This is exciting! I have been chomping at the bit wanting to tell every one about this for the past 2-3 weeks, I was asked to wait but I will explain later. For those that do not want to read my endless rambling here it is in a nutshell;

The stock clutch hose (going from the master to slave clutch cylinder) is rubber and over two feet long . Over two weeks ago mine was replaced with a prototype braided stainless line, and the difference was night and day! The stainless clutch line retails for $59.95 and can be purchased at: RX7.COM (972-530-3335), Alamo Auto Sports (817-860-4300), and many other vendors soon.


Sorry, like most of my post's this is going to be a bit long, but it's a story about how the (IMO) biggest short coming of the EVO has been fixed! It's also cheap and easy, No BS!

Dirk from ACT told us that after testing the clutch disk and pressure plate, they were first-rate materials and very strong. Yet the clutch engagement feels soft/weak and the actual engagement point is difficult to hit accurately, causing everyone to slip the clutch more than they needed/intended too.
While removing the one-way clutch line restrictor helps the engagement it still not right. Replacing the clutch hose with stainless has a far more significant improvement, you really should do both IMO.
The stock EVO has a 2-foot flexing/expanding rubber hose controlling the clutch action! HMMM could that be a problem? Oh you better believe it, I have no doubt this is what is causing most of the clutch frying launches and premature wear problems.

The source of this wonderful fix is unexpected, but let me explain this also. The designer/manufacturer of this stainless clutch line is Ari Yallon of Rotary Performance (RX7.COM), the EVO clutch hose is now part of the Bonez Racing product line. They are an RX7,8 specialty Tuner/component manufacturer and race team. They do not, nor do they have any interest in offering a full line of EVO aftermarket products. For the time being they will sell the clutch line directly (972-530-3335), also Alamo Auto Sports (817-860-4300) has them in stock. I am told that many of the vendors on this forum will also be offering this product soon, probably in the next few days.

Before getting the EVO I was an old FD RX7 tuning/racing hobbyist and have been friends with Ari and Chris of RP for many years. Even though it's a piston engine, because of our friendship they are helping me somewhat with my tuning efforts. Ari was so impressed with the EVO he also went and bought one as his daily driver. RX7.com already offers a stainless clutch line for the RX7 and it is only six inches long, when Ari saw the two-foot clutch hose in the EVO he immediately knew this was a problem. He made a small batch of prototype hoses and asked me to try one on my car.
My car has over 12,000 very hard miles, no drag racing but I have tried to perform fast launches, and like many had mixed results frying the clutch 3-4 times at least. While my clutch has not slipped under power yet it only engaged with significant torque near the very top of the pedal travel. There was some engagement in the middle of the pedal but I was sure that I needed a new clutch very soon.
After installing the Bonez clutch line it now engages hard in the middle of the pedal, it felt like I got a new clutch! While I am sure my clutch has a lot of wear, it is so much easier to engage confidently, I was absolutely thrilled. I even tried several hard/fast launches and hit it every time, even normal starts are so much easier. I figured this hose would help but had no idea what a significant difference it would make, it's an amazing improvement.

Installing the line entails removing the air box, battery, and battery tray. The line end at the master clutch cylinder is jammed way in the corner, so getting a wrench on the fitting is a bit challenging. Beyond that it's a very simple hose swap, thoroughly bleed the system, reinstall the battery and air box, and your done.

I was asked to not mention this product until there was large productions run in stock, they did not want people hounding them while the production run was being made.
Some of you are probably familiar with Rotary Performance (RX7.COM) they are a large, well established, reputable vendor. There is such a significant improvement with this line that they are absolutely positive you will be impressed by the results. Ari told me that if any one is unhappy with it, they will gladly take it back and refund your money. I do not work for them so I don’t know all the details regarding there return policy, but trust me it’s a very reputable company and your not going to want to return it.

Here is a PIC of the stock hose, unfortunately I did not think to get a shot of the new hose. The Bonez hose is an exact replacement with all the same fittings, braided stainless with a clear rubber coating, it's a very nice piece.

 

Oh I also forgot to mention that with the hard line the clutch disengages much better/faster, which also helps with the occasional gear grinding with fast shifts. This should reduce syncro wear because the clutch will disengage faster and more reliably, allowing the syncros to do there job faster and easier.

 

I was going to ask if it helped with the 2nd gear grind... Happens if I miss hitting the floor with the pedal on fast shifts. How does the part fit in the car? No zip ties or anything crazy is there?

 

I think very hard miles doesn't clearly explain the car's usage! How many hours of road racing has your clutch seen? His car has been running hundreds of hard laps at Motorsport Ranch and Texas Motor Speedway. His clutch has been getting a lot of cycles.

 

It's an exact replacement, no fitting issues. I cannot thank Ari enough for comming up with this, it just rocks!
RX7.COM has a great deal of experience designing and manufacturing aftermarket performance parts, they are very good about testing and getting it right before they offer to the general public. This is also why I was asked to wait, so they could do additional test fitting and on road testing.

 

Does this hose work in conjunction with the free mod of removing the solenoid that slows the clutch's engangment?

 

uh a spongie pedal from the line ballooning will still be there with a different clutch, possibly more so with a stiffer pressure plate putting more strain opn the rubber.

 

sounds good, but we still need a stronger pressure plate...
but thanks for sharing the info because this is another good mod that will help us enjoy our evo's better.

 

hmmm, $60 fix or $1200 fix? For people who are just sick of the burnt clutch smell, this seems like a godsent. Just called alamo auto sports, the lines should be in tomorrow.

 

They have been thourghly tested and are in stock ready to ship right now.
You can get it from RP directly or Alamo Auto Sports, Alamo is an EVO Vendor/tunner offering a full line of EVO products. I got the impression that if RP gets enough volume through the EVO vendor's they will stop selling directly. They are not interested in becomming an EVO vender, they manufacter certain products for other cars but do not sell directly, there main focus is Mazda rotary cars.
Any products carrying the Bonez Racing name are designed and manufactured through Rotary performance. Unlike a couple of vendor's on this forum they seem to have healthy, productive relationship with other vendors/manufacturers, they try not to step on each other's toes whenever possible.
Alamo is also doing some extensive development work on the EVO right now, I do not think they are quite ready to release there full product line just yet. I have also worked with them, testing some of there toys for my car, I have some interesting/positive test results with some of there products that I plan to post on soon. Just waiting on those dyno files, Kory?

 

There is no solenoid, just a spring and washer type of restrictor. Yes this will work in conjunction.

 

Let me get this straight. There is nothing wrong w/ the stock clutch parts, rather this heavy-duty wire? Could you elaborate more on the testing of the clutch itself? This all sounds fantastic, just need some clarification for the ignorant. Thanks.

 

We have worked with Ari for years. Replacing the long rubber line sounds like a great idea. He asked me to keep quiet about this for a while too, but I guess the cats out of the bag now. I am sure Mitsu. put the long rubber line in to give a little dampening between the pedal and the clutch.
This new line should improve feedback to the driver, reduce pedal travel requirements, and give a more positive (less mushy) feel. It sounds like it accomplishes just that. The drawbacks might be: increased clutch pedal vibration, and having to adjust the release point a little lower since the hydraulics work more efficiently. To me it's worth it. It's not meant to be a luxury car.

 

I wouldn't go so far as to say that nothing is wrong with the clutch parts. We are familiar with the friction material and it has always tested really good, the pressure plate seems to have adequate clamp load for the torque, and the working range is correct. Still people are frying the EVO clutches and wearing the discs out. But, it doesn't happen to everyone. Something is wrong.
Whether it's the restictor preventing quick enough engagement, the rubber line reducing driver feedback, the gearing being too high, stupid driving, or the clutch parts not being up to the task is up for debate. Solving any of these problems is an improvement.

 

Thanks for the insight. Do you think these new clutch lines would prevent the clutch problems; aside from feel/performance? If so, might as well buy one right now while my clutch is still good. It seems from your post that we still don't know for sure what's wrong w/ the clutch (as opposed to the first post). Thanks.