Great. Thank you very much for the answer. Looks like I know what I will be doing this weekend now.

 

Ok, I asked this question in another thread but there were no answers, so I will try again. Does the US Evo have the same clutch as either the JDM Evo VII or VIII? If it does have the same clutch have the oversees markets been having the same problems as we have? If it is not the same then why not? Did we get shorted? I they have a different clutch from us that does not have problems then the US Evo owners need to ask for a recall, it is that simple. I don't know if there is a federal organization that we would need to approach, but if we could show that the US market has an inferior product then it may be a place to start. If the oversees market do have the same clutch but are not having problems then we may just be screwed. At least two magazines are running Evo's and one of them is already having clutch slippage issues. Maybe the other car in the "long term test" will have problems in a widely read public syndication thus forcing Mitsubishi to step up to the plate and admit that there is a problem. Lets hope that they pay attention.

 

Did you read this post?

I don't know the answer to your question but it appears they are probably the same. I have read elsewhere on here that VII have some problems, too. It appears at this point that it may be poor breakin of the lining and abuse. I am not trying to step on anyones toes with that comment, but with the information ACT has posted, it doesn't appear that there is a major flaw in either the design or materials of the clutch. At stock level and properly broken in, it should last for a reasonable amount of time. Problem is not many are leaving the car stock and the increased power is going to affect the clutch.

 

I'm still in break-in, so no clutch problems yet.

However; I've noticed that the clutch pedal feel seems rather non-linear, compared to other cars I've owned. On my other cars, both with hydraulic and cable operated clutches, there's a somewhat linear relationship between pedal position and clamping force.

Not so with the EVO. As you release the pedal you get a little drag, a little drag, then BOOM, the clutch is relased (mostly). But this happens below full release travel of the pedal. The temptation is to leave your foot resting there -- which can cause extra slippage and wear on the clutch.

The only car I've had with a similar feel was the twin plate clutch on the Alfa GTV-6 -- and that's the only clutch I've ever worn out. (I still have the factory clutch in the '79 Alfa Spider and the '88 ST-165.)

This non-linear clutch release profile might be contributing to premature clutch wear.

Or perhaps not. Just an initial impression.

A '97 M3 I test-drove had a similar clutch feel. Anyone know if those M3s had clutch issues?

 

The non-linear feel is a result of the fluid restrictor which is there to slow the engagement and like Timz said to protect the drive line from drop launches.

 

The EVO VII has a stronger pressure plate (2600 vs. 2200 on our scales) but uses the same part number for the disc and release bearing the EVO VIII but . I imagine the decrease in clamp load is because of the decrease in torque. The flywheels apear to be the same as well but I haven't confirmed this yet. There is no doubt that the hydraulics and/or linkage are different on the two cars because the geometry of the EVO VII pressure plate is quite a bit different from the EVO VIII.

 

Let me clarify a bit. As you disengage the clutch the flow of fluid colapses the spring and the the fluid goes through the hole and around the outside of the restrictor plate. As you lift your foot off the clutch pedal to engage the clutch, the spring bottoms the restrictor against a shoulder and now the flow can only go through the center hole. Look at the photo again, and imagine how much restriction that is!

 

Perhaps drilling the hole out to make it a bit larger would be a good compromise. Still having the benefits of added safety for the tranny, while giving a bit more bite. This may also keep the disk from slipping and overheating as frequently?

 

Definitely, but how much is too much and how much is just right? I tend to be a control freak. I would rather let my foot tell the clutch how fast to engage and learn what feels right.
Obviously if you side step the clutch pedal at 6000 rpm from a stand still without a restrictor something is going to give. The question is: Will it be clutch? Will it be trans? Will it tires? Differential, axle, rear end?
If it's clutch, we will make you a stronger one and we do it all over again until something else breaks and the clutch holds. Oh, the fun of experimentation! Any volunteers? We will no doubt all applaud your efforts.
Of course we have to duplicate the failure several times to be sure we have consistent results.

 

So my question is:

Should this restrictor be removed?

Will the clutch last longer if removed?

Any warranty concerns if sees it removed??

Will the clutch be a better performing clutch if removed??

Sorry about the questions..
Love the topic, hate the reason for the topic..

I have driven LOTS of cars, and this EVO clutch is so "non-communitative"

Really doesn't let you spped shift or slick it right into gear like the others..

 

Most of the folks that have removed the restrictor like the feel of the clutch afterwards. If your a side stepper I would think this will lead to failure in a big hurry. My regional rep has already voided drivetrain warranty on at least one car. The clutch disk was in severl pieces and the driver admitted to a 6,000 rpm drop launch so....

Not sure if that guy had removed the restrictor.

Removing it will most likely void the warranty, as it was put there for a reason, though it probably could use a redesign or a tsb calling for it's removal if the owner complains about too much slippage.

Thanks again to Dirk! I knew ACT made to notch parts but I had no idea what a the folks at the top were like.. Now I do, and will always favor ACT when they have an applicaiton available...

O.K. gotta go whipe the brown off my nose!

 

I think the answers are pretty obvious.
You will not notice any difference at all if your tendancy is to slowly engage the clutch to begin with. All the restrictor does is make slow engagement mandatory. The problems occur when you apply too much power as you are slowly engaging the clutch (whether that's controlled by the restrictor or not). Simply put, it generates too much heat and creates too much wear. So you have to engage the clutch faster or use less power (or compensate with a performance clutch). Should the restrictor be removed? For spirited driving, I would say yes. For racing, definitely. Mitsu. is expectiing you to take off completely or shift completely before planting the throttle and getting it on boost, not launch or speed shift under full boost (extreme example). They are intentionally preventing you from doing so with the restrictor. Will it void Mitsu warrantee? Most likely, because it allows you to be more abusive on warranteed parts such as the trans instead of non-warranteed parts (clutch). You play, you pay. Don't expect Mitsu to.

 

You must be the one who is waiting on the answer to the sponsorship proposal. Now I see how you work. Thanks for the props. My favorite customer is an educated one. It makes me feel like we earned their business rather than just marketing a product with hype.

 

Nahh no sponsorship request here, though I did mention a while back that I had talked to my regional rep already about doing an aftermarket clutch to see if it would help with the decel noise. He agreed that I could give it a shot... so if you have need for someone on the east coast to tryout a new setup.... I may be able to help.

 

yeah sign me up for an ACT clutch as well