WCM ultralite stiff clutch pedal info.

[MudHut]

I cannot find the thread that talks about how to remedy the very stiff clutch pedal in the ultralites. Something about bore size on the wildwood setup.

 

Can anyone direct me to the thread or supply some information?

 

Jay

[DeanD3W]

My half-built WCM Ultralite has a Wilwood .625" diameter clutch master cylinder. Maybe not so useful to know what my car has, since my car is not yet functional so I don't yet know how stiff the pedal will be, but I hope good for a data point at least.

 

Does your car use a stock clutch, or something stiffer? Maybe your car needs different master cylinder to work well with a stiffer clutch? To gain the same line pressure, a master cylinder with a smaller (edited to correct my earlier mistake - thinking before typing would have been a good thing ) diameter piston will reduce pedal force and it will also move more fluid for a given amount of pedal travel. Shortening the upper leg of the pedal to change the leverage ratio would also reduce pedal force, but it will also reduce the amount of fluid moved for a given amount of pedal travel. I hope someone who has sorted their system, and who happens to have a pressure plate with stiffness similar to yours, replies with specific specs that work for them.

 

Dean

Edited December 25, 2016 by DeanD3W

[Davemk1]

I use this engine and trans in my Westfield and when I first built the car the engine had 70,000 miles on it. I put it in the car and it was so hard to push the clutch that I thought it was broken. It turned out to function just fine but it was very stiff to push and I too suspected the size of the master might not be a good match to the slave.

 

I'll save you the rest of the story but I ended up taking the engine and trans out for other reasons and when I looked at the throwout bearing I could see the issue.

 

The Honda throwout slides on a collar and this collar is supposed to have a special Honda grease on it and mine was bone dry and badly galled. I replaced it and used the proper grease and the pedal effort was much, much lower. Now it feels normal and good.

 

So.....it's certainly possible that yours is the same way and that all that pedal effort is being put into grinding the bearing in/out on the collar.

 

Something to check.

 

I hope that helps.

 

Dave

[Dave W]

You want a smaller diameter master cylinder. Will give you higher pressure but a longer stroke. You my also want to look at changing the clutch pedal ratio. Typically they are around 5 to 1, but depending where you are at right now, you could go to a 6 or 7 to 1 ratio. Dave W

[DeanD3W]

Yes, Dave is right. Smaller master cylinder piston will give higher pressure. I edited my mistake in my post above. Oops.

[MudHut]

Thank you for all the replies. I have gotten used to the weight of the clutch because it doesn't require very much pedal travel to disengage and engage. I'm only reminded whenever someone sits in the car and comments on it. It would make for a more pleasurable experience if I could get it a bit easier to depress.

I'm going to figure out the factory specifications on the S2000 transmission slave and clutch

and contact wildwood about what I currently have and what would work a bit better. I will update the post.

 

Jay

[Dave W]

You can actually have both a lighter pedal and short travel. Install a clutch stop! I feel the same way, I definitely prefer a short travel cltuch pedal. You can adjust the stop so you only have about 1/4" of pedal travel after the clutch disengages. Dave W

[jimrankin]

just downsize to a .500 inch bore Wilwood clutch master cylinder. .625 is what seems to be the standard size on the 3-4 cars I've had the chance to work on. You don't need much travel if you set it up correctly and the smaller cylinder will make it a lot lighter feel.

[RGTorque]

just came across this thread. i had a very stiff pedal on my wcm and after a lot of bruhaha i figured out that the grease on the input shaft was dry and the t-bearing was actually BINDING. when i pulled the trans i saw scoring and replaced the parts and now my pedal is about 50% lighter.

[Davemk1]

just came across this thread. i had a very stiff pedal on my wcm and after a lot of bruhaha i figured out that the grease on the input shaft was dry and the t-bearing was actually BINDING. when i pulled the trans i saw scoring and replaced the parts and now my pedal is about 50% lighter.

 

I hear you. That is what I found on my S2000 too (see post 3 above).

 

I look forward to hearing who the OP's deal works out.

 

dave

[MudHut]

Roman and Dave, you guys are killing me with this talk of binding and especially of pulling the transmission. It's not a lack of know-how, it's the 'I don't want to, what a pain in the ass' part that is getting me. My pedal is very linear, and take-up and release are fine. Suspect there is no other way to troubleshoot what you guys are eluding to without tearing into it.

I may resize the clutch master cylinder first.

Ugh,

 

Jay

[Davemk1]

When I suspected the dry collar I decided to do a diagnostic test first. I strongly suspected the clutch needed replacing anyway but didn't want to jump right into it as I had some time left in my short driving season.....so....I sprayed some spray grease into the area through the slave cylinder opening. I knew this would compromise the clutch but did't care as it needed to be replaced anyway. It took some creative spraying but once I figured it out and got some of the grease on the sliding collar the resistance went way down. The spray grease is crap and didn't last long but it told me what I needed to know.

 

FWIW my clutch felt like it sounds yours does.....even take up and "normal" aside from the very high effort. I assume Westfield had given me the wrong size master but that wasn't the case in the end.

 

Frankly the design is weak......you spread grease on the parts and they are exposed to air so the grease dries and wears out in time. My engine is from 2001 so that grease had sat in there drying for 15 years. That is a long time to expect it to do its job. if yours has never been apart I've got $100 that says the grease is toast and the collar is scored. It's super easy to fix once you are in there and Honda stocks the parts.

 

While you're in there replace the stock flywheel with a lightweight Fidenza version and it will really allow it to spin up quickly.

 

I'd plan on pulling it out sooner rather than later.

 

dave

[RGTorque]

i did a bit of reading and chose NOT to go with a lightened flywheel. engine spins fast enough for me. i did go with a competition stage 2 or 3 clutch disc and a nice lightly used pressure plate.