1987 C4 Brake Upgrade 11.5" rotors to 12 or 13" rotors
08-31-2010, 11:51 PM
#1
Cruising
Thread Starter
Member Since: Aug 2010
Posts: 12
Likes: 0
Received 0 Likes
on
0 Posts
1987 C4 Brake Upgrade 11.5" rotors to 12 or 13" rotors
Hello All:
I would like to upgrade the front brakes on my 87 Z/51 with 11.5" rotors to 13" rotors using the dual piston calipers from a 1988 or later C4. Does anyone know if these bigger rotors and calipers will work with the stock 16" x 9.5" wheels? Also will I need the caliper brackets from the 88 to mount on my 87? Thanks to anyone who can supply info. I do believe at one time I read that you could use the larger rotors with the 9.5 wide rims. I do not want to do anything in the rear of the car as to preserve the inner emergency brake shoes as you all may know 88 and later Vettes use the primary brake pads as the emergency brake and GM did away with the small brake shoe setup within the rear rotors. Thanks!!!
Regards,
Tony
I would like to upgrade the front brakes on my 87 Z/51 with 11.5" rotors to 13" rotors using the dual piston calipers from a 1988 or later C4. Does anyone know if these bigger rotors and calipers will work with the stock 16" x 9.5" wheels? Also will I need the caliper brackets from the 88 to mount on my 87? Thanks to anyone who can supply info. I do believe at one time I read that you could use the larger rotors with the 9.5 wide rims. I do not want to do anything in the rear of the car as to preserve the inner emergency brake shoes as you all may know 88 and later Vettes use the primary brake pads as the emergency brake and GM did away with the small brake shoe setup within the rear rotors. Thanks!!!
Regards,
Tony
09-01-2010, 01:12 AM
#2
Le Mans Master
Member Since: Aug 2000
Location: Sydney Australia
Posts: 8,837
Likes: 0
Received 30 Likes
on
29 Posts
http://www.coppercorvette.com/c4togsbrakes.htm
DRM and Baer used to make the adapters
Given the current pricing on J55 parts ,many are going to the superior C5 brakes but they require certain 17" rims for clearance
Last edited by rodj; 09-01-2010 at 01:29 AM.
09-01-2010, 09:40 AM
#4
Cruising
Thread Starter
Member Since: Aug 2010
Posts: 12
Likes: 0
Received 0 Likes
on
0 Posts
Lemme:
Thanks for the pic of your 87 with the J55 upgrade. Where did you purchase the bracket to mount the J55 caliper as I know the J55 does not bolt to the 87 spindle? Also, are you running 13" rotors. Going to pass a great place to buy parts online with fairly good shipping rates and turn-around time, go to Rock Auto.com. Actually, this company was started by two former GM engineers. The pricing is really terrific so check them out. Now they do not have everything but most general maintenance stuff can be found there. The Raybestos Advanced Technology rotors are decent and fairly priced. Late model Chevy owners (especially trucks & SUV's) need to get those factory re-claimed steel rotors off their vehicles. My 3 trucks all had rotor changes and the ones on my 03 Trailblazer looked like they had over 100K when they actually had 32K. Also, check your brake lines many before 03 came as raw steel void of paint. Do not even think of doing a pad job only without replacing the rotors and forget about having them cut.
Thanks for the pic of your 87 with the J55 upgrade. Where did you purchase the bracket to mount the J55 caliper as I know the J55 does not bolt to the 87 spindle? Also, are you running 13" rotors. Going to pass a great place to buy parts online with fairly good shipping rates and turn-around time, go to Rock Auto.com. Actually, this company was started by two former GM engineers. The pricing is really terrific so check them out. Now they do not have everything but most general maintenance stuff can be found there. The Raybestos Advanced Technology rotors are decent and fairly priced. Late model Chevy owners (especially trucks & SUV's) need to get those factory re-claimed steel rotors off their vehicles. My 3 trucks all had rotor changes and the ones on my 03 Trailblazer looked like they had over 100K when they actually had 32K. Also, check your brake lines many before 03 came as raw steel void of paint. Do not even think of doing a pad job only without replacing the rotors and forget about having them cut.
09-01-2010, 09:45 AM
#5
Drifting
Member Since: Nov 2009
Location: Perth Western Australia
Posts: 1,340
Likes: 0
Received 2 Likes
on
2 Posts
St. Jude Donor '10
Lemme:
Thanks for the pic of your 87 with the J55 upgrade. Where did you purchase the bracket to mount the J55 caliper as I know the J55 does not bolt to the 87 spindle? Also, are you running 13" rotors. Going to pass a great place to buy parts online with fairly good shipping rates and turn-around time, go to Rock Auto.com. Actually, this company was started by two former GM engineers. The pricing is really terrific so check them out. Now they do not have everything but most general maintenance stuff can be found there. The Raybestos Advanced Technology rotors are decent and fairly priced. Late model Chevy owners (especially trucks & SUV's) need to get those factory re-claimed steel rotors off their vehicles. My 3 trucks all had rotor changes and the ones on my 03 Trailblazer looked like they had over 100K when they actually had 32K. Also, check your brake lines many before 03 came as raw steel void of paint. Do not even think of doing a pad job only without replacing the rotors and forget about having them cut.
Thanks for the pic of your 87 with the J55 upgrade. Where did you purchase the bracket to mount the J55 caliper as I know the J55 does not bolt to the 87 spindle? Also, are you running 13" rotors. Going to pass a great place to buy parts online with fairly good shipping rates and turn-around time, go to Rock Auto.com. Actually, this company was started by two former GM engineers. The pricing is really terrific so check them out. Now they do not have everything but most general maintenance stuff can be found there. The Raybestos Advanced Technology rotors are decent and fairly priced. Late model Chevy owners (especially trucks & SUV's) need to get those factory re-claimed steel rotors off their vehicles. My 3 trucks all had rotor changes and the ones on my 03 Trailblazer looked like they had over 100K when they actually had 32K. Also, check your brake lines many before 03 came as raw steel void of paint. Do not even think of doing a pad job only without replacing the rotors and forget about having them cut.
09-01-2010, 10:00 AM
#6
Cruising
Thread Starter
Member Since: Aug 2010
Posts: 12
Likes: 0
Received 0 Likes
on
0 Posts
Lemme:
Helo, and thanks for the quick reply. I left a message at Baer Brakes to see if they make the bracket in question. Now, I know the J55/GS calipers and 13" rotors will work I need to get a handle on that bracket to mount everything up. Glad to see Vettes are appreciated around the world and down under. Here in the states, the best Vette deals can be found in the C4 models and that is good because I have had mine since new and refuse to pay thousands of dollare for vintage Vettes that I paid hundreds of dollars for as a kid. I guess it is just a mind thing but no C1 or C2 Vette is ever going to outperform a C4. in stock form.
Helo, and thanks for the quick reply. I left a message at Baer Brakes to see if they make the bracket in question. Now, I know the J55/GS calipers and 13" rotors will work I need to get a handle on that bracket to mount everything up. Glad to see Vettes are appreciated around the world and down under. Here in the states, the best Vette deals can be found in the C4 models and that is good because I have had mine since new and refuse to pay thousands of dollare for vintage Vettes that I paid hundreds of dollars for as a kid. I guess it is just a mind thing but no C1 or C2 Vette is ever going to outperform a C4. in stock form.
09-01-2010, 10:12 AM
#7
Drifting
Member Since: Nov 2009
Location: Perth Western Australia
Posts: 1,340
Likes: 0
Received 2 Likes
on
2 Posts
St. Jude Donor '10
Lemme:
Helo, and thanks for the quick reply. I left a message at Baer Brakes to see if they make the bracket in question. Now, I know the J55/GS calipers and 13" rotors will work I need to get a handle on that bracket to mount everything up. Glad to see Vettes are appreciated around the world and down under. Here in the states, the best Vette deals can be found in the C4 models and that is good because I have had mine since new and refuse to pay thousands of dollare for vintage Vettes that I paid hundreds of dollars for as a kid. I guess it is just a mind thing but no C1 or C2 Vette is ever going to outperform a C4. in stock form.
Helo, and thanks for the quick reply. I left a message at Baer Brakes to see if they make the bracket in question. Now, I know the J55/GS calipers and 13" rotors will work I need to get a handle on that bracket to mount everything up. Glad to see Vettes are appreciated around the world and down under. Here in the states, the best Vette deals can be found in the C4 models and that is good because I have had mine since new and refuse to pay thousands of dollare for vintage Vettes that I paid hundreds of dollars for as a kid. I guess it is just a mind thing but no C1 or C2 Vette is ever going to outperform a C4. in stock form.
It cost me $2K to get the brakes upgraded on the front. Not cheap at all.
09-01-2010, 10:21 AM
#8
Cruising
Thread Starter
Member Since: Aug 2010
Posts: 12
Likes: 0
Received 0 Likes
on
0 Posts
Lemme:
Hi again, all I need are the parts I know how to do the labor as I have been doing brakes as a kid. Not a mechanic by any shot but good enough to change rotors, pads and calipers. Just finished a stock brake job on my daughter's 1st set of wheels a 98 Olds. Intrigue with 128K on it. Man, the labor here in the states is NUTS even with the economic downturn which is more serious than you hear (many real estate foreclosures) but you cannot do everything yourself and the newer the vehicle the more impossible for self service of it. If you can find out anything at all about the bracket be sure to give a good yell. My 87 has 13K on it, all the years spent working for GM and family gave it little drive time but have been retired from the General for 2 yrs. now and I am getting back into Vettes.
Hi again, all I need are the parts I know how to do the labor as I have been doing brakes as a kid. Not a mechanic by any shot but good enough to change rotors, pads and calipers. Just finished a stock brake job on my daughter's 1st set of wheels a 98 Olds. Intrigue with 128K on it. Man, the labor here in the states is NUTS even with the economic downturn which is more serious than you hear (many real estate foreclosures) but you cannot do everything yourself and the newer the vehicle the more impossible for self service of it. If you can find out anything at all about the bracket be sure to give a good yell. My 87 has 13K on it, all the years spent working for GM and family gave it little drive time but have been retired from the General for 2 yrs. now and I am getting back into Vettes.
09-01-2010, 10:28 AM
#9
Drifting
Member Since: Nov 2009
Location: Perth Western Australia
Posts: 1,340
Likes: 0
Received 2 Likes
on
2 Posts
St. Jude Donor '10
Lemme:
Hi again, all I need are the parts I know how to do the labor as I have been doing brakes as a kid. Not a mechanic by any shot but good enough to change rotors, pads and calipers. Just finished a stock brake job on my daughter's 1st set of wheels a 98 Olds. Intrigue with 128K on it. Man, the labor here in the states is NUTS even with the economic downturn which is more serious than you hear (many real estate foreclosures) but you cannot do everything yourself and the newer the vehicle the more impossible for self service of it. If you can find out anything at all about the bracket be sure to give a good yell. My 87 has 13K on it, all the years spent working for GM and family gave it little drive time but have been retired from the General for 2 yrs. now and I am getting back into Vettes.
Hi again, all I need are the parts I know how to do the labor as I have been doing brakes as a kid. Not a mechanic by any shot but good enough to change rotors, pads and calipers. Just finished a stock brake job on my daughter's 1st set of wheels a 98 Olds. Intrigue with 128K on it. Man, the labor here in the states is NUTS even with the economic downturn which is more serious than you hear (many real estate foreclosures) but you cannot do everything yourself and the newer the vehicle the more impossible for self service of it. If you can find out anything at all about the bracket be sure to give a good yell. My 87 has 13K on it, all the years spent working for GM and family gave it little drive time but have been retired from the General for 2 yrs. now and I am getting back into Vettes.
Even I am now attempting to do more work myself. Only way to learn and save at the same time.
I will ask the club mechanic where he got it from and let you know.
09-01-2010, 07:55 PM
#10
Cruising
Thread Starter
Member Since: Aug 2010
Posts: 12
Likes: 0
Received 0 Likes
on
0 Posts
Lemme:
Thank you, good to talk to you. Spent the day under my Chevy Trailblazer grinding the rust of the frame and painting same. The driveshaft looked like it went down with the Titanic. GM bankruptcy no mystery, the truck has 32K on it. Yeah you gotta do what you can for service cause things is expensive and nobody looks after them better than the owner.
Best Regards,
Tony
Thank you, good to talk to you. Spent the day under my Chevy Trailblazer grinding the rust of the frame and painting same. The driveshaft looked like it went down with the Titanic. GM bankruptcy no mystery, the truck has 32K on it. Yeah you gotta do what you can for service cause things is expensive and nobody looks after them better than the owner.
Best Regards,
Tony
09-01-2010, 08:20 PM
#11
Le Mans Master
Member Since: Aug 2000
Location: Sydney Australia
Posts: 8,837
Likes: 0
Received 30 Likes
on
29 Posts
Baer machined and modified the J55 abutment bracket and supplied a adapter plate
DRM made billet adapters ($180) that bolted the J55 bracket in unmodified form to the early spindle
IIRC
Baer stopped production a long time ago and DRM no longer have them listed on their site
Last edited by rodj; 09-23-2010 at 05:07 AM.
09-23-2010, 02:08 AM
#17
Advanced
Member Since: Jul 2009
Location: virginia beach va
Posts: 59
Likes: 0
Received 0 Likes
on
0 Posts
does anyone have a part number for the adapter plate that corvette central or DRM make? i cant seem to find it any where. i need it, to mount the GS calipers i got for my '86. thanks everyone
09-23-2010, 09:08 AM
#19
Team Owner
Is the reason for going to the J55 brakes because you want to keep the 16" wheels and tires??
Vette Brakes has a C5 brake conversion kit for the front but the C5 front brakes require 17" wheels.
Either upgrade will change the brake bias. Doug Rippie has a replacement brake bias spring that will correct the bias once bigger brakes are installed up front. Make sure you get the 87-88 version for ABS cars. The cost is about $20 delivered and it can be installed in the master cylinder without removing it from the car. Without this spring, the ABS system will be constantly engaging with anything more than 50% braking force.
Vette Brakes has a C5 brake conversion kit for the front but the C5 front brakes require 17" wheels.
Either upgrade will change the brake bias. Doug Rippie has a replacement brake bias spring that will correct the bias once bigger brakes are installed up front. Make sure you get the 87-88 version for ABS cars. The cost is about $20 delivered and it can be installed in the master cylinder without removing it from the car. Without this spring, the ABS system will be constantly engaging with anything more than 50% braking force.
