CG Rear Disc Conversion questions

steeaboo

Member
Hi All,

I'd been eyeing up the rear disc conversion that RPW had listed for quite some time for my CG. I don't *need* to do this mod, but into the future this is supposed to be my show car and rear drums just aren't gonna cut it behind the 17in BBS' haha.

The reason I'm posting is I've done a bit of reading on here about rear disc conversions but a lot of it is for CEs and I'm not sure how much of that info is useful to CGs. I know a bolt-on kit using (assumedly) OEM parts is doable, as RPW was selling the kit. They no longer offer it and David told me it's due to supply issues. I don't mind playing the long game to wrangle up parts, but I don't know what I actually need to do the job.

My only criteria is retaining 4x100 as the wheels I have are the focal point of the build.

I've seen a lot of info about using stuff from CC-based protons, Magnas and FTOs but can't quite wrap my head around it. Can anyone simplify or direct me to some knowledge that can?
 
Suzie sparkles

Have a read of this thread. I’d guess you are going to need a modified/different wheel bearing - otherwise all the same as CE conversion.

Alternatively you could find a custom hub that suits the CH trailing arm, 4x100 and accepts a disc. Then redrill 4x114.3 or 5x114.3 discs and use a CH setup.
 
Suzie sparkles

Have a read of this thread. I’d guess you are going to need a modified/different wheel bearing - otherwise all the same as CE conversion.

Alternatively you could find a custom hub that suits the CH trailing arm, 4x100 and accepts a disc. Then redrill 4x114.3 or 5x114.3 discs and use a CH setup.
I had read this thread shortly before posting mine - I couldn't discern much useful info for my case from it unless I've missed something.

Most of those 12 pages are discussing how to go to 4x114.3 which doesn't help unfortunately. Unless I was meant to be reading between the lines regarding some of that?
 
considering its a CG, if it was me, i'd be re-drilling a set of 4x114.3 hubs and discs to 4x100. ezpz. no need to muck about with other bearings and spigots etc.
 
considering its a CG, if it was me, i'd be re-drilling a set of 4x114.3 hubs and discs to 4x100. ezpz. no need to muck about with other bearings and spigots etc.
So CH stuff redrilled? Seems fairly straightforward compared to replacing trailing arms and almost everything attached to them. Was somewhat hoping for a more low maintenance (read: not getting rotors drilled every time i have to replace pads and rotors) solution but if that's the solution so be it!
 
yeah makes sense to me.

handbrake cable: bolt on
no mucking around with camber and toe arms
everything else (ie: not the hubs and the discs) are off the shelf
many many engineering shops are capalabe of PCD redilling. (ie: commodores to 5x114.3)

plus rear discs dont get that much use, im sure a brand new set of discs will see out the life of the car.

the caveat to this: you'll have to lay eyes on a 4x114.3 hub and measure up the clearances behind the hub. there might be a reason a 4x100 rear disc setup doesnt exist in a OEM CH/CH chassis (compared to CE/FTO....no drum hand brake in a CE/FTO rear disc)
 
the caveat to this: you'll have to lay eyes on a 4x114.3 hub and measure up the clearances behind the hub. there might be a reason a 4x100 rear disc setup doesnt exist in a OEM CH/CH chassis (compared to CE/FTO....no drum hand brake in a CE/FTO rear disc)
This is the part that dumbfounds me, the kit does/did exist! There was a bolt-on solution for the CG that retained 4x100. I just need to find that secret sauce :lol:

But honestly for the time being the CH route as you've laid out seems to be the current easiest route. This was a lot more attractive of an idea when it was a 2k parts shotgun kit from the internet that was just gonna "work" :sweatsmile:
 
I had read this thread shortly before posting mine - I couldn't discern much useful info for my case from it unless I've missed something.

Most of those 12 pages are discussing how to go to 4x114.3 which doesn't help unfortunately. Unless I was meant to be reading between the lines regarding some of that?

The info on bear size difference ect between trailing arms was the main bit of info.

I forgot you can redrill hubs, so that is 100% the option to go with. I dont think you’ll find a 4x100 hub that’ll mate up to the CH bearing.

Also I dont think you’ll ever replace the rear disc - my CH is at 220k km with original rear discs…
 
I've been absolutely busting my own balls trying to figure this out, and I have a hypothetical solution.

There is a variant of the CS5W Cedia wagon in Japan that was both rear disc and 4x100 according to the breakdowns on megazip combined with googling PCDs on each specific trim for the car.

I've gotten the P/Ns for everything from park brake components (drum-in-disc) to the hard brake lines that run under the car.

I have it written on paper at the moment and will update over the next few hours when I'm at home on PC.

I may be able to actually do this OEM like the stubborn bastard I apparently am
 
Right, so here is my list. Keeping in mind this is hypothetical, so until I guinea up to be the test mule, I can't confirm this will be 100% accurate. But I will put the parts list here for posterity. If I'm right not *all* of this will be required (trailing arms etc) so I'll note that as well.
https://docs.google.com/document/d/1ffnPa4mqV4COukJgrv-KLee-hJfHvoOa1MjYfBT8-SI/edit?usp=sharing

Diagrams below:
1671788938698.png1671788976848.png
1671788995922.png

A couple of interesting wrinkles - David from RPW advised me that his 4x100 kits are soucred from a CK Lancer, a turbo GSR equivalent I don't know enough about to track down. Given the general consensus of "me casa su casa" for CS5W parts fitting any other CS based lancer within reason, this might just work. Everything in the above google doc is still available new according to megazip/amayama so take that with a grain of salt.

Variant of Lancer Cedia Wagon used for this research was a 2002 CS5W-LTUC which is a 2wd 4 stud touring with the 4g93. Looking up this variant on a couple of wheel sizing sites implies they're 4x100.

I'll have to at the very least try with the hub first, and confirm 100% if they're 4x100 or not. if they are, I can't see how the rest of this wouldn't just work.

Am I overdoing this? Yes. Is this a superfluous waste of my time when there's already a solution above? Also yes. But sometimes you get an idea and can't shake it til you've done something about it, for better or worse.
 
Right, so here is my list. Keeping in mind this is hypothetical, so until I guinea up to be the test mule, I can't confirm this will be 100% accurate. But I will put the parts list here for posterity. If I'm right not *all* of this will be required (trailing arms etc) so I'll note that as well.
https://docs.google.com/document/d/1ffnPa4mqV4COukJgrv-KLee-hJfHvoOa1MjYfBT8-SI/edit?usp=sharing


A couple of interesting wrinkles - David from RPW advised me that his 4x100 kits are soucred from a CK Lancer, a turbo GSR equivalent I don't know enough about to track down. Given the general consensus of "me casa su casa" for CS5W parts fitting any other CS based lancer within reason, this might just work. Everything in the above google doc is still available new according to megazip/amayama so take that with a grain of salt.

Variant of Lancer Cedia Wagon used for this research was a 2002 CS5W-LTUC which is a 2wd 4 stud touring with the 4g93. Looking up this variant on a couple of wheel sizing sites implies they're 4x100.

I'll have to at the very least try with the hub first, and confirm 100% if they're 4x100 or not. if they are, I can't see how the rest of this wouldn't just work.

Am I overdoing this? Yes. Is this a superfluous waste of my time when there's already a solution above? Also yes. But sometimes you get an idea and can't shake it til you've done something about it, for better or worse.

Steeaboo, thanks for your work on this. I have also been trying to work out how to get those parts since the RPW ones have been taken down. I too emailed them about the kit and told them I was interested, so I'm partially waiting to see if anything comes of that, while at the same time working on similar research.

Your work confirms some of what I have found as well. As for the hubs, the P/N you gave are the same hubs I bought last year to replace worn out ones on my 2002 CS5A with the drums. So, it looks as though there is no need for a new trailing arm and the hassle that comes with all of that, but rather to take off all the drum related parts and then install the backing plate and so forth for the new disc brake setup.

I'm considering buying the backing plates first to give a test fit, and pull an old front caliper to see if I can just use those, or if either the bolt holes don't line up or the spacing is wrong for the disc, and then go from there.

I am wanting to do this setup because I am building it into a regional rally car and could really use the extra clamping force as well as an inline hydraulic handbrake, which would be far more useful with discs rather than the drums. I am also considering just not even having the drum handbrakes installed at all, which would cut down on parts needed.

I'd love to see any updates as you have them. And thanks for keeping the work alive on our aging Lancers.
 
I just noticed that the hole pattern for the rotors P/N MB668083 is listed as 4x114.3 not 4x100. The hubs you have listed are 4x100.

I would assume that part numbers would be associated with the same exact specs no matter where the location is, but I do know that we did not get all of the variants in the US, so maybe there is a 4x100 rear disc somewhere in the world.

I'll keep poking around, maybe try to track down parts for the CK Lancers if possible.
 
I just noticed that the hole pattern for the rotors P/N MB668083 is listed as 4x114.3 not 4x100. The hubs you have listed are 4x100.
This is the confusing thing I've noticed as well - all of those parts came from the same page on EPC-data.

You're right that the discs come up as 4x114.3, I've been looking at CS5X/CS2X/CS6X aftermarket stuff in japan and any rear discs that aren't 5 stud come up as 4x114.3 also.

Honestly at this point I'm feeling it's easier to sacrifice my wheel setup and just chuck on stock *poo* from the CH/OZR from the states which I believe are also 114.3 according to their Wilwood front kit. Or worse, I could keep the wheels by running a hub adapter switching it back to 4x100.

Very strange that there is a 4x100 rear disc hub in the CS family somewhere, a thread i've still been trying to pull.
 
I know next to nothing about the CC/CE/CK platform so that's not something I can research as accurately. RPW didn't elaborate on which variant of the CK he used and which parts from where were needed, and frankly I feel it'd be rude to ask for so much information for free.

There is also a possibility of RG/Z27A colt rear discs being an option, as they share the same rear drum as the CG. Unsure how much else lines up as I know even less about Colt variants than I do about mirages and CKs, but I'd assume the hubs would at least be the same or compatible enough.
 
This is the confusing thing I've noticed as well - all of those parts came from the same page on EPC-data.

You're right that the discs come up as 4x114.3, I've been looking at CS5X/CS2X/CS6X aftermarket stuff in japan and any rear discs that aren't 5 stud come up as 4x114.3 also.

Honestly at this point I'm feeling it's easier to sacrifice my wheel setup and just chuck on stock *poo* from the CH/OZR from the states which I believe are also 114.3 according to their Wilwood front kit. Or worse, I could keep the wheels by running a hub adapter switching it back to 4x100.

Very strange that there is a 4x100 rear disc hub in the CS family somewhere, a thread i've still been trying to pull.
Yeah it's really frustrating trying to find parts for our cars, it seems like the parts exist somewhere, its just finding the right combo from various versions. It is also frustrating to me that they made just slightly different variations on the models like the ES having 4x100 and the LS/OZ having 4x144.3. I have a set of LS wheels that I use for street driving and have spacer/adapters to use those, but my racing wheel/tire combo only fits with the 4x100 pattern, and the rally tires won't fit in the wheel well with a spacer because it pushes the wheel out too far and the tire rubs. I've thought about going up to the five lug since those are the easiest parts to source here, but then I'd have to find two or more sets of wheels and tires and I just don't have that kind of cash for it.

On a more positive note, Dave at RPW got back to me a few days ago and said they will be selling the kit again, but only to those on the waiting list, so you could reach out to him again to see if you can get on the list for the kit, he said they are going for AUD$1,500, which I think is a little higher than it use to be listed, but might be worth it for having all the parts sourced and good quality pads and rotors.

I've decided to wait a bit on the brake conversion and focus on a few other things for the time being.
 
After a pretty intensive back and forth with RPW the CG 4x100 appears to be a dead end. He had a kit in stock however it was used and ended up being 4x114.3.

It has more or less killed my motivation for keeping 4x100, at this point it seems more cost effective to buy a written off CH with rear discs and swap it all over. I can't find the forum posts that I was looking for that mentioned CH compatibility with CG but I remember them being almost bolt-up if memory serves. Might even go 5x114.3 from a VRX if I can find a whole car cheap enough.

Frustrating mod to chase LOL
 
Back
Top