Zeus

iTrader: (66)

Sorry for the slightly OT Noize...

Dirk,

I NEED a clutch now, but I think I'm looking for something a little bit more than the street disc. What do you have to say about the six puck? Is it sprung? What's are the pucks made of? Will it kill me in stop and go traffic?

Noize

iTrader: (24)

Its really not too heavy at all! For the first day or so, it was really different, but now that I've gotten used to it over a week, I barely notice any pedal change. In fact, I bet if I got into a stock clutch Evo, the pedal effort would feel limp wristed.

Upshifts are very nice, and I'm quite happy now! My original statement about the pedal effort only existed because I drove this car for 25,000 on that crummy factory unit, and when the pedal feel changed, it just took me a few drives to synchronize my left foot and brain again. Buy one, you won't regret it.

Zeus

iTrader: (66)

Noize,

Did you have to adjust your pedal freeplay? I'm not sure if ACT plays with the ratios or not...

Noize

iTrader: (24)

I didn't have to. Everything was gravy with shifting after the break in.

j8

iTrader: (4)

Noize,

I could not agree with you more. I have had the ACT in my car for 10,000 miles. I have had no problems, the car also see's the track at least once a month.

ACTman

iTrader: (5)

First, I would make sure you need more than our street clutch. John Shepherd runs 8's on a street clutch (but I wouldn't recommend trying it). Our 6 puck is good enough for Jeff Hill to run 9's but I wouldn't recommend it for the street unless you really need it. We do not offer a spring center puck disc yet, but in hopefully 2-3 months the tooling will be done for that so at this point all our puck discs are solid. So, let's get technical:

The material we use on our puck discs is a cerametallic (ceramic and metallic) compound that is higher in friction by about 30% over a street disc and very tolerant of heat. In our own dyno testing a couple years ago, the material showed a very consistent coefficient of friction even when it is overheated to the point of melting the material apart. It also proved to be easier on the mating surfaces during the bedding process than our previous material.

Contrary to popular belief (and false advertising) the springs do nothing to give smoother engagment. With aggressive materials like the ceramic we use, a spring center will tend to make chatter worse not better. A properly designed spring center disc will help absorb torsional vibrations which cause the gears to rattle when not under load. The springs are basically designed to quiet down the sound of the gears.

Other benefits and tradeoffs: Another benefit of the springs is to make the splines last longer. Spline life is especially affected on 4 cylinder turbo engines because of the severity of the torsional vibrations. Besides increased chatter, another tradeoff of a spring center disc versus a solid center is that the added weight slows down shifting.

To all clutch shoppers: It is important to ge the right combination of benefits and tradeoffs that suits your needs, whether it is high torque capacity, high abuse tolerance, smooth engagement, pedal feel, quiet operation, or quick shifting. Cost obviously is a factor too, but an expensive clutch is not necessarily better and two clutches that look similar can perform totally different because of materials, internal design and construction.

954DRGSR

iTrader: (2)

HDSS - Noize is this the one with the 2900 lb pressure plate?

ACTman

iTrader: (5)

We only make one plate at this time. They generally start off between 3000 and 3100lb and settle at 2900-3000. We don't use these numbers in our advertising since they are subjective depending on how the tests are done. We prefer to use % of increase in clamp load and maximum torque capacity.

Zeus

iTrader: (66)

What I'm worried about Dirk, is that your street material will not provide the "life" I require. Your street disc appears to have a OEish material that may not last as long as I'd like. However, my OE clutch has lasted 38k now with exactly eight 5-6000rpm slipped drag launches. I added about another 50 or so wheel ft lbs of torque to the equation (well over 300 ft lbs now), and the OE clutch is not liking it. I just refuse to have to swap clutches every year to year and a half on my daily driver. For this reason, I'm researching my options pretty heavily.

ACTman

iTrader: (5)

Our material is first class but I understand your concern. You and I have heard of those people who have burned up the stock EVO clutch in 2 thousand miles. Remember that how long a clutch lasts has everything to do with how it is treated. If you are doing research, I would be glad to have a conversation with you over the phone or email to give you my perspective.

EVOTEXAS

iTrader: (12)

Can you just post your perspective here? How about this scenario:

Street driven Evolution that is taken to the track 5 times a year to have the clutch quickly slipped out (but not dropped) and raced around most of the time it is driven. This Evo has problems knocking into second gear (have to wait a second before it accepts the next gear) so I guess I need something lighter that will disengage faster (puck?). I also want it to last for a good amount of time but most importantly, I don't want to break any gears or differential in my transfer case or transmission (street?).

Thanks!

Noize

iTrader: (24)

IIRC, you and I are pretty similar in the mods department. It sounds like we are also the same in the driving habits department as well. At 27k, my OE disc was almost perfect. The reason I was getting slippage was the fact the pressure plate couldn't hold the torque. I believe that guys like you and I will do well with this clutch, as it will hold our torque, and should last a long while.

If the stars align someday, I want to pick up a much more serious turbocharger and results on the same dyno have shown an add'l 50wtq and 120 more whp. I don't know if this clutch can go _that_ far, but since that't out of the window of its rating, I don't expect it to.

What I do know is that this ACT holds over 300wtq on a Dyno Dynamics, which reads much lower than what most people are accustomed to. My upshifts at ~7500rpm don't feel like butter anymore, they grab and go!

Zeus

iTrader: (66)

Dirk,

akazeus@excite.com Who has time for phone calls anymore ? Really though, I agree that I think everyone would like to hear what you have to say on the issue.

jfh

iTrader: (38)

I am very interested in Dirk sharing his insights about a performance clutch as described above. I have 17k on my stock clutch with mods and driving style very similar to those that Seth has described. No slippage yet, but I have a Quaiffe front LSD on order and plan to replace the clutch during that install.

Vroompsh

iTrader: (5)

i've got the HDSS installed now, great clutch. Much better pedal feel, and the ACT really makes the best of your power/torque. Doesn't require feathering as much as the stock one did. Hats off to ACT. Granted, my mods are just at the bolt on stage but i'm sure it will hold up.

EDIT: i forgot to mention, my stocker started to slip at 17k.