The brake upgrades I've read about (Lebarron, Grand am, C4) all seem to say they're best suited for either 84-87 or 88 fieros, but not both as far as I can tell. What brake upgrade would be my best bet when I have an 88 cradle on an 85se?
I've read (if I remember correctly) that the Grand Am upgrades on front and stock '88 (refreshed) on rear is a good balance. If I'm wrong, I apologize.
The brake upgrades I've read about (Lebarron, Grand am, C4) all seem to say they're best suited for either 84-87 or 88 fieros, but not both as far as I can tell. What brake upgrade would be my best bet when I have an 88 cradle on an 85se?
The 12" C4 brake upgrade using the stock 88 Fiero calipers was offered in the 84-87 and 88 styles, so you can use it for the hybrid cars (84-87 front/88 rear) and retain factory brake bias and parking brake functions while significantly improving the braking potential of the car. I offer the brackets for the 12" C4 rear on the 88, but do not offer the needed front brackets for the 84-87.
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Originally posted by akademikjeanius:
I've read (if I remember correctly) that the Grand Am upgrades on front and stock '88 (refreshed) on rear is a good balance. If I'm wrong, I apologize.
That combo severely biases the front brakes and isn't an ideal setup.
My 84 has an 88 cradle and I swapped over the 88 front calipers and C4 vette rotors on front. I machined an adapter bracket from 6061-T6 aluminum to mate the 88 front calipers with the 84 front spindle. I also transferred over the 88 master cylinder and brake booster. The rear is stock 88, I was going to use the larger vette rotors on the rear but the braking is very good already so I never did that mod.
My 84 has an 88 cradle and I swapped over the 88 front calipers and C4 vette rotors on front. I machined an adapter bracket from 6061-T6 aluminum to mate the 88 front calipers with the 84 front spindle. I also transferred over the 88 master cylinder and brake booster. The rear is stock 88, I was going to use the larger vette rotors on the rear but the braking is very good already so I never did that mod.
While you saw a noticeable improvement, you only increased the front bias. So at the limit (especially in rain/snow), you will prematurely lock the front up and not see the full potential of the brake upgrade. If you add the rear portion of the kit, it will stop even better and you can stop at a much quicker rate before the fronts will lock up.
That may be true but the stopping improvement over the 84 brakes (which were in good working order before the swap) is so much better just as they are. I have the rear adapter brackets, I will probably upgrade the rears to vette rotors when I do the V8 swap.
The 12" C4 brake upgrade using the stock 88 Fiero calipers was offered in the 84-87 and 88 styles, so you can use it for the hybrid cars (84-87 front/88 rear) and retain factory brake bias and parking brake functions while significantly improving the braking potential of the car. I offer the brackets for the 12" C4 rear on the 88, but do not offer the needed front brackets for the 84-87.
I have this setup on my car. 85gt with 88 cradle swap. I got my brackets from Jon @ Fieroaddiction when he was still around. However, I had to modify the front brackets and grind a small portion of the knuckle to get the pad to ride correctly on the rotor. If you are interested in the new measurements I came up with, and/or pictures I would be happy to help. I have no interest in helping to take Jon's design but since I had to mill out mine to make them work right I feel then are not quite his design anymore.
It would be a big help in designing a new set. Nobody offers this setup for 84-87 anymore, let alone a mixed setup for the 88 cradle swappers. I'll be taking my front apart in the next week anyway and it would be easy to provide the needed info. Since you already offer the machined hubs and 88 brackets I think you would be the perfect person to offer the 84-87 set to the community again (plus you are trustworthy and offer great products). Email or PM me if you're interested.
Here is a link to my build thread where I mounted them. This is before my needed modification. Notice the calipers sit too far away from the rotor edge as compared to the rears pictured lower in the post. This is what I fixed by cutting off the tubes, milling new holes 3/16" in, and welding the tubes back on.. I did not get pics of them after modification... but I will in the next week or so. https://www.fiero.nl/forum/F...ML/000059-2.html#p71
[This message has been edited by Fieroseverywhere (edited 10-05-2014).]
I have looked at the 84-87 front brake setup several times. The big issue is the convenient surface to mount the caliper bracket to isn't a machined surface, so the caliper might not be parallel to the rotor on all installations.
When I do an 84-87 brake kit, it will use the machined surface so it can be installed with consistent results. Right now I am focused on other projects and any further brake kit developments are on hold
You can use that but its not plug and play. You need to install a larger banjo rod by cutting the S-10 rod and welding a piece of the Fiero rod to the appropriate length. Then you must free up more space where the S-10 booster will sit by hammering on the inner fender well; IMO not a clean way to do it. If Rodney ever comes out with the installation kit, the modified booster is supposed to fit like a glove. There is a member here who builds and sells modified used boosters in the mall but I do not know if they are direct fit.
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IMO, any upgrade that uses the '88 Fiero calipers in front will be your best bet. Because as mentioned above, front calipers with larger diameter pistons are going to shift the brake bias even more to the front. And IMO the brake bias is too front-heavy to begin with.
I have looked at the 84-87 front brake setup several times. The big issue is the convenient surface to mount the caliper bracket to isn't a machined surface, so the caliper might not be parallel to the rotor on all installations.
When I do an 84-87 brake kit, it will use the machined surface so it can be installed with consistent results. Right now I am focused on other projects and any further brake kit developments are on hold
When I made my brackets to adapt the 88 calipers to the 84 spindles, it required some machining to the caliper mounting pads on the spindles to provide a mounting surface so that it was parallel to the rotor braking surface. You are correct, it is not a direct bolt on swap and the main reason why I never offered to make the brackets for others.
Stock 88 rear and grand am front upgrade is a great balance and a great setup for anything youll be doing in a fiero.
Only thing this setup is good for is burnouts while staging for a 1/4 mile run where you want to the fronts to try and hold the car (doesn't work well from my experience) and let the rears spin.
When you either increase rotor diameter or caliper piston diameter, you increase stopping power at a fixed input pressure and lower the pedal input needed for specific rate of decel when compared to the stock setup.
The issue with this setup is that all the gains happened on the front and no gains were had in the rear (I am neglecting the benefit of going to the 10.43" vented rotors front/rear as the gain from them is equal front and rear - the choice of calipers is the issue). So at a fixed rate of deceleration, you will apply less pedal pressure. Since the rear brakes are unchanged, this lower pedal pressure = less stopping power in the rear, so the rear brakes will contribute less effort to stop the car than if you didn't do any brake upgrade at all. This brake combo will still initially "feel" stronger than stock, but since the fronts are now doing a much higher % of the total braking, you can lock them up easier (in rain/snow or under aggressive braking) and over heat them sooner. Neither of these are signs of a brake kit with great balance.
I have looked at the 84-87 front brake setup several times. The big issue is the convenient surface to mount the caliper bracket to isn't a machined surface, so the caliper might not be parallel to the rotor on all installations.
When I do an 84-87 brake kit, it will use the machined surface so it can be installed with consistent results. Right now I am focused on other projects and any further brake kit developments are on hold
Correct me if I'm wrong but I believe the early front ends do have a machined surface to mount the bracket to. At least the bracket style I used. Its small, only around the threaded bolt holes, but it is there. It is on my 85. Also since it was a caliper mounting surface already that would lead me to believe they are parallel to the rotor/hub surface. I could be wrong as I only have a 85 and an 84 here to look at. Not sure about the 86-87 cars or the consistency between caliper mounting surfaces though. I hope someone finds a way to make it work again.
I think I read once that the 88 fiero calipers have the same bore size for all 4 calipers. Is this true? I didn't measure mine when I had them apart for rebuild. If so It might make finding other suitable replacements easier. Parts are starting to get hard to find and rebuilt calipers are approching 150 each + core charge. I'm starting to look into something else myself.
[This message has been edited by Fieroseverywhere (edited 10-07-2014).]
Only thing this setup is good for is burnouts while staging for a 1/4 mile run where you want to the fronts to try and hold the car (doesn't work well from my experience) and let the rears spin.
When you either increase rotor diameter or caliper piston diameter, you increase stopping power at a fixed input pressure and lower the pedal input needed for specific rate of decel when compared to the stock setup.
The issue with this setup is that all the gains happened on the front and no gains were had in the rear (I am neglecting the benefit of going to the 10.43" vented rotors front/rear as the gain from them is equal front and rear - the choice of calipers is the issue). So at a fixed rate of deceleration, you will apply less pedal pressure. Since the rear brakes are unchanged, this lower pedal pressure = less stopping power in the rear, so the rear brakes will contribute less effort to stop the car than if you didn't do any brake upgrade at all. This brake combo will still initially "feel" stronger than stock, but since the fronts are now doing a much higher % of the total braking, you can lock them up easier (in rain/snow or under aggressive braking) and over heat them sooner. Neither of these are signs of a brake kit with great balance.
The problem is... the grand am upgrade is NEARLY identical to stock 88 brakes... He is already upgrading the rears so whats wrong with a similar upgrade up front?
This doesnt make sense even on paper, but i know in reality it works fine because Justin's car has this setup.
The best brake upgrade is the bigger booster, and it works with all upgraded rotors too. (so you can combine them, for even better brakes) Yes you do have to dent the fender to fit, but it is only like an 1/8in easy to do. The ones sold in the mall are not welded but the correct banjo, and made in the U.S.A.
(BTW rodney's prototype is made in china and is not the correct fit and the firewall still had to be dented)
Fieroguru makes some good rotor upgrades, and is well versed in the braking setup.
The problem is... the grand am upgrade is NEARLY identical to stock 88 brakes... He is already upgrading the rears so whats wrong with a similar upgrade up front?
This doesnt make sense even on paper, but i know in reality it works fine because Justin's car has this setup.
Grand Am has a 57mm piston vs. the stock Fiero 48mm. Clamp load for a given line pressure is based on the area (not the diameter) of the piston. The Grand Am calipers has 41% larger area, so it will have a 41% larger clamp load. A 41% difference isn't what I (or most other people for that matter) would call "NEARLY identical". Yes the rotor diameters are nearly the same, but the overall brake system performance is based on many factors, not just rotor diameter.
"Works fine" does not equal properly balanced. He went from the 84-87 brake setup that didn't raise the bar very high at all, so he saw an improvement where his car can stop faster. No one is disputing this. The issue is he is leaving a lot on the table and his brakes are not nearly as good as they could be because the rear brakes are doing much less than they were before and the fronts and doing much, much more. If he has ever locked up the front wheels or faded the front brakes under braking, then restoring his rear brake bias will help him stop even faster.
Having the fronts prematurely lock up in the rain or in snow isn't a good condition and this is what happens when the fronts are overly biased.
I tend to agree with Fieroguru on this. And unfortunately, I made the mistake of creating the very situation he talks about. You see, I did an '88 cradle swap on my '87 Fiero. Naturally, it means my Fiero now has '88 Fiero rear brakes. The car had Grand Am brakes before the cradle swap, but I didn't like having bigger rotors on the rear (the '88 Fiero rotors are 10.5" diameter, whereas the Grand Am ones are 9.75" diameter). So I did the LeBaron brake swap up front, using GM metric calipers (2.25" diameter caliper pistons).
The end result: the rear calipers don't even develop enough clamping force to wipe the surface rust off the rotors. Basically, the front calipers are doing all the braking. I've stopped driving the car, until I can find a suitable solution to that problem. But I think I'll try to make or buy some caliper brackets that allow me to install '88 Fiero calipers up front. That should fix the brake bias problem.
Originally posted by fieroguru: I don't sell a brake kit for the 84-87.
Maybe you could correct that? A set of caliper backets that allow the '88 Fiero front calipers to be mounted on the '84-87 front spindles would be a good start... you know, for the guys with '88 cradle swaps.
I tend to agree with Fieroguru on this. And unfortunately, I made the mistake of creating the very situation he talks about. You see, I did an '88 cradle swap on my '87 Fiero. Naturally, it means my Fiero now has '88 Fiero rear brakes. The car had Grand Am brakes before the cradle swap, but I didn't like having bigger rotors on the rear (the '88 Fiero rotors are 10.5" diameter, whereas the Grand Am ones are 9.75" diameter). So I did the LeBaron brake swap up front, using GM metric calipers (2.25" diameter caliper pistons).
The end result: the rear calipers don't even develop enough clamping force to wipe the surface rust off the rotors. Basically, the front calipers are doing all the braking. I've stopped driving the car, until I can find a suitable solution to that problem. But I think I'll try to make or buy some caliper brackets that allow me to install '88 Fiero calipers up front. That should fix the brake bias problem.
Not postive on the 88 calipers, but on the 84-87 on the back, if the E-brake is not adjusted right the piston is so far away from the rotor I bet it doesn't clamp enough to wipe off the rust, it has to be adjusted and USED to keep it working right, (auto people never use it and thus have bad brakes)
Maybe you could correct that? A set of caliper backets that allow the '88 Fiero front calipers to be mounted on the '84-87 front spindles would be a good start... you know, for the guys with '88 cradle swaps.
hehe
As Fieroguru stated in an earlier post, the brackets for the front would not be a simple bolt on. I know from experience because I have an 88 cradle using 88 calipers on the rear of my 84. The front uses 12" vette rotors mounted on hubs made from modifying the original 84 rotors. The bracket I made to hold the 88 front calipers to the spindle requires some rework to the original caliper mounting pads to get the bracket to fit properly so that it is parallel to the rotor surface. Also, the original bracket that holds the 84-87 caliper has a steering stop cast into the bracket so that goes away and I needed to fabricate something for that as well. The adapter bracket that I made required the threaded holes that hold the 84 caliper to be drilled out for clearance for bolts which hold the adapter bracket in place. The new bracket mounts to the opposite side from where the original caliper mounted and since that is not a machined surface (it is just an "as-cast" surface) that required some machining as well. It does work well though, even with the smaller stock 88 rotors on the rear. The car stops so much better than it used to and the 84 calipers were in good working order. I also swapped in the 88 proportioning valve, booster and master cylinder. The car is off the road now, the Duke gave out and it is awaiting an engine swap so I will probably go for the rear brackets and make all 4 rotors the same, especially since I will have a bit more weight in the rear after the 327 goes in.
The problem is... the grand am upgrade is NEARLY identical to stock 88 brakes... He is already upgrading the rears so whats wrong with a similar upgrade up front?
This doesnt make sense even on paper, but i know in reality it works fine because Justin's car has this setup.
I love my brakes. Grand am front, 88 rear. Ebc yellow pads all around. The bigger master cylinder and bigger brake booster upgrade. If anything my bias is shifted to the rear which I find great as I have bigger softer tires on the rear. Only time it gets a little hairy is autocross when I'm heavily braking while decelerating in gear.
As Fieroguru stated in an earlier post, the brackets for the front would not be a simple bolt on. I know from experience because I have an 88 cradle using 88 calipers on the rear of my 84. The front uses 12" vette rotors mounted on hubs made from modifying the original 84 rotors. The bracket I made to hold the 88 front calipers to the spindle requires some rework to the original caliper mounting pads to get the bracket to fit properly so that it is parallel to the rotor surface. Also, the original bracket that holds the 84-87 caliper has a steering stop cast into the bracket so that goes away and I needed to fabricate something for that as well. The adapter bracket that I made required the threaded holes that hold the 84 caliper to be drilled out for clearance for bolts which hold the adapter bracket in place. The new bracket mounts to the opposite side from where the original caliper mounted and since that is not a machined surface (it is just an "as-cast" surface) that required some machining as well. It does work well though, even with the smaller stock 88 rotors on the rear. The car stops so much better than it used to and the 84 calipers were in good working order. I also swapped in the 88 proportioning valve, booster and master cylinder. The car is off the road now, the Duke gave out and it is awaiting an engine swap so I will probably go for the rear brackets and make all 4 rotors the same, especially since I will have a bit more weight in the rear after the 327 goes in.
Are the 84 knuckles different from 85-87? The only issue I had involved the caliper brackets I used. Just wondering why our experiences differed so much.
Are the 84 knuckles different from 85-87? The only issue I had involved the caliper brackets I used. Just wondering why our experiences differed so much.
Yes, 84 thru 87 knuckles are the same. Are you using 88 calipers with the Vette rotors up front?
Just wondering why our experiences differed so much.
Variations in the casting (or however the knuckles were formed) process. There were a lot more than 1 mold per side to make them, and not all of them were precisely the same.
Nearly every 84-87 front brake kit uses this non-cast surface and it has worked for many of them (or they just didn't notice and the caliper sliders had enough slop to align things). However, there have been quite a few comments about this issue over the years, so results will vary if you choose to use that non-machined surface... which is why I refuse to do so.
When things slow down on other projects, I might get setup to offer the service to machine the outboard surface on an exchange basis. But that will require stocking up on 84-87 front knuckles and right now I only have 1 set on an 86 parts car. Once that hurdle is done then offering the 12" C4 front kit to match my current 88 12" C4 rear kit would be a no-brainer.
[This message has been edited by fieroguru (edited 10-15-2014).]
