Different 276mm brake piston sizes

[Spetz]

Hi everyone,

I've come across a few threads that mention the difference in piston sizing in the 276m brake range (Evo 3, Galant VR4 etc).

What impact does dose this have?

The only thing I could think of is that there would be a need to match larger pistons with a larger BMC, but could not see how those few mm would affect braking performance in any other way?

 

[bazeng]

Big piston = more pressure required on the foot to apply the same amount of pressure to the pad. Greater surface area on the pad.

Small piston = less pressure on the pedal but reduced surface area on the pad.

My feedback with this, smaller piston worked better in my situation with a 1" bmc. Brakes were not standard Mitsubishi though.

Overall the larger piston setup was squishier on the pedal.

This may not apply to the stock mitsu brake setup as the ones I had were much larger than the stock mitsubishi items.

 

[Ross Cox]

G'day, I have 1" Master, EVO 1,2,3 twin piston calipers with 276mm rotors on my rally VR4. Top shelf pads Winmax or Forza. It stops from high speeds quite well with good feel when trail braking.
Cheers
Ross

 

[Spetz]

Is there any correlation between piston size and whether the caliper is a banjo or straight fitting type?

I had a look at my brakes, they are banjo fitting and have 4304 stamped on the caliper

 

[bazeng]

Banjo = Magna I believe.

Vr4 are not.
Unsure about lancers.

 

[BYBY5L]

Arent the banjo fittings off the evo's and the screw fittings are off magna?

 

[evo-gsr]

Arent the banjo fittings off the evo's and the screw fittings are off magna?

Yep.

 

[Spetz]

So which rebuild kit would I require with my calipers?
4304 casting, banjo fitting.

 

[evo-gsr]

You dont know what they are off?

 

[BYBY5L]

The kit to suit evo

 

[evo-gsr]

This link suggests that 4304 casting mark are FTO calipers.

Viamoto Mitsubishi Car Parts Front Brake Caliper - Mitsubishi FTO 2.0 V6 Mivec, FTO - Other Brake Parts
http://www.viamoto.co.uk/proddetail.php?prod=Front+Brake+Caliper+-+Mitsubishi+FTO+2.0+V6+Mivec

 

[evo-gsr]

And E3 are same according to the same company...


Viamoto Mitsubishi Car Parts Front Brake Caliper - Mitsubishi EVO 2 3 CE9A, EVO 2 3 CE9A - Other Brake Parts
http://www.viamoto.co.uk/proddetail.php?prod=Front+Brake+Caliper+-+Mitsubishi+EVO+2+3+CE9A

 

[evo-gsr]

So as Jamie said above you buy a rebuild kit to suit Evo 3 or alternatively FTO.

 

[Spetz]

I don't know what they are off, I was under the impression they were from a Galant VR4 (the hub carrier they came with were 4X114.3).

Best thing would be to take the piston out and measure it I assume?

This guy rebuilt his E3/VR4 brakes that were stamped 4304 and stated he had 42mm pistons:
http://ayu452.blogspot.com.au/2013/11/evo-iii-caliper-rebuild-vr4-galant-42mm.html

Anyone know what the larger piston size is?

 

[bazeng]

My mistake. Vr4 are 100% not banjo.

Must be Lancer.

 

[Spetz]

If VR4 is not banjo then they must be from an Evo III.
I'll measure the piston to be sure before ordering