[jpsimon]

Originally Posted by GeorgiaTech335coupe

I won't go on a rant, so I'll just wish you the best of luck!

I know some people have had issues but I know of many more with zero issues. I'll post up my comments after the break-in period

[jpsimon]

Originally Posted by shyestsparks

Yeah, I bought Turkish335's Spec stage 3+ clutch, he had it installed and taken out because it wasn't engaging, he returned it to Spec for inspection, tear down to check, Spec said that there is nothing wrong with the clutch except that one of the adjustment sping was a bit extended, they set it to default and sent it back to him; guess what, it's working beautifully for me, no problems at all. It's the installation.

I bet this is the case more often than not

[Former_Boosted_IS]

Originally Posted by jpsimon

also incase people were wondering.. stock flywheel is 38lbs.. this aluminium one is 15lbs

Uh oh, that is way to light. You are going to have pretty severe chatter on that. Mine is about 8 lbs heavier and there is still chatter at idle. Launching is also going to require a whole lot of rpms.

[robin@epl]

For what it's worth, the problems that we've seen with Spec clutches are due to the retention of the stock SAC (self adjusting clutch) mechanism on the pressure plate. It is designed to keep the engagement point on the pedal the same as the clutch material wears... it's not designed for making power.

This Spec 3+ clutch uses a different pressure plate that removes the SAC feature and is intended for much higher loads. It's a full-faced carbon/metallic clutch that is very manageable and easy to drive. It's a shame that Spec has a bad 'internet reputation', most of the people who comment have never even used the products! We use the 3+ clutch in almost every 500whp+ Audi S4 that we build, it makes perfect sense to use it in this application. Shuddering during engagement is almost 100% due to not breaking the clutch in properly, or reusing a flywheel with deposits or high/low spots on it. These clutches take 750-1000 miles of easy city driving to break in properly and hold the rated power. If installed or broken in improperly, they will *not* perform as advertised.

As for the chatter, it's a matter of personal taste. I enjoy mechanical noises from the cars I drive, it's part of the experience. A BMW straight six is one of the smoothest motors possible... chatter is less pronounced on these cars than say a 60 degree V6 or 4cyl. I don't think you'll be able to hear the gear chatter over jpsimon's exhaust anyway

[jpsimon]

Originally Posted by Former_Boosted_IS

Uh oh, that is way to light. You are going to have pretty severe chatter on that. Mine is about 8 lbs heavier and there is still chatter at idle. Launching is also going to require a whole lot of rpms.

I don't mind!

[SPEC-01]

I thought that I would take some time to make sure that everyone is on the same page when it comes to terms and definitions as well as provide some insight from the perspective of the manufacture.

Terms
Dual-Mass Flywheel (D-M): Dual-mass flywheels, which are comprised of two halves and connected by way of a set of dampening agents (bearings/springs/shims) are intended to reduce NVH on modern automobiles (well actually post 1992 for most BMW applications). Flywheels of this type were originally intended to provide improved drivability, better gas mileage, and a more “luxurious” experience for the driver and passengers.

Chatter: Chatter, which is felt during clutch engagement (pedal release) occurs as a result of several factors. Flywheel flatness, break-in, and proper adjustment of the SAC mechanism play a huge part in having a clutch that performs well and that has as little chatter as possible. It is also worth noting that some disc types will be more prone to chatter than others. For instance, pucked discs, like our stage 3 and 4, will chatter more than full faced discs. This happens due to pucked discs having less usable surface area than full faced units.

Clatter: Clatter (a.k.a. Gear noise/Gear lash) is the sound heard at idle and during high-load/low RPM situations that results from replacing a D-M flywheel with a lighter Single-Mass flywheel. This sound does not evidence any issue with the part or the car but rather results when the dampening associated with the D-M flywheel is removed. This sound originates due to play between the lay-shaft/gear and the main-shaft/gear within the transmission. Again, this does not evidence an issue.

Self-Adjusting Cover (SAC): The stock clutch assembly utilizes a SAC-type pressure-plate which is intended to maintain consistent clutch engagement throughout the life of the clutch. This differs from more conventional non-SAC-type clutches that will evidence wear by way of the engagement point getting higher.

It’s all about Options!
We offer two different variants of our clutch assembly for this application, one using the SAC unit which is intended for use with the stock flywheel and one using our non-SAC pressure-plate and intended for use with our flywheel. We have sold large numbers of both of these kits and have seen great results with both. In fact, as with all the products we manufacture we have a less than 1% return rate on these items.

The SAC unit and DM flywheel are for those that do not want clatter. The non-SAC unit and SM flywheel are intended to provide a higher capacity, higher performance, lighter weight option for those that are not worried about clatter. Offering both means that we can cater to those seeking a more stock-like set-up and those seeking a more performance oriented set-up.

The easiest way to avoid issues when installing any clutch with a dual-mass flywheel is to replace the flywheel. Dual-Mass units are not easily resurfaced and as a result many machine shops will not touch them. At this time the stock DM flywheel is only available through the dealer-network and as you may know it is quite costly.

Which ever option you choose it is important to remember that installation, flywheel flatness, break-in and common sense when choosing the kit that's best for you play a big part in your satisfaction with the product. Should you have any questions about any of our offerings please don't hesitate to contact me at any time. I can be reached by PM, Phone: 800-828-4379 x.109, or email: Jeremy@specclutch.com. Thanks for your time and interest in our products!

[Former_Boosted_IS]

Originally Posted by robin@epl

For what it's worth, the problems that we've seen with Spec clutches are due to the retention of the stock SAC (self adjusting clutch) mechanism on the pressure plate. It is designed to keep the engagement point on the pedal the same as the clutch material wears... it's not designed for making power.

This Spec 3+ clutch uses a different pressure plate that removes the SAC feature and is intended for much higher loads. It's a full-faced carbon/metallic clutch that is very manageable and easy to drive. It's a shame that Spec has a bad 'internet reputation', most of the people who comment have never even used the products! We use the 3+ clutch in almost every 500whp+ Audi S4 that we build, it makes perfect sense to use it in this application. Shuddering during engagement is almost 100% due to not breaking the clutch in properly, or reusing a flywheel with deposits or high/low spots on it. These clutches take 750-1000 miles of easy city driving to break in properly and hold the rated power. If installed or broken in improperly, they will *not* perform as advertised.

As for the chatter, it's a matter of personal taste. I enjoy mechanical noises from the cars I drive, it's part of the experience. A BMW straight six is one of the smoothest motors possible... chatter is less pronounced on these cars than say a 60 degree V6 or 4cyl. I don't think you'll be able to hear the gear chatter over jpsimon's exhaust anyway

Robin, I am not sure you have heard the LWFWs on this car yet. BMW uses the dual mass flywheel to mask the noises from the engine. It may appear smooth, but by no means is it quiet. The DMFW does a lot to reduce the harmonics translated to the drive train. The LWFW will trasmit those engine pulses a lot more and you can feel some of the harmonics more in the lower rpms.

I am not saying that it is not acceptable because I have a LWFW on my car, but going super light as you are does have drawbacks.

[Ironring Racing]

Originally Posted by Former_Boosted_IS

Robin, I am not sure you have heard the LWFWs on this car yet. BMW uses the dual mass flywheel to mask the noises from the engine. It may appear smooth, but by no means is it quiet. The DMFW does a lot to reduce the harmonics translated to the drive train. The LWFW will trasmit those engine pulses a lot more and you can feel some of the harmonics more in the lower rpms.

I am not saying that it is not acceptable because I have a LWFW on my car, but going super light as you are does have drawbacks.

Yes, and those harmonic modes may in fact be significantly increased without the higher order phasing that the DMFW provides, which can heavily stress the components and reduce the lifespan. Less of an issue in a shorter i4, V6, etc engine, but in a long block 6 the danger of damage is higher.

[robin@epl]

Clutch and flywheel assembly showed up this morning!





It should be going together later today and then handed back to jpsimon for his agonizing week of break-in

Can't wait to get some race fuel numbers with the new turbos and clutch soon.

[Mr. 5]

Originally Posted by Former_Boosted_IS

Robin, I am not sure you have heard the LWFWs on this car yet. BMW uses the dual mass flywheel to mask the noises from the engine. It may appear smooth, but by no means is it quiet. The DMFW does a lot to reduce the harmonics translated to the drive train. The LWFW will trasmit those engine pulses a lot more and you can feel some of the harmonics more in the lower rpms.

I am not saying that it is not acceptable because I have a LWFW on my car, but going super light as you are does have drawbacks.

I agree with what you are saying.
I'm happy for jpsimon with the setup because rev matching is going to be awesome, but the chatter is going to be loud.
I went with a single mass flywheel on my previous car and will never do it again.
There were so many people that came up to me asking, "What's wrong with your car? There's something wrong with your car!"
I can hear the chatter right now with my DMF so I can just imagine what it would be like with such a lighter flywheel.
Sprung hub clutches do help but not much.

[Former_Boosted_IS]

Originally Posted by Mr. 5

I agree with what you are saying.
I'm happy for jpsimon with the setup because rev matching is going to be awesome, but the chatter is going to be loud.
I went with a single mass flywheel on my pprevious car and will never do it again.
I can hear the chatter right now with my DMF so I can just imagine what it would be like with such a lighter flywheel.
Sprung hub clutches do help but not much.

Rev matching is absolutely awesome. At speed the car is so much more fun to drive with a lightweight flywheel. The entire driving experience is just hands down superior with a LWFW. The tradeoff is chatter at idle. The sprung hub is not the answer at all. I am not sure if fluid change would help, but I haven't felt the need to try at this point. The other option would be to raise the rpms, but I am not sure if that would throw a code?

I am sure he will shoot videos, so we should get a good idea of the sound. The funny thing is despite some chatter, I don't think I would go back to the DMF on this car. It is so heavy and bulky that it just ruins the driving experience.

[jpsimon]

I'll post up some videos once it's all broken in for folks curious about the sound. I personally am not worried about the sound. I just want a clutch/flywheel combo that performs well. And in the end every little bit of weight reduction, especially on my car, is important so dropping 30lbs is nice

The entire clutch/flywheel shipped box weighs less than the stock flywheel