Need brake caliper specs (piston sizes, etc)

[TypeSH]

What are the piston sizes of the rear calipers on an NSX? Did they change throughout the years (97+ any diff from 91-96?)?

and does the parking/E-brake pull the rear calipers? (checking because acura Legends seem to have a drum/rotor combo where the parking brake actuates the drum rotor while calipers are the main braking unit).

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and if anyone knows, front piston sizes for 91-96 calipers? i think its 40mm and either 34 or 36mm?

and piston sizes for 97+? what exactly was changed for the 97+ front calipers?

 

[DanO]

Originally posted by TypeSH:
does the parking/E-brake pull the rear calipers?

Yes.

Originally posted by TypeSH:
if anyone knows, front piston sizes for 91-96 calipers? i think its 40mm and either 34 or 36mm?

The front piston sizes for the pre 97 cars is: 40 and 36.

[This message has been edited by DanO (edited 10 February 2003).]

 

[TypeSH]

thanks! now anyone know the rear piston size? and if they changed over the years like the front caliper? I know the rear rotor size changed in 97 i believe, but did the piston size or caliper change w/ it?

 

[RyRy210]

Originally posted by TypeSH:
thanks! now anyone know the rear piston size? and if they changed over the years like the front caliper? I know the rear rotor size changed in 97 i believe, but did the piston size or caliper change w/ it?

Yes, 97+ have larger calipers too.



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2001 NSX-T
- Bilstein Shocks
- '02 OEM Wheels

 

[Forums Nazi]

Originally posted by DanO:
The front piston sizes for the pre 97 cars is: 40 and 36.

nsxtasy said in this topic that the front piston sizes for the pre '97 cars are 40 and 34 mm, and they increased to 40 and 36 after that.

 

[TypeSH]

ahh, there we go... umm still the question of rear piston size of pre-97 calipers? and post 97 calipers?

 

[Lud]

Originally posted by Forums Nazi:
nsxtasy said in this topic that the front piston sizes for the pre '97 cars are 40 and 34 mm, and they increased to 40 and 36 after that.

That's what Honda's literature says, but DanO's brakes clearly have 40 and 36 as pictured above and he does not have '97+ calipers.

Has anyone broken down a set of '97 calipers yet?

 

[DanO]

Originally posted by Lud:
That's what Honda's literature says, but DanO's brakes clearly have 40 and 36 as pictured above and he does not have '97+ calipers.

Has anyone broken down a set of '97 calipers yet?

Regarding the front piston size disagreement, one of three possibilities has happened:

1) Honda’s literature has a misprint
2) Someone snuck a set of ‘97+ calipers on my ’92 without my knowledge (I’ve owned the car since ’96)
3) The “36” stamping on the piston is a misstamp

I’m going with #1 and can verify #3 this afternoon. Regarding the rear piston size, there was quite a discussion on the nsx-tech mailing lists somewhere back in '98-'99 and I think someone finally took off their rear caliper and measured the piston and reported back to the list—-but I can’t remember the results. If someone has those list emails archived they may be able to do a search and find the answer.

Conventional wisdom is that the rear piston diameter did not change in ’97 but I have not seen any physical proof to verify. It is my understanding that the rear caliper is the exact same in all years, only the bracket and rotor are different sizes in '97+

DanO

 

[Forums Nazi]

Do I get credit for finding an error by nsxtasy?

 

[nsxtasy]

Originally posted by Forums Nazi:
Do I get credit for finding an error by nsxtasy?

Well, if it's information that came from the FAQ, it's not my error, it's...

Originally posted by DanO:
Regarding the rear piston size, there was quite a discussion on the nsx-tech mailing lists somewhere back in '98-'99 and I think someone finally took off their rear caliper and measured the piston and reported back to the list—-but I can’t remember the results. If someone has those list emails archived they may be able to do a search and find the answer.

I did a search on the tech list e-mails (how's that, Mr. Forums Nazi?

) on all tech list digests (all years) with the words "brake", "piston", "diameter", and "mm", and did not find the answer there. However, I did find DanO asking the question on two occasions:

Date: Thu, 6 Jan 2000 14:09:39 -0500
From: DanO
Subject: [NSX-TECH] Re: NSX Brake piston diameters?

>Does anyone know the piston sizes for the OEM front and rear brake rotors?

Front caliper, 40mm and 36mm. I don't know what the rears are?? I have
some pictures of the front brakes that show the pistons at http://www.danoland.com/nsxgarage/brakes/overhaul/overhaul.htm

Date: Tue, 9 Jan 2001 13:11:25 -0500
From: DanO
Subject: Re: [NSX-TECH] Celebrity Deathmatch!

>EACH OEM front: 40 and 36 mm pistons ("Wow, that's odd," you say??) Total
area: pi x 20mm^2 + pi x 18mm^2 = 2274.5 mm^2

Sounds right for the pre '97 cars. I think the piston size(s) changed in
'97 for the fronts. I have no idea what the rear piston diameter is, and
I've looked through the service manual for this number a few times.
Interesting point, in the FAQ
(http://www.nsxprime.com/FAQ/General/changesbyyear.htm#1997) it says "Front
caliper pistons went from 40mm and 34mm to 40mm and 36mm" but my '92 has
piston sizes 40mm and 36mm
(http://www.danoland.com/nsxgarage/brakes/overhaul/overhaul.htm). So, I
don't really know what the 97+ cars have for piston diameter, maybe someone
out there knows the answer?
DanO

 

[Larry Bastanza]

Guys,

FYI, I just checked the 1991-1992 parts book on-line and the smaller piston is 36mm, Sounds like it has been the same all the time.

Maybe very early NSX's had 34mm pistons, not really in the US??

HTH,
LarryB

 

[nsxtasy]

Originally posted by Larry Bastanza:
Maybe very early NSX's had 34mm pistons, not really in the US??

I really, really doubt it. Most of the major systems were the same for all markets and did not change in the first few years of the car.