Ok background first:

I worked for a major clutch oem supplier for a year in design and testing. Rob at Hoosier Performance installed the clutch and is letting me stay at his house for free. We will be working for solutions on this problem as I see all modded cars running these heavier clutches will be having these problems.

Ok Now the review:

My old clutch has over 100 passes on it 80 stage 3 + and it was immaculate...like brand new looking...then again i get a lot of wheel spin and not a lot of hooking lol. My flywheel was in such nice shape we didnt have to resurface it at all.

Ok actual install went easy as cake. Rob said the disc fit much better than his spec did and was impressed with the quality. Anyway get it in and start it up and with the pedal on the floor the wheels are spinning like crazy. So we manually bleed the system...take it for a ride and all the gears are hard to engage and reverse clunks...we run a test spec told us to run which is place it in first, clutch pedal to the floor and rev it...if it moves its not disengaging properly. We did this and guess what...it was moving alright.

So we called CM and to our suprise they were there on Sat. They said they had to vacuum bleed the system to make it work so we got out the vacuum bleeder and hooked it up. We used a whole quart of brake fluid on my car today flushing it. We got good pedal feel now but its not disengaging completely.

We are able to hold 25in of mercury in the resivoir without leaking or air bubbles and we spent over 2 hrs rebleeding and checking and i guarantee there is no air in there as my brakes feel better than the day I got the car lol.

Clutch starts engaging about 1/2 inch off the floor and is completely engaged by 2". You can still be slipping the clutch (not fully engaged) and spin the tires it bites soo hard...feels really good tho...it could definately be a daily driver...as mine will be. If u drive it like u do the stocker it will judder and shake off the line. If u slip it more itll leave the line like stock. It was raining here so there was lots o wheel sping today.

Problems are since the clutch doesnt completely disengage i have to drive it like a dumptruck double clutching up shifts and down shifts. Reverse is a kinda pain and I think the synchros are taking a licking. It is IMPOSSIBLE to speed **** i took it up to 6000rpm real slow and went to jam 2nd and all I got was gear and synchro grind. Basically powershifting with any of these HD clutches is out for the time being.

Here are my thoughts as to why:

These cars has never been able to be tested above 6500rpm until a few weeks ago..none of these clutches have been tested for proper release characteristics above 6500 and I think we are finding problems where rob's spec 3+ I think hs springs between his plates are spreading out causing dragging of the disc.

Also robs spec is a dual lever design meaning less pressure meaing the hydraulics dont have it as hard as mine which is a single lever design...robs car will pass the first gear rev test...mine wont as noted above.

But here is the big problem from what I think...the stock hydraulic system SUCKS. A lil birdie told me the cup cars use a corvette master cylinder and have to run a seperate resivour and use SS braided lines...but that is what I heard. BUT...we watched my stock plastic line and quick connects when u push the clutch in...u can watch the line swell and the connector fitting will actually pull back from the tranny housing and u can watch the whole bleeder block rock and move from the pressures...pressure moving lines and blocks means it is not moving the pressure plate...and my clutch is barely not releasing so I feel that line flex is what is causing all our problems with disengagement.

So now I drive like a granny...but I really like the clutch...and hate our stock hydraulic actuator engineer.

Whew,

Dan

 

More bad news

BTW hurry up and get back.

 

yea i wanna race you before you get used to double clutching...muahahaha

 

The clutch master sylinder is what someone told me was our problem, but now you have confirmed it.

 

i feel its more the line between the master and slave more than anything but we definately need to try something

Dan

 

how difficult is this to change? (the line between the master & slave cylinder)

 

looks like wed have to pulls the pcm tray and move the fusebox then itd all be right there...atleast on my redline

Dan

 

thats a pain in the a$$.

 

anyway for steel braided lines to be used as a replacement?? Maybe with a slightly larger ID and less flex in the line might help with the pressure issue. If it's just a line issue of course.

 

Yah its the same on the cobalt.

 

Dan
Check the clip that retains the apply rod into the clutch pedal upright.
I've seen them break and/or loose detent/retention allowing the shaft to engage too far into the pedal, reducing master cyl travel/stroke
It's a bit of a PITA to get access to though...
HTH
Wop

 

It was good to meet you Dan. Nice redline you have and im sure once you get all the kinks worked out, itll be blazing down that strip.


Aaron

 

What i wonder is this car like the LS1 cars where GM actualy put a reducer fitting in the main line to make the tranny slightly smother? Also how hard would it be to replace the line with a better one? I was thingking about getting that clutch but if you still have problems maby i will wait.

 

So basically what your saying is that GM built a bitchin ass motor, and pretty much just half-assed everything else. Hmmm why does that not suprize me?

 

I replaced ALL my components in attempt to fix my car but still no go.

Yes, it is a pita where the clip engages the clutch pedal.

There are issues, gm knows it, they have fixed it on the race cars. We are up to our own to do the "fix".

 

Fast06SS, did you just replace the slave cylinder etc. with another stock one? I am wondering if Earl's or someone has a stainless steel line we could use to replace the crappy plastic ones GM has, and if that would do the trick.

 

YIKES !!

Im gonna try to do some digging on the cup cars . Glad to hear the clutch got in and its driveable . Fun times discovering all the weaknesses is a somewhat new car .I gotta assume that the time of attack Cobalt is running a similar or same master cylinder set up as the cup cars . I wish GM would be more forthcoming about some of the mods like that they have done , rather than just saying its a stock trans with a exedy clutch . You may want to try to contact some of the guys at Mantapart.com . From the looks of their site , they seems to be involved somewhat with the grand am cup cars .

Nice to meet ya at Muncie dude , I can still see that chick humping the trailor

 

You mean SAAB built a kickass motor

 

Just because Saab was the first to use this version of the ECOTEC (in the 2003 9-3) doesnt mean it was THEIR engine.
In fact... it wasnt.
It was developed at GM Opel's Engineering facility in Rüsselsheim Germany by an international consortium of GM Powertrain Engineering divisions.
WopOnTour

 

lol ya ill look that part up in the FSM this week and see if I get a break in finals to check it out. I mean we tried everything to get this thing to work. I mean I can drive it but I am granny shifting and double clutching...just like the FNF lol. We also installed a new slave cylinder included with the CM kit.

Dan

 

Am I The Only On Not Having Problems With The Fx400???????

 

You are having problems, read your own thread!! You said you missed the 1-2 shift a couple of times at the track. That is do to your clutch. A manual noob could shift the 1-2 shift w/o missing it

 

question is, has anyone installed their clutch without changing the throwout, if it works fine at that point then it is definitely a bleed problem....

 

SilverSS/SC
I would take that route.Im sure one of these teams would be able to point everyone to the right path with this problem.Im kinda suprised that one of the cluth builders dont have info on this type of work around our stock cars.

 

very interested in the outcome of the uncovering of this information