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So I've been reading a bunch of old posts about brake upgrades. (And laughing my *** off at all the bickering) and I decided to just do the basic C5 front calipers and nice drilled rotors. This is just a street car and will never autocross it. Also this is an 84 but I'm upgrading to 86-87 front knuckles so I can have a front wheel speed sensor to feed pulses to my Holley ECU and my on board PLC. So I figured while I have it apart swapping knuckles and wheel bearings I might as well upgrade the brakes.
So I started collecting parts and have some questions for the guys who have done this swap.
First are PBR calipers worth it? I can get knock off calipers for way less than original. But not sure if the cheaper calipers have issues or not.
Second some old posts talk about installing a bias spring. Is this necessary?
Third I read that everyone seems to recommend stainless hoses. Do C5 hoses fit or do I need C4?
Fourth do you guys recommend also changing the rear hoses out for stainless or is that a waste of money?
Thanks for any advice.
Last edited by Phobos84; Nov 28, 2023 at 12:35 PM.
First are PBR calipers worth it? I can get knock off calipers for way less than original. But not sure if the cheaper calipers have issues or not.
My preference is to have the factory original calipers. Just guarantees I know everything fits right and works together. Caliper, slider pins and abutment bracket.
Originally Posted by Phobos84
Second some old posts talk about installing a bias spring. Is this necessary?
Not necessary at all.
Originally Posted by Phobos84
Third I read that everyone seems to recommend stainless hoses. Do C5 hoses fit or do I need C4?
Use the hoses designed for your year vehicle.
Originally Posted by Phobos84
Fourth do you guys recommend also changing the rear hoses out for stainless or is that a waste of money?
Those hoses are now 40 years old if they have never been replaced. You are buying the hoses in a package of 4, might as well install them.
Originally Posted by Phobos84
Also this is an 84 but I'm upgrading to 86-87 front knuckles so I can have a front wheel speed sensor to feed pulses to my Holley ECU and my on board PLC.
What's the scoop on this. Is this so you can get a speed input into the Holley?
What's the scoop on this. Is this so you can get a speed input into the Holley?
Well yes and no. I have a Click PLC that deals with all my progressive nitrous permissives. It looks at bottle pressure, line pressure, regulates the blanket heater and looks for wheel spin. Being it's a progressive nitrous system if the rpm goes up so does the nitrous shot. So I'm installing high speed inductive prox switches in the wheel speed sensor holes on one front and one rear wheel (drivers side). That way the PLC knows if I lost traction because it knows both the front and rear wheel speed. If there is traction loss it pulls the signal to the Holley and shutting off the nitrous. I'm also going to use one of the other wheel speed sensors to feed my speedometer instead of tying into my VSS.
All the data from the PLC is displayed on a small HMI screen in the car. So far it's all in and mostly working just not the front wheel speed prox switches.
I'm a nerd and I love programming so this was a fun project. I made a post about it a while back.
Thanks for all the in help guys. I'm hopefully getting the last of the parts for the brakes after Christmas. I still need calipers, adapters and hoses.
Well yes and no. I have a Click PLC that deals with all my progressive nitrous permissives. It looks at bottle pressure, line pressure, regulates the blanket heater and looks for wheel spin. Being it's a progressive nitrous system if the rpm goes up so does the nitrous shot. So I'm installing high speed inductive prox switches in the wheel speed sensor holes on one front and one rear wheel (drivers side). That way the PLC knows if I lost traction because it knows both the front and rear wheel speed. If there is traction loss it pulls the signal to the Holley and shutting off the nitrous. I'm also going to use one of the other wheel speed sensors to feed my speedometer instead of tying into my VSS.
All the data from the PLC is displayed on a small HMI screen in the car. So far it's all in and mostly working just not the front wheel speed prox switches.
I'm a nerd and I love programming so this was a fun project. I made a post about it a while back.
Cool deal. Are you running Throttle By Wire? or are you still old school with a cable?
Not sure yet. I haven't ordered that yet. I was leaning towards Vansteel but I might try the sendcutsend.com being they already have the CAD file for them and have been making them for a while.
Last edited by Phobos84; Nov 28, 2023 at 08:32 PM.
Not sure yet. I haven't ordered that yet. I was leaning towards Vansteel but I might try the sendcutsent.com being they already have the CAD file for them and have been making them for a while.
You meant sendcutsend.com?
User 76LS1BIRD has done quality caliper adapters for many years. He's also on eBay as maybe 1976Ls1. Maybe he would share the CAD file for his. I believe he was supplying 12.9 hardware for his when they were very popular. His I recall were quite nice, I don't remember anyone posting issues.
User 76LS1BIRD has done quality caliper adapters for many years. He's also on eBay as maybe 1976Ls1. Maybe he would share the CAD file for his. I believe he was supplying 12.9 hardware for his when they were very popular. His I recall were quite nice, I don't remember anyone posting issues.
Good to know. I'll see if I can find him. I read a thread here that I posted on a while back where someone shared the CAD file for them. It may have been him I'm not sure.
I just put the c6 base front brakes on my 86 earlier this year. My understanding is their a little more ridged than the c5 calipers. I got the calipers at advance auto parts and the brackets from send cut send. I will post some more info of the part numbers a little later.
The calipers came bare I painted them. If you use the c6 brakes like I did just make shure they are the base ones and not the z51. The brackets for the base c6 are the same as the brackets for all c5's.
I bought these bolts and nuts locally. They are 12mm x 35mm and 12mm x 45mm socket cap bolts 12.9 grade. Hope this info helps. The brakes were a major improvement. I had also before doing this got the master cylinder bias spring years ago.
Here is one more picture of everything bolted up. I actually only need to use the 35mm bolts I bought and reused the longer factory hex ones. And my existing lines worked.
Thank you so much for all the info. I really appreciate it. Any issues with the brackets being made of mild steel? If you had to do it again would you have had them made out of something else?
I see they offer AR500 in 9.5mm. That might be the route I go depending on the price.
Last edited by Phobos84; Nov 28, 2023 at 09:15 PM.
I'm about to order a set from sendprintsend in AR500. When you ordered yours did you have them countersink any of the holes? I see some of the brackets online have two of the holes countersunk but I'm not sure that its necessary. Even though I have an 84 I need the 9.5mm thick bracket because I have 86-87 front knuckles.
No they are just flat pieces of metal. I had the same thought when I did mine. I used nuts for the bracket to spindle bolts. Tonight I can take a picture with the wheel off so everything can be seen better.
No they are just flat pieces of metal. I had the same thought when I did mine. I used nuts for the bracket to spindle bolts. Tonight I can take a picture with the wheel off so everything can be seen better.
Thanks again for all the info. I'm going to order these tonight. Knowing that you got them to fit without issue makes me feel better.
After the brackets then I just need calipers and hoses.
Hey on that bias spring. Im assuming it gets installed inside the master cylinder? If so do you have to bench bleed that after you install it?
C5 brake upgrade questions
