Saml01

iTrader: (9)

Ok. I'm sold on the XTSS.

I drive in to much highway traffic and city stop and go to risk a puck clutch. I also like to take off from a stop at less then 1200 rpm, and I need to be able to feather my clutch when approaching stop signs. This thread leads me to believe a puck will destroy the cars street manners and drive-ability. Also the potential for destroying my tranny with it is very disconcerting.

Thanks for all the tips guys.

Saml01

iTrader: (9)

Heres a small follow up question.

Should I go get a OEM throwout bearing?

I heard it is more reliable then the one that comes with the ACT kit.

patsmx5

iTrader: (16)

Timekon or some brand like that makes GOOD bearings. Also FWIW I have a centerforce clutch... In my 86 Isuzu trooper II. Stock clutch went to hell mudriding spinning 33's. Centerforce clutch the pedal is actually lighter (just as Brainy said) yet it's stronger. At low revs the clutch isn't that strong. Kinda like stock. But as the name hints, at higher RPM's the clutch holds very well. If I dump the clutch at 3500 it grabs so damn hard it's crazy. Truck has 70hp, yet it will bark 2nd gear if I want it to. The clutch holds STRONG at high RPMs, basically 3500 and up it's a beast. Below that it's soft. If I didn't have an ACT XT sitting in my room, I'd buy a centerforce clutch for a turbo car. Note: It does kinda suck for low RPM power. It will slip sometimes. Like If I'm in 4L at 1K RPMs, and have the throttle on and the things under a hard *** load, the clutch slips. And if it overheats from slipping it doesn't work at all. But If you keep the revs up it never slips no matter what.

thesnowboarder

iTrader: (15)

Savington's ACT throwout bearing seized upon first startup one his install. Mine has been working fine for about 4k miles now, 2k of which has seen about 9psi of boost.

Saml01

iTrader: (9)

I think ill pick up an OEM piece just in case.

Braineack

iTrader: (62)

I have a Centerforce I in my altima and I see the same thing....the real "gimic" to the Centerforce clutches are the weights on the diaphragm...the higher the RPMS, the more they hold the diaphram down.

Since I never launch the miata hard, I never experienced this...however it would slip with more than 10psi of boost instantly once it got cold. But like i said before, my flywheel had hotspots so I didn't torque it evenly and with a CF or Kevlar disc, that's a no no.

woodc

I have the XT and 6 puck as well...no complaints...

Here are some pics of it FWIW: http://www.hardknockracing.com/galle...miata/20071021

ZX-Tex

iTrader: (15)

Good thread by the way. I have been agonizing between HDG6 and HDSS for my street car and went through all of the same thinking as Sam. Like ACT told me the same thing when I called them, that is "6-puck discs are not for street use, period."

But I bought the HDG6 after reading some past threads and talking to cjernigan who told me basically the same things as written above. Don't be a ***** Most of my driving is not stop and go so I think I'll be OK. I was also concerned about transmission shock but I'll take it easy on the shifting. I want the extra torque capacity if (when) I run my '99 1.8 at 15 psi; I plan to go to at least 12 psi. Accounting for drive train loss, say 15%, and looking at some of the RWHP dyno plots posted here, the motor at that boost level is capable of significantly exceeding the HDSS torque rating.

I am about to pull the trigger on the install as soon as I get the flywheel lightened. Then, time to turn the boost up. The stock clutch slips now at just 7-8 psi. It is frustrating... I have all this power ready to go, and all I have to do is adjust the EBC, but I cannot because of the weak stock clutch

ZX-Tex

iTrader: (15)

Looks like the stock flywheel? How many miles on your clutch? Daily driver?

woodc

Fuji-Racing flywheel The car is 95% track only...so...I have probably 1200 miles or so on it... I did do a good bit of street driving with it after the 99 engine swap so I could get it happy to pass emissions before installing a MS.

Here are a couple pics of the flywheel/pp when I had it out most recently...

http://www.hardknockracing.com/galle...ngine/20080712

iluvspd

I have 8 years (Edit - 70,000 miles) on a Clutchmaster stage 3 Kevlar unit. 15 psi all day long.

It was good until oil seeped into the surface.

Didnt like the centerforce ... seemed to not release quickly @ high rpm's.

Pucked discs always were horrible on the street. Great in a race situation if needed, but they tend to transmit too much driveline stress/on~off swith for street duty.

woodc

Wow! That is interesting... You could not *give* me a kevlar clutch...dealt with one in a Subie back in the day and once you slipped it a little and it got hot...game over until it totally cooled down. Worst clutch ever IMHO.

patsmx5

iTrader: (16)

Anyone else here use a Centerforce in a turbo miata? I'd like to hear some more reviews about them. I hate mine in my truck as the clutch seems to be designed around a turbo car where as my truck needs a clutch with a badass PP all the time, not at just high revs. Hell my powerband is done by 4K in the trooper.

miataspeed1point6

iTrader: (1)

I did some searching for what clutch I should get. It sounded like an ACT zm1-xtss would be perfect. I found some posts saying they don't make this setup. I searched and couldn't find one online. They don't make it?

I'm not sure I want to risk breaking anything with a 6 puck. From the sound of it the HD isn't strong enough for the 15psi in my future. There are no 1.8 flywheels local that I know of.

So what the hell are my choices?

Saml01

iTrader: (9)

Just upgrade to a 1.8 flywheel.

The local autozone sells 1.8 flywheels for like 110 bucks.

Ben

iTrader: (33)

you are a retard if you want to run over 200 whp and don't get a "large" 1.8 clutch.

miataspeed1point6

iTrader: (1)

well every time I turn around someone is saying the 1.6 will hold plenty of power, and the 1.8 setup is just more rotating mass. Then someone else will say the 1.6 is too small go 1.8.

So which one is it? I read almost all the clutch threads here, m.net, cr, rd...seems hardly anyone was happy with the route they took.

The problem with getting a new flywheel is that I have $400 tops to replace the clutch. I'm pretty sure the xtss was $460? No money for a flywheel at that point.

ZX-Tex

iTrader: (15)

Opinions are like ********... everyone has one, and sometimes they stink

patsmx5

iTrader: (16)

True statement of the year.

IMO you're worrying too much. I personally am a power oriented kind of guy. I want to build my car to haul ***. That's my main goal. (that and look stock doing it.) I'm not really not looking for peak throttle response. I'm not gonna worry about "what if my car takes .247 seconds longer to rev from idle to 5K? What will people think!?" That's not me. I'm not concerned with it.

If I'm gonna spend my hard earned money and a considerable amount of time upgrading a part, I'm going to select the one I feel will do the job and do it well. I don't like having parts that are working at their maximum rated capacity. That increases the chance of a failure. It also limits your future upgrade path.

When I selected an intercooler, I put the biggest that would fit. (20x12x3 core). When I built my exhaust 3" was the only tubing I would use. When I purchased fuel injectors I bought 550cc low ohm injectors because I wanted the headroom. When I ported my head I did the best job I knew how to do. When I upgraded my engine management system I skipped all the B.S. and went straight to MS2E. When I bought my clutch/flywheel it was a 1.8 flywheel and ACT Extreme clutch.

Now sure you can argue I could have used a smaller IC and saved a little weight and it might have been a bit cheaper and produced similar IAT's. I might could have built a 2.5" exhaust system and still had good spool and saved some weight there too. I could have bought some 440cc injectors and saved a little money since they would have worked. But that's not me. I could go on a diet and work overtime to makeup for what I sacrificed with my choices and in the end be happier and have a faster car.

Saml01

iTrader: (9)

What do you guys think of the Spec brand of clutches?

Stage 3+ is equivalent to the XTSS in terms of construction and rating, price is the same.

Any better, any worse? Whats the difference between brands? Any feedback on them?