FancyHonda

Hey guys,

Can those out there with the XLR8 flywheel setup tell me how your clutch behaves in daily driving? Launching from a stop specifically. I've had this setup in my car since March of this year, and I've maybe put 2,000km on it total. Covid has kept me from driving it that much.

Setup so far:
XLR8 flywheel + Daily clutch
EM2 spec master without delay valve
Luk slave with check valve deleted
Hybrid racing shifter bushings
All new OEM engine mounts (Front, side, rear and 3 on trans side)
Redline MTL trans fluid

What I'm experiencing is when the car is sufficiently warm, or if I spend a lot of time riding the clutch in say a parking lot or drive through I get some engagement chatter and or shudder when launching from a stop. Replacing the mounts made things significantly better. I'm just trying to get a feel for what is and isn't normal for this setup. When my car is cold and idling higher, it's always buttery smooth. Most of the time the car is pretty good and I could definitely chalk this up to being an aftermarket setup.

Things I have considered:
- A running condition causing the engine not to deliver power smoothly near idle once warmed up. I have a few other sensations that the car is not running 100%, but it's quite subtle if so. I've done plugs, PCV, replaced the TB and MAP sensor, car doesn't have any vacuum leaks but it does probably need a valve adjustment. Most would probably drive the car and say it runs great, but I'm quite particular.
- Clutch contamination via oil. I had the rear main seal replaced when the clutch was replaced, but the plate wasn't removed or resealed. My valve covers have been leaking and the tech who worked on the car claims that they are what leaked oil into the bell housing. I had thought it was the rear main as I had oil visible between the engine and trans prior to the clutch job, but that's what he asserts, whether true or not.
- Engine torque damper. This is a long shot, but from how much the mounts improved the car I'm very tempted to just buy an XLR8 ETD and throw it in the car anyway.

Thanks. I'll post the pictures from the install below.

FancyHonda

Bump. Anyone?

Anyone comment on clutch chatter in general? I'm wondering if maybe a different master cylinder would help. Probably not.

oraclem20

I can't speak to the exact XLR8 setup however it is a lightweight flywheel setup with a full face disc similar to the AASCO/Stage 3+ Spec I have. I have the no check slave as well, and a Wilwood 3/4" MC, also on Redline, and upgraded mounts, however I additionally have the ETD installed.

There's still chatter on hookup. I would imagine it's technically from imperfect slippage (operator error) as in some cases I get none, some cases I get a bit especially when hard launching and dropping the pedal on a 3-4krpm engine. I've been tempted to try swapping back in the slave cylinder with a check valve to get a bit more control on the slip, as some higher performance cars do still have adjustable "check valves" (chokes in the clutch line) for when you're dealing with harder to control 3/4" + Master Cylinders and twin discs or puck discs. I'd suggest trying to stiffen the transmission mounts before getting the ETD as the vibration feels like its all coming from the driver side of the engine. Which makes sense given how soft the mounts are and how small when compared to the other 3 mounts. Someone was making a 95A trans mount a while back, but he left the platform for now. If you'd like to do some experimenting, there's 80a+ urethane available in a quart like paint. The lower mounts for the transmission have a massive amount of free space that could be filled, you'd have to make a jig or tape them off to keep the urethane contained, however casting your own mounts will look a little sloppy for $40 vs getting custom ones made for $500.

FancyHonda

Interesting. You describe a similar style of engagement chatter, sometimes, not always. I definitely feel like I have a hard time slipping the clutch well on my car, the em2 master and clutch (I think it's a South Bend) combine to form a very small engagement window right near the top of the pedal. I feel like the clutch in my car may be a bit more mild, but perhaps I'm wrong. I've yet to actually hard launch my car in any fashion since it's mostly been in break-in period so far.

In terms of adding some dampening to the clutch hydraulic system would you go back to the check valve slave, or perhaps try the OEM master with it's built in delay valve? What made you go to a willwood MC? Required some kind of fabrication or modification to make work, I assume.

Unfortunately, that sort of fab or work to the trans side mounts is definitely out of my wheelhouse. I'm trying to retain some sort of comfort via OEM mounts as well. I guess you have to make compromises somewhere when running these performance aftermarket setups.

zeta

iTrader: (1)

Maybe a clutch pedal adjustment (see attachment) making the engagement point closer to the floor would aid in reducing the chatter?

FancyHonda

Thanks!
This is a pretty good suggestion. I did not adjust the EM2 master before I put it in the car.

Acura TL Builder

Zeta is my knight in shining armour.

860_TypeS

Did you ever try anything to smooth out the clutch engagement? I have the XLR8 daily and it's hard to get a very smooth engagement from a stop or shifts quite often.

Basically same mod list as you, but with XLR8 ETD and innovative 75A front and side motor mounts and 75A trans mounts. I debated going back to the stock CMC from the EM2, but wanted to ask first because that's not the most fun install to have to do again.

Also to note, my EM2 CMC was set at the same exact length as my OEM CMC right out of the bag. I measured them both

FancyHonda

I haven't done much else, and I've just sort of lived with the car as is. I think the more you drive the car the better a sense you get for what kind of engagements the clutch does and doesn't like. I will note that my current setup is all brand new OE engine mounts and then the XLR8 ETD with the softer bushings. I don't really get any clutch chatter on launching from a stop, but I do if I don't rev match a downshift or if I re-engage the clutch while rolling without a little bit of throttle. I find that a little bit of throttle input with any clutch engagement usually smooths things out.

What's your idle speed set at? What RPM are you shooting for while launching? I'm running a hondata and my idle is ~900 and I usually shoot for above 1,500 RPM to get a smooth launch. I can lug the car at 1,200 or 1,300 but you can tell the clutch prefers faster, higher RPM launches.

Have you replaced your rear engine mount? The Acura dealer I deal with told me they thought my original rear engine mount was fine, but I paid them to replace it anyway and it definitely improved the clutch chatter and feeling overall. If you haven't done your rear mount, I definitely would - with whatever you prefer, OEM or aftermarket. If I was to do this again I would buy Euro_R's front and rear engine mounts instead of OEM, and I still might do that in the future. He posted some pictures and info on them in another one of my threads.

I have definitely also grappled with the idea of going back to the stock CMC to see if that would help, but I'm pretty sure it wouldn't. The problem that's causing this clutch chatter is the XLR8 daily clutch disc and it's lack of marcel springs. It's a great disc that's pretty smooth overall for an aftermarket clutch, but it's not perfect. The stock CMC would probably feel smoother in the pedal itself, but the EM2 CMC offers more direct and controllable engagement, and I think that's more beneficial when it comes to these aftermarket setups that are quite sensitive in terms of how you use the clutch.

As a complete tangent - what suspension are you running? Do you find your car jerky since going XLR8? I find my car is quite jerky currently and I think it's just my suspension is soft or worn, but some part of me thinks the single mass flywheel and all of the other changes are cars share are responsible or at least play a role.

860_TypeS

New OEM rear motor mount when I did the rest of them last summer. I saw Euro_R's mounts after the fact and am considering them, but that install sucks and I don't feel a lot of vibration with the 75A mounts.

Suspension is Tein street advance coilovers, I think they have maybe 60k or so miles on them. It's definitely jerky at times. I believe idle is ~750, I also have Hondata and basically just trusted Dom with everything having to do with that.

And I never launch the car or do you mean like just getting going from a stop? From a stop I'd say 1200-1400RPM. Honestly I feel like it was jerky before too, but my OEM clutch was pretty bad when I got it replaced.

When you installed the EM2 CMC did you reuse the OEM hardline and bent it to work or use the P2R braided SS line?

FancyHonda

If I end up going over to Eric's mounts I'll let you know my thoughts - they might be a nice balance of stiffness and comfort.

I found the car way easier to drive with the idle set at 900 RPM. I talked to Dom when I got my Hondata but he wasn't super interested in what I wanted from a tune - drivability improvements.

I do mean just typical driving when I saying launch. I find the clutch is smoothest above 1,500 RPM. It might even be that engine has a certain resonance or vibration around 1,100-1,200 that I notice if I try and ride the clutch at that RPM.

I used the OEM line when I installed the EM2 master. I've read the same thing before, that you have to modify the line to make it work, but I didn't have any issues.