Help me pick a clutch...
 

So yesterday I was on my way to get my car dyno'd when my clutch started slipping in fourth or fifth at WOT from 4k rpm. It's about time considering I am putting 12psi through the stock clutch, its held up long enough I think.

The kit will definitely be from ACT. The question is which clutch disc do I want.
The choice is either the HDSS(organic street disc) or the HDG6(sprung 6 puck).

Something to keep in mind. I wont be running more then 15 psi on the setup in my sig.

I have spoken to several people whos opinions I highly value as a first step to deciding.


Braineack said, that he uses the 6 puck sprung and its a bit of getting used to but totally worth it. He had to relearn how to drive, and sometimes it even catches him off guard. He says its funny watching his dad drive.

Savington said, get the 6 puck sprung because if I need the capacity its the one to have. Then he flat out called me a pussy when I said it might be hard to drive in stop and go traffic. Then asked if my mom plans to drive the car. He says in stop and go its not that bad but can be troublesome.

Cjernigan says, if you have to get the HD get the 6 puck badass one. Says puck style is easy to drive and then called me a pussy for not going for one. He believes most people bitch about the puck clutches but have never actually drove one and dont speak from experience. He says its the pressure plate that causes the most trouble with the puck clutches.

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Basically I would like some accounts from those who have a sprung 6 puck.


How do you like it? Big change from a regular organic disc? Problems in stop and go? Would you go back to a regular?


Thanks guys.

talk to paul about his setup. i forget the specs but i know he is happy with it. oh, and it has held 300hp.

It's honestly not that bad. but it does get taking used to. if i didnt have a ACT clutch that engages so low it wouldn't even be a deal in the least. Pussy ;)

The HDSS is rated to 233ftlbs. Even though ACT is rumored/proven to underrate their products, that's too close to the limits at what you'll put down at 15psi for my comfort. Others may disagree.

You should decide whether pedal effort or engagement characteristics are more important.
HDG6 and XTSS both hold same amount of torque... right at 300ftlbs.
I'll be looking at one of those two for my 300whp NB build. I'm gonna have to drive both of them before I decide.

You are right Sam. The matter of 100 bucks also comes into play, and I just dont know if its really worth it if its not that much trouble to have the puck. I also dont mind having a heavy clutch, but id rather have a lighter one. I have sat in a car with an XT and it was quite a bit more effort compared to stock.

I'm curious of other benefits of the puck disc with the weaker pressure plate vs the street disc with the stronger.

No DIRECT experience with a puck clutch, but take this for what it's worth.

Friend of mine had a motor swapped integra. He ran a step up from stock clutch and it started slipping. Well he was pissed his new clutch slipped so he ordered and installed the puck clutch. Well it didn't slip. Problem was it was an on/off switch. Car lost a lot of the driveability and smoothness it had before. Maybe that doesn't matter to you, and over time you'll adapt and somewhat overcome this, but in all seriousness it sucked. You have to be good at rev matching when shifting or you would shake the car and put a hard load on the drivetrain. Plus shifting it fast when driving hard is PURE HELL on everything behind that poor clutch. His stock transmission lasted for 4 weeks. Then one day shifted into 2nd and the transmission exploded.

The clutch in the drivetrain is like a fuse in an electrical system. Bigger is not always better. Now I'll admit I HATE a slipping clutch. But then again I'd rather it slip for half a second when I grab second gear in the 1/8 mile driving 10/10ths then it grab so damn hard that torque loading breaks shit that's behind the clutch. You can be more gentle with a strong PP and stock disk vs a puck setup.

Look at it this way. ACT lets you achieve 300 ft-lbish torque in 2 different ways.

1. High clamp force, lower friction with the SS(organic street disc) in the ZM2-XTSS is rated at 307 ft-lbs.

2. Low clamp force, higher friction with the G6(sprung 6 puck) in the ZM2-HDG6 is rated at 298 ft-lbs for about $130 less than the XTSS.

I have a Spec Stage 2+ clutch I'll be replacing very soon. For a non street driven car I will have gotten barely 3 seasons of track driving on it at about 6-7 events/year which is probably around 25 hours total track time. The 2+ clutch is a Spec standard pressure plate with a high friction Carbon Fiber/Kevlar disc. That would make this clutch a low clamp force, higher friction configuration. I love the clutch. Driveability and grip has been great. I'm just disappointed in it's life span, which has been all track time.

When it was time to decide on a replacement, I was in the dilema of high clamp force, lower friction or low clamp force, higher friction. I had just seen what a low clamp force, higher friction clutch life span was. Additionally the low clamp force, higher friction types of clutch seem universally more cost effective (cheaper).

I have no personal experience with puck clutches. Folks I know of in the SC'd Miata community with 6 puck discs always comment that they would not take that path if they had it to do again. Even ACT advised me to stay away from the 6 puck G6. Their input was too much sacrifice in driveability and chatter in the drive train.

Being a firm believer in "you get what you pay for", I went with the ACT ZM2-XTSS for its high clamp force, lower friction configuration and hopefully longer life span. It should be going in this month.

Check out TurboImport.com for an ACT clutch. I got mine for $225 below retail plus free shipping this spring. They didn't stock it and wouldn't drop ship it, so it took a while to come in and get shipped from their warehouse.

I was a bit worried when i got into savington's car the first time and drove his puck clutch. After a few engagements i had already began to understand how to drive one but still needed some practice. The peddle feel is very close to stock in my opinion. I went with the hd pp with the 6 puck sprung disc as well. It took all of one week to get used to, stop and go traffic is no big deal. Plus now i have an excuse for my gf not to drive me car :D The only downside i can see is the clutch chattering in reverse, people think i dont know how to drive if i let it chatter and if i rev it a bit more people think i dont know how to drive, but who gives a fuck what other people think right?

Dont be a pussy get the 6 puck and be done with it :p

Gotta be nice to your tranny if you do the 6-puck, though. Both tsb and I have blown 5-speeds.

Standard ACT HD is proven to stand up to ~300whp. The 6 puck will grab faster but comes with additional risk of driveline damage. Get whichever one you think fits your driving style better.

I wish there was something between the 2.

I'm keeping the stock flywheel, and love the engagement of my Spec Kevlar disc. I wonder how important gearing plays a role in smooth engagement. I'll be running the 5-spd and 3.6gear. No idea on which Torsen yet (if it matters). I have yet to drive a puck clutch on any car... so I need to... and even though I love Ben... I'm leaning heavily towards the XTSS.

Not sure if a 5 spd + 3.6 + wee T25 is the best combo or not... Hmm, interesting experiment at least.

You're a big dude. The extra pressure won't bother you. Get the standard XT.

<edit> wait, you're going to be running a 1.6 flywheel?

I think I have decided to go ACT HDSS. Won't ever see more than 10 PSI and I want the driveability.

Who has the best prices on them?

typically carolina clutch does.

search honda-tech for their 5% off coupon for prostreetonline.com i think it's (ht-05), and compare the prices.

I run the ZM2-XTSS and haven't had any trouble with it. I think it acts pretty much like the stock clutch, besides it being harder to push, and that goes away quickly. Pretty satisfied with it.

FWIW, I had a Spec stage 3 puck clutch in the Mazdaspeed Protege. It held the power great (stockie wouldn't hold almost 250 ft-lbs), and engagement/drivability wasn't too bad. I wouldn't want to drive it in low-grip conditions though (like slowly pulling out in snow), as it was hard to feather.

My only grip was it would sometimes squeek when engaging. Not sure what that was all about.

prostreeonline is running a sale @ 10% off, but Carolina Clutch is still another 10% lower and has free shipping. I was suprised that the HDSS was higher priced than both the 4 puck and 6 puck.

It's funny, becuase you can buy the disc itself for like $80. It's actually very possible to buy the PP and disc separately and save. It also makes sense as the street disc has a lot more friction material than a pucked.

I like my XT PP and stock disc...rated to like 276 ft-lb...

Easy to drive...grabs nicely. I went and picked it up from carolina clutch since they are local to my parents house back home...small shop, all clutch related stuff. Pretty cool guys.

If I were to do it again, I'd probably go for a XTMM or XTSS, just because it's more of a street car than anything. I don't have issues with a heavy pedal and I do miss feathering the clutch in stop-n-go traffic.

This comes from someone who's driven miatas with the following:

1.6 and 1.8 ACT HD Street
ACT XT Street
ACT XT with 6-puck
Centerforce Dual Friction
Exedy Stage I
F1 stage III (OEM PP and 6-puck)

Gotta say my favorite was actually the Centerforce...felt exactly like stock (actually lighter) yet held my 200tq. Only issue I had was improper torquing of the PP which lead to hot spots, darned carbon composite.

But like I said, I don't even notice I have the 6-puck anymore. Only sometimes when I drive a stock clutch too long and go back to the miata.... you really do hook up like crazy with a pucked disc, it's very fun.

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.

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.

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 ass 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.

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.

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

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.

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

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 pussy :) 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 :vash:

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

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

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.

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.

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.

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?

Just upgrade to a 1.8 flywheel.

The local autozone sells 1.8 flywheels for like 110 bucks.

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

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.

Opinions are like assholes... everyone has one, and sometimes they stink :)

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 ass. 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.

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?

Tilton all the way!!!

expensive.

i don't get spending the extra money for a 1.8 setup, act is rated at 277 for the 1.6, i don't even think there is anyone who is regular on this board making that much torque. it's also simple to drive after like 5 minutes of use, and seemed to get easier after it's fully broken in.

i've also had a centerforce cfdf in my 97 eclipse gst, never really pushed the power envelope in that car as it became my ex's daily, which should tell you something being she was 5'1" and about 100 pounds and she had no problem with it

Which is true.

I guess I will pick up the ZM1-XTMM. I don't track the car (just auto-x) so I highly doubt I will overpower it. Best of all it comes in under budget which lets me replace the slave and the rest of the seals at the same time.

Any thoughts from anyone on the Spec clutches?

I have been reading more and more that the ACT engages very close to the floor, which is obviously very different from the stock. I dont think I would like that.

What other clutches, should I consider?

A lot will tell you that SPEC clutches suck balls. I've got a 1.6 Stage 2 that has seen a greddy turbo at 15psi and now a 2554r based set up at 15psi. All is good. I guess the only negative I found was autocrossing and doing many runs pretty much back to back. The clutch lost the crisp engagement as it got hot. Once it had time to rest and cool it came back. Aside from that it's never slipped, and I really wouldn't call what it was doing slipping ... just getting soft.

I've got a light flywheel as well. Drivability with this combo is sweet, clutch feels like OEM in terms of pedal effort and engagement.

I would recommend SPEC for sure. If I have to pull the transmission off this winter I'm going to replace my stage 2 disk with a stage 3. Just for that little piece of mind.

Low engagement is for people who don't go under the dash and adjust the rod on the pedal.

qft

But all that rod does is introduce more dead area to the pedal.

Think this through Sam. If you can introduce "dead area", what is the other thing you can do...

I dunno man. Last time I played with it, all it did was change freeplay at the top. Meaning it just changed how far the pedal traveled inward you can feel resistance of the slave.

Maybe I just dont remember well enough, but if you say I can adjust it in such a way to make it engage at least half way then I will believe you.

There needs to be a bit of dead pedal. If not, the throwout bearing stays loaded all the time and could fail prematurely. Taken to the extreme, it could hold the pressure plate slightly open and cause slippage.

When I first installed my clutchnet red2x clutch it released on the floor. I adjusted the rod and now it releases almost at stock height and it doesn't slip at 12+psi.

I love my ACT. Very glad I didn't go cheaper. Holds the power and my wife didn't even notice it. But she has huge legs. ;)

^ with replies like that proof better follow soon.

there is two adjustments, one to change at what point the pedal engages the pp, and the other to adjust freeplay at the top. Sounds to me like you never touched the other one. you have to loosen the nut on the rod and physically spin the rod in and out or something like that.

make the rod longer. so so only have to push it so far for it to extend the slave rod faster.

Yeah I have adjusted mine and that is how you do it. Loosen the lock nut, turn the rod, retighten. I think there is a how-to on m.net somwehere. It is just a bitch to crawl under that dash and get to it as it is confined just like most everything else under there.

I've got an ACT 6-puck (unsprung) with a SPEC pressure plate in my GT and like it a fair bit. I do get occasional chatter, and miss the ability to feather it (driving in the snow was... interesting) but it will take all the abuse I can throw at it (6500rpm launch with the flatshift engaged) and still be reasonable to drive every day.

Plus, no one ever asks to borrow the car :bigtu:

sam, the reason I decided to stay away from spec was the construction of it. the spring tabs to be specific, they are poorly designed and have been known to fail and let the spring just out of place. act and the rest doesn't use tabs but rather keep the spring in place with a solid indention. cannot fail.

I am still undecided between act and clutchnet, but either way I go it will be a solid sprung organic disc with the highest rated pressure plate either offers.