Learn me: Slipping clutch on 2006 Miata

My buddy has a miata that he just bought from somewhere down south (Georgia, I think). he is a bit of a car newb. He want to track / autocross / have fun with this car. He owns a Honda Civic that is his daily driver.

The car is modded a bit. It has a hardtop with "spec miata" clips (not sure what that means). It also has a header and an intake on it. It seems to make good power.

However, when launched aggressively, the clutch slips and stinks pretty bad. To put it in prespective, If I did a launch like that on my 2nd gen RX7, it would NOT slip.

This car will NOT spin the rear tires at all. The clutch just slips. The car is on some falken street tires (not azenis).

To give a bit more back story, the car was modified more than it currently is by the PO. The PO had the original type brakes and suspension back on teh car. The front caliper bolts backed out the other day while my buddy was driving. I helped him fix that, but decided to look over other parts of the car. The rear eccentrics on the rear control arms are out of their "pocket". I am not sure if this is a problem or not. Also, the passenger side rear lower strut mount bolt was not in the entire way. The captive nut was fubar'd. I had to tack the nut in place (It was spinning) and remove the bolt. I then had to find another bolt and hold it in place with 2 screwdrivers like chopsticks.

On to the question....

What would make one of these clutches slip? it supposedly has about 4000 miles on it. The 3 possible scenarios I see are as follows:

1)The clutch is worn out. Replace clutch

2)the clutch has oil on it. Find which seal is leaking and replace seal AND clutch.

3)The clutch has some oily residue left from installation. Clean clutch? Replace clutch?

4)nothing noticeably wrong with clutch.

There is nothing leaking under the car. Is there an inspection panel somewhere on these trans?

Does anybody have a good how to on clutch replacement for these?

Thanks for any help!

Rob R.

5) Wrong throwout bearing(too tall) not letting clutch out all the way, still pull it apart and spend money.

No free play in the pedal.

First thing to check.

In reply to iceracer:

Good call.

If the master cylinder pushrod is adjustable(under the dash), you might try that, you should have something like 1/4" of free travel. Judging by other parts of the car, this thing was simply beaten on by an idiot and needs a new clutch already.

I am gonna try to adjust the pedal first.

After that, I may tell my buddy to have a shop look at it. I don't need a dead car in my garage taking up space!

Thanks everybody!

Rob R.

Update. Adjusted freeplay in clutch pedal. No more slip. However, the take up point is still really high.

Does this indicate a worn clutch and or wrong throwout bearing?

Adjust it more? Is there a vent/drain hole on the bottom of the bellhousing? If so you can look up in there and see the clutch disk between the pressure plate and flywheel, you should be able to see the grooves that are cut in a fresh disk. If its worn to a point of the grooves being gone, its about used up. Asduming it has a regular organic clutch disk.

How about pedal height ? My zx2 manual gives a whole bunch of adjustments . Height is 8.5" on the ZX. Miata would probably be close.

Adjusting the rod only adjusts freeplay. It still disengaged at the end of travel

No inspection places that I can see.