[Sniz]

good news, here, still getting these made by SouthBend?

their Feramics are top notch.

[ETS Michael]

Originally Posted by HPF Chris

All clutch disks except the factory organic disks can weld themselves to lightweight flywheels. It may even be possible to weld an organic if you slip it long enough but I have never seen this occur. The reason the HPF feramic is so popular and "doesn't" exhibit this behavior is because the melting point of the material is so much higher (1200 degrees) than the other clutch disks on the market. The other reason is because it uses a full face clutch surface instead of 4 or 6 pucks taking the entire load of the engine. HOWEVER, even with the HPF Feramic if you take it out without a break-in and do very hard, long, high rpm launches with a lightweight flywheel and very sticky tires it is "remotely" possible to fuse this clutch if you can get enough heat in it. In the past when I have seen fused clutches of any type, I've often (about 50-75% of the time) determined the cause to be that one or two of the pressure plate bolts backed out.

Chris.

Don't get me wrong, I would still run it and I might when our single kit is completed. Not sure what else would hold the power. I would just recommend a steel flywheel.

[dzenno]

Southbend clutches rock...I heard this is a Southbend make as well..

[TheJacka]

Chris,

When will the HPF Charge Pipe w/ BOV be released? The preview tease was over a year ago if I recall correctly.


-

[AYF80]

Going to the Shop in the AM.

[Sniz]

Originally Posted by dzenno

Southbend clutches rock...I heard this is a Southbend make as well..

yup they sure do! my clutchnet red in still holding strong and will see the drag strip for the 1st time tomorrow.

next clutch will be SB for sure. even for my e36 a SB clutch/PP setup will cost a grand.

[Alpina_B3_Lux]

Originally Posted by Alpina_B3_Lux

If you apply your logic to your clutch replacing the stock clutch, wouldn't you also have to replace the stock flywheel at the same time (as it has previously mated to the OEM clutch)? Or would you recommend to at least have the OEM flywheel resanded?

Alpina_B3_Lux

Bump for an answer to that question.

[vasillalov]

Railgun,

All this is correct and I agree with it!

You forget however that the flywheel is attached directly to the crankshaft. The more weight you have in the crankshaft, the more rotational inertia the engine has. Torque is just that: amount of force applied over a length of distance. If you reduce the weight of the flywheel, you are reducing the amount of torque it is exerting on the clutch and the drivetrain components.

P.S.: Ever heard of knife edging the crankshaft?

[dyong]

Originally Posted by Alpina_B3_Lux

If you apply your logic to your clutch replacing the stock clutch, wouldn't you also have to replace the stock flywheel at the same time (as it has previously mated to the OEM clutch)? Or would you recommend to at least have the OEM flywheel resanded?

Alpina_B3_Lux

I would resurface the flywheel for every clutch change. It makes the marriage of both components perfect and smooth.

[jb's335]

Originally Posted by dyong

I would resurface the flywheel for every clutch change. It makes the marriage of both components perfect and smooth.

Is it possible to resurface a dual mass flywheel? Chris did HPF resurface the 135i's FW before installing your clutch?

[vasillalov]

I think I stand corrected! I was confusing angular moment vs angular momentum. Mixing up the two is not difficult.

Torque is angular moment. It is r * F, where r is radius (more properly, displacement vector) and F is force.

Angular momentum is r * p, where p is linear momentum.

Sorry for stirring up the mud.

[XPO186]

Thanks for clarifying things guys! This is really helpful to understand when shopping for a new clutch/flywheel combo.

So it seems like a lwfw would improve responsiveness and make the motor "rev happy" as many ppl have stated. However, there should also be a little bit of a learning curve involved since you're changing shifting characteristics of your car. Might effect daily drivability for some performance benefit that may not carry over well to the street.

[HPF Chris]

Originally Posted by Railgun

It's a bit of an overexaggeration in regards to the shift characteristics. Would they change, yes, but as it translates to not being streetable, I wouldn't say so, however, YMMV.

Where I probably wouldn't mind, you may. Unfortunately in most cases, a change like this is hard to test drive.

The benefits to the heavy factory flywheel is #1) transmission noise elimination, #2) dampening during clutch engagement, #3) launching. A lightweight aluminum flywheel will not change how the clutch engages. You typically see a 20rwhp/20ft-lbs increase in power and torque when dropping 10 lbs off the flywheel. This is that is at "every" rpm, not just peak. The transmission can make a rattle sound at idle and with the AC on can often sound like a diesel truck with a lightweight flywheel. This is normal and doesn't hurt anything. The other disadvantage is heat resistance as the aluminum flywheel can warp under heat and won't dissipate heat as quickly as the dual mass OEM flywheel. The problem with heat is that the clutch disk and pressure plate can get too hot. The pressure plate can lose clamp load under extreme heat and the disk can fuse to the flywheel. Bronze clutches have a much lower melting point and will often fuse to aluminum flywheels if they are pushed too hard. The reason heavier flywheels help launches at the drag strip is because the engine has that extra weight spinning at higher rpms. When the clutch is engaged, this extra rotational inertia helps keep the engine at the higher rpm while getting out of the hole. When you are drag racing and the rpms drop too low, the engine will often bog especially if you have great traction.

In most cases, the factory OEM flywheel will not need to be resurfaced the first time you run an aftermarket clutch such as ours. This is because the OEM organic material creates very little wear on the flywheel. If you've run an aftermarket clutch already, be sure to check the flywheel very closely for grooves and any sign of wear as this wear will increase the break-in time and cause extra wear on the new clutch as it breaks in.

Chris.

[dyezak]

Originally Posted by HPF Chris

That is coming.

HPF has been saying that for 2 years. Quit talking and prove it.

[jippii ensio]

Originally Posted by HPF Chris

The benefits to the heavy factory flywheel is #1) transmission noise elimination, #2) dampening during clutch engagement, #3) launching. A lightweight aluminum flywheel will not change how the clutch engages. You typically see a 20rwhp/20ft-lbs increase in power and torque when dropping 10 lbs off the flywheel. This is that is at "every" rpm, not just peak. The transmission can make a rattle sound at idle and with the AC on can often sound like a diesel truck with a lightweight flywheel. This is normal and doesn't hurt anything. The other disadvantage is heat resistance as the aluminum flywheel can warp under heat and won't dissipate heat as quickly as the dual mass OEM flywheel. The problem with heat is that the clutch disk and pressure plate can get too hot. The pressure plate can lose clamp load under extreme heat and the disk can fuse to the flywheel. Bronze clutches have a much lower melting point and will often fuse to aluminum flywheels if they are pushed too hard. The reason heavier flywheels help launches at the drag strip is because the engine has that extra weight spinning at higher rpms. When the clutch is engaged, this extra rotational inertia helps keep the engine at the higher rpm while getting out of the hole. When you are drag racing and the rpms drop too low, the engine will often bog especially if you have great traction.

In most cases, the factory OEM flywheel will not need to be resurfaced the first time you run an aftermarket clutch such as ours. This is because the OEM organic material creates very little wear on the flywheel. If you've run an aftermarket clutch already, be sure to check the flywheel very closely for grooves and any sign of wear as this wear will increase the break-in time and cause extra wear on the new clutch as it breaks in.

Chris.

Good post.

[HPF Chris]

Originally Posted by Railgun

Well, I wasn't suggesting that how the clutch engages would change, rather how the motor responds to the lighter FW when engaging, especially one that may bite harder. The "feel" will change from the perspective of the driver.

I agree that a street car drag racing, a heavier FW is beneficial. What I wouldn't agree with is the heat issue with an Al FW. As I've mentioned, I've run many track days with my Al FW and never have I had an issue thats been clutch related. I've run with this FW for the last eight years. Pure street driving with the occasional romp would even be less of an issue. The occasional pass down the strip falls in the same bucket...3 shifts and you take a break.

I burnt through 17 clutches in my Supra with about 20-50 passes on each clutch variation before we discovered the Feramic material. The aluminum flywheel was the cause of most of the failures. The clutches would literally get too hot and fuse. This was because of the poor heat dissipation of the flywheel and the flywheel warpage under extreme heat. This was with 500rwhp at the beginning to 800rwhp before I went auto and over 1,000rwhp.

We can run a turbo large enough to make these numbers in the 335i with our turbo kit, but we have a few more parts to make first.

Chris.

Chris.

[ar design]

FWIW, we used to get a lot of our clutches the same place you do, and have welded a number of Ferramic clutches with ease...

[HPF Chris]

Originally Posted by ar design

FWIW, we used to get a lot of our clutches the same place you do, and have welded a number of Ferramic clutches with ease...

The clutch manufacturer that makes our clutches does not sell them to any other company either retail or wholesale. So what you think you are getting is not be what we sell. Even other companies that make clutches have tried to copy ours and they aren't the same. We've even had people call us and complain that our clutch fused only to find out some other company sold them what they thought was the same as an HPF clutch and it wasn't.

We've sold over 500 Supra Feramic clutches and 200 M3 Feramic clutches. With over 100 E46 turbo M3's each making between 600rwhp and 1,000rwhp and over 3 million cummulative miles on them, we've only had one clutch disk fuse and that was in my personal M3. I fused it when I cut a 1.5 60 ft on a brand new disk with a used flywheel. Only 25% of the clutch was in contact. I don't have time to break in clutches and I usually road race. If it was broken in properly it would have never fused, even with 1,000rwhp.

You will not fuse this clutch even if you are pushing 800rwhp+ and coming out of the hole at over 20psi.

Chris.

[JD75]

Originally Posted by HPF Chris

It is perfect for your set up. I'd recommend our stage 2 which has a 2600 lb pressure plate. I also recommend running a factory OEM flywheel for high rpm launches and doing a full 300 mile break-in. The OEM flywheel dissipates heat way better than lightweight flywheels and it also helps you get out of the hole due to the extra weight on the end of the crankshaft. It also resists warping under heat which can often happen with an aluminum flywheel. The longer break-in allows the clutch to mate all the way across the disk. We run these nearly identical clutches full tilt with no break-in on every HPF turbo'd M3. However, if you are going to do high rpm launches with slicks I recommend doing a break-in.

Chris.

Hey Chris,

thanks for the response.

Can you please send me a PM with regards the availability of your "stage 2" clutch kit and pricing.

We pulled the gearbox our today and as we suspected the ACT Street clutch has seen better days.

Lastly can you supply an option on a replacement single mass steel flywheel?

We are looking at having a replacement flywheel machined up locally, however it's going to take several weeks to manufacture.

Cheers,

Justin.

[HPF Chris]

Tim's car is now completed. The HPF clutch now engages at the correct pedal height. There was an error in the machining process on the fulcrum of the pressure plate in the initial design which affected both of the prior installations. The driveability is now perfect along with the correct engagement height. I'll post up some videos shortly.

Chris.

[nafoo]

I see on the website that Stage 1, 2, and 3 are all the same price. Is the only drivability difference between the three stages the amount of pressure it takes to engage the clutch?

I guess my real question is, why get Stage 1 when Stage 3 is the same price?

[HPF Chris]

Originally Posted by nafoo

I see on the website that Stage 1, 2, and 3 are all the same price. Is the only drivability difference between the three stages the amount of pressure it takes to engage the clutch?

I guess my real question is, why get Stage 1 when Stage 3 is the same price?

The pedal effort is a little stiffer for stage 2 and a little stiffer for stage 3. Even the stage 3 pedal effort is modest in my opinion. The engagement for all three stages feels the same. I recommend getting stage 1 for just about everyone. These definitely hold all the power and are the closest to the factory pedal feel. Unless you drag race or have over 700rwhp, the stage 1 will be perfect.

Chris.