Currently the C4 12" brake rotor kit for the 88 Fieros is one of the best bang for the buck upgrades for the 88 fieros (Phil's $100 master cylinder upgrade is probably the best). The only real downside to the 12" rotor upgrade is the rotor to lower a-arm contact issue, which is more common on the lowered 88's.
I set out to find a better 12" rotor that would allow similar bracket simplicity of the 12" Vette rotor upgrade, but with slightly less rotor depth to avoid the lower a-arm interference. Unfortunately, I didn't find a better 12" rotor.... but I did find a 13" one! The 13" fieroguru rotor is about 3mm less deep than the 12" Vette rotor, so it should not have any clearance issues with the lower a-arm on a stock 88 fiero.
One of the major downsides of the larger rotors is their higher weight: Stock 88 rotor: 11.2 lbs 12" vette rotor: 14.6 lbs 13" fieroguru rotor: 18.x lbs
At around 18 lbs, the 13" rotor upgrade would add about 30 lbs in weight overall, but the benefit will be about 31% increase in braking torque vs. the stock 88 rotors.
Along with the additional braking performance, the larger rotors better fill out the wheels. Here are some pics with 16x7 Mille Miglia wheels: Stock 88 Rotor: 12" Vette Rotors: 13" fieroguru Rotor (in a 16" wheel):
Here the rotor was drilled for the 5x100 pattern (I will have concentric rings, but for mock up the wheel studs are precise enough):
Rotor on the wheel bearing:
Back side showing the caliper clearance as well as the general shape/size of the needed bracket:
The next step is to slide the 13" rotor in place on my stock 88 and confirm clearance to the lower a-arm, then finish the design of the brackets to optimize the available clearance between the rotor/caliper and caliper/wheel. If I can get it all worked out to my standards, then I will entertain selling a 13" rotor upgrade kit for the 88's (and only the 88's).
[This message has been edited by Cliff Pennock (edited 10-26-2011).]
I couldn't remember what size the stock ones are. =/
They are 15".
So I could do something like this in the rear, but what about the front? I have a 86 with 88 rear cradle, so I'm not sure what would work with that setup other then what I have now which is Grand am in the front, and stock 88 in the rear.
[This message has been edited by mattwa (edited 10-27-2011).]
So I could do something like this in the rear, but what about the front? I have a 86 with 88 rear cradle, so I'm not sure what would work with that setup other then what I have now which is Grand am in the front, and stock 88 in the rear.
There are several options already for the 84-87 cars anywhere from Grand Am to 13" and options even use the 88 calipers on the 84-87 front... but all those options are significantly more expensive than the 88's that can upgrade rotors while keeping the stock calipers. If you want to learn more about the brake options for the 84-87, then you can look up the info from the various brake upgrade vendors (WCF, Archie, Held - or whatever they are called these days). Here is WCF: http://www.westcoastfiero.c...ake_accessories.html
I am an 88 only guy, so all my R&D efforts are focused specifically on the 88's.
Guru, Thanks for even thinking about selling this someday. Two questions. I have the 12" upgrade already, do you see any added performance to upgrading to the 13" with the additional weight? And, I see that the original bolt pattern was 6 lug, do you feel that there is enough "meat" left around the Fiero lug pattern that it will not crack/break with the heating/cooling cycles the brakes can see. I only ask because from the pics I can't get a good understanding of the thickness and amount of metal left after the Fiero (5x100) pattern is drilled into the rotor.
Thanks again and I look forward to watching this thread to see how it all works out.
Originally posted by qwikgta: Two questions. I have the 12" upgrade already, do you see any added performance to upgrading to the 13" with the additional weight? And, I see that the original bolt pattern was 6 lug, do you feel that there is enough "meat" left around the Fiero lug pattern that it will not crack/break with the heating/cooling cycles the brakes can see.
Currently there is a 13" brake upgrade kit on the market that uses a 6 lug rotor. My setup has more material between the fiero pattern and the oem 6 lug pattern than the other available kit (that has never had a problem with cracking). Also, the pilot bore ID of my rotor is smaller than the C4 setup, so there is more material between the fiero studs and hub than even the C4 setup. With the rotor properly torqued between the bearing flange and wheel, the loads the rotor are subjected to will be spread across the contact area vs. concentrated at the studs.
My primary goal with this project was to find a better fitting brake kit, not necessarily a better performing one... because the ability to use any increase in braking potential is limited by available traction at the tire/road contact patch. The leverage effect going from the 12" rotor to 13" rotor is approximately 10%, the 13" rotors should do a better job dissipating heat and be more resistant to fade due to the increased size, and they may be easier to modulate at the limit of traction... but whether any of these will be of any benefit really depends on the car and its intended use.
[This message has been edited by fieroguru (edited 10-27-2011).]
It is a worthwhile upgrade, but I found that it took me a bit of time to cut and thread the 2 brake rods. It also took more time than I thought it would to cut the support bracket from the old brake booster.
Here is a comparison of the C4, stock 88 and the 13" rotors:
The bracket to mount the caliper is very similar to C4 brake setup:
Rotor/caliper and wheel back together to confirm fitment... and it does fit, just some slight contact with the wheel weight that can be relocated to the wheel lip:
Then the moment of truth... will the rotor clear the lower a-arm for its full range of motion. To check this, I took a spare lower a-rm and bolted it to the upright. Then using the mechanical limits of the lower ball joint, the lower a-arm was moved all around trying to make contact and it just was not possible. In fact in the tightest position I was able to pass a large washer between the a-arm nose and the rotor. The reduced depth and the larger rotor diameter work together to eliminate any chance of interference when using stock lower ball joints (the non-lowering kind).
I already have the autocad prints for the bracket (slightly different shape than the mock up one) and rings and will be sending them out to a couple of places for quotes. Since none of my 88's are currently drivable, the first set will be given to a PFF member for free to install/test on their 88. I have already chosen this person and they have agreed to test, so I do not need any more volunteers...
[This message has been edited by fieroguru (edited 10-28-2011).]
It would appear that you've got a winner here. Let me know when you're ready to produce this kit and put a price on it. Very interested.
------------------ Ron "While you cannot control the length of your life, you can control the width and depth." Live life to it's fullest, you may not see tomorrow.
If everything checks out on the test installation, then I will start selling complete kits... not the individual brackets. The key to this brake setup is the OEM application of the rotors, once that information is out there, then there will be 5 threads in the mall selling knock off brackets. It will happen eventually, but until then I will only be selling complete kits.
I am trying to keep this upgrade affordable, but there will always be those who do not think it is cheap enough. The two comparable 88 brake upgrade kits are: WCF 12" C4 rotor upgrade lists at $440+ shipping WCF 13" Viper rotor upgrade lists at $742+ shipping
My target price is going to be somewhere in between these two with free shipping. My rotors cost more than the C4 rotors but my bracket setup is less complex than the Viper kit as well. Right now it all depends on what I can get the brackets/rings produced for and I will not know that for a couple of weeks.
I have confirmed that the rotors I am using are available cross-drilled & slotted, so that will be an option (with a slightly higher cost due to the increased cost of the drilled/slotted rotors)
[This message has been edited by fieroguru (edited 10-29-2011).]
Originally posted by fieroguru: If everything checks out on the test installation, then I will start selling complete kits... not the individual brackets. The key to this brake setup is the OEM application of the rotors, once that information is out there, then there will be 5 threads in the mall selling knock off brackets. It will happen eventually, but until then I will only be selling complete kits.
You should only be worried about that if your price is out of line... Giving us the option to buy the rotors local would save a fortune on shipping; thus reducing the overall cost. You say shipping will be free; but every time I go to the post office or UPS, then never have a "free" shipping option for me to chuse from
[This message has been edited by ALJR (edited 10-29-2011).]
You should only be worried about that if your price is out of line... Giving us the option to buy the rotors local would save a fortune on shipping; thus reducing the overall cost. You say shipping will be free; but every time I go to the post office or UPS, then never have a "free" shipping option for me to chuse from
WCF's kit is likely going to still be more expensive than this one, IF you can get WCF to ship in any kind of timely manner. Archie's kit is $1400+, although it includes more stuff. Heck... Archie's brackets, alone, are $240.
Give the man a break. At least let him make some money before it gets reverse engineered. (We've all seen guru's work in the numerous build threads. No question that everything he does is "top shelf".) I haven't seen anyone (well... except for the Fiero Store) try to reverse engineer any of Rodney's stuff.
Give the man a break. At least let him make some money before it gets reverse engineered. (We've all seen guru's work in the numerous build threads. No question that everything he does is "top shelf".) I haven't seen anyone (well... except for the Fiero Store) try to reverse engineer any of Rodney's stuff.
I am not questioning the quality of his work! Just looking at his project (soon to be product for the Fiero Community) from a business stand point (aka, doing the math).
13" rotors on an 88 are not a necessity; rather a performance luxury. So the number of Fiero owners willing to spend $500+ on an upgrade is significantly smaller then the number who would spend $200+ (just a guess) on brackets and concentric rings... So if he could get 5 ppl (again, just a guess; we all know how many ppl say they want something but when the time comes to pony up, all the seller hears is crickets) to buy the full setup and 25 to buy just the brackets. He would have made more $$ by selling just the brackets...
I am not questioning the quality of his work! Just looking at his project (soon to be product for the Fiero Community) from a business stand point (aka, doing the math).
13" rotors on an 88 are not a necessity; rather a performance luxury. So the number of Fiero owners willing to spend $500+ on an upgrade is significantly smaller then the number who would spend $200+ (just a guess) on brackets and concentric rings... So if he could get 5 ppl (again, just a guess; we all know how many ppl say they want something but when the time comes to pony up, all the seller hears is crickets) to buy the full setup and 25 to buy just the brackets. He would have made more $$ by selling just the brackets...
That’s the way I look at it at least
It's all about determining your target market, volume goals, and price point.
As I have told my tester, if I sell 10 sets at my target price, I will consider this project a success (I have no interest in being a high volume/low price vendor... I am more of an R&D guy). If there happens to be a higher demand than I want to deal with, then I will probably hand over the details/prints to a dedicated fiero vendor and move on to the next project. To me it is less about the $$$ and more about the R&D challenge and if you follow some of my other projects you will see this time and time again.
This swap is an original development and not a copy of any other currently existing kit... I have a lot of time/effort and soon to be $$$ wrapped up in it and I will not make it easy for the copy cats (by selling just the brackets, or sharing my rotor application).
[This message has been edited by fieroguru (edited 10-29-2011).]
I am not questioning the quality of his work! Just looking at his project (soon to be product for the Fiero Community) from a business stand point (aka, doing the math).
13" rotors on an 88 are not a necessity; rather a performance luxury. So the number of Fiero owners willing to spend $500+ on an upgrade is significantly smaller then the number who would spend $200+ (just a guess) on brackets and concentric rings... So if he could get 5 ppl (again, just a guess; we all know how many ppl say they want something but when the time comes to pony up, all the seller hears is crickets) to buy the full setup and 25 to buy just the brackets. He would have made more $$ by selling just the brackets...
That’s the way I look at it at least
I know of more than 20 that spent near $500 to setup a full low bucket headlight mod (me included). That is mainly for looks. So why not improving safety in a real way? The 88 Fiero brakes are ok for a stock car but in todays standards they really suck bad. Whomever thinks otherwise I guess is still driving some other 80s car. Also there are a lot of people out there with engine swaps with real good power that really need to stop quick because we can go fast very rapidly. Don't ask me how I know
The bracket still concerns me. For proper thread engagement you normally need 1.5x bolt diameter. In this case with M12 bolts you need a plate 18mm thick (~ 0.75" thick).
The bracket still concerns me. For proper thread engagement you normally need 1.5x bolt diameter. In this case with M12 bolts you need a plate 18mm thick (~ 0.75" thick).
dave
I understand your concern. As a general rule the thread engagement should be 1 1/2 times the bolt diameter to ensure that the bolt breaks before the threads strip out of the hole. When using a bolt and nut of the same grade, the nut is generally less than 1.0 x diameter. If you look at a grade 10.9 nut for a 12 x 1.75 it is 10mm thick (or .83 x diameter).
My first consideration is what the thickness of the attachment point from GM was (1.18 x diameter):
Then next was review of the current 88 brake upgrade brackets from vendor kits... they have all been in the 3/8" (.79 x dia) to 5/16" (.66 x dia) thick with the threads in the bracket. There was 1 run by a few PFF members that has a nut welded to the backside as well.
Based on this review, I am currently planning the brackets to be flat with the threads tapped. However, there is room between the back side of the bracket and the rotor to use a nut on the back side as well:
And if it was used, then the total material thickenss would be 1.47 x diameter (my mock up bracket is thinner than the final one, so there is a spacer in the picture):
If the customer wants the additional nuts for use on the back side, that will not be an issue.
Apologize if I missed it, but do you expect these to work with lowering ball joints?
Would you be able to do a set in 5x130 for me?
The lowering ball joints move the nose of the a-arm away from the pivot of the ball joint, so the nose will move towards and away from the rotor at a much faster rate. The issue will be once the lower a-arm breaks the horizontal plane under compression, then it will approach the rotor very quickly and eventually make contact... the question is if this contact will happen during the "normal" range of motion allowed with the bump stops. If you only use lowering ball joints with stock height bump stops, then I do not think it will make contact (but don't take this as certain until I can verify), but if you use lowering ball joints with shorter springs and shortened bump stops I am pretty sure the nose will make contact to the rotor.
Drilling the 5 x 130 won't be any issue. A couple of the stud holes will become slotted due to the increase in bolt circle diameter and the 6 pattern and 5 pattern interference, but that should be an issue.
Originally posted by Alex4mula: ...The 88 Fiero brakes are ok for a stock car but in todays standards they really suck bad. ... Also there are a lot of people out there with engine swaps with real good power that really need to stop quick because we can go fast very rapidly. Don't ask me how I know
Heh. They say it's bad "netiquette" to say "me too", but yeah... My brakes faded lots more than I'm comfortable with (if anyone is really "comfortable" with any brake fade) during RFTH.
I was gonna do the Corvette brakes, but I really don't like the idea of grinding my LCAs. Since my car is lowered, this appears to be a real possibility. I think I'll wait.
Sent the prints for the brackets/rings along with the print for my LS4/F40 aluminum flywheel to a local CNC vendor I deal with at work. On Tuesday I will send them off to a vendor I used to deal with before I transferred. They have a lot more capabilities (better source for my flywheel) and decent prices as well... but they would need to be shipped 350 miles vs. local pickup. I am asking for a price based on 40 brackets/rings (10 sets) and 5 flywheels.
Order the 3 other rotors for the prototype set, 50 each of the 10.9 bolts/nuts, and should have the estimates next week from the 2 shops for the brackets and rings... slowly making progress.
Order the 3 other rotors for the prototype set, 50 each of the 10.9 bolts/nuts, and should have the estimates next week from the 2 shops for the brackets and rings... slowly making progress.
$565 shipped to the lower 48 for the Standard 13" Brake Rotor Kit (w/ 4 standard rotors, 4 brackets, 4 rings, 8 grade 10.9 bolts, 8 grade 10 nuts) $640 shipped to the lower 48 for the Cross-Drilled/Slotted 13" Brake Rotor Kit (w/ 4 cross-drilled/slotted rotors, 4 brackets, 4 rings, 8 grade 10.9 bolts, 8 grade 10 nuts) . . . Assuming $80 for shipping, my standard 13" kit is $45 more expensive that the WCF 12" C4 kit and $257 less expensive than the WCF 13" Viper kit. Even if you opt for the drilled/slotted option you will still save $182 vs. the WCF 13" Viper kit (non-drilled/slotted).
I think these prices are highly competitive, but I am sure some will see them as too high. I am willing to knock off $50 per kit for multiple kits sold to the same individual (88 people seem to have more than one 88). So purchase 2 kits, save $100 or purchase 3, save $150.
The plan right now is when all the parts are here for the first test kit, I will install the first kit on my black 88 (never had a brake kit before) to check for fitment and to create the instructions. Then it will be removed from my 88 and sent to my tester for assembly via the instrutions on his 88. He will then provide his feedback to me and confirm the instructions are more than adequate, then I will start accepting orders for the brake kits.
Feel free to PM me feedback on the pricing and if you are really, really, really interested in having one of these kits. Interest will determine if my first order from the machine shop will be for 5 sets of brackets or 10 sets.
What kind of rotors would you be suppling? China stuff or North American?
Any chane on lowering your price if you get enough of us to get you a better qty. deal from your machine shop? I know the price goes down quite a bit if you do a larger production run... Of course we would give you a deposit so you don't get burned...
What kind of rotors would you be suppling? China stuff or North American?
Any chane on lowering your price if you get enough of us to get you a better qty. deal from your machine shop? I know the price goes down quite a bit if you do a larger production run... Of course we would give you a deposit so you don't get burned...
Rotors I assume are from China...
The price differential on all the kit components is about $28/kit when the order quantities go from 20 (5 kits) to 100 (25 kits). So yes, there is a chance I could lower the cost if there is enough interest, but I just do not see an actual market for more than 10-15 of these kits in the near future. As such, I prefer to pass on the potential mfg. scale savings (and a portion of my margin) to those who purchase more than 1 kit. Which is why I offered up the $50/kit savings when purchasing more than 1. So theoretically, 3 people could pool their order (I get the order/$$ from 1 person and ship to 1 address) and save $150.
