Switched to RAM dual-disc clutch, some questions
 

All,

I just switched to a RAM dual-disc clutch with a hydraulic bearing. I made various measurements and will write these up shortly. Old fork and old slave (clean fluid coming out) both seemed OK.

Anyway - filled up the transmission with the Castrol M-Series BMW oil per latest advice on same, and put everything back together. All good.

Clutch engagement is as expected - quite high - but not a problem. Pedal effort is about the same, and feels "certain", meaning I feel that there is a clean engagement and disengagement.

Rounding it off, hat tip to Jerry at Jerry's Gaskets for all of his help. Supplied kit included the flywheel from Jerry also. So, new flywheel, new dual disc clutch setup, new hydraulic slave bearing throwout (push spring in). This coming from OE dual mass flywheel for info.

Questions if anyone can help.

1. I've driven reasonably sedately to break in clutch to new flywheel.
Smell of burning clutch, not severe, but certainly there.
I cannot find if this is expected on a new flywheel mating surface, and I think it is (so far only 120 miles), but if not would be good to know.

2. When I put everything back together, started up, very little noise. Slight chatter, which was expected, and good.
Funnily enough, this week (it is colder), started the car up and a real metallic tick-tick-tick with clutch engaged. Push my foot on clutch pedal, disengage, ticking goes away. Foot off, clutch re-engages, ticking again... and rises with revs. This at idle or in gear.
Drive for less than 1 mile / 2-3 minutes, sound goes away completely - back to slight chatter (chatter / slight "scrape" noise).
Clutch disengages (no problem shifting) and feels very engaged.
It seems like after it "warms up" the ticking sound disappears. Ticking does not appear whatsoever until everything back cold again...

3. I believe this is symptom of no-longer having the DM, but I do get more noise through the transmission on any throttle. Does not sound bad, no bad vibration, just more noise.
I have read that this may be normal, but again just double-checking.

Any input appreciated, thanks!

Steve

Re: Switched to RAM dual-disc clutch, some questions
 

Steve is the engagement high as in when starting from a stop.. you are letting the pedal out almost fully before it engages?

Re: Switched to RAM dual-disc clutch, some questions
 

Mike - no, the engagement is gradual enough, just high on the pedal. Hard to recall, but with the OE fork/throwout, I'd reckon on the bite around half to two-thirds high, full bitten in by 3/4 to 4/5, and last inch or so of pedal fully released no difference... with this, bite doesn't kick-in until around 2/3 to 3/4, and is full bite is at around 7/8 or even 15/16 (ever so light tap on clutch you can feel disengagement...) ... So in short, "full bite" seems to be 3/4 (stock) vs. 7/8 (this), just from my own personal observation.

Anyway, it works well, just the questions above :-)

Re: Switched to RAM dual-disc clutch, some questions
 

I was just thinking.. and I need to sit and try and think it through lol just at work atm but Since its an adjustable bearing.. setting it up with different shims should let the clutch engage at different points ie move the engagement point slightly. As you know Im no expert on the hydraulic setup just speaking my mind. I have had 3 clutches done in the past.. one centerforce on my lt1 car, then the McLeod street twin and a setup on my m3.. ive never had any clutch burning smell.

Have you tried upping a gear at a low speed and giving a bit of throttle to see if it would slip? that clutch has a ton of holding power.

Re: Switched to RAM dual-disc clutch, some questions
 

Mike - it's currently seated without any shims, all measurements confirmed this ... as did the final fitting. With the bearing fully retracted, there's 0.150-0.200" of space between the bearing face and the springs, with it fully engaged it pushes the springs in, and clearly dis-engages the clutch. This was tested before I bolted everything together: put the transmission in 4th (1:1 ratio, btw) and clutch pedal out (clutch engaged), I could not turn the driveshaft by hand... clutch pedal in, everything disengaged, still in 4th, I could turn the driveshaft by hand.

I drilled a 1.5" window in the bell-housing (necessary to easily adjust the bearing onto its guide) and can visually see the engagement/dis-engagement too.

So, the high pedal is itself just how it is. You can buy a pedal adjuster which can move whereabouts in the pedal it bites, but I'm fine with it as-is.

Re: Switched to RAM dual-disc clutch, some questions
 

I've had the same experiences with the Ram DD I installed a few months ago. The ZF gear rattle became to much to live with so I'm replacing the aluminum FW with a heavier steel version from Ram. To address the high pedal and clutch smell I will be installing the pedal height adjuster dashpot Ram offers in the clutch line.

Re: Switched to RAM dual-disc clutch, some questions
 

Hi Phil -

Thanks for your note. High pedal is fine for me. I have the FW supplied by Jerry in his kit, I believe it's still Aluminum but not a super light-weight FW, more weighted for the ZR1 I believe, based on his specs. I shoulda weighed it before I put in in to check, but didn't think to.

In any case, I still get the ticking on startup, but it goes away when warm... but always a good rattle on throttle through the ZF.

Interesting that you're still getting clutch smell after a few months... mine is not bad, just it's definitely there...

Steve

Re: Switched to RAM dual-disc clutch, some questions
 

Phil, Let us know what you had to get for parts besides the pedal height adjuster. My Ruby and LPE have Carolina Stage II clutches that engage high, I would like to adjust the engagement back to the floor where it belongs.

Re: Switched to RAM dual-disc clutch, some questions
 

I have added the RAM Pedal Adjuster System to our store.

http://www.jerrysgaskets.com/ram-ped...nt-system-000/

Re: Switched to RAM dual-disc clutch, some questions
 

As Jerry just posted, this pedal adjuster is for the hydraulic bearing, which has replaced the OE clutch slave, fork and pull-type throwout bearing.

I am not aware of any such adjustment for the OE pull-type which you may have on your CC Stage II clutch.

Re: Switched to RAM dual-disc clutch, some questions
 

Phil,
I can special order the billet steel flywheel for the RAM dual disc clutch for you.

Let me know if I can assist.

Re: Switched to RAM dual-disc clutch, some questions
 

No worries as you get older you won't hear as much :)

Have these on 3 FBI Z's
I have the prototype on my Z since i did the R&D on this with my friend Bob's connects this one is a bit louder and rattles a bit more but then i have big cams.

The other 2 are big inch LT5's w/cams same set up as yours and really not that bad, they are as if you installed Fidanza Alum flywheel.

If you have stock idle (650rpm) try raising idle a bit to 750

Pete

Re: Switched to RAM dual-disc clutch, some questions
 

I suspect part of the noise issue is the change in mass for the dual clutch mechanism etc. creates a requirement for re-tuning. At the very least, it would be interesting to datalog a before and after. Having installed 2 Fidanzas on different motors, the tune for idle needed to be changed. Interesting that you are also getting a rattle even when on throttle.

Re: Switched to RAM dual-disc clutch, some questions
 

I am not sure what the weight of the RAM Aluminum Billet flywheel is compared to the Fidanza, but in any case for sure it's lighter than the OE dual mass and pressure plate, so I imagine that there will always be some noise.

My questions were more about why I get a ticking when cold - it's a noticeable RPM-related tick-tick-tick that only happens with the clutch engaged (pedal out), and goes away 2-3 minutes into driving... it's get quieter, and quieter over a few minutes of driving, and disappears...

Seems like the noise through the ZF is just a factor of the change in mass, and nothing to be concerned about.

Slight clutch smell - is it a breaking-in phase or is it just a symptom of the new setup?

I should also have asked: in my stock application, the clutch was pretty much sealed, with the exception of the flywheel inspection cover, it was pretty airtight with the slave cylinder in place... now I have just the SS hydraulic lines, perhaps there's just less air-tightness, allowing the slight smell to escape... ??

Anyway, as I said in my first post, the clutch visibly (if I look at my inspection hole made to fix the hydraulic bearing onto the guide) engages and disengages, so other than my comments, I cannot feel / see / notice any problem...

Just learning the new setup, I suppose...

Re: Switched to RAM dual-disc clutch, some questions
 

I also had a ticking noise, or to be more precise a screeching noise. Turned out to be the valley drain tube rubbing on the front side of flywheel. A few love taps with a hammer and piece of wood solved it.

Re: Switched to RAM dual-disc clutch, some questions
 

I have had a Rippie 15lb. flywheel, (machined down GM stock single mass Camaro unit), for a long time. It has given good service, but rattles badly.

The reason I mention this is that I believe the rattle is not directly proportional to the weight of the flywheel, and getting a slightly heavier flywheel wouldn't necessarily cure it.
Mine rattles up to 2,500 rpm in 1st gear.

Q?- Do these dual disc units hold up to the big inch LT5's? (Not that I have to worry:)).

Re: Switched to RAM dual-disc clutch, some questions
 

I think dual discs by nature rattle twice as much as a single. The holding power is much greater though so it's a trade off. I have a McLeod street twin on my 93 and it rattles at low rpm on throttle but it sounds glorious with the B&B, solid roller valvetrain racket and big cam.

I also agree the weight of the flywheel in my opinion won't matter much. A smooth idle will help and raising the idle rpm will also help. Sometimes a very slight change in idle rpm is enough to keep things smooth and quiet down the gears in the trans. I know with my 93 I played with rpm at idle and the difference was from tank like ticking to totally quiet (700 vs 900)

Re: Switched to RAM dual-disc clutch, some questions
 

Has anyone ever put scantool on these to see if the rattle is inducing knock retard?

Re: Switched to RAM dual-disc clutch, some questions
 

Great question. I'd like to know the answer to that.
I'd like to have a switch to shut off all knock retard when using 110 octane gas at the track. What could go wrong?:))

As to the rattle, I don't think that can be attributable to the dual disc. The rattle is caused by vibration from the engine transmitted to the input shaft of the trans. This is only when the clutch is engaged and the whole assembly vibrates as a unit. So, vibration wise, the dual disc wouldn't react any differently than a single disc when engaged.
The only thing that can alleviate that rattle is a dual mass flywheel, (or a smoother idle).

Re: Switched to RAM dual-disc clutch, some questions
 

you would think the gear knock would drive the knock sensor crazy but they seem to be tuned to a different frequency or something and I don't see any knock at all

does sound like a woodpecker trying to get out of the tranny though

I've contemplated going back to a stock dual mass as the gear rattle is beyond annoying on the big cam cars and having a bit heavier flywheel is better for driving on the street

especially with stock gears.

I do like the way the old LSV winds up when provoked with it though!

Re: Switched to RAM dual-disc clutch, some questions
 

To answer my own question, I would be surprised if it did set off KR. The filters for the sensor are pretty specific ie sensor from an L98 won't work on LT-5. I have done scans of my motor with the Fidanza and any knock detection only shows up at start-up. Other than that, I don't see any knock I could attribute to the trans. Decel, accel, cruise does not show anything. I might get a brief period of knock, mainly on decel at lower rpm so it really is inconsequential. But other than hot idle, I don't get any gear rattle at cruise or when clutch is engaged.