Who is using C5 Brakes and What is your Offset? - Team Camaro Tech
Wheels & Tires What fits what?

Reply
 
LinkBack Thread Tools Display Modes
post #1 of 21 (permalink) Old Feb 18th, 11, 01:57 PM Thread Starter
Tech Team
 
Join Date: Jun 2001
Location: Seffner, Fl. U.S.A.
Posts: 44
Question Who is using C5 Brakes and What is your Offset?

Hey guys,

I'm hoping someone here can help me out. I've been trying to order rims for my '68 since Thanksgiving and am having no luck with the wheel manufacturer on the offset for the front wheels. The sales rep I've been dealing with has very little experience and keeps telling me he has to check with his manager when I ask him how he comes up with his numbers. He keeps giving me offset numbers that seem WAY out of the ballpark and, because my calculations are different, he wants me to sign off on them before I order. While I understand his position, I think that our numbers should at least be close. So, I'm turning to you guys hoping that some kind soul can help me out. I need numbers to compare for a sanity check.

I'm using the 13" 'Vette rotor and will be buying 18" wheels to clear the PBR caliper and valve stem. I want to use an 8" wide rim and a 245 tire. I would like to push the wheel out as much as possible to fill the wheel opening.

If you are using the C5 conversion (front), meaning a hat style rotor on drum hubs:
Question - What is your offset?
Question - What size wheel are you using?
Question - Do you have any rubbing issues?
Question - Are you using a spacer?, If so, how thick?
Question - Anything you'd like to add or warn me of?

Thank you for helping,

Roy
69 Firebird
68 RS TPI Camaro (in process)
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
mrfixit58 is offline  
Sponsored Links
Advertisement
 
post #2 of 21 (permalink) Old Feb 20th, 11, 03:39 PM Thread Starter
Tech Team
 
Join Date: Jun 2001
Location: Seffner, Fl. U.S.A.
Posts: 44
Re: Who is using C5 Brakes and What is your Offset?

Anyone? I sure could use your help.

Roy
69 Firebird
68 RS TPI Camaro (in process)
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
mrfixit58 is offline  
post #3 of 21 (permalink) Old Feb 21st, 11, 08:58 AM
Senior Tech
Dan
 
Join Date: Aug 2001
Location: Connecticut, USA
Posts: 719
Re: Who is using C5 Brakes and What is your Offset?

My fronts are c5's (well, just pulling them off now for c6z06) on 17x8 ROH wheels, zero offset, 4.5" backspace, 245/45/17, slight rub mark on the frame at full lock, otherwise just fine. I think a 4.25" backspace would be good too. I also changed the fender bolts to button heads where the inner fenders bolt on for a bit of insurance on rubbing. Rears are 17x9 zero offset, 255/50/17


62 Corvette (Stock Restoration)
68 RS/SS Camaro, LS7/T56
68 RS Convertible project LS3/480/4L70
2006 Corvette Z06
2011 Corvette GS Convertible
68sixspeed is offline  
 
post #4 of 21 (permalink) Old Feb 21st, 11, 11:00 AM
Senior Tech
Robert
 
Join Date: Jul 2008
Location: Middle of MN
Posts: 235
Re: Who is using C5 Brakes and What is your Offset?

Here's another one for you to reference. Fireball Camaro
I believe he either did a thorough and comprehensive writeup here on Team Camaro or or on Pro-Touring.com about the C5 conversion you are describing too.

When I have been talking to "wheel guys" about a similar setup I have learned that the C5 calipers require at least a 7/8" pad at the wheel to hub mounting surface for spoke clearance. I intend to use Boyds Vintage5 which is a cast version of the "Junkyard dog" which is the wheel on the Red Camaro in my link. I would get mucho shiny ones instead of matte black though.

FWIW I would most definitely talk to a completely different source for wheels. Life is too short to keep messing with those guys. Avoid the flaming hoops whenever possible, let them get somebody else to jump through them. My $.02 at no charge to you.

Try DriverzInc/ and I think you will find the flow of useful information comes towards you instead of you trying to educate your current rep.

Same old '68 since 6/24/89
(Well, with a few changes along the way)

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Roberts68 is offline  
post #5 of 21 (permalink) Old Feb 21st, 11, 11:42 AM
Senior Tech
Al
 
Join Date: Nov 2002
Location: Vancouver, USA
Posts: 10,511
Re: Who is using C5 Brakes and What is your Offset?

Maybe not applicable - but I was leery of caliper interfernce, so I used the C5/C4 hybrid set-up. It uses a 13.0 x 1.10 C4 Corvette Grand Sport rotor with C5 calipers. The C4 rotor has a taller hat, which moves the caliper in closer toward the middle. You lose a little in rotor thickness, gain a little in rotor diameter. Speed Tech makes the caliper bracket. 17 x 8.0 AR CL205 wheels, (TTII w/ painted centers), 4.75" backspace. 235/45-17 tires . No spacers, no rubs.

You might do a little research on the difference between "offset" and "backspace". I'm pretty sure that they are not interchangeable terms.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
BPOS is offline  
post #6 of 21 (permalink) Old Feb 21st, 11, 12:37 PM Thread Starter
Tech Team
 
Join Date: Jun 2001
Location: Seffner, Fl. U.S.A.
Posts: 44
Re: Who is using C5 Brakes and What is your Offset?

Quote:
Originally Posted by Roberts68 View Post
Here's another one for you to reference. Fireball Camaro


When I have been talking to "wheel guys" about a similar setup I have learned that the C5 calipers require at least a 7/8" pad at the wheel to hub mounting surface for spoke clearance.

7/8" spacer? OUCH!!! That's the first I've heard of that. I measured 11/16" from rotor-hub face to edge of the caliper protrusion. If the spokes are flat, I can see where a 3/4" spacer would be required. Even that would suck as it would kill any lip.

I just found out that the guy I've been dealing with is no longer there. So, I'm now waiting on another guy to find my paperwork and call me back. He's supposed to be their most experienced guy. We'll see.

I would have "fired" them a long time ago but I'm saving around $500 because it was a "show special". Since I can't drive the car, I've been holding their feet to the fire to make good on their quote. If this doesn't work, I will probably try Boyd's.

Thanks for the replies and please keep them coming.After this whole think is over I plan to post my exact measurements and the results. Hopefully that will help the next poor soul who's trying this project.

Roy
69 Firebird
68 RS TPI Camaro (in process)
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
mrfixit58 is offline  
post #7 of 21 (permalink) Old Feb 21st, 11, 12:39 PM Thread Starter
Tech Team
 
Join Date: Jun 2001
Location: Seffner, Fl. U.S.A.
Posts: 44
Re: Who is using C5 Brakes and What is your Offset?

Quote:
Originally Posted by 68sixspeed View Post
My fronts are c5's (well, just pulling them off now for c6z06) on 17x8 ROH wheels, zero offset, 4.5" backspace, 245/45/17, slight rub mark on the frame at full lock, otherwise just fine. I think a 4.25" backspace would be good too. I also changed the fender bolts to button heads where the inner fenders bolt on for a bit of insurance on rubbing. Rears are 17x9 zero offset, 255/50/17

That is a fine looking ride. I love the stance. Are you using the 13" rotor? I was told that you couldn't run a 17" rim with the 13" rotors.

Roy
69 Firebird
68 RS TPI Camaro (in process)
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
mrfixit58 is offline  
post #8 of 21 (permalink) Old Feb 21st, 11, 01:23 PM
Senior Tech
Chris
 
Join Date: Sep 2006
Location: Melbourne Australia
Posts: 235
Send a message via Yahoo to cluxford
Re: Who is using C5 Brakes and What is your Offset?

I am running an Art Morrison front end which runs C5 vette spindles and 330mm discs (DBA but they are the same as on the vette's). Also PBR calipers (again exact same ones on the vette's)

I have 17 x 7 Rushforth's on the front.

They have a 1" mounting pad so the rim clears the caliper.

They started as 5" backspace, but rubbed out the outer guard as I have the car quite low, so I changed it to a just under 6" backspace (had the centers cut out and re-welded in).

The 1" inch mounting pad is the critical piece.






Here is a shot of the inside of the rim with the mounting pad. This isn't the wheels you see on the pics above, this is on another set of wheels I was originally going to run but decided not to. But the same mounting pad and offset




I can get you a real close up shot of the wheel on showing caliper clearance, even with the 1" pad there ain't a lot of room under there
cluxford is offline  
post #9 of 21 (permalink) Old Feb 21st, 11, 02:16 PM
Senior Tech
Dan
 
Join Date: Aug 2001
Location: Connecticut, USA
Posts: 719
Re: Who is using C5 Brakes and What is your Offset?

Quote:
Originally Posted by mrfixit58 View Post
That is a fine looking ride. I love the stance. Are you using the 13" rotor? I was told that you couldn't run a 17" rim with the 13" rotors.
yes, that is with the 13" c5 setup which is for sale if anyone is after one, I just put 14" c6z06 on it, yes you shouldn't get 14" rotors in less than an 18" rim but it fits so I won't complain.

edit- that picture is old, may have had 12" c4 at that time, the car has lived a few different lives, I just noticed the 350 badges on the car too! But it had 13" c5's on it until last weekend with those rims/tires...

62 Corvette (Stock Restoration)
68 RS/SS Camaro, LS7/T56
68 RS Convertible project LS3/480/4L70
2006 Corvette Z06
2011 Corvette GS Convertible

Last edited by 68sixspeed; Feb 21st, 11 at 05:19 PM.
68sixspeed is offline  
post #10 of 21 (permalink) Old Feb 21st, 11, 02:18 PM
Senior Tech
Dan
 
Join Date: Aug 2001
Location: Connecticut, USA
Posts: 719
Re: Who is using C5 Brakes and What is your Offset?

Quote:
Originally Posted by BPOS View Post
You might do a little research on the difference between "offset" and "backspace". I'm pretty sure that they are not interchangeable terms.
Offset- measured from rim centerline
Backspace - measured from the inside lip of the wheel

62 Corvette (Stock Restoration)
68 RS/SS Camaro, LS7/T56
68 RS Convertible project LS3/480/4L70
2006 Corvette Z06
2011 Corvette GS Convertible
68sixspeed is offline  
post #11 of 21 (permalink) Old Feb 21st, 11, 05:18 PM
Senior Tech
Dan
 
Join Date: Aug 2001
Location: Connecticut, USA
Posts: 719
Re: Who is using C5 Brakes and What is your Offset?

cluxford- do you know the track width (outside/outside measurement from where the wheels bolt on) for the AME front clip? I'm thinking that with the vette front end stuff they might have a wider track which would explain your deep backspace? especially with only a 7" wide rim?

62 Corvette (Stock Restoration)
68 RS/SS Camaro, LS7/T56
68 RS Convertible project LS3/480/4L70
2006 Corvette Z06
2011 Corvette GS Convertible
68sixspeed is offline  
post #12 of 21 (permalink) Old Feb 21st, 11, 05:57 PM
Senior Tech
Chris
 
Join Date: Sep 2006
Location: Melbourne Australia
Posts: 235
Send a message via Yahoo to cluxford
Re: Who is using C5 Brakes and What is your Offset?

Quote:
Originally Posted by 68sixspeed View Post
cluxford- do you know the track width (outside/outside measurement from where the wheels bolt on) for the AME front clip? I'm thinking that with the vette front end stuff they might have a wider track which would explain your deep backspace? especially with only a 7" wide rim?
I don't off the top of my head but will find out. yeah it surprised me also. I did a lot of research on backspace and was positive a 7" rim and 5" backspace would tuck in nicely on a 68...wrong. Well maybe fine on a std front end, I never went and measured the track width, once I had the wheels bolted up it sat flush which was nice but meant I could not go as low as I wanted, so had to change the backspace the xtra 1"

I suspect the AME does have a wider track, will do some quick research
cluxford is offline  
post #13 of 21 (permalink) Old Feb 22nd, 11, 07:11 AM Thread Starter
Tech Team
 
Join Date: Jun 2001
Location: Seffner, Fl. U.S.A.
Posts: 44
Re: Who is using C5 Brakes and What is your Offset?

Quote:
Originally Posted by 68sixspeed View Post
Offset- measured from rim centerline
Backspace - measured from the inside lip of the wheel
You are correct. In my frustration I typed "Offset" and should have typed "Backspace". Thank you for bringing that to my attention.

Roy
69 Firebird
68 RS TPI Camaro (in process)
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
mrfixit58 is offline  
post #14 of 21 (permalink) Old Feb 22nd, 11, 07:18 AM Thread Starter
Tech Team
 
Join Date: Jun 2001
Location: Seffner, Fl. U.S.A.
Posts: 44
Thumbs up Re: Who is using C5 Brakes and What is your Offset?

Quote:
Originally Posted by cluxford View Post
I am running an Art Morrison front end which runs C5 vette spindles and 330mm discs (DBA but they are the same as on the vette's). Also PBR calipers (again exact same ones on the vette's)

I have 17 x 7 Rushforth's on the front.

They have a 1" mounting pad so the rim clears the caliper.

They started as 5" backspace, but rubbed out the outer guard as I have the car quite low, so I changed it to a just under 6" backspace (had the centers cut out and re-welded in).

The 1" inch mounting pad is the critical piece.


Here is a shot of the inside of the rim with the mounting pad.




I can get you a real close up shot of the wheel on showing caliper clearance, even with the 1" pad there ain't a lot of room under there
I see. When you are referring to the "mounting pad" you are referring to the size of the pad that part of the wheel center. In other words, if I ordered the rim without a mounting pad, I'd need a 1" spacer to get the wheel to clear the caliper. The mounting pad is actually part of the wheel. Makes sense.

Roy
69 Firebird
68 RS TPI Camaro (in process)
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
mrfixit58 is offline  
post #15 of 21 (permalink) Old Feb 23rd, 11, 01:28 PM Thread Starter
Tech Team
 
Join Date: Jun 2001
Location: Seffner, Fl. U.S.A.
Posts: 44
Smile Re: Who is using C5 Brakes and What is your Backspace?

Well Guys,

I've pulled the trigger on the wheels. I ordered 18x7 4.5BS front; 18x10 6.5BS rear. The rims come with a 1" mounting pad standard that should easily clear the calipers. My set measurements tell me that I should have about 1/2" clearance from the fender lip. I will be running 225/45 18 front; 295/35 18 rear.

For reference for future searcher:

Front:
Stock subframe
Tubular arms
Gouldstrad conversion
Drum hubs (formally drum brake car)
13" C5 rotors
PBR Corvette 2 piston calipers
Unisteer Rack & Pinion conversion
Heidt drop spindles (Yet to verify clearance)
Coilover shocks

Rear:
9" from a '68 Bronco
11.5" rotors ('89 Firebird)
Calipers w/ built-in parking brake ('89 Firebird)
DSE Mini tubs
DSE Quadra Link

Once I get the rims and have the tires installed I'll mount them and take some pictures. If I can figure out how to post pictures I'll do it.

Thanks for your help.

Roy
69 Firebird
68 RS TPI Camaro (in process)
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
mrfixit58 is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Team Camaro Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address.
NOTE we receive a lot of registrations with bad email addresses. IF you do not receive your confirmation email you will not be able to post. contact support and we will try and help.
Be sure you enter a valid email address and check your spam folder as well.



Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome