The Authoritative Galant VR-4 Resource

Join the best E39A 1991-1992 Mitsubishi Galant VR-4 community and document your GVR4 journey.

  • Software Upgraded - Reset Your Password to Login
    In order to log in after the forum software change, you need to reset your password. If you don't have access to the email address you used to register your GVR4.org account, you won't be able to reset your password. In that case, follow the instructions here to regain access to the forum.

Which rotors for Diamante calipers?

BeerySquash

Well-known member
Joined
Jan 12, 2022
Messages
52
I picked up a pair of early dual piston front brake calipers from a 94 Diamante, as far as I can tell they're the same units that came on the NA 3000GT's. I'm trying to figure out which rotors I will need to run these on a 90 Galant GSX. I want to stay 4-lug, the rotors I've been looking at on rockauto look like multi 5-lug. Does anyone know if one of the patterns on these are 4x114.3 or are the just 5x100 and 5x114.3? If they won't work I'll need to order a pair of 5-lug rotors and drill them for 4-lug, but I don't think they can be the multi-lug ones I've been seeing because there's not enough meat on them to drill new holes. Has anyone here tried this before? Any help would be appreciated.

121.46032_Back__ra_p.jpg
 
Last edited:

slugsgomoo

Well-known member
Joined
Oct 16, 2003
Messages
3,744
Location
Tacoma, WA
91-92 GVR4 rotors are 4 lug, and use the same calipers as the NA 3000GT, so I'm not sure why they wouldn't work for you?
 

BeerySquash

Well-known member
Joined
Jan 12, 2022
Messages
52
91-92 GVR4 rotors are 4 lug, and use the same calipers as the NA 3000GT, so I'm not sure why they wouldn't work for you?
That's one of the things that confused me, because the part numbers come up different for the VR4.
For example I found the following on Rockauto:

1992 3000GT NA CALIPER CENTRIC [ 14146047 ]
1992 DIAMANTE CALIPER CENTRIC [ 14146047 ]
1992 GALANT VR4 CALIPER CENTRIC [ 14146051 ]

Do you think it's still worth a shot trying a 4-lug VR4 rotor even though the calipers part numbers seem to be different?
 

tyeler18

Well-known member
Joined
Jul 16, 2012
Messages
130
Location
Casa Grande, AZ
The rotors for an N/A 3SI are 10.8 outside diameter which is the same as a VR4, same as a 92.5+ DSM, which we can assume means the caliper is identical to a VR4 caliper. I know the caliper is the same, I assume the bracket is the same. The difference comes in what style (banjo vs flare) the brake line is.
 

BeerySquash

Well-known member
Joined
Jan 12, 2022
Messages
52
The rotors for an N/A 3SI are 10.8 outside diameter which is the same as a VR4, same as a 92.5+ DSM, which we can assume means the caliper is identical to a VR4 caliper. I know the caliper is the same, I assume the bracket is the same. The difference comes in what style (banjo vs flare) the brake line is.
Awesome, thanks for the info. I'll order a couple rotors and see how they fit.
 

slugsgomoo

Well-known member
Joined
Oct 16, 2003
Messages
3,744
Location
Tacoma, WA
The 1g 92.5 rotors are the same as the SL, and the gvr4 used the same caliper as both, but the 3s & DSM are 5 lug hence the very different part number
 

stevep

Well-known member
Joined
Oct 23, 2004
Messages
415
Location
St. Charles, IL USA
Besides the Brake line attachments on the later calipers there are other differences.
The DSM and GVR4 dual piston calipers (M-R56W) has a slightly different piston size from the Diamante and 3000GT NA dual piston calipers. (M-R57W) 41.3mm vs 42.8mm. Hence the part# difference.

I doubt you would feel the increase but it would make a difference when looking for seals, boots, and pistons for maint.

As noted you want the GVR4 rotors for swapping onto a GGSX.
 

iceman69510

Turn Right Racing
Staff member
Joined
Mar 5, 2001
Messages
10,922
Location
Michigan
Steve is right on the piston sizes. You need to look carefully at the casting numbers on the caliper and compare to Centric's info. they actually have pretty good technical info. I ran into this with 2005 Outlander calipers last year when rebuilding a set of them and a set of GVR4 calipers both. The have different casting numbers, but appear the same from the outside. Piston size is different as well as the brake hose attachment which I knew about already. Outlander pistons were about 1mm diameter larger so the kits were not the same.
 

BeerySquash

Well-known member
Joined
Jan 12, 2022
Messages
52
Besides the Brake line attachments on the later calipers there are other differences.
The DSM and GVR4 dual piston calipers (M-R56W) has a slightly different piston size from the Diamante and 3000GT NA dual piston calipers. (M-R57W) 41.3mm vs 42.8mm. Hence the part# difference.

I doubt you would feel the increase but it would make a difference when looking for seals, boots, and pistons for maint.

As noted you want the GVR4 rotors for swapping onto a GGSX.

Got it, I just checked with a gauge and the pistons are 42.8mm, so I should be okay just ordering a caliper service kit for a 94 Diamante, rockauto shows the bore size for the service kit as 1.68" (42.8mm). Then just order standard rotors for a Galant VR4. This will be a lot easier than re-drilling rotors like I thought I would have to do.

I should be able to clear most 15" wheels with the 3K NA/Diamante brakes right? That's the main reason I didn't go for 3K TT big brakes.
 

slugsgomoo

Well-known member
Joined
Oct 16, 2003
Messages
3,744
Location
Tacoma, WA
You'll have to test fit with some 15's, but obviously, the OEM GVR4 wheels are 15s and fit. There are some spoke designs that won't clear on them, but I don't think that's the majority.
 
Support Vendors who Support the GVR-4 Community
Boosted Fabrication ECM Tuning ExtremePSI Fuel Injector Clinic Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications RixRacing RockAuto RTM Racing STM Tuned
Top