PDA

View Full Version : Best rear disc brake setup?



1GCustomAccord
08-18-2011, 10:54 AM
As the title says, i am searching for the best (proven) rear disc setup to install in my 1979 Honda Accord sedan.
I know that some guys did the upgrade, so any tips on the correct parts will be very welcome.
I think on upgrading to vented in front with bigger calipers also, but for now the rear conversion is the goal.

Thanks in advance!

79cord
08-19-2011, 02:44 AM
Unfortunately the 2nd gen Prelude (or even rarer 1g Prelude or 2g Accord) is the only option I know of for rear discs.
All the later Honda switched to a very different rear wheel bearing arrangement that will not match the Accord rear stub axle... Unless you get devious/clever with a custom rear hub to bolt the disc to (preludes hub was incorporated into disc rotor like the drum brake setup, while later Honda have a separate hub for the disc or drum to sit upon).

2ndGenGuy
08-19-2011, 07:53 AM
Cygnus developed a rotor-over-hub conversion kit for the 2g Prelude. It's a much stronger setup than the stock 2g Prelude brakes, and has been proven buy a guy who races Preludes and was having trouble with them breaking on him. I bet a kit like that could be adapted to the 1g Accord quite easily. Again, only fuss being the e-brake cable.

1GCustomAccord
08-19-2011, 04:20 PM
Well, i was hunting for parts yesterday and found a nice set of rear discs from a 1993 Civic Si, but the disc/hub seem to bolt to the strut by a huge bolt right in the middle. I was thinking on some way of bolting the disc/hub of the Civic to my Accord strut, cutting the original hub carrier.

OR i can make a custom disc-to-bearing hub bo fit ANY suitable disc to my existing hub carrier, but that involves more engineering and i am extremely lazy:sad2:. But if in any case i decide to go this path, what do you guys think about what metal to use in the new carrier?

2nd gen Accord and Preludes are a very rare find over here, seems like there was a jump from the 1st gen directly to the 4th gen in the imports over here, so i will be very lucky if i find a 2nd gen Lude or Accord for parts. Unless i import the parts from USA, but that is a real pain in the arse, a lot of wainting and sometinas the wrong part comes and you can only use it as paperweight or bizarre decorative implement in your desk.

I was also sharching the net for Cygnus and couldnt find it.

Whaddaya think guys?

79cord
08-20-2011, 01:20 AM
We should point out to others that you have already converted to 4x100 via 1g prelude rear drums lest we get them excited about 4x120 rear disc conversions!

Ok you would have spotted my 4x100 conversion here:
http://www.cardomain.com/ride/2051977/1979-honda-accord/page-3
http://carphotos.cardomain.com/ride_images/2/3208/4541/20519770022_large.jpghttp://memimage.cardomain.com/ride_images/2/3208/4541/20519770020_large.jpg
original accord (drum backing plate & internals omitted)
and 2nd gen Prelude
also showing its dust shield and rear caliper bracket (that bolts on where the Drum brakes backing plate bolted)

Giving this once assembled the the Accord:
http://memimage.cardomain.com/ride_images/2/3208/4541/20519770029_large.jpghttp://memimage.cardomain.com/ride_images/2/3208/4541/20519770027_medium.jpg
but needing this small custom adapter, required to convert the calipers handbrake actuation from fore-aft as used by most later Honda to the transverse cables of the Accord, the later style cable arrangement would be a big pain to fit to pre '81 Accords due to their front seatbelt mounting location directly behind the handbrake.

_________________________

I like the idea of the later disc rotor -over- hub idea also but it does have complications.
And I still don't have ideas/knowledge of alternative calipers and particularly the caliper mounting bracket.

Here's the Preludepower thread mentioned.
http://www.preludepower.com/forums/showthread.php?t=334489
Where an aftermarket Prelude rear disc failed, so with proper Honda disc rotors unavailable they decided to make & fit an adapter to the Preludes stub axle (same as accord) bringing it up to the size of the 1984-2000 Civics & Integras so that those cars rear hub (including wheel bearings) and 1988-2000 disc rotor could be used (1g Integra has less offset to disc if that was useful for other applications).
____________________

The 1g civic 4x100 rear Disc conversions are also useful reference.
http://www.1stgencivic.org/world/c1zr/m1/forum/viewtopic.php?t=12530.
The Civic have a shorter rear stub axle and members instead machined out a used '84-00 hub in order to fit different rear wheel bearings that would fit properly to their cars. I must admit to preferring their concept.

Another crazy idea would be to machine the drum portion off a 2g Accord, 1-2g prelude or 2g Civic rear drum leaving only the useful hub portion for the newer rear disc rotor to fit over, though the thickness of the disc rotor would push the wheels outward which would likely be undesirable and may not position it to match whatever caliper and caliper bracket you are able to source.

(not sure if the offset of the rear drum varied between these cars & so one might actually match the disc positioning of another Honda.)

I would also wonder if any front engine-rear drive cars might have had a front stub axle with similar dimensions to our rear & 4x100 stud pattern (chevette?) so that its front hub might be used..

79cord
08-20-2011, 03:25 AM
Looked this up
http://www.hondapartsnow.com/diagrams/small/rear-brake-disk-460726.png
'90s Civic rear disc brake mounting, presumably Integra would use the same parts
Shows its separate hub under the disc (shared with drum brake models)
from other online partsbook pictures it looks like the caliper mounted directly off the rear suspension arm with no separate caliper bracket for you to use.

1GCustomAccord
08-22-2011, 09:15 AM
Amazing info! I will research on this and think on the best solution. Last saturday i sold the complete *almost new* rear drum brakes and hardware from my car, so it is now brakeless, and there's no turn back,(i sold it to have a BIG excuse to really get involved in the disc conversion... and yeah, to gather some money in the process!) so i will be performing the rear disc swap right now.
I'll keep you posted!

cygnus x-1
08-22-2011, 08:53 PM
Hey guys! I just saw the thread title and thought I might poke my head in to see what it was about. I think this is probably my first post in the 1g forum. :wave:

It's cool to see people doing hard core mods on these old cars. Very rare indeed.

When I was designing the rotor-over-hub conversion for the 2g 'lude I spent quite a bit of time investigating different solutions. The two primary constraints were strength, and availability of parts. After looking at the exploded hubs (literally!), I determined that the major issue was that the cast hub/rotors were just not up to race duty. The first idea I had was to make a totally new hub that would use (probably) the stock bearings. The problem with that was that machining and material costs would be prohibitive. Changing the spindle was not really an option since finding something compatible would be exceedingly difficult at best. I looked at a lot of cars at the junkyard but nothing was even close. Reusing any part of the stock hub/rotor was out due to lack of confidence in their quality. Adding another bearing to a Civic hub is a neat idea, and would likely have worked but Dave wanted to be able to replace the hub periodically. The bearings in the newer type hubs are not replaceable so every hub would need machined for the outer bearing. Finally I discovered that a 2/3g Integra hub would fit with an adapter sleeve and was easily available. The Integra rotors are also the same size as the stock 'lude rotors so virtually no modification was needed to get the brakes to work. This was clearly the way to go so we went with it.

Something else I'll mention that I haven't really make public yet is that I've also reverse engineered the caliper mounting plate on the 2g 'lude and redesigned it to work with larger calipers and rotors. In my case I'll be using 4g Accord calipers and 10.3" Civic SI rotors. The SI rotors are the biggest you can get in 4x100 without redrilling and will be a good match for the 11" rotor setup I'll have in the front.

I still have several sets of the hub conversions left so if any of you guys are interested let me know. Or if you just need measurements of any 2g Prelude parts l can do that too.


Cheers, and happy modding!


C|

dedens
04-16-2019, 09:46 AM
Hi All...

I know this is an old thread but thought I would jump in... I completed a rear disk brake upgrade on my 1983 Honda Accord Sedan. As others have stated, I used the rear hub assembly (really only needed the caliper bracket), rotor, and caliper from a 2nd gen (1985) Prelude. My install differed from other posts with the emergency brake cable. I didn't want to fuss with welding.

I use a 3rd gen accord right emergency brake cable for both sides. They are a bit too long (5 inches) but i just loosely looped where the cable penetrates into the car. No adverse effects at all! The other slight modification is that I had to enlarge (with a Dremel) the slot on the hub where the emergency cable end goes through the hub/caliper bracket. Let me know if there are questions:

https://photos.app.goo.gl/81v8FyGHa4334gtM8

dedens
04-16-2019, 10:06 AM
Do you still have or can PM me instructions for your hub conversions.

dedens
04-16-2019, 10:06 AM
Hey guys! I just saw the thread title and thought I might poke my head in to see what it was about. I think this is probably my first post in the 1g forum. :wave:

It's cool to see people doing hard core mods on these old cars. Very rare indeed.

When I was designing the rotor-over-hub conversion for the 2g 'lude I spent quite a bit of time investigating different solutions. The two primary constraints were strength, and availability of parts. After looking at the exploded hubs (literally!), I determined that the major issue was that the cast hub/rotors were just not up to race duty. The first idea I had was to make a totally new hub that would use (probably) the stock bearings. The problem with that was that machining and material costs would be prohibitive. Changing the spindle was not really an option since finding something compatible would be exceedingly difficult at best. I looked at a lot of cars at the junkyard but nothing was even close. Reusing any part of the stock hub/rotor was out due to lack of confidence in their quality. Adding another bearing to a Civic hub is a neat idea, and would likely have worked but Dave wanted to be able to replace the hub periodically. The bearings in the newer type hubs are not replaceable so every hub would need machined for the outer bearing. Finally I discovered that a 2/3g Integra hub would fit with an adapter sleeve and was easily available. The Integra rotors are also the same size as the stock 'lude rotors so virtually no modification was needed to get the brakes to work. This was clearly the way to go so we went with it.

Something else I'll mention that I haven't really make public yet is that I've also reverse engineered the caliper mounting plate on the 2g 'lude and redesigned it to work with larger calipers and rotors. In my case I'll be using 4g Accord calipers and 10.3" Civic SI rotors. The SI rotors are the biggest you can get in 4x100 without redrilling and will be a good match for the 11" rotor setup I'll have in the front.

I still have several sets of the hub conversions left so if any of you guys are interested let me know. Or if you just need measurements of any 2g Prelude parts l can do that too.


Cheers, and happy modding!


C|

Do you still have or can PM me instructions for your hub conversions.

dedens
04-19-2019, 02:28 PM
Hi All...

I know this is an old thread but thought I would jump in... I completed a rear disk brake upgrade on my 1983 Honda Accord Sedan. As others have stated, I used the rear hub assembly (really only needed the caliper bracket), rotor, and caliper from a 2nd gen (1985) Prelude. My install differed from other posts with the emergency brake cable. I didn't want to fuss with welding.

I use a 3rd gen accord right emergency brake cable for both sides. They are a bit too long (5 inches) but i just loosely looped where the cable penetrates into the car. No adverse effects at all! The other slight modification is that I had to enlarge (with a Dremel) the slot on the hub where the emergency cable end goes through the hub/caliper bracket. Let me know if there are questions:

https://photos.app.goo.gl/81v8FyGHa4334gtM8

A quick update. Drove the car about 10 miles yesterday. I noticed that the wheel hubs felt loose. During install, I was cautious to not over tighten the spindle nut. Did a quick Google search and found the following instructions. Worked like a charm...hub is nice and tight!

1. Slip rotor over the spindle, then insert the outboard bearing, hub, washer, and spindle nut.
2. Tighten the spindle nut to 18 ft. lbs. (24 Nm). Rotate the rotor 2-3 turns by hand, then retighten the spindle nut to 18 ft. lbs. (24 Nm). Repeat until the spindle nut holds the proper torque after the rotor is rotated.
3. Loosen the spindle nut until it just breaks free
4. Retorque the spindle nut to 4 ft. lbs. (6 Nm).
5. Set the pin holder so the slots will be as close as possible to the hole in the spindle.
6. Tighten the spindle nut just enough to align the slot and hole, then secure it with a new cotter pin.

dedens
04-26-2019, 11:52 AM
Update:

I have driven 100 miles or so since tightening the spindle nuts. Everything is great and nothing is loose. I did have to adjust the parking brake cable at the handle. Upgrade well worth the effort!