R34 GTR Rear Rotors late model (version 2)

[amritgtr]

I'd just like to find out why rear brakes for 2001 r34 gtr (nok Vspec) are such a mystery. Maybe its not a mystery for most here as these cars were sold here but they weren't in North America. 

Story:

I researched for months and settled on 322mm rotors to replace my current rotors on 2001 R34 GTR. Then i find half the world saying it's actually 300mm rotors like the R32 and R33 (gtrusablog and others). So I contacted my local trusted and well established store to get me DBA rotors after they told me "our system says 300mm". I went with their recommendation thinking they know better and ordered DBA 4929S. 

 

Fast forward a month, i get my brakes and guess what - they are smaller. 

 

Then I finally measured mine and some might say I should have measured them before ordering. True. They were 322mm. 

 

So i guess my post is to let everyone know that stock Aug 2000+ R34 GTRs are 322mm rotors in back and seems like 350z brembos (dba4601 as an example) might fit according to kudos motorsports (but DBA's website doesn't state that). 

 

[Duncan]

The 350z ones are unlikely to fit. As well as diameter you need to consider offset of the disc (vertical distance from top of hat to rotor)

[joshuaho96]

Weird how Nissan decided to basically match the brake rotor sizes towards the end, I've heard that there was no modification to the rest of the car either so presumably that impacted brake bias?

Edited October 4, 2020 by joshuaho96

[amritgtr]

4 hours ago, joshuaho96 said:

Weird how Nissan decided to basically match the brake rotor sizes towards the end, I've heard that there was no modification to the rest of the car either so presumably that impacted brake bias?

Hence the mystery. Kudosmotorsports lists dba 4601 for version 2 r34 gtrs but there is clearly a debate there as well from reading the above forum. Seems like only Project Mu makes them for the R34 and dba is close enough part for it. I am jumping on this again only to find out its not what I need/fits the car. 

[joshuaho96]

9 hours ago, amritgtr said:

Hence the mystery. Kudosmotorsports lists dba 4601 for version 2 r34 gtrs but there is clearly a debate there as well from reading the above forum. Seems like only Project Mu makes them for the R34 and dba is close enough part for it. I am jumping on this again only to find out its not what I need/fits the car. 

Yeah, dba 4601 seems to fit from what people say but it's not actually exactly correct. If you need to unload your 300mm rear rotors I can buy them off of you, my R33 needs new rotors I believe.

[amritgtr]

I dropped them off last weekend from the same place I got them from. I'll check if they still have them. Where are you located bud?

[joshuaho96]

32 minutes ago, amritgtr said:

I dropped them off last weekend from the same place I got them from. I'll check if they still have them. Where are you located bud?

If you already returned the rotors it's fine, I'm located in CA though.

[amritgtr]

@Duncan I have heard about the 0.5mm offset difference with DBA4601 but have also read that most companies round 62.5(350z) to 63 (R34) so it would be a very minor/un-noticeable difference. In any case either these fit and I am happy or I will put these up for sale locally till I can find the correct ones. I wish I had more affordable and accessible options.

[GTSBoy]

On 10/4/2020 at 7:43 PM, joshuaho96 said:

I've heard that there was no modification to the rest of the car either so presumably that impacted brake bias?

OEM have the easy option of different pad material specs to set the braking torque also.

That's why, when you buy a set of genuine pads for front and rear, they are unlikely to be the same compound. But when you put on a set of any aftermarket pad, both front and rear will likely be the same compound (if they're the same type of pad, not talking about the size/shape of them). And thus with an aftermarket set you will already have a bias change. That's one reason why R32s (in particular) often had excessive rear bias. Same (aftermarket) pads in front and rear. Go back to stock pads (if you can find them!) and the bias becomes less wrong (but still wrong, because I'm convinced R32s had crappy excessive rear bias anyway, but I digress).