Miata clutch master cylinder

The clutch master cylinder on my 04 MSM looks...different, than the
one for the 97 NA. It has an extra protrusion and uses a banjo bolt to
transition to the flare fitting for the metal piping.

Having looked at the FSM, it appears that there is a restrictor in
there that is designed to keep the clutch from releasing too quickly,
i.e. you push the pedal to the floor, change gears, and no matter how
quickly you take your foot off the clutch, the slave cylinder is only
going to retract so fast.

Hyundai pulled this same stunt on the tiburon and elantra,
contributing to early clutch failure on both models.

Has anyone removed the spring and restrictor from the clutch master
cylinder on an MSM? I'm considering doing it only because the idea of
having the car 'ride' the clutch for me every time I switch gears is
kinda bothersome. So far, I've never gotten less than 100k out of a
clutch, and I would prefer to keep it that way if possible.

Thanks,

Chris

Hal wrote:
> The clutch master cylinder on my 04 MSM looks...different, than the
> one for the 97 NA. It has an extra protrusion and uses a banjo bolt to
> transition to the flare fitting for the metal piping.
>
> Having looked at the FSM, it appears that there is a restrictor in
> there that is designed to keep the clutch from releasing too quickly,
> i.e. you push the pedal to the floor, change gears, and no matter how
> quickly you take your foot off the clutch, the slave cylinder is only
> going to retract so fast.
>
> Hyundai pulled this same stunt on the tiburon and elantra,
> contributing to early clutch failure on both models.
>
> Has anyone removed the spring and restrictor from the clutch master
> cylinder on an MSM? I'm considering doing it only because the idea of
> having the car 'ride' the clutch for me every time I switch gears is
> kinda bothersome. So far, I've never gotten less than 100k out of a
> clutch, and I would prefer to keep it that way if possible.
>
> Thanks,
>
> Chris

I did not know anything about this, but I would appreciate an update on
what you do. I am considering a 2004 MSM as my next Miata if my current
job prospects work out and would like any information like this that is
specific to the MSM.

Pat

In article
>,
Hal > wrote:

> Having looked at the FSM, it appears that there is a restrictor in
> there that is designed to keep the clutch from releasing too quickly,
> i.e. you push the pedal to the floor, change gears, and no matter how
> quickly you take your foot off the clutch, the slave cylinder is only
> going to retract so fast.

I wonder if that's intended to protect the rest of the drivetrain from
brutal shifting? Maybe they were thinking its better to fry the clutch
than to grenade the transmission or differential. Not that a stock MSM
makes all that much more power than a normal Miata--I hardly think
there's significant risk of damage.

--
Lanny Chambers
St. Louis, MO
'94C

>
> I wonder if that's intended to protect the rest of the drivetrain from
> brutal shifting? Maybe they were thinking its better to fry the clutch
> than to grenade the transmission or differential. Not that a stock MSM
> makes all that much more power than a normal Miata--I hardly think
> there's significant risk of damage.
>

I suspect you are correct. But as you noted, 178 hp versus 120hp isn't
that big of a jump, and the 6spd that ships with the MSM supposedly
has shot-peened gears and a better Bosch torque sensing limited slip
differential that even Honda sourced out for the S2000. So being able
to chirp(or maybe a little more...) 2nd gear shouldn't result in a
destroyed drivetrain.

Then again, I could be wrong. But what I don't like is the notion that
on a hard launch the clutch is getting scrubbed a bit each time I
shift. That can't be good for the longevity of the clutch disc.

Chris

Some of the older Mazda vehicles had a similar device. The MPV vans were
one. Seems that on them, it was there to help eliminate clutch shudder.
How they worked was anybody's guess.
"Hal" > wrote in message
...
> >
>> I wonder if that's intended to protect the rest of the drivetrain from
>> brutal shifting? Maybe they were thinking its better to fry the clutch
>> than to grenade the transmission or differential. Not that a stock MSM
>> makes all that much more power than a normal Miata--I hardly think
>> there's significant risk of damage.
>>
>
> I suspect you are correct. But as you noted, 178 hp versus 120hp isn't
> that big of a jump, and the 6spd that ships with the MSM supposedly
> has shot-peened gears and a better Bosch torque sensing limited slip
> differential that even Honda sourced out for the S2000. So being able
> to chirp(or maybe a little more...) 2nd gear shouldn't result in a
> destroyed drivetrain.
>
> Then again, I could be wrong. But what I don't like is the notion that
> on a hard launch the clutch is getting scrubbed a bit each time I
> shift. That can't be good for the longevity of the clutch disc.
>
> Chris

"Hal" > wrote in message news:4a50c90e->
> I suspect you are correct. But as you noted, 178 hp versus 120hp isn't
> that big of a jump, and the 6spd that ships with the MSM supposedly
> has shot-peened gears and a better Bosch torque sensing limited slip
> differential that even Honda sourced out for the S2000. So being able
> to chirp(or maybe a little more...) 2nd gear shouldn't result in a
> destroyed drivetrain.
>
> Then again, I could be wrong. But what I don't like is the notion that
> on a hard launch the clutch is getting scrubbed a bit each time I
> shift. That can't be good for the longevity of the clutch disc.
>
> Chris

Chris, don't make me feel any worse than I already do, the NB has ~142 hp
compared to the ~178 hp of the turbo.

As for Chuck's post referencing clutch shudder, that might be related. I
know that there were several years that the NB had some BAD clutch shudder
problems. Never heard exactly what the fix was.

Chris
99BBB

> Chris, don't make me feel any worse than I already do, the NB has ~142 hp
> compared to the ~178 hp of the turbo.
>

Well....it's still going to outrun an NA, right? :-) FWIW, the MSM
engine is very 'peaky'....the turbo comes on rather late, and the ride
is over before it starts in first and second. It sags
badly....throttle response just plain sucks when you aren't in the
turbo power band. But past that it is a fun ride. As far as overall
comfortable driving goes, my 97 wins, hands-down. On the '97 the power
delivery is much more linear without the turbo 'surge' that the MSM's
have.

> As for Chuck's post referencing clutch shudder, that might be related. I
> know that there were several years that the NB had some BAD clutch shudder
> problems. Never heard exactly what the fix was.

I heard about that, and read a few articles on the subject. I've not
had the problem myself, but I doubt that the clutch master cylinder
would have much to do with it. Usually issues with the drivetrain/
clutch shuddering are related to engine mounting problems or a
contaminated clutch disc....at least in my experience. I went through
that mess with a '67 beetle I owned a long time ago. In that case it
boiled down to bad mounts on the transaxle and insufficient deflection
in the bowden tube.

The workshop manual seems to show that at least in '04, the non-turbo
miatas got the same master cylinder for the clutch as the 97 NA did,
so the master cylinder is probably not the issue.

Best,

Chris