The lug bolts still retain the original location and pattern. The rim will center just as it did on the original hub. You will be installing longer lug bolts on the front to account for the thickness of the added rotor.
The concentric rings are designed to center the rotor, not the rim.
Oh, BTW, If anyone would like AutoCAD drawings of the adapters needed for this upgrade, drop me a line at dcampbell@rgv.rr.com
All you have to do is take the drawings to any machine shop with the right tools and they can run the parts for you. These are the same drawings I used on my swap and the adapters worked perfectly.
Originally posted by 87GTBro: The rims do not even touch the 1/8" protrusion or hat (dust cover) that covers the castle nut on the front hubs. If you have ever noticed the tapered edge on a lug nut, that taper is designed to center each hole in the rim over the lug bolt. This is what centers the rim on the hub. If the rim was indeed centered by that lip on the hub, it would be necessary that all rims be manufactured with identical center bore diameters. This just isn't the case.
The answwer to your original question though is:
No, this swap has no affect on the centering of the rims on any of the four wheels. Because the lug bolts are all still in the stock location, the rims still stay centered on the hubs.
Incorrect. From the factory, the wheels DO center on the hub pilot. Using brake upgrades with separate rotors does indeed reduce the length of the protrusion such that the wheels no longer contact it. After doing the upgrade, the wheel is then centered by the lug nuts. This is NOT the same and is NOT as good as a positive location via pilot & bore. However, this seems to be "good enough" that people don't have any problems with it.
I think it's sloppy and one of the major problems with Fiero brake upgrades. Would you trust that the lug studs locate the wheel well enough that it won't shake you into a crash at 150+ mph?
Originally posted by Will: I think it's sloppy and one of the major problems with Fiero brake upgrades. Would you trust that the lug studs locate the wheel well enough that it won't shake you into a crash at 150+ mph?
Got a 150 mph Fiero? Anyone...Bueller? ;-)
------------------ ..from beautiful Caledonia, WI 87 GT 5 speed Electron Blue V8 SBC TPI 87 GT 5 speed med red (for sale) 94 BMW 850Ci V12 (for sale) 93 GMC Typhoon (for sale) 05 Caddy STS 00 Pontiac GTP with GTX package 96 Suburban 92 Dodge Shadow 28K miles
Right on Will. Pilot & bore locating is the only way I would be comfortable. I hope all the brake conversions out there are retaining that feature. And some of us do have 150MPH capable Fieros.
Incorrect. From the factory, the wheels DO center on the hub pilot.
Thank you.
Didn't mean to steer this toward (yet another) hub vs. lug centric discussion, but figured it would go that way the moment I started typing. ...and look, it did.
So once again for anyone who has this modification in progress, or has completed it and doesn't mind pulling a wheel to measure... How much, if any, of the hub pilot protrudes past the 'Vette rotor once the front components have been modified and assembled?
edit: Never mind. Will's comment above answered my concerns.
[This message has been edited by dguy (edited 01-29-2007).]
Didn't mean to steer this toward (yet another) hub vs. lug centric discussion, but figured it would go that way the moment I started typing. ...and look, it did.
So once again for anyone who has this modification in progress, or has completed it and doesn't mind pulling a wheel to measure... How much, if any, of the hub pilot protrudes past the 'Vette rotor once the front components have been modified and assembled?
and "hijack" what do you mean hub vs. lug centric?
Is there any problems if i wana go with 88 calippers? I have a chanse to buy front calippers from a 88 vette, for a realy good price, complete with rotors. I realize the adapters in the drawings are for 84-87 calippers, but is there other differences than the mounting holes being wider appart on the 88 calippers?
Guys! I have a widow of oportunity here (Or so i think!) i can buy front calippers and discs from a 88 vette, but since all guides and wright ups i can find only talks about 84-87 calippers, for the front, i don't dare to buy. (Even though the discs alone is worth the $$$...) From what i can se, the 84-87 calippers are ONE piston, and the 88's are TWO piston calippers. I have a set of adapters at home (Boroved) and i can tell the mounting holes for the 84-87 are 9cm apart, for the 88's they are 13cm apart. I have not made adapters for my self yet, and i might make adapters for the newer 88 calippers instead. I would like to know if there is any other known isues going with newer calippers..? (Iwe been searching Peenock's, and reading to my eyes bleed for two nights now, trying to get info on 88 calippers, or why not use them. I'm sure the info is out there, but i need to know yesturday... The guy selling, is waiting for my answer.) Any one, please send me in the right direction.
I think the oportunity is lost by now. But i would still apriceate directions on where to find more info in what calippers work, witch doesent, and why not.
The 88 calipers do need different adapters because in 88 they used a dual piston caliper. But they will work with the correct adapter plate because I used 88s on my car. The design drawings on the forum here are for the 84-87 only.
OK, thats just what i wanted to hear. Thank' Ryan. The mounting wholes on the 88 is 13cm, 4 cm wider than the pre88. I have not made the adapters yet, so the dual piston calippers looks better for me. When i made the adapters i will post the drawings here if you like.
When I built the brackets, i first built them out of wood then I transfered it to a 1/2 piece of steel. It worked out perfect with a couple of washers as spacers. I really didn't do any drawings or measurements. I found this to be an easier way.
Thats just the way i planed on doing it. I will mount the brake parts, and then look that i can turn full in both directions with the suspension in all angels. I will have the car on stands, and just use a garage jack to compress the spring to make sure the calipper doesent touch anything. Then i will take the wooden adapter and have it made in construction steel. (Or posibly Titanium, if i can afford it.)
Just want to confirm that this swap will work on an 88 as I know that the brakes are a little different due to the different suspension.
I do not believe this question has been answered yet. Does anyone know the answer for us 88-ers? Are the adaptor plates the same or at least similar?
As an alternative, there are offset brackets available that allow the use of larger Corvette rotors while still using the 88 stock caliper - http://www.westcoastfiero.com/brakes/brakes.html. This does not look like much of a different setup and could also be "homemade". What kind of compromise might this be? The larger rotor would be the same, but what is the comparison between the "squeeze" of the 88 stock Fiero caliper and those of the Corvette? WCF says 20% improvement over stock Fiero for his setup - it also appears to be studcentric for the rim.
Another question: Can the hub-centric vrs stud-centric problem be remedied with wider more elaborate concentric rings? Perhaps wider ones with a step to the same OD as the raised lip on the stock Fiero hub? Are any factory arrangemets (any car) lug centric or are all original hubs hub-centric? Any I've had appart I believe are all hub-centric.
------------------ Daviero - 88 N* GT
[This message has been edited by Daviero (edited 02-05-2007).]
OK, thats just what i wanted to hear. Thank' Ryan. The mounting wholes on the 88 is 13cm, 4 cm wider than the pre88. I have not made the adapters yet, so the dual piston calippers looks better for me. When i made the adapters i will post the drawings here if you like.
Please post the drawings. Everyone would appreciate it
Will do, if i can find another set of 88-> calippers. The once i had in mind was sold. I was to slow deciding. Now that i know they would fitt, it will be easyer to find me a set. Not to big market in swden for Corvette calippers though, so it might take a while.
Please help, I hope someone see's this soon. I am planning and buying the parts for this Corvette brake upgrade on my Fiero. I have the calipers and brackets. I ordered the adapter brackets from the Cheetah site. Waiting for them to show up but, haven't heard anything yet?
Anyway, I was about to order the ROTORS and when I asked for 88 to 96 12 inch standard duty ROTORS they told me the rears are 12 inch but, the fronts are actually 12.8 inches. Is this right???
Would love to hear from those who have done this. Thanks, Bob
Front and rear rotors should both be 12 inches in diameter. If you have the bigger front rotors they are wrong. The larger rotor is for the J55 option heavy duty and are the larger rotor.
I don't know if anyone else has ran into this problem or not. I made my parts, to the prints, found here, on the forum. Everything is fine, accept the front caliper adapters. The prints say to make them .875" thick. I did that and it held the rotor off the hub, when I tried to assemble the brakes. I machined it to .725 and it is still hitting the back of the rotor, but the rotor can spin now. Am I missing something or is the print wrong? I still need to machine another .050" off the adapter to center the caliper bracket over the rotor. I did grind the spindle flat as Bubba Joe says to do.
Has anyone else used the 67-80 MC and not had to change the lines?? I was told by a friend that there were no mods needed on this setup. I am just looking for others that have used this MC.
Has anyone else used the 67-80 MC and not had to change the lines?? I was told by a friend that there were no mods needed on this setup. I am just looking for others that have used this MC.
We had to make new lines, others have said they switched lines and got them to work with some gentle finesse.
I don't know if anyone else has ran into this problem or not. I made my parts, to the prints, found here, on the forum. Everything is fine, accept the front caliper adapters. The prints say to make them .875" thick. I did that and it held the rotor off the hub, when I tried to assemble the brakes. I machined it to .725 and it is still hitting the back of the rotor, but the rotor can spin now. Am I missing something or is the print wrong? I still need to machine another .050" off the adapter to center the caliper bracket over the rotor. I did grind the spindle flat as Bubba Joe says to do.
We had to use small washers to space the caliper adapter. If its the same issue as I'm thinking, I mentioned it earlier. From Page 1:
quote
You can now position the preassembled assembly onto the spindle. You will need to check for clearances. When we put ours together, we found that the outer edge of the caliper adapter was rubbing against the rotor. We fixed this by installing washers between the spindle and the mounting bracket. We used blue locktite, and tightened everything down once we were satisfied with fitment.
[This message has been edited by Jncomutt (edited 03-09-2007).]
Well I am going to need to redo the small lines from porporting valve to 80 corvette m.c. I was hoping not to have to remake them, but you know the old saying!! What does it take to actually make lines? I will need to find the two fittings that fit the vette m.c. the 85 fiero ones WILL NOT BOLT up I don't care how careful you are.
Any advice on doing this small task would be helpful.
I am collecting parts for this upgrade and noticed that the hub didn't stick out much past the rotor after it was put on, will it not contact the wheel at all? I thought it may still some. I would rather not have the wheel centered by the lug nuts. Any way to remedy this?
quote
Originally posted by Will:
Incorrect. From the factory, the wheels DO center on the hub pilot. Using brake upgrades with separate rotors does indeed reduce the length of the protrusion such that the wheels no longer contact it. After doing the upgrade, the wheel is then centered by the lug nuts. This is NOT the same and is NOT as good as a positive location via pilot & bore. However, this seems to be "good enough" that people don't have any problems with it.
I think it's sloppy and one of the major problems with Fiero brake upgrades. Would you trust that the lug studs locate the wheel well enough that it won't shake you into a crash at 150+ mph?
Well here is a small update for those of you who intend to use the 67-80 corvette m.c. I originally bought a Napa reman m.c. part no. 10-1749, the fiero would not bolt to it. I took the lines and m.c. back to napa, the guy pulled out a new m.c. and bam, the fiero lines bolted right up. The part no is Napa 39052. of course it was another 48.00
My advice is take your lines with you when you want to buy the darn thing.
Here's an update. Been almost 2 months and I got parts from Cheetah but they were made wrong. I returned them and have not heard from Cheetah. I think I got screwed. Anyone else get the brackets from Cheetah yet???
I have the same problem. The guy is impossible to contact. I did get my brackets and the holes didn't line up on one set, I forget wether it's front or back right now. I tried to contact him with no luck at all. If you ever get anywhere with this please let me know.
I am in the process of designing brackets to use the 88 vette front calipers and have been shopping various machine shops in my area as a cost study. I talked to one that deals exclusively with aluminum machining (for motorcycles mainly) and he was mildly comfortable with making the front bracket out of 6061 aluminum and thought the rear was too thin to make out of alum. He was also worried that since aluminum expands at 5 times the rate of steel concentric rings made out of it would stick unless you waited for the rotor to be absolutely cool. Even then you have your rotor being hub centric using 2 differing metals. I'm thinking of making the brackets in steel only since I'm not sure how safe using a thin aluminum bracket is.
What is everyones opinion on this and those that have used the aluminum adapters, how have you found them and has there been any warpage?
Got word from my machine shop that it is cost effective to produce these brackets if I get them in large enough Quantities. I will be making them in steel, it has a better tensile strength and I will feel much safer that way.
I will be prototyping/ machining the front 88 dual piston caliper brackets and testing them out this month. If all goes well in the fitment and test drive department I should be making these along with concentric rings available for purchase in a month or so.
Luke, I really hope you go through with this because i definitely want the twin piston vette calipers. Then you can use the calipers all the way around from the same year vette instead of mixing and matching years like the old setup. Just let me know when your ready to accept money. Thanks Daniel
