# R34 GTR front calipers on the rear



## xxfr (Apr 28, 2009)

The rotor specs on most R34 GTR's are 

*Front *
Diameter - 324mm 300mm
Height - 53.8mm 63mm
Thickness - 30mm 22mm

*Rear *
Diameter - 300mm
Height - 63mm
Thickness - 22mm

Say if I upgraded my fronts to 6pots and wanted to move my front calipers to the rear, what would be a suitable rotor? 

The 370z rear ones are not thick enough, specs are as follows. 

Dia - 350mm
Height - 62mm
Thickness - 20mm

Any help guys/girls?


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## Sub Boy (Jan 28, 2008)

You couldn't run the front 4pot on the rear, The piston sizes are too big, You would never get enough pedal pressure and would have way too much bias to the rear if you could.

Do a search, this has been discussed many times before....I looked at doing it ages ago and was told on here and by brake and race car experts that it wouldn't work.


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## xxfr (Apr 28, 2009)

I tried to look but couldn't find anything concrete. 

I would only use the original fronts on the rear if I was upgrading the fronts to 6pot calipers with 355mm rotors. 

Brembo supplies a GT kit with 6pot fronts for 355mm rotors and 4pot rears with 350/355mm. 

Essentially I would only be utilising my current fronts with new 6pots on the front to match the above GT kit.

I cannot see why it wouldnt work if suitable rotors can be sourced. I would like to know what could be the cons of doing such an upgrade.


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## Sub Boy (Jan 28, 2008)

xxfr said:


> I tried to look but couldn't find anything concrete.
> 
> I would only use the original fronts on the rear if I was upgrading the fronts to 6pot calipers with 355mm rotors.
> 
> ...


Have a look at the piston size on the 4pot rears that Brembo do, and then look at the size of the front set you have, The bias ratio is too great, You would end up with the backs locking up and a very spongy pedal.
I looked into this ages back when I could get a set of Brembo/Porsche 8 pots, And was told by many people that it wouldn't work.
Talk to some motorsport/brake experts, I'm sure they will tell you the same thing


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