be negligible.

If the Fiero has a 2" rear piston, the clamping will be significantly reduced and you will need to get an aftermarket brake bias like you showed already. You will need to remove or disable the factory proportioning valve and install the aftermarket in the rear brake line. If you want it in the car, you have to run an all new rear brake line through the interior. I personally would mount it near the mastercylinder, keep the interior clean...

Oh, and since the rotors are drastically larger, the lower clamping force probably won't matter as much to actual braking as you are now working with a bigger 'lever' than the factory rotors provide. Personally, I would mount the rotors and calipers, add the aftermarket proportioning valve and do some testing on an empty road...

------------------
2005 Smart ForTwo CDI
1986 Austin Mini
1986 Fiero GT 5-speed (waiting on a brake upgrade)
2007 Ninja 500

I converted my brakes a couple of years ago using junkyard parts where possible. It's a cobble of Porsche, Fiero, Mazda, Firebird, and Corvette. Stay with me and I'll lay it out in a Readers Digest version:

Front

Combined Porsche (89 944) and Fiero spindles: Cut the snout off of the Fiero spindles and the mounts off of the Porsche and welded them together. This allowed me to re-mount the spindles on the stock upper/lower control arms. I did this so I could use the Porsche aluminum hub and bolt on rotor (two piece design).

I used '89ish Mazda RX7 Turbo calipers. They are a four piston design that I picked up at a u-pull-it yard for $10. Believe it or not, they bolted directly onto the Porsche (portion) of the new spindles. I used grade-8 flat washers for spacers (one for each ear).

For clearance I had to re-position the lower shock mount back and inboard.

Rear

Machined a new flange using to accommodate the 130mm bolt pattern and welded them to the Fiero hubs.

Used one piece rear rotor from an 89 Firebird GTA re-drilled for 130mm bolt pattern.

Rear calipers are from the same 89 Firebird but I used 89 Corvette E-brake cable brackets to give me better routing of the E-brake cable.

Master Cylinder

I'm using the stock Fiero caliper and an external adjustable proportioning valve. IMPORTANT: Remove the internal spring and piston from the stock Fiero valve.

Results:

Stand on your head brakes. Almost 12" rotors front and rear. Allows me to the ultra light weight 16" Fuchs Wheels. Cost for junkyard parts, new parts, wheels: less that $1000.

Not sure if any of that is useful but you have it anyway.

------------------
Roy

double-click on this link to follow my interior build-up https://www.fiero.nl/forum/Forum1/HTML/023174.html

Blue 87 GT w/ 4th generation Firebird interior.
Suncoast Fieros

Judged "Best Custom Interior" at the 20th Anniversary Show @ Pontiac, Mich - 7/2003
Judged "Best Custom Interior" at the 8th Annual Fiero Fun Weekend @ Daytona - 3/2004
Judged "Best Custom Interior" at the 9th Annual Fiero Fun Weekend @ Daytona - 3/2005

Any luck yet? What about using WRX Subaru rotors? Or Lancer Evolutions Rotors? They are 5X100 bolt pattern...and they for sure come in either 12 or 13 inch.

JG

I did the same search and couldn't come up with anything that didn't require some sort of machining (center bore or bolt pattern).

DBA has a complete catalog that includes all of the critical dimensions (overall diameter, centerbore, offset, bolt pattern, and rotor thickness):
http://www.dba.com.au/dba_c...2006_1c_251006V2.pdf
I don't know of any better place to look.

Thanks for the additional info. I measured the center bore of a fiero disc with a simple ruler, its about 57mm if I'm right.
scrolled through all 171 pages of the pdf Steven posted, looking for a matching center bore..

-Fiero 57mm-
mazda 55mm but 4bolt
Alfa Romeo / Fiat 59mm
Toyota Avensis 55mm
elise is 56.6mm but is only 4 bolt
pontiac vibe 55mm 5 bolt
scion tc 55mm 5 bolt
subaru 58mm 5 bolt/100mm ....! Subaru is most close, how bad is the possible difference of 1mm ? ( 0.5mm all around)

I talked to mypride today about subaru rotors, he is closer to find a stock subaru impreza rotor to see if it will fit..fingers crossed (thanks Daniel!)

One main reason for me to try this swap is there are many different adapters available already. Many made (and approved) in Germany for popular Audi/VW/Bmw > Porsche-brake upgrades. Havent found an exact fit so far, but..they also make universal brackets

Here are some rough measurements of the parts that need to bolt up to an adapter:

Best option so far looks to be this universal porsche caliper adapter as a starting point...but need more measurements first.

(theyre made from GGG50)

Fie RO, those are some great looking brakes.

[This message has been edited by atleastitruns (edited 03-09-2007).]

Fie RO, how are you doing on your Porsche brake upgrade? Those brakes look so awesome. I like how you're going a different route on brakes, off the beaten path.

quote Originally posted by Steven Snyder: I did the same search and couldn't come up with anything that didn't require some sort of machining (center bore or bolt pattern). DBA has a complete catalog that includes all of the critical dimensions (overall diameter, centerbore, offset, bolt pattern, and rotor thickness): http://www.dba.com.au/dba_c...2006_1c_251006V2.pdf I don't know of any better place to look.

That seems to be my problem too. I guess the only lucky ones are people with '88's as there is a less than $400 upgrade for their brakes.

Anything I found so far is either way north of $1000, or requires lots of fabricating, machining, etc. I just don't have the guts or know-how for that. I don' t know if I could trust my life into something I've machined myself. I don't want to set the wrong bias and lock up the wrong wheels and start a slide.

Or is there a junk yard upgrade that has been tested and reliable in the $500 range and I'm not looking in the right places? (for '84-'87 Fieros) (I do wish to retain my e-brake)

-M

quote Originally posted by Fie Ro:

Watch out! If I remember correctly the bolt holes are NOT on the same circle! Take measurements off your spindle. I don't know why GM didn't put them on the same circle, but I remember measuring and they're not.

so, how did this turn out? You wouldn't happen to have any drawings for those calipers would you?

Did anyone ever try converting the fiero hub/rotor for use with 2-piece rotors (just modifying the hub to mount the separate rotor)? did it work? any reason it wouldn't?

What is the URL of old europe
Cause i'm looking for a heater fan motor and want to know if there is a replacemnt for it .
I'ts a 1981 924 Porsche

[This message has been edited by Robert 2 (edited 01-16-2008).]

quote Originally posted by PerKr: so, how did this turn out? You wouldn't happen to have any drawings for those calipers would you? Did anyone ever try converting the fiero hub/rotor for use with 2-piece rotors (just modifying the hub to mount the separate rotor)? did it work? any reason it wouldn't?

I need to put some more time into this project...but theres still info to post. Btw 2- piece rotors would be the best way because you can have the 'hub' made to whatever specification. But they would also be a lot more expensive, the goal of this project is to find existing rotors that will work without (too much) modification.

I have played with 2 types of Impreza rotors and a Corrado rotor. All were front rotors,vented and (semi) crossdrilled, tried to look if they would fit.
The Impreza rotor is basically an exact fit like the Fiero rotor ! Bolt pattern, center hole and depth of the hub (front to the rotor surface) are the same. The difference is the Impreza rotors are vented and thicker...so 'they are thicker at the back'...
At the front knuckle it looks they could fit and clear, but I still need the Fiero front rotors shaved to hubs to testfit and continue...
At the back, first theres a lip that has to be grinded off the knuckle to clear a bigger rotor (I guess that is part of any bigger brake swap). Issue with the rear knuckle is the shape and mounting holes are relatively close to the stock rotor already...max distance measured is 22mm frontface rotor to knuckle...so the impreza rotor (24mm thick) does not fit without a spacer...behind the rotor..yeah right. I also tried a Corrado (Ebc) frontrotor at the back but it sits too much outward to my taste, I need that space for the wide caliper, the rotor would also need a concentric ring because of the larger center hole of the corrado rotor. Need to find a different solution here.

Some numbers:
porsche rotor diameter 318mm thickness 28mm
subaru rotor diameter 276mm thickness 24mm
subaru rotor diameter 295mm thickness 24mm

front caliper sized(max) for 28mm thick rotors
rear caliper sized(max) for 24mm thick rotors

Another issue I have is that these calipers are pretty wide and I have low offset wheels. I recall they are 32mm offset and they need a 10mm spacer to clear....and I am not a fan of spacers..give me a reason to buy new wheels lol

Bump for an update.

bump for update