Potential 11 1/8" Brake Upgrade for 88 Fieros with Stock 15" Wheels (Page 3/4) Notorio JUL 13, 12:22 AM quote Originally posted by qwikgta: Like, Like, Like. Thanks from all of us "88" folks out here. Rob What Rob said. Great little research project you have going there for the benefit of the Community. Sundowner JUL 13, 10:45 AM Definitely keeping an eye on this one. The brakes on my stock Formula won't lock up no matter how hard I put my foot in it... I've replaced both master and slave cylinders, brake hoses, lines, and bled and bled. fieroguru JUL 13, 07:51 PM quote Originally posted by blackrams: I applaud and appreciate your efforts to continue to improve these fun little rides. What you do, you do so well. Keep it up. quote Originally posted by qwikgta: Like, Like, Like. Thanks from all of us "88" folks out here. quote Originally posted by Notorio: What Rob said. Great little research project you have going there for the benefit of the Community. Thanks guys! quote Originally posted by anaverin: does this mean your close to a new kit? I wouldn't say I am close, just still looking for possibilities as I R&D for my personal car finds new options for consideration. I would love to find a simple bolt on upgrade that didn't require any brackets or other custom parts... which is really stupid from a business perspective... quote Originally posted by GTFiero1: I've kept an eye on brakes of some cars for possible conversions, havent physically tried putting parts together but Ford Transit 250 (2017ish) rear calipers have integrated parking brake, a 54mm piston, and are cheap. They sit on a 12.1" solid rotor -that being not compatible in any way. The Caliper bracket width for the rotor is 18mm, so a somewhat thin rotor would have to be utilized. A 2010 WRX STI rear rotor is 12.4" at 20mm thick. Could be turned down to 18 (its minimum thickness), or maybe transit caliper bracket opened up slightly. 2007 GTI rear rotor is 11.26" at 12mm wide. Unsure if the Transit caliper piston can make up that 6mm distance, and if the caliper would sit ok on a rotor 3/4" smaller diameter. Just out loud thinking and this could all be useless information 54mm is a 27% increase in piston area, which is large enough to require changing the master cylinder. There are a lot of calipers in the 48, 51 and 52mm range that would be a better starting point. The WRX STI rear rotor is 10mm too deep to clear the nose of the lower a-arm on the 88s in the front. Might work OK in the rear. GTI rotor almost certainly will not fit over the 88 front wheel flange and also not a fan of going from vented to solid. quote Originally posted by Sundowner: Definitely keeping an eye on this one. The brakes on my stock Formula won't lock up no matter how hard I put my foot in it... I've replaced both master and slave cylinders, brake hoses, lines, and bled and bled. That isn't normal. You should focus on fixing this issue before making any major changes to components Have you measured the vacuum assist at the booster - a vacuum leak would make for a harder pedal and greatly reduced braking. Also, if the pad gap in the rear isn't properly adjusted, you will have a soft pedal and poor braking. fieroguru AUG 01, 07:26 PM While I was doing some research on quad piston calipers for my car, I came across this one. The mounting bolt pattern is very close to the stock 88 caliper bolt spacing, so it should bolt directly to the 88 knuckle. Not sure if there is an acceptable rotor to work with it yet, or if that rotor would have to be larger or smaller than stock 88 size. It has quad 38mm pistons, so it would result in 25.3% increase in clamp force, but might require a master cylinder change. I ordered one just to check it out further... 87_special SEP 22, 02:40 PM quote Originally posted by fieroguru: I still need to develop the concentric rings and find the proper brake hoses as the hose connections are slightly different, but most of the hard work is done. Unfortunately, this is front only option at the moment, as this caliper doesn't have a parking brake setup. We could think of it as the grand am style upgrade for the 88s, where it is plug & play using stock parts w/o needing any caliper brackets. I might be able to pair the Caliper X front kit with an other 88 stock wheel kit I was working on, but stopped because it wouldn't fit under the stock 88 front wheel (but did fit the 15" rear). I have found a rotor slightly smaller than 11 3/4" that can be made to work with the 88 Fiero 15". It will need a caliper bracket, concentric ring, and either a small wheel spacer (1/16" would be plenty), or clearance the head of the brake line bolt. This kit would provide about 19% increase in braking leverage and allow reusing the stock 88 rear caliper for parking brake function. This would end up being a slightly less overall improvement vs. the front using 52mm Caliper X , but it could be an option for a more closely balanced approach. quote Originally posted by fieroguru: In the event I bring this kit to the market, anyone who purchases the kit, will get the application information for all parts, so they will be able to source replacement parts from where ever they wish, when ever they need to. Any update to this product Mr. Guru? I'm interested in a front only kit but prefer a front and rear kit. I like the idea of using 88 rear calipers to keep the e-brake functionality. I like your 13" kit but want the option of being able to put the stock wheels back on for winter, storage, paint, construction time. Would this kit be possible with fancy slotted and zinc rotors? fieroguru SEP 22, 07:55 PM quote Originally posted by 87_special: Any update to this product Mr. Guru? I'm interested in a front only kit but prefer a front and rear kit. I like the idea of using 88 rear calipers to keep the e-brake functionality. I like your 13" kit but want the option of being able to put the stock wheels back on for winter, storage, paint, construction time. Would this kit be possible with fancy slotted and zinc rotors? I haven't played around with Caliper X in a while. This thread is 3 years old with only 24 posts and 8 of them are mine. That is the community speaking very loudly that there isn't much interest in an brake upgrade that fits under stock 15" wheels. I am OK with this reality, as I have plenty of other fun things to focus on. I have continued to find what I think are cool caliper options that might work for brake kit that fits under the 15" wheels, but most of these discoveries are byproducts of research for other goals. I haven't given up on it, just way back on the back burner until something about it motivates me to bring it closer to the forefront. 87_special SEP 22, 11:11 PM quote Originally posted by fieroguru: I haven't played around with Caliper X in a while. This thread is 3 years old with only 24 posts and 8 of them are mine. That is the community speaking very loudly that there isn't much interest in an brake upgrade that fits under stock 15" wheels. I am OK with this reality, as I have plenty of other fun things to focus on. I have continued to find what I think are cool caliper options that might work for brake kit that fits under the 15" wheels, but most of these discoveries are byproducts of research for other goals. I haven't given up on it, just way back on the back burner until something about it motivates me to bring it closer to the forefront. Thank you for the reply. I just got back into Fieros after a 10 year hiatus so I've been out of the loop. I'd be interested in a set of hub centering rings and rotors with info on "caliper X" so I can source them. Have you thought of doing a small job like that? I understand not wanting to give the info online for IP purposes. Maybe we should move this to email for confidentiality. ltlgt88 SEP 26, 09:16 PM Would caliper X be a good replacement for stock calipers since they are becoming hard to find? And is there a rear caliper with parking brake functionality for 88 that is still being made that would be a good replacement? Those are the 2 things I think we need to find. Because that is the biggest complaint of 88 owners is findings brake caliper, because they were a one off year. Even if they fit the stock size rotor and 15 inch wheel I think there would be a market. ltlgt88 JUN 09, 12:11 PM Been another bunch of years... Anything Paul? Looking for easy replacement and easier to find for the stock 88 calipers since they are hard to find. Front and or rear fieroguru JUN 13, 09:01 PM quote Originally posted by ltlgt88: Been another bunch of years... Anything Paul? Looking for easy replacement and easier to find for the stock 88 calipers since they are hard to find. Front and or rear Haven't done anything more with Caliper X, Caliper Y or the quad caliper. As you can see from this thread, there is very little market interest in this brake kit. I am currently doing validation tests on a 13" Brembo front upgrade to my current 13" brake kit, but that is a topic for another thread.