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View Full Version : 13" G-body brakes on the cheap



dgumoe
10-23-2005, 09:08 AM
Hey guys, havent been around in awhile. I quit working at the speed shop a month ago and havent had internet access since then. But in the meantime I've been doing research. and it has paid off in spades. Cheapest conversion I can find to do Corvette brakes on the G-body is around 1600 bucks. Sorry, too rich for my blood considering I now know how bad some of the markup is on performance parts. Well since I'm back at NAPA for the time being, I have many many many books full of dimensions, and application listings so I've been digging around and I've got a solution. I have seen the guys who are using G-body rotors as a hub and making custom mounting brackets, and I was going to do it, but after talking with Marcus at SC&C, I've decided against it. There is another easier (and in MHO safer) way of doing it. 99-2003 s-10 Blazer's use a bolt on Hub assembly with a slip on 11" rotor. They also use a double piston PBR style caliper. Well, its quite easy to replace the rotor with a 13" rotor, from a C4 corvette grand sport. Then you need a C5 caliper. The caliper mounting bracket will have to be made custom, but that is not a big deal. The biggest cost is in the front hubs. For whatever reason, there is little aftermarket support for the front hub assembly for a 2wd blazer. as a matter of fact I cant even get them from my bearing supplier, i have to go to an outside source and they are not cheap. Usually around 300 dollars EACH!! So i went digging and I found another hub that works. And isnt it befitting that it is from a C4 corvette. So here's the rundown now that ive bored you to death.

2WD s-10 BLAZER (not pickup theyre different) spindles. Belltech number 2102 $260/pr
these will net a 2" drop, if you want stock check the boneyards
C4 rear hub assembly Napa Pt# BR 930024 $150 each at Rockauto
C4 grand sport rotors Pt# 86494 and 86495 around 60 each
C5 front calipers Pt# 442-2262m and 442-2263m. these are 113 each, what is the killer is the core charge of 88 dollars each.
So add it all up. it comes to around $920 if you have caliper cores. And that is using Napa pricing.,If you were to go to Advance or Auto Zone, or an online source it may come up cheaper. So for a little more than half the cost, youve got 13" brakes, and the best part is you can buy the parts a piece at a time (locally i might add) if you cant drop a lump sum.

P.S. the other nice thing is you can upgrade to the double piston blazer calipers and 11" rotor and keep your 15" wheels if you like. I also havent done this to mine yet. Ive ordered the parts into work and test fit them and they all fit, i just havent been able to assemble them on the car so i dont know if you need new brake hoses or not (thats a cheap enough incidental) good luck, i hope this helps my fellow pro-touring G-body bretheren. Happy motoring! -Jon :cheers:

elcamino80
10-23-2005, 09:37 AM
Nice!! One question though, are the wheel bearings included in the hub assembly??

And please remember to post after you have installed them how everything fitted together and if you had to buy/fabricate some extra parts

rkw1969
10-23-2005, 11:22 AM
I just put some prices together using zo6 corvette calipers and gm drilled and slotted rotors and came up with $743.70 for everything brand new, front and rear. This includes all the little washers, pins, brake line gaskets and pads. Now this doesnt count for the caliper/spindle brackets cause im going to make my own. Should be a hell of a system especially with a hydraboost. Might want to look into it. It may just be what you are looking for.
Only draw back is you would have to use a 17" wheel for it to work I think.

dgumoe
10-23-2005, 11:26 AM
thats pretty cheap, i take it youre going to be using the g-body rotors as a hub?
elcamino80 yes, the 150 is for a complete hub and bearing assembly. i will defiently be posting on here when its done, right now im working on getting the interior stripped so i can herculine it.

WS6
10-23-2005, 11:30 AM
yes the Hub assembly is a sealed unit with bearings. it is nonservicable and can only be replaced as a whole if it goes bad.

im curious to know how you plan to use a rear hub on the front of your car? the rear hubs on corvettes have a hole in them for the spindle to slide though. the brake rotor slips onto the spindle. the rotor is not on the hub.

dgumoe
10-23-2005, 12:03 PM
yes the Hub assembly is a sealed unit with bearings. it is nonservicable and can only be replaced as a whole if it goes bad.

im curious to know how you plan to use a rear hub on the front of your car? the rear hubs on corvettes have a hole in them for the spindle to slide though. the brake rotor slips onto the spindle. the rotor is not on the hub.
the rear hub on a C4 corvette bolts to the rear upright, spindle, whatever you wanna call it on that car. then the rotor slips over it. the hole in the middle of the hub assembly is for the splined end of the driveshaft to slip into. since there's no driveshaft up front, the hole is just left open. and before anyone asks, no i dont see it being an issue having a open hole in the hub, the s-10 hub assembly is the same way, just no splines for a driveshaft.

Q ship
10-23-2005, 12:07 PM
You can get brand new calipers at Gmpartsdirect (http://www.gmpartsdirect.com/results.cfm?singlepart=1&partnumber=88895128) for around $88, no core charge. The non bling grey ones are about the same price.

white79bu
10-23-2005, 12:13 PM
I bought a set of brackets and hubs from a guy on ebay named Joe. They are 3rd gen camaro hubs (uses either a b body or third gen bearing depends on what spindle you have) and a custom bracket for the calipers. All you have to do is modify a set of B body spindles and buy a set of C5 calipers. I think that I will probably have $400 in everything. That's with everything being brand new. I didn't think that was too bad considering Baer wants your first born for pretty much the samething.

dgumoe
10-23-2005, 12:54 PM
right, here's the problems with that type of conversion. and dont get me wrong im not picking on anyone who has done it that way, i myself was going to until marcus told me a few things. first of all, the b-body swap causes more trouble than its worth, bumpsteer is worse, and the ackerman angle is out of wack. also, you have to give hotckis or GW 400 dollars for control arms. i'd rather give marcus the 400 for his adjustable arms with the tall ball joint and get the handling benefits without the steering headaches. Also, the hub idea and to be perfectly honest marcus confirmed my feelings about the hub setup. the b-body, g-body, fbody rotor and hub is an INTEGRAL design. meaning that the loads and stresses placed on that hub are displaced throughout the rotor hub assembly. by turning the rotor down you're removing some of the strength of the center hub, and becuase of the grain structure of the rotor material, its weakened considerably. also, the mounting brackets are mounted to the old dustshield holes which were 10mm to begin with and then must be drilled out for a larger bolt to hold that caliper mounting bracket. there again, more qustion of structural integrity. marcus actually is the one who turned me on to the blazer spindle. i did the research to find a hub that was compatible with the spindle that didnt cost an arm and a leg. also, the 113 for the calipers at napa is for a loaded caliper with pads and hardware, with a lifetime guarantee against defects. again guys, im not picking on anyone one for doing it with the machined g-body rotors, i thought it was a good idea, and if i could feel confident with the machined rotor and modified spindles i would do it that way, but i dont, so i wont. good luck with whatever path you guys go with. i just wanted to post my findings for anyone who was interested. i know most of you are like me on limited budgets, and personally i hate the aftermarket.

WS6
10-23-2005, 03:05 PM
the rear hub on a C4 corvette bolts to the rear upright, spindle, whatever you wanna call it on that car. then the rotor slips over it. the hole in the middle of the hub assembly is for the splined end of the driveshaft to slip into. since there's no driveshaft up front, the hole is just left open. and before anyone asks, no i dont see it being an issue having a open hole in the hub, the s-10 hub assembly is the same way, just no splines for a driveshaft.

you're correct i was thinking about it the wrong way in my head. i wouldn't worry about a hole being in the front hub unless it somehow causes a problem with how the bearings rotate. it should not in this case. good luck with the build

white79bu
10-23-2005, 03:34 PM
In my situation I am already running b body spindles and the tubular UCA's. So it just makes sense to me to go ahead and use what I've got. Also I have never had any steering issues with the b body spindle. It handles great and it steers fine. I guess I will have to do some research on all that.

sinned
10-23-2005, 04:03 PM
. I’d rather give Marcus the 400 for his adjustable arms with the tall ball joint and get the handling benefits without the steering headaches. Just to set the record straight...first of all they are Pole Position arms that he sells, not his arms.
Also, the hub idea and to be perfectly honest Marcus confirmed my feelings about the hub setup. The b-body, g-body, fbody rotor and hub are an INTEGRAL design. Meaning that the loads and stresses placed on that hub are displaced throughout the rotor hub assembly. By turning the rotor down you're removing some of the strength of the center hub, and because of the grain structure of the rotor material, its weakened considerably. Also, the mounting brackets are mounted to the old dust shield holes which were 10mm to begin with and then must be drilled out for a larger bolt to hold that caliper mounting bracket. There again, more question of structural integrity. . Second, this entire quote is untrue. There is no scientific data to back up that cutting the rotor off of the hub will in any way affect the integrity of said hub. The molecular grain is in no way disturbed as all the machining is done to the component being discarded. That statement is as asinine as saying turning rotors ruins the molecular composition and is therefore unsafe.



Why in the world would drilling 10mm holes to 7/16" cause an harm to the spindle, does drilling block oversize for Heli-coils make them less sound? The answer is no, in fact in many cases the Heli-coil provides a more structurally sound mounting location.



I will concede that the "B" spindle swap sucks in that it ruins the geometry of the front suspension, but please leave the metallurgy to those who have studied and trained at evaluating it, throwing out blanket statements of "weakening the metal" makes your entire post less credible.

79T/Aman
10-23-2005, 04:29 PM
well Denny beat me to it but I will add this in fact cutting the rotor off will lessen the load on the hub thefore making it "stronger" or less prone to breakage as is being implied

MrQuick
10-23-2005, 06:49 PM
Take it easy professor I think its a nice cheap alternative for those not in direct contact with machinery. Jon was just stating his obvious. Remember the same is being achieved, C5 brakes on a non Vette.

dgumoe
10-24-2005, 09:20 AM
79bu, good luck, like i said i wasnt bad mouthing anyone who did it that way, i dont feel comfortable doing it that way so im not going to. thats the beauty of the hobby, to each his own.
dennis, first of all, i never said marcus made his arms, i said i was going to buy his, whether he gets them from jim bob in bfe or makes them himself, i really didnt care. they come from him, for all intents and purposes its his product. secondly, it doesnt take a genious to understand grain structure of a metal, they teach it to you in a basic level materials class when going to school for engineering. how would i know? i took the course. i didnt claim to be a metallurgist, nor did i once say that anyone doing the conversion that way was wrong. i simply stated MY concerns with it and offered another way of doing things. besides that, i got my info from a guy that gained nothing from telling me not to do it that way, as a matter of fact he';s the one who turned me onto the blazer spindles. as far as the dustshield holes go, i neglected to be precise, the bolt HEAD is 10mm, the actual threads are 6mm. if you want to drill out those holes and use them to mount a caliper which they were never designed to do,go ahead, i never said its wrong, i said its not for me. its crap like this why i never post on forums anymore. all i wanted to do was help out my fellow G-body guys not start a flamewar but i guess what my father said was true. welcome to the automotive business, there's an ass in every seat. larry, ralph i apologize for getting this way, feel free to close the thread, i think the technical info speaks for itself and anyone with half a brain can weed through the b/s to get the point of this post in the first place.

derekf
10-24-2005, 10:06 AM
I think we're done here.

Nobody's attacked each other (for the most part) and I'd prefer it stay that way.

dgumoe, I removed a possibly inflammatory phrase from your post, because I think both sides have said their bit and adding fuel to the fire won't help any.