Just wondering what clutch/flywheel setup you guys are running. I'm currently on the AA LTW flywheel/Centerforce clutch.

I'm thinking about switching to another clutch, not sure what though.

Any ideas? What clutches are you guys on? Thanks in advance.

I am currently using the AA High Performance Clutch Kit.

There's another company called SPEC Clutches. This brand is more common on domestic cars though and I dont know of any BMW that has it but they do have clutch kits that are very cheap and come in different stages. Here is the description;

Stage 1 kit - High clamp pressure plate, steel-backed woven organic disk, bearings and tool. 350ft.lbs torque capacity. MSRP $549.00

Stage 2 kit - High clamp pressure plate, segmented chatter-free Kevlar disc, bearings and tool. 425ft.lbs torque capacity. MSRP $609.00

Stage 3 kit - High-clamp pressure plate, 3-piece disc with carbon or ceramic material, bearings and a tool. ULTIMATE STREET/STRIP CLUTCH! Sharp but smooth engagement with light pedal. 500ft lbs. torque capacity. MSRP $639.00

Stage 4 kit - High-clamp pressure plate, 2-piece rigid disc, bearings and a tool. Available in 3 or 6 wing design for serious road racing and drag racing. 500ft.lbs torque capacity. MSRP $659.00.

Originally posted by LY95
Just wondering what clutch/flywheel setup you guys are running. I'm currently on the AA LTW flywheel/Centerforce clutch.

I'm thinking about switching to another clutch, not sure what though.

Any ideas? What clutches are you guys on? Thanks in advance.

right about 730ftlbs/+same hp rating
custom modded

I'll be running a custom flywheel/clutch combination very shortly... it'll be made of chrome-moly and should hold up to the power. I'll have more info shortly...

great thread.. I, myself, is in the market for one:)

Jon -


would that stage III clutch be good enough for stage II AA guys? What exactly is the difference b/w stage II and stage III clutch?

How streetable is the stage III clutch? I drive in heavy stop-n-go traffic...I swear my left thigh is larger than my right one now with AA's setup ...

Also, how will those clutches work in conjunction with ltw flywheels?

I need a new clutch as well :(

I wasn't looking forward to spending $1g's on AA's setup again ...

what about the centerforce clutch?

Also, how good is the e34 M5's clutch ... how much power can that one hold?

What about the e39 M5's clutch?

I've installed 2 stage 2 SPEC clutches, one in a customers car and one in my own car. The pedal pressure is as light, maybe even lighter than stock. It drives like the stock clutch did. Myself and the customer are very satisfied.

NoSoup4U-

I personally dont know anyone with a FI BMW that has a SPEC clutch installed. Drifto is actually the first person that I know that has a SPEC clutch on a BMW but doesnt have forced induction.

The StageIII Spec Clutch is good enough for the Stage 2 AA turbo kits. The difference that I can tell from the stage II and stage III clutch kits is that the clutch disc is different.

Cant say for sure if the SPEC clutch is compatiable with all lightweight flywheels.

I dont think the centerforce, the E34 and E39 M5 clutch kits wont be enough for the power of the AA Stage 2 turbo kit.

I'll be adding SPEC clutches to the MPerformance website tomorrow so check it out this weekend for prices.

Thanks Jon -

I checked out your website. Nice! I'll look forward to this weekend. Have you been able to dyno the UUC pulley's? As you might know, there's a huge controversy ongoing with these things. Any worthwhile gains for $180.00?

This an AA Stg2 clutch after a little 400+/400+ rwhp/tq abuse:

This is my current clutch:

I rode in ///MCubed's M3 last December when he had the AA High Performance Clutch on his vehicle and I was shocked to see that the clutch was slipping at WOT on 4th and 5th gear!

That was insane. Because of that slipping clutch I didnt get to experience the real power of the Great White. :(

He later told me that this was the same clutch on his pervious Stage 2 Turbo M3 so it was a "used" clutch that has been severly abused.

This is what I currently use on my car it feel a bit heavy especially when you press and hold the clutch down when in gear so I dont anyway when Im at idle.

Sometimes I also get a slight shudder when Im going up a slight grade from a complete stop. Like driving up a parking garage and have to stop and then move forward again.

There is no slip hold up at the 1/4 track fine but then again Im not running the Big power.. :)

im using the UUC stage 2 11lb flywheel with the e39 m5 clutch and it works fine and holds up to the power, IF my upcoming Turbo upgrades make it slip then I will be looking into the SPEC clutches that Jon offers.

Here are pictures of the different stage kits offered by SPEC Clutch. I dont know if these pics are the same ones that are used for the BMW models... especially on the M3 lineup. http://www.speclutches.com/products.html

Kaliboy,
I saw you and your car at Bimmerfest. Wanted to say whats up but I was so dead tired from lack of sleep! I was shocked to see that fat lip on your rear wheels though.

Jon, no worries, there will always be a next time!!!

Rob at UUC has said the M5 clutch will hold over 400/400 no problem. He had one on his turbo M5 with something like 450/450 and had no issues.

Eventually, I'll be switching to the UUC Stage2 flywheel and M5 Clutch.

I don't have any problems holding 14psi with the 3 clutch setups I've tried. But at higher boost is where other clutches start falling off/dying and where good combos will pull strong.

My current setup has AA's 3 puck, stock fly, AA pressure plate (still awaiting reimbursement for the last setup that failed which was an AA pressure plate, TMS fly, and AA stage 2 clutch).

I would safely say that turbo clutch combos are different from SC clutch combos hence the topic heading. But even most turbo clutch combos are good for 400 at the wheels.

EMC,

Not totally sure about the E39 M5 clutch. I know a customer who tracked his mildly stock E39 M5 at Road Atlanta and roasted the clutch and flywheel after a few DE events. After a new flywheel and clutch was installed, he came back to the dealer with warped rotors. They were literally blue and purple just like how his old flywheel was.

I may be lucky or something but I've got like nearly 20k miles on my AA high performance clutch that uses the OE disc and red SACHs pressure plate; this includes like 12+ track days (probably over 1000+mi worth), a few drag strip days and tons of <15psi boosting on the roads. It's still strong and I've yet to notice it slip anywhere, knock on head! :D

Torque Capacity - 425 ft/lb --

Jon -

thanks for posting the prices on your website. There's a pretty big difference b/w the stage II's and stage III's price. The stage II is rated for 425 ft/lbs of torque. Is this ACTUAL Torque generated or crank torque?

If it is ACTUAL torque, do you think if a person is around 400 ft*lbs of torque, that stage II is adequate, or is that cutting it to close?

Thanks!

NoSoup4U,

I have to call SPEC Clutches on Monday and ask if the torque capacity ratings on their website is at the crank or to the wheels. The mustang websites have big numbers like 400rwhp for like a stage I and 475rwhp for a stage II.

I may also just get one of the pressure plates and find a place to figure out how much clamping force they have. AA Tuning's Pressure plate is like 66% more clamping force than OEM spec.

Drifto,
Do you remember if the clutch disc is sprung hub style?

Originally posted by Jon Caldito
AA Tuning's Pressure plate is like 66% more clamping force than OEM spec.


I had my stock pressure plate checked (used, 40k mi--although dunno how much actual force deteriorates at this mileage, if at all):
and it was 1669-lb of clamping force.

The red AA/Sachs one I got tested 2608-lb, new. That's 56.3% gain in clamping force over stock for me at least. :D

I think I'm going to try the SPEC clutch. The price seems reasonable(Jon, hopefully with your help), and it appears it can handle the power I'm putting down.

When it comes time to swap it out, I'll be sure to contact you for this clutch setup. Thanks Jon.

Can one of you experienced guys recommend the best clutch for my setup. Standard 50000 mile clutch slips like a dog as soon as I hit it in 3rd gear. Especially if I change quick. Need to make a decision while my machine is off the road. If you could suggest the most economical choice based on the fact that I am planning to increase boost to 12 psi. Currently producing 337HP at wheels on 9.5psi.
Thanks
GB

I think torque is the killer on clutches and not necessarily rwhp. (someone correct me if I'm wrong). So, your torque numbers would also be needed.

LY - I think I'm closer to replacing mine than yours :(

Jon -

Any word?

P.S. -- does anyone remember what Rob Levinson had on his car when it was a turbo??

Thanks
My Torque peaks at 283.5 around 5200rpm.
HP peaks at 337 around 6500 rpm
Any suggestions regarding suggested clutch?

NoSoup4U,

Sorry about the late response. SPEC said that they advertised their torque capacity at the flywheel but they are conservative enough to be wheel numbers.

Gday mm8,
An AA Tuning High Performance Clutch kit or SPEC Stage 2 Clutch kit is what I recommend. I also think you should look into getting a Lightweight flywheel for your setup.

I am using an M5 clutch that Centerforce modified because of the increase in power.
It is new so I don't have a idea of the life expectancy yet.
I'm doing a DE with the RTR Porsche Club at Pocono Raceway on Memorial Day weekend so I'll get a chance to beat on it a bit then.
I hope it holds up to the abuse.

>>Thanks
My Torque peaks at 283.5 around 5200rpm.
HP peaks at 337 around 6500 rpm
Any suggestions regarding suggested clutch?<<

Gday, those are similar numbers to mine. In your sig line, you say that youre making 9.5 psi in your RMS stage II setup. What Im curious about is, since you have an aftercooler, Im guessing the 9.5 psi is what you measure off a boost line off the manifold. Since the intercooler probably eats at least 1.5 psi across the core, are you really running more like 11 psi gross?

Gday Paul.
I guess the question I have is what size is my crank pulley and S/C pulley compared to yours to be sure regarding comparisons. Yes I am measuring boost from the intake manifold after the cooler. Can you measure the outside diameter of both your pulleys and I will do the same? Particularly what is the outside diameter of your crankshaft pulley? I am trying to buy a 6" one and I don't wish to make a mistake. The 6" doesn't mean that it is exactly 6" outside diameter across the front of the pulley does it? Please measure yours and let me know.

bump

pm paul .. he might have forgot this thread.

Sorry guys. I think I skipped this thread a few days cause its subject says turbos, and I usually concentrate on SCs, although I always check the turbo threads too. So I dont know why I skipped this one. Anyway, Im back, and we can continue our discussion.

Gday, my Crank pulley measures 6" across, and my SC pulley measures 3.125" across, and I believe I have the V1 Vortech. Now I think we can see why we're making different boost: Since you are at 9.5psi after the intercooler, you were probably making near the same as me, ie, 11 psi, before the core. I have water/methanol injection; you have an aftercooler. Hence, we produce very similar dynojet numbers. Id expect nothing less.

>>The 6" doesn't mean that it is exactly 6" outside diameter across the front of the pulley does it?<<

Well, it does on mine... Since were making the same gross boost, I assumed you also had the 6" crank pulley. Since I sourced mine from rms, I naturally assumed this was the size he uses on his Stage II systems, of which you have one. How else do you get to a gross of near 11 psi?

What kind of 'custom ecu' do you have? Did you get someone beside Osh to do it for you? The only thing on mine that Id change, maybe, was to add and intercooler, if it could be done inexpensively, and well. Although, with the water/methanol injection, Im not sure how much more benefit Id derive. Which is why Ive stayed put for over a year with this setup. Thats unusual for me, but, things have been running so well that I dont like to tempt fate, if you know what I mean.

Paul,
I also would like to figure what the difference is in our systems. My S/C is V2SQ. I believe my crank pulley is approx 5.5" dia. The car is at a shop right now so I can't confirm. I will measure both pulleys accurately on Friday and get back to you on the pulley sizes for accurate comparison. The Intercooler obviously does make a difference to my boost guage numbers. I have also purchased the Aquamist setup and am planning to install it as well, so I can run higher boost safely.
My software is Carls effort at AA. He installed a removable chip in my ECU so that I can revert it from S/C software back to N/A just by swapping the chips out. Not the usual way it is done with my ECU but was how I wanted it. Useful if I want to sell the setup separate to the car later. Once I am ready to do the Aquamist install I would appreciate your advice re setup. What are you using for your water/meth tank? Is the tank higher than the pump?
Thanks

Hi Gday,

>>My software is Carls effort at AA. He installed a removable chip in my ECU so that I can revert it from S/C software back to N/A just by swapping the chips out.<<

Thats interesting. I was talking to Karl about doing the same thing. I sent him the afr curve from my dyno run last year. When he saw it, the thought he could lean it out a little where its running very rich in the upper middle, but he didnt think it would get me that much more power. So I left it alone. Do you have a dyno pull and afr plot for me to look at? If so, can you email it to me, or post it here?

Im bought my aquamist kit from AA, so IM running their 2 gallon tank in the trunk, and I have a 50-50 distilled water and methanol mixture back there.

Re pulley size, if 6" crank pulley and 5.125 SC pulley gets me to 11 psi, and youre running a 5.5" crank pulley, then youd have to be running a SC pulley something like 2.93, or even a little smaller, assuming that without your intercooler, youd be at 11 psi also.

Ive thought about trying the rms aftercooler in my car, but for $3200 or whatever it costs, Im not sure how much it would get me. I think we're running pretty similar numbers, me with my water injection, and you with your aftercooler, so Ill probably just hang on to my money for now, until Im convinced the payback will be substantive. Also, I wont give up my traction control throttlebody like Id have to. Besides, Id rather have an air to air unit, but Id still have to be convinced...And, it would also help if I knew someone else who did it, and what they got from it, before and after. There are still so relatively few of us FI M3 guys, that sometimes its hard to find a good representation of different configs out there to learn from.

What do you guys think of Centerforce clutches?

My car is at evosport right now.

I've been using the red Sachs pressure plate/OE disc setup from AA, and just pulled it off the other day because my tranny had to come out (something let loose). I thought the disc would be worn (we're talking OE M3 disc here, folks, handling 320-400whp!) and it was fine...after 20k miles!! this includes some 4-5 days drag racing/ a few days radar gun testing, and lots of track time, as some of you already know.
Sure, I don't slip the clutch in first gear (maybe once every few weeks) to launch the car hard off the line like most people do, but I was still impressed with how long it's been lasting. Since it's already off I'm putting another new one in to buy me some time. But it just goes to show if you've got a good pressure plate you can have a long lasting OE disc with lots of power, too! :)

that's pretty good news to hear about the stock clutch.

I ended up going with Rogue's solution as well as with the red pressure plate as well in anticipation of FI.

I'm just hoping that my amatuer stick shift skills won't kill a clutch as fast as a seasoned manual stick shift FI driver.

nice thread here guys, keep it going.

I spoke with one of my friend's, whom I graduated with from UVA Law School(he has a built 944 Turbo with a K27/6). He's running a little over 400 to the wheels on a Centerforce clutch.

He basically told me the clutch is one of the best if the works on the car. He told me that it tends to fail on some cars, and works like a champ on others. Overall, he said he would pick Centerforce over any other brand name performance clutch, only because it has been proven to hold tremendous torque numbers. The only risk is, if it works right on your car and doesn't malfunction or cause other problems. He said the clutch comes with "weights" on the actual pressure plate? Anybody know what this means or the purpose for using weights on the plate?

Anybody have any experience with Centerforce Clutches or heard of any cars running them?

I'm currently on the AA LTW flywheel/Centerforce clutch.

LY, I think you answered your own question when you started this thread :dunno ...

P.S. LY do you have any pics of your car? I'd love to see them so I know what M3 to stay away from in MD

The weights are there to increase clamping force, as the weights spin faster they (through centrifugal force) try to move "out", the clutch is designed in such a way that this outward force is partially converted into clamping force.... The beauty is they can have a higher 'useful' clamping force w/o requiring you to be a worldcalss squatter:)

I thought Centerforce didnt have an application in which the pressure plate has the weights for BMW?!?!

Originally posted by 96technoM3
LY, I think you answered your own question when you started this thread :dunno ...

P.S. LY do you have any pics of your car? I'd love to see them so I know what M3 to stay away from in MD


Sorry for the confusion here. I meant to say I'm on AA's Flywheel and AA's Clutch, but am thinking about going to Centerforce(don't know what stage yet).

That may be true Jon, I was just explaining their purpose. :)

Jon Caldito,
Will the Spec stage 2 clutch handle a bit of a beating re launches etc with 350-360 WHP and 290-300 torque?
Does it suit the AA LFW?
Will the pedal be heavier or lighter than stock?
What's the best price you can do one for me?
Why is the Stage 3 cheaper than Stage 2?
(My stock clutch slips in third gear.)
Gordon

can any of you guys verify this .. i heard from someone in the business that the aa turbo clutch kit .. is basically a sach's sport clutch kit .. liek the pressure plate and stuff ?

I've decided to go with a AA LWF and Sachs Stage 2 clutch. I'll let you know how it is once installed. Anyone know whether the clutch pedal position will change with this setup. Do I need a different fork?
Regards
Gordon