VR6 Brakes - Piston Surface Area?

[n3p 3]

As per title,

 

Does anyone know the Piston Surface Area of a std VR6? And if possible, the formulae behind it? I think i'm failing in selecting good google keywords!

 

I bought some calipers on a whim and I'm trying to figure out if it's worth putting them on.

 

Cheers,

 

Nick

[fla 9]

circular piston. Area of the face is pi (3.142) x radius squared or pi x diameter squared /4. Is that what you're looking for?

[n3p 3]

Thanks for the reply - that would I guess make sense, so maybe I'm missing out something or asking the wrong question!

 

From trawling the net it appears that:

 

"288mm caliper with 54mm piston has a total area of 2290mm^2"

 

Unless i'm having a stupid moment (and it happens often!), using 54mm as the dia doesn't work with the standard circular area formula. Just wondering how they arrived at 2290mm^2

 

I guess i'm looking for the above using corrado dims (280 with Xmm piston?)

[boost monkey 0]

54² = 2916 mm²

 

divide by 4 = 729mm²

 

multiply by pi = 2290.22

 

or using radius: 27² x pi = 729 x 3.141 = 2289.79mm²

 

:D

[Kevin Bacon 5]

:scratch:

 

I hate maths :lol:

[n3p 3]

Ah! I definitely was having a stupid moment then! Cheers boost, failed to see the "/4" that fla mentioned...d'oh!

 

So can anyone tell me the piston diameter for a VR6 caliper? Or is it 54mm, same as the 288s?

 

I got some porsche 996 4 pot rears I wanted to slap on the front which have yet to arrive (I heard it's a good setup), from what I've read I think the piston sizes are 2x28mm and 2x30mm (will have to check). I'm guessing I only have to take into account 2 of the pistons? (i.e one side) so I've got:

 

28mm area: 616mm^2

30mm area: 707mm^2

 

Which gives me 1323mm^2 overall surface area (Am I doing this right, maybe I take into account all 4 pots to give 2646mm^2?)

 

If the 288s have a similar-ish surface area to the 280s, then that's a significant difference! But how does that translate into real world braking? To me it seems worse...Like I said, I'll have to check the porsche piston sizes once they arrive, I could be basing them on a different caliper but it's still interesting to know.

 

Obviously putting rears on the fronts sparks more debate, i.e. balance and whatnot, but I still need to read up about floating vs fixed calipers, weight, clearance etc.

 

Thanks in advance for any input.

 

Nick

[Kevin Bacon 5]

We've already had a member on here try Porsche rear brakes on the front of his VR6 and from what I can recall, he wasn't terribly happy with results. I think they're a bit on the small side.

 

To give you an idea, the AP Racing CP5200 front brake kit I used on mine had 38.1 and 41.3mm pistons and the pedal felt the same as stock with awesome power.

 

Maybe look at the front calipers from a Boxster?

[KADVR6 0]

:scratch:

 

I hate maths :lol:

 

same here, thought i had gone on the wrong forum for a while lol

 

---------- Post added at 04:26 PM ---------- Previous post was at 04:23 PM ----------

 

to the op, if your looking for a simple but very effective brake upgrade on the front, just use some 288 front callipers with some ferodo ds pads and brembo discs. Job done and wont fry your head with mathematical equations!!

[Kevin Bacon 5]

same here, thought i had gone on the wrong forum for a while lol

 

---------- Post added at 04:26 PM ---------- Previous post was at 04:23 PM ----------

 

to the op, if your looking for a simple but very effective brake upgrade on the front, just use some 288 front callipers with some ferodo ds pads and brembo discs. Job done and wont fry your head with mathematical equations!!

 

Exactly, just use something where all the complicated stuff has already been done for you :D I'm happy to mince about with engines but I never take any chances with brakes and suspension!

[n3p 3]

We've already had a member on here try Porsche rear brakes on the front of his VR6 and from what I can recall, he wasn't terribly happy with results. I think they're a bit on the small side.

To give you an idea, the AP Racing CP5200 front brake kit I used on mine had 38.1 and 41.3mm pistons and the pedal felt the same as stock with awesome power.

Maybe look at the front calipers from a Boxster?

 

Assumed that this may be the case if mine do turn out to have 28mm & 30mm :( Will look into boxster/S fronts and the APs, although they sound huge!

 

to the op, if your looking for a simple but very effective brake upgrade on the front, just use some 288 front callipers with some ferodo ds pads and brembo discs. Job done and wont fry your head with mathematical equations!!

 

Thanks for the advice, will have to start reading the definitive guide although I have been told in the past that if going down that route to go 312 as 288s aren't really worth it? Would it be similar if I got the ferodo/brembo combo on stock 280s?

 

I'm happy to mince about with engines but I never take any chances with brakes and suspension!

 

This is why I'm doing my homework :D

 

Cheers,

 

Nick