Jump to content

Lumina Big Brake Conversion???


deafmetal

Recommended Posts

gtpbrk.jpg

 

Anyone here bought and installed the RSM big brake conversion kit into your Lumina? It's the kit that converts the front 10.5" to 13", and rear 10.5" to 12".

 

Word is it'll also require 17" rims. A VERY pricey conversion, but for those who have experienced the Lumina's lack of stopping power with the 10.5" -vs- 3500 lbs, you know it's an worthwhile upgrade, just expensive ($1400 front, $1300 rear, then rims and rubber...).

Link to comment
Share on other sites

It's WAY overpriced, IMO.

That is a C4 Corvette brake system. C5 Corvette brake system is considerably far superior. I think you can get complete C5 Corvette front brakes (calipers, rotors, etc.) for less than $300 from GM Parts Direct. I could be wrong, but I think the $1100 you'd save over the RSM kit should be enough to get the rotors redrilled and a bracket welded to the knuckle to mount the new calipers.

 

The C5 rear brakes are also far superior, because they no longer have the integrated park brake in the calipers. The park brake is a separate drum brake like the gen 2 W-bodies. I haven't priced this setup since I can't find part #'s for it, but again I think it wouldn't cost you more than $1300 including labor for any necessary welding and fabrication of brackets.

 

Of course, I could be greatly underestimating the price of machining brackets and having them welded to your knuckles so I don't know.

A C5 brake system is among one of my planned future projects though. I think I want to buy a Lincoln wirefeed welder and attempt it myself on my spare set of knuckles.

Link to comment
Share on other sites

Sure, I have complete part #'s on the C5 front brakes at home. I'll post it tonight.

 

I've even thought about a low-budget way to get the rotors on. The rotor BP is 5x120.5mm (or something like that) while ours is 5x115mm. Instead of having a machine shop redrill the proper bolt pattern, it should be possible to use a Dremel or something similar to elongate the holes. They'd only need to be elongated inwards about 2.5mm to fit. Since the rotor will be hubcentric with the center bore being exactly the same size, I don't think it will be a problem. The rotor will fit very snug on the center bore, and with the wheels clamping down on it, I doubt it could shift or pose any kind of safety hazard.

 

That's just one thought I had, because it'll be hard for me to find a machine shop locally that would do this kind of work.

Link to comment
Share on other sites

i'm just looking at having a new thing made that welds to the knuckle im place of the stock one(you know that thing, between the spindle and where the hub bolts on and it accepts the caliper bracket). that is longer and would move the stock caliper out to accomodate bigger rotors. of course, the rotor would need to be the same thickness and depth off the hub as a stock one for this to work. was thinking 12" to keep it inside the 16" wheels. my buddy works at a CNC shop and i'm going to see if he can do it.

Link to comment
Share on other sites

C5 rotors are almost $100 each so its going to cost over $300 total. I read that the DIY C5 brake conversion for Camaro's cost about $650.

 

Depends on where you get 'em.

I buy my parts from Jason Cromer and he can sell 'em to me at close to what GMPD charges, but with much more reasonable S&H. It shouldn't cost $650 at all. I'll post a parts list with GMPD prices tonight.

 

i'm just looking at having a new thing made that welds to the knuckle im place of the stock one(you know that thing, between the spindle and where the hub bolts on and it accepts the caliper bracket). that is longer and would move the stock caliper out to accomodate bigger rotors. of course, the rotor would need to be the same thickness and depth off the hub as a stock one for this to work. was thinking 12" to keep it inside the 16" wheels. my buddy works at a CNC shop and i'm going to see if he can do it.

 

Where are you going to find 12" rotors of the same thickness and depth as the original? F-Body and Intrigue 12" rotors will both be 1.25" and more inset.

All 97+ GM cars use 1.25" front rotors (including C5 'vette) while ours are 1", and I know for fact the Corvette rotors are more inset than ours.

Link to comment
Share on other sites

Sweet.

 

I know the RSM kit uses a spacer behind the rotor and the mounts for the caliper bracket are welded on the side of the strut knuckle. They are definately much more inset then ours are.

Link to comment
Share on other sites

Brian,

You were right... it does cost a bit more than $300... I forgot to consider peripheral things like brake pads, pins, boots, lines, etc. Anyway, here's the list. I didn't add brake lines or pads to it since you can probably get those anywhere and we might need custom lines anyway.

 

GM       Description                          Unit   Quantity    Ext.
Part #                                       Price               Price			
88895128 Z06 LEFT FRONT CALIPER             $83.81      1       $83.81
88895129 Z06 RIGHT FRONT CALIPER            $83.81      1       $83.81
10445856 RIGHT FRONT ROTOR                  $50.00      1       $50.00
10445857 LEFT FRONT ROTOR                   $50.00      1       $50.00
12455799 FRONT CALIPER BRACKET              $25.47      2       $50.94
10139097 GASKET                              $0.34     10        $3.40 (min order of 10)
12530697 PIN                                 $3.30      4       $13.20
12530703 BOOT KIT                            $2.83      4       $11.32
22163795 FITTING                             $2.21      2        $4.42

                                                    Total:    $350.90

 

GM Parts Direct adds almost $100 for shipping!!!

I'm guessing Jason Cromer could sell all of this together for less than $400 shipped.

Link to comment
Share on other sites

For the other parts, keep in mind GM uses a sequential numbering scheme.

 

So, since the front rotors are P# 10445856/7, I tried 8/9 and voolah!!

 

http://www.auto-parts-for-less.com/

 

RR Rotor P# 10445858

LR Rotor P# 10445859

 

LR Caliper P# 88895130

RR Caliper P# 88895131

 

Rear Caliper Bracket P# 12455800

 

Will the stock master cylinder be able to push enough for the larger caliper pistons??

Link to comment
Share on other sites

Good find on the rest of the stuff!

I would just hope it's for the C5 and not some other car. :)

The front caliper bracket p/n works for GMPD.

 

The stock MC shouldn't be a problem. RSM doesn't change it for their C4 brake upgrade, and Baer's C4 brake upgrade for 97+ doesn't change the MC either.

Link to comment
Share on other sites

Ok Shawn, will use their site then, looks like they're cheaper than most anywhere else anyways... KEWL!!

 

 

On a separate note: Dropped my car off this morning to have a tranny cooler installed. The guy called me back a few minutes ago asking why I wanted one. He said he has never installed one on a FWD car before, even though his shop is pretty reputable. He couldn't understand why I'd want one, and even when I explained my reasons, he kept trying to talk me out of it. WTF??? If the customer wants it, put it in... Pisses me off.

Link to comment
Share on other sites

Updated Z06 Brake Conversion Listing

ACFA15F.jpg

GM Part #   Description                   Price   Pkg Qty   Qty Rqd    Ext
------------------------------------------------------------------------------------- 
88895128    Z06 LEFT FRONT CALIPER        $83.81     1        1        $83.81 
88895129    Z06 RIGHT FRONT CALIPER       $83.81     1        1        $83.81
88895130    Z06 LEFT REAR CALIPER         $61.01     1        1        $61.01
88895131    Z06 RIGHT REAR CALIPER        $61.01     1        1        $61.01
10445856    RIGHT FRONT ROTOR             $50.00     1        1        $50.00 
10445857    LEFT FRONT ROTOR              $50.00     1        1        $50.00 
10445858    RIGHT REAR ROTOR              $50.50     1        1        $50.50 
10445859    LEFT REAR ROTOR               $50.50     1        1        $50.50 
12455799    FRONT CALIPER BRACKET         $25.47     1        1        $50.94 
12455800    REAR CALIPER BRACKET          $25.47     1        1        $50.94 
10139097    GASKET                        $0.34      10       ?        $0.34 
12530697    PIN                           $3.30      1        8        $26.40 
12530703    BOOT KIT                      $2.83      1        8        $22.64 
22163795    FITTING                       $2.21      1        4        $8.84

                                                              Total:  $650.74

Link to comment
Share on other sites

  • 4 weeks later...

I dunno about you, but I haven't made any progress on this project. I'm in the process of an intermediate step of swapping in 96 knuckles. After that, I'll start playing with my original knuckles.

Link to comment
Share on other sites

$650 for an almost complete set of Corvette brakes -- boy do I really feel ripped off now!

 

A couple of years ago I had the rear brakes done on my '89 gp at Sears. At the time, it was the only car I had that was running and I had no garage (it was winter) and I had a toddler. So, in other words, I couldn't do it myself. I really hate having to take my car to a garage and pay full retail for the parts and a crapload of labor! But to the point: I think I payed over $500 to have new crappy factory style stuff put on (rotors, pads, calipers).

 

Right after that I got a letter in the mail about the lawsuit against GM for the W-Body rear brakes. The letter claimed that up to 80% of your repair costs would be reimbursed if you provided receipts. It took like a year, and I got back about $40. I guess they settled on a fixed sum and divided it up to everybody that sent in a claim.

 

This is why I feel ripped off! Just thought I'd share that.

Link to comment
Share on other sites

  • 1 month later...

Dragging this back up again :D

 

Anybody happen to know the surface area of the C5 front pads? Also, why do you have to use the C5 rotors with their huge offset, I am sure there is another 1.25" thick rotor that has little offset like ours do then its just a matter of mounting a caliper. Worth investigating.

 

And on the subject, i've been pondering how will 4 or 6 piston calipers will work on the stock larger 96 front brakes?

Link to comment
Share on other sites

You don't need to use C5 rotors, almost all GM cars have a 1.25" thick rotor these days. The only difference is the C5 is the only one with 13" rotors. The next biggest are 12". The C5 rotor offset is really not that huge, I think it has less offset than gen 2 W-body rotors.

Either way you would need to be fabricating/welding caliper mounts, so the larger rotors just seem preferable.

Link to comment
Share on other sites

I was thinking along the lines of keeping my stock 16" wheels :P

 

From pictures of the 97+ rotors and the C5, the 97 look to have less offset. Since my 5spokes are tucked under as it is (the crosslace's 1" extra in width is put on the outside of the mounting plane, the 5spokes are 1" tucked further in :( ) I was contemplating a 1/2 roughly behind the rotor depending on the 97 offset. Hopefully it will give enough clearance so that the strut knucle can be left alone and just a caliper adapter bracket could be used. It would also push my wheels out some to give the car a better look. You can get 97+ rotors up to 12" which i think is plenty acceptable.

 

For the rear the C5 uses 1" thick rotors, just use either the stock 10.9 or 11.25 first gen front rotors back there and use a caliper bracket.

 

I got bigger fish to fry first but I can't help but think about this.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...