They say its good for "110% over stock", which by my calculations should be somewhere around 475 RWTQ.

Can anyone confirm that from experience? I am putting a built shortblock in at the moment, and I am trying to figure out which part of my setup will be the limiting factor on the dyno. Its either going to be the clutch or the DW600's/Walbro 255/stock fuel feed line.

 

not even close. stock tq is like 200 so you are like 220rwtq. I wasn't even up to 400tq with 507 hp on a vortech.

I had a compclutch stage 4 which is the same as the clutchmasters fx400. It overheated after 2 passes on the dragstrip with my 500hp vortech (390tq). The 300 (or stage 3) won't hold near that. I would stay away from them. I thought it was grabby and didn't engage smoothly. I switched to an os giken twin then to carbonetics triple. I think the stage 4 was worse than either of those and didn't hold the power even after 1000 miles of break in. The stage 3 is probably smoother but if it doesn't hold your power then it's no good.

 

Well first of all 110% over stock should be a little more than double, so even if you say stock rwtq is 200 then it should hold 420 rwtq. At least, according to the manufacturer.

I already have the FX300, and I like it. I am just wondering when it's going to start slipping. It's a lot easier to swap it out now while the motor is out, BUT I don't really want to spend $2k on a clutch just for good measure. For that kind of money I will take chance and see what it does on the dyno. I may end up running out of fuel first, in which case the clutch would have been a waste (for the moment). Not to mention I hated the sound of a lightweight flywheel so much that I took it out. So I am not real excited to go to a twin or a triple that includes a flywheel - I would really like to keep the stock dual mass flywheel.

I also only have a 2-3/8" true dual so that may kill some torque as well.

 

Could be a common error in terminology. Are they saying "of" or over?
At any rate, I'd trust binder's experience.

 

Clutch master stuff is rated over stock. So when it says 110% that means 110% over stock.

 

When I spoke with them on the phone about the 400 that's exactly what they told me. It was percent of stock power so 100% means exactly stock. I'm pretty sure the 300 (stage 3) is recommended for bolt ons and NA engines. They told me the 400 would "easily" handle the vortech on my stock block and it didn't. Maybe just cruising and street stuff but if you do any launches at all it will be toast. Dyno might cause some serious wear as well. If it's already in the car I wouldn't replace it just for dyno'ing. I would use it until it fails.

I'm not sure what lightened flywheel you had but when I ran my light flywheel, had the low weight os giken and now the low weight carbonetics I never had any bad noises unless I lugged the engine in a parking lot. Idling or keeping the rpms where they should be while driving I never heard (or hear) any funny noises.

Don't have to spend 2k on a clutch for stock block power but you can't run an NA clutch for FI applications. South bend clutches are great and not too expensive and they have many applications from NA to FI. Select a clutch to hold that power and it will work out just fine. I don't think your 300 will last long if you do any hard driving IMHO.

 

There is no way the FX300 is only rated for 10% more torque than stock. If that was true, then #1 who would buy them, and #2 what the hell would the FX100 and FX200 be rated for (they say 70% over stock)? So you are telling me they make performance clutches that are rated for less than stock power??

#3 I am already way way beyond 220 RWTQ and the FX300 is holding no problem (twin GT2871's at 8-9 psi).

Finally the FX300 is a segmented kevlar disk, which looks identical to this Southbend clutch which is rated at 475 TQ:

http://conceptzperformance.com/Cart/...76.112.112.119

Which is exactly what I estimated the FX300 would hold.

now the question is, how much torque will 2871's make at 14 psi?

And to answer your question I had an ACT Streetlight, which is the heavier of the two, and it made a horrible cementer mixer rattle noise right at 1500 RPM.

 

Sounds like you are asking questions that you know the answers to, then. I'll leave you to it.

 

most hyundai cars look exactly like the luxury cars they copy (lexus, mercedes, etc) but that doesn't make them the same car just like the fact that the kevlar disk "looking" the same on the internet does not make it the same quality as a south bend clutch.

I'm telling you from EXPERIENCE. I'm not just making up theoretical numbers. i had the stage 4 (400) and it didn't hold a vortech so it's unlikely the model below it will.

People that buy them are people with NA bolt ons that the stock clutch won't hold. I also had an ACT clutch with ACT flywheel. Mine made no noise unless I lugged the engine like crap. Normal driving with proper rpms it made no noises.

 

Binder knows his stuff; i highly suggest taking his experience into consideration.

from what i googled just now it offers 110% over oem; some oem 350z clutches have burned out prematurely or havent held up to what they should. Could be binder just had a bad experience but reliability isnt cheap; I suggest looking into a clutch that a few people have had experience with and have good reviews about. The extra 2-300 will be worth it in the end

 

Kevlar will hold just about as much power as ceramic IF IT IS BROKEN IN CORRECTLY. It has a .34 friction coefficient IIRC. Ceramic at .36 where Organic is around .2. Kevlar will go away a little if it is extremely overheated.

Kevlar HAS to be given time to break in without burning or overheating the material, 1000 miles normally. Clamp load plays a big part in how much power the clutch will hold and also if they are using a 240mm disk or 250mm disk. South Bend uses all 250mm Clutch disk in the 350z kits.

South Bend gives you TQ ratings on there kits and doesn't make you guess, Although most of them will hold far more than their rating.

 

The South Bend torque ratings are flywheel torque, not wheel torque correct?

 

That is correct and the correct way to offer it.

 

I think the stage 4 was worse than either of those and didn't hold the power even after 1000 miles of break in.

 

standard terminology is that 100% = same as original, so 110% would be 1.1x original.

Maybe thats too advanced for the general public so 110% meaning 2.1x is used...

either way, unless you have to drop your motor to change your clutch, use what you have for the time being.

If you have to drop your motor, get something rated at 2x your expected trq value.

 

I'm thinking about just having southbend make me a heavier pressure plate, keeping the ClutchMasters kevlar disk and calling it a day.

 

In this case it is undoubtedly the latter - 2.1x - otherwise it would already be slipping! I think the key word here is "over" stock. In fact if you look at the Southbend stage 3 "endurance" (NSK1000-SS-TZ) it has the SS pressure plate and the segmented kevlar disk - it is rated at 575 flywheel torque, which coincidentally is exactly 2.1x the stock torque (274 x 2.1 = 575). So I would say it is pretty much identical to the FX300 in design and thus torque rating. 575 flywheel torque is probably somewhere around 470 rwtq so yeah, its probably going to slip at some point. But if I can boost the pressure plate force ~20% then I should be able to increase the torque capacity ~20% which would be more like 560 rwtq. The pedal is already really light so it shouldn't affect drive-ability too much.

And no, I don't have to drop the motor to change the clutch and I have access to a lift so I'm going to keep a couple grand in my pocket and use what I have for the time being, possibly get a heavier plate.

 

Just because you go over a TQ rating does not mean it's all of sudden going to slip. A lot of quality clutches will hold well over their rated TQ, and there are some that will not hold their rated TQ (Over rated clutches)

I have Kevlar in cars here doing well over 550 to the wheels. Kevlar with the DXD SS plate will actually rate out (on paper) at over 700TQ.

Different companies set their pressure plates and disk up differently, Sometimes the disk need to be thicker/thinner to work correctly with the cover so be careful trying to swap covers with different vendors disks, you could end up with less clamp load or a kit that will not release correctly.

 

again, I highly down a stage 3 will hold 470tq when my metallic stage 4 (rated even higher than the stage 3) didn't hold the 390 tq I threw at it. Haven't heard of anyone else pushing past 400tq with any of those clutches as well. Maybe for a few dyno pulls but with the load on the drag strip or street it will find the weakness in it.

Clamp load will help but it's not a direct correlation like 20% increase in clamp load means 20% more power. Not even close. Also, clamp load does add strength but it will not make up for proper friction material. There are plenty of clutches that offer a light pressure plate that retain significant tq ratings and there are other cheaper clutches that use super heavy pressure plates so they can make claims about holding XX power due to the heavy pressure plate yet they fail below the level of competitors with softer pressure plates.

also, just because SB clutch plate is made from the "same" material as the brand you have doesn't mean it's equal. There are so many blends and designs of kevlar, organic, and metallic friction materials it would be like saying any rubber tire is the same as another rubber tire. So SB could have a far superior friction disk made from similar material.

example: my os giken failed around mid 500 tq. I called them (os giken cali) to see what the deal was. They said it was rated for 500tq with my 1100kg pressure plate. They said without going to a triple disk they could sell me a 1400kg pressure plate and they rate them at 550 tq. So even OS giken only rates a 10% increase in tq for a 27% increase in pressure plate clamp force.

If you are going to waste the time to pull the trans I would just get a complete South bend unit and run their tried and true clutch systems. Every user that has experienced SB clutches has pushed them beyond their ratings and loved them. Save yourself a future headache.

 

interesting, my south bend clutch is rated at 800 ft lbs(feramic full face with ss pressure plate) and is slipping at 600 wheel torque far less then 800 at the flywheel and definitely not far more then the rating.

the paperwork from southbend said 500 miles for the feramic for break in which i did as well prob wont buy one again unless they respond next week with really good customer service im very very disappointed with it.