C4 front brakes - Third Generation F-Body Message Boards

Brakes Looking to upgrade or get the most out of what you have stock? All brake discussions go here!

C4 front brakes

Reply

Old 08-30-2018, 10:46 PM
  #1  
Member
Thread Starter
iTrader: (3)
 
SirReveller's Avatar
 
Join Date: Aug 2017
Location: Toronto, ON
Posts: 269
C4 front brakes

Stock ‘89 but given this

Four wheel disc optioned (J65) IROC-Z's rear brakes were increased in size from 10.5 inch rotors to 11.65 inch rotors with PBR Australian built aluminum calipers and more reliable parking brake actuators. Front discs still had 10.5 inch rotors with Delco-Moraine single piston calipers.

have been considering upgrading just the front brakes to get a little more bite. This caught my eye in the classifieds not too far outta town
https://www.kijiji.ca/v-other-auto-p...ationFlag=true
so thought I’d ask the braintrust:

1) direct bolt on or some new base or spindles or whatever required?
2) probably require a rebuild? Too costly to bother given all the wilwood etc full kits for $4/500? Kinda wanted to stay in the era with some old stuff vs the new kits..
3) even if these are rusty junk, if they were gleaming new would the incremental improvement in stopping power be that noticeable?

Cheers
SR
SirReveller is offline  
Reply With Quote
Old 08-31-2018, 07:45 AM
  #2  
Supreme Member
iTrader: (1)
 
Join Date: Sep 2005
Posts: 20,838
Re: C4 front brakes

They're better than the old 10" DM from the Stone Age; roughly comparable in effectiveness to the 1LE system, if memory serves.

But not a bolt-on. You'd need to modify your spindles and buy or make brackets. Not insurmountable in either case, but not quite trivial either.

The C4HD setup was MUCH better than the regular C4 stuff.

Of course it would require a rebuild. I can't imagine just sticking a bunch of old used brake stuff on a car I was going to drive, without that. Look up the price of rebuilt calipers at CT or wherever; might be a deal-breaker, might not be too terribly $$$. I have no idea.
sofakingdom is offline  
Reply With Quote
Old 08-31-2018, 02:01 PM
  #3  
Member
Thread Starter
iTrader: (3)
 
SirReveller's Avatar
 
Join Date: Aug 2017
Location: Toronto, ON
Posts: 269
Re: C4 front brakes

Thanks sofa, great guidance. These arent the HDs b/c 12” not 13” rotors, correct?
SirReveller is offline  
Reply With Quote
Old 08-31-2018, 09:04 PM
  #4  
Moderator
iTrader: (5)
 
JamesC's Avatar
 
Join Date: Aug 1999
Location: Lawrence, KS
Posts: 19,081
Re: C4 front brakes

Originally Posted by SirReveller View Post
Thanks sofa, great guidance. These arent the HDs b/c 12 not 13 rotors, correct?
Correct. The non-HDs are 12.01, the HDs 12.99. The following link is a goldmine of info that should be very helpful:

https://lukeskaff.com/projects/

JamesC
JamesC is offline  
Reply With Quote
Old 08-31-2018, 11:21 PM
  #5  
Member
Thread Starter
iTrader: (3)
 
SirReveller's Avatar
 
Join Date: Aug 2017
Location: Toronto, ON
Posts: 269
Re: C4 front brakes

Wow what a wealth of info. Thanks James.

Given
The C4 NON-HD brakes have thinner rotors, 0.81 inch, then the 1LE (1.1 inch) rotors. The C4 NON-HD caliper also has a smaller rotor opening to accommodate the thinner C4 rotor. The C4 HD 13 inch brakes have about the same thickness router as the 1LE but have a 1 inch larger diameter.

can I assume my rears are the 1.1 inch?

Also some interesting reading against these two types of C4 brakes here.
https://www.thirdgen.org/forums/hist...e-history.html
SirReveller is offline  
Reply With Quote
Old 09-01-2018, 08:02 AM
  #6  
Supreme Member
iTrader: (1)
 
Join Date: Sep 2005
Posts: 20,838
Re: C4 front brakes

can I assume
No. Not really whatever you were asking, or much of anything else either.

Well, you can; but that's the road to disaster.

If memory serves, the rears are quite a bit thinner than the fronts.
sofakingdom is offline  
Reply With Quote
Old 09-01-2018, 08:16 AM
  #7  
Moderator
iTrader: (5)
 
JamesC's Avatar
 
Join Date: Aug 1999
Location: Lawrence, KS
Posts: 19,081
Re: C4 front brakes

Originally Posted by SirReveller View Post
can I assume my rears are the 1.1 inch?
According to the link above rear PBRs are 0.78.

JamesC
JamesC is offline  
Reply With Quote
Old 09-01-2018, 09:50 PM
  #8  
Member
Thread Starter
iTrader: (3)
 
SirReveller's Avatar
 
Join Date: Aug 2017
Location: Toronto, ON
Posts: 269
Re: C4 front brakes

Thanks James. Given the rarity of solid thirdgen 1LE front brakes coming up regionally (shipping, currency and brokerage would murder any long distance deal) I’m still kinda considering this 12” nonHD conversion. Get some period double piston PDRs and a proper rotor, thickness notwithstanding, in the front- some more bite and visually pretty damn close to the rears. I note Ed at flynbye has brackets. Dude in the original ad got back back to me, said they worked perfectly when they came off the car to make way for an upgrade.
SirReveller is offline  
Reply With Quote
Old 09-02-2018, 09:20 AM
  #9  
Member
Thread Starter
iTrader: (3)
 
SirReveller's Avatar
 
Join Date: Aug 2017
Location: Toronto, ON
Posts: 269
Re: C4 front brakes

Ok two more questions for anyone still following this thread
1) would the surface rust on the one rotor be a fairly simple machining clean-up or a deal ender?
2) negotiate the steel flex lines outta the deal or would they fit on an f-body too?
SirReveller is offline  
Reply With Quote
Old 09-02-2018, 10:24 AM
  #10  
Supreme Member
 
skinny z's Avatar
 
Join Date: Dec 2005
Location: 1,198 miles due north of Las Vegas. Yes. That's Canada.
Posts: 6,062
Re: C4 front brakes

Originally Posted by SirReveller View Post
Ok two more questions for anyone still following this thread
1) would the surface rust on the one rotor be a fairly simple machining clean-up or a deal ender?
2) negotiate the steel flex lines outta the deal or would they fit on an f-body too?
For the cost of replacement calipers having them turned down is probably not the most economical approach.
As for the steel lines, I can't say for certain if they swap over or not.

Since it's an OEM swap, your best bet would be over the counter replacements.
When I did my LS brake conversion I picked up new rotors from Canadian Tire (on sale too). The calipers from the 2000 Camaro were salvageable with a decent clean-up.
Regardless, you'll still have to modify the stock spindles as well as getting hubs for the rotors to fit over.
The link to Luke Skaff was what I used as my information source. Modified the spindles myself and had my machinist co-worker cut down a pair of 3rd gen rotor/hub assemblies to get the hub I needed.
I moved up to the PBR rear brakes as well.



I polished up the donor calipers and purchased new rotors and brake lines.

Last edited by skinny z; 09-02-2018 at 10:28 AM.
skinny z is offline  
Reply With Quote
Old 09-02-2018, 10:31 AM
  #11  
Supreme Member
 
skinny z's Avatar
 
Join Date: Dec 2005
Location: 1,198 miles due north of Las Vegas. Yes. That's Canada.
Posts: 6,062
Re: C4 front brakes

Check out this chart. It's got some interesting info too regarding caliper volumes and piston area, rotor dimensions, etc.
skinny z is offline  
Reply With Quote
Old 09-02-2018, 11:11 AM
  #12  
Supreme Member
iTrader: (1)
 
Join Date: Sep 2005
Posts: 20,838
Re: C4 front brakes

getting hubs for the rotors to fit over


Sorry I forgot to mention this one... it's possible to take a stock rotor and cut the entire "rotor" part of it off, and turn it into just a hub, which the other rotor then slips over. Alternatively you can buy ones already done like that from some of the places that sell this sort of thing, like bigbrakeupgrade.com for example.
sofakingdom is offline  
Reply With Quote
Old 09-02-2018, 01:22 PM
  #13  
Member
Thread Starter
iTrader: (3)
 
SirReveller's Avatar
 
Join Date: Aug 2017
Location: Toronto, ON
Posts: 269
Re: C4 front brakes

Thanks gentlemen. Yeah I get the modification of my cars front spindles and bracket purchase from Ed part but the hub bit is a little trickier.. Some other nonHD C4 front brake threads on here touch on the fact you can modify the 12 C4 rear rotor for use on the front but not the C4 front rotor, if I have that right.

With all the trouble (for non machinist 3G enthusiasts) you see pretty fast why most only go to the effort for the C4 HD 13 upgrade. Reviews from the vette folks are mixed, some claim the thicker 13 setup is way better others claim not a massive improvement. Against my 10.5 DM single piston fronts the dual piston 12 looks damn good to me. I think to avoid spending nearly as much as a basic brand new modern front brake kit Id wanna use the rotor/hub in the guys sale if at all possible- or Im basically buying the calipers, possibly needing a rebuild themselves, and pads! lol On the other hand Eds full 12 C4 front kit (new and turnkey) is $850 USD so could be worth it still.

skinny agreed new 12 rotors arent too bad (eg corvette depot up here) if necessary- more importantly you got a shop in Oshawa familiar with all this stuff?
SirReveller is offline  
Reply With Quote
Old 09-02-2018, 01:50 PM
  #14  
Supreme Member
 
skinny z's Avatar
 
Join Date: Dec 2005
Location: 1,198 miles due north of Las Vegas. Yes. That's Canada.
Posts: 6,062
Re: C4 front brakes

Originally Posted by SirReveller View Post
- more importantly you got a shop in Oshawa familiar with all this stuff?
Not Oshawa but just west of Barrie.
An old friend (and former neighbour) has been running what remains of the Performance Improvements installation division. The current operation is a one man, one hoist arrangement and Tom, through his Altered Images "brand" has been building full on race cars and hot rods for decades. He did all of the welding on my past and present third gens. That said, with the small scale he does, slotting yourself in can be difficult. I'll be talking with him later this week (and will be at this shop when I take holidays at the end of this month) and will see if he's into the job.
skinny z is offline  
Reply With Quote
Old 09-02-2018, 08:44 PM
  #15  
Junior Member
 
Join Date: Mar 2017
Location: IL
Posts: 14
Re: C4 front brakes

Check out big brake upgrade.com. He makes all the brackets and machines the original rotors down to use as hubs. I installed his LS1 front kit (brackets, hubs,& ss hoses on my 86 and my friends 92. We both bought powder coated calipers from eBay, Callahan Brakes. 3 years and 3k miles on his, only 600 miles on mine, but zero issues.
Pet_ROC is offline  
Reply With Quote
Old 09-03-2018, 05:45 PM
  #16  
Member
Thread Starter
iTrader: (3)
 
SirReveller's Avatar
 
Join Date: Aug 2017
Location: Toronto, ON
Posts: 269
Re: C4 front brakes

Ah cool thanks Skinny. Hold off on buggin him please until I take these down. I’ve asked if he has the rear rotors available as the old C4 12” brakes threads seem to suggest these are preferable over the fronts.

ROC I’ve definitely perused bbu, very cool stuff. Way more money but this kinda thing is awesome
http://bigbrakeupgrade.com/product/l...te-conversion/

My vintage aim for an upgrade closer to ‘89 remains so I’m gonna ask if he can create a hub for the C4 12”- the menu has moved with the times past these it seems, lol, and flynbye is apparently a don’t-expect-em-anytime-soon kinda thing.

Bit of a PITA that for this particular upgrade operation I can’t have the hubs created out of the 10.5” stock DM fronts nor the very C4 rotors I’d be buying.
SirReveller is offline  
Reply With Quote
Old 09-03-2018, 06:56 PM
  #17  
Supreme Member
iTrader: (1)
 
Join Date: Sep 2005
Posts: 20,838
Re: C4 front brakes

Yeah Ed is full-time employed some kind of way, and only does the brake thing on the side. A great guy (I've dealt with him in the past), honest and hard-working and dedicated, but stretched to his limit. He must work his butt off 24 hrs a day from all I can see. Not the kind of guy you want to rely on for commodity-type high-volume production, or for something you need in a hurry; best used for "custom" or similar "thought provoking" applications, where somebody that "cares" can make a difference.
sofakingdom is offline  
Reply With Quote
Old 09-03-2018, 07:14 PM
  #18  
Member
Thread Starter
iTrader: (3)
 
SirReveller's Avatar
 
Join Date: Aug 2017
Location: Toronto, ON
Posts: 269
Re: C4 front brakes

That’s seems to be the verdict. He himself is on half the 15+ year old threads that developed this concept. I figure since “winter is coming” if not in bbu’s wheelhouse I’ll ask Ed with an eye through to Feb/Mar if he can handle it.
SirReveller is offline  
Reply With Quote
Old 09-03-2018, 09:15 PM
  #19  
Supreme Member
iTrader: (8)
 
Join Date: Sep 1999
Location: NJ
Posts: 2,511
Re: C4 front brakes

If you got them from Ed, they may ship in a day, or two months. His wife ships a lot of the stuff AFAIK, I assume she kind of runs the side business in actuality.
scooter is offline  
Reply With Quote
Old 09-03-2018, 10:26 PM
  #20  
Member
Thread Starter
iTrader: (3)
 
SirReveller's Avatar
 
Join Date: Aug 2017
Location: Toronto, ON
Posts: 269
Re: C4 front brakes

Well I just now bought’em for a cool 100 northern pesos so I’ll be calling Ed tomorrow lol. My readings indicate a different kind of bracket is called for to get the front C4 rotors on thirdgen hubs.
SirReveller is offline  
Reply With Quote
Old 09-04-2018, 07:12 AM
  #21  
Member
Thread Starter
iTrader: (3)
 
SirReveller's Avatar
 
Join Date: Aug 2017
Location: Toronto, ON
Posts: 269
Re: C4 front brakes

BBU is not in the C4 brake business - I’ve PM’d alloy/machinist, the inventor of the front brackets solution, and if he’s not into the job will try Ed on the phone.
SirReveller is offline  
Reply With Quote
Old 09-04-2018, 06:26 PM
  #22  
Supreme Member
 
skinny z's Avatar
 
Join Date: Dec 2005
Location: 1,198 miles due north of Las Vegas. Yes. That's Canada.
Posts: 6,062
Re: C4 front brakes

Originally Posted by SirReveller View Post
Ah cool thanks Skinny. Hold off on buggin him please until I take these down.
No worries. Let me know. I'll be at his shop in and around the last week of this month.
What exactly did you buy? Hubs?
skinny z is offline  
Reply With Quote
Old 09-05-2018, 07:06 PM
  #23  
Member
Thread Starter
iTrader: (3)
 
SirReveller's Avatar
 
Join Date: Aug 2017
Location: Toronto, ON
Posts: 269
Re: C4 front brakes

Well after a bit of phone tag got Ed of flynbye on the phone and he’s down for spindles brackets hubs studs all set up to go for these and able to make and send over the next couple weeks.. Super nice guy. Scott of BBU was very responsive and friendly as well but either way this route should shave off a few hundred bucks from Ed’s C4 12” full kit or Scott’s LS1 full kit. Before I even broached the job I was after Ed explained he had the C4 12” on his fronts for years and the difference was “night and day” over the DM 10.5” stock fronts, later moving to the C4 13” HD which he said was a not very noticeable improvement over the 12s. Obv great to hear and reaffirms my whole plan.

Skinny thanks for the offer on your guy (I used to go into Performance Improvements on the Queensway all the time) but with work and kids gonna have the whole deal as a simple simon to go on with some other suspension stuff this Fall.
SirReveller is offline  
Reply With Quote
Old 09-10-2018, 10:36 PM
  #24  
Member
Thread Starter
iTrader: (3)
 
SirReveller's Avatar
 
Join Date: Aug 2017
Location: Toronto, ON
Posts: 269
Re: C4 front brakes

So since thie deal came with some braided lines for the fronts that should hook up I’m now looking for some for just the rears. Russell 692370 seems to be the only game in town for ‘89 J65, but it’s all around. Summit’s got nada else and eBay is telling me StopTech Brake Lines Braided Stainless Steel Rear Chevy Pair 950-62501 fits ...any p/n recos?
SirReveller is offline  
Reply With Quote
Old 09-11-2018, 07:26 AM
  #25  
Supreme Member
iTrader: (8)
 
Join Date: Sep 1999
Location: NJ
Posts: 2,511
Re: C4 front brakes

Ed (Flynbye) sells rear brake lines too.....
scooter is offline  
Reply With Quote
Old 09-12-2018, 08:40 AM
  #26  
Supreme Member
iTrader: (1)
 
Join Date: Sep 2005
Posts: 20,838
Re: C4 front brakes

I would avoid the Russell if I could; many people over the years have had their fittings just break right off of the ends of the hoses. Not nearly as robust as the old Earl's were. Too bad they discontinued those.

I haven't seen the StopTech ones other than the ads. Not sure what Ed sells; whether he makes something himself, supplies someone else's, or what. You could ask.
sofakingdom is offline  
Reply With Quote
Old 09-13-2018, 08:39 PM
  #27  
Member
Thread Starter
iTrader: (3)
 
SirReveller's Avatar
 
Join Date: Aug 2017
Location: Toronto, ON
Posts: 269
Re: C4 front brakes

Thanks gentlemen- Ed indeed does have a bunch of setups and confirmed added to the job.
SirReveller is offline  
Reply With Quote
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
88fastgta
Brakes
2
06-26-2011 10:34 PM
iroc stangs
Brakes
1
03-15-2010 07:39 AM
calioak510
Suspension and Chassis
1
12-28-2009 01:50 AM
92Z
Suspension and Chassis
2
03-09-2004 01:02 PM
Night Hawk
Tech / General Engine
4
09-21-2000 08:48 PM


Thread Tools
Search this Thread
Advertising
Featured Sponsors
Vendor Directory
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: