I am not sure if this is common knowledge or not, but I was certainly not aware before this. Long story short, got exedy performance clutch "zm022sd" installed that most people on this forum claims to have near stock drivability. Did not like how on/off the engagement point was. Driving in traffic was a pain. I thought I was **** outta luck. Did some digging and found this FEED clutch slave cylinder on RHDjapan that was supposed to be larger than stock which is supposed to improve performance clutch drivability.

https://www.rhdjapan.com/fujita-engi...nder-fd3s.html

Got it installed. Clutch now feels stock like in terms of weight and engagement point. Much easier to live with when modulating the clutch in traffic. The feel has been restored to stock whilst allowing me to run a clutch capable of handling more power. Thumbs up in case anyone is looking for a solution to improve the drivability of their race/performance clutch!

 

Nice! Thanks for the info

 

 

Cool! So does this essentially reduce how far the release bearing travels relative to the pedal, making the friction point feel wider? I agree that the Exedy twin is a bitch, not even closer to stock.

 

I am no engineer but that's exactly what it felt like to me.

 

Ding! Ding! Ding! ^^^ You are correct. With an on/off type of clutch face material, you don't need as much travel as you would with a stock organic disc or a clutch with marcel in it so you can change the clutch master/slave ratios and get better articulation and reduce the pedal force too. As long as you have enough travel to fully disengage the clutch, you're good.

A few years ago I wanted to mitigate a similar on/off problem I had with a 6 puck and a very heavy clutch plate. I couldn't locate a suitable FD type slave cylinder and so I did the next best thing and made one. I took an old FD slave which I bored and honed to 21mm ID (IIRC) and used the piston/seal from a Toyota 4Runner slave cylinder rebuild kit. It worked great; well worth the effort. (I don't recommend boring a slave unless you have the proper tools and experience to do this.) However, I also seem to remember that one could fit a 21mm slave cylinder from an older model Jeep Cherokee onto an FD with a minimum amount of work to achieve the desired result.

It's good to know that there's a proper fitting, off-the-shelf part available for those that want to take advantage of this mod. Other than for lack of a part, I never understood why no one else was doing this--it's a common adjustment on some bikes, and race/track cars since it allows you to get the 'feel' dialed in just right.

 

Nice! I've seen that part before but was curious if it actually helped out.

A biggie with a heavier pressure plate is getting a stainless clutch line. The stock rubber hose will swell and the clutch engagement point will be VERY close to the floor, some times so much so the car is undriveable.

This is also a product an enterprising US shop could duplicate .

Dale

 

It's likely that this is just some off the shelf OEM part originally designed for some other Japanese car. I wonder what car that would be.

 

i do not know, but i know how to find out, https://www.opticatonline.com/search?pt=2044

the world is your oyster

 

This is great—I've got an Exedy twin disk (not the carbon or unsprung version), and my biggest complaint i not effort or travel so much as it doesn't seem to engage in the same place consistently, so when I let my foot out the amount I anticipate I need, sometimes it grabs like hell right away, other times not. I find I end up giving it more gas than I would normally think needed, and let it out very carefully to avoid stalling it.

Is this the phenomenon you're talking about?

 

 

 

Yes! You are describing my exact experience with my exedy twin disk clutch. This mod pretty much gets rid of that. Although I still feel that it wants to stall when I don't give enough gas but I chalk that up to the lightened flywheel that comes with the kit.

 

22000 yen for a slave cylinder is ridiculous. And that's not inclusing shipping etc. Would be much cheaper to get a second hand resleeved with a larger ID bore and seal to suit. I've had this done for a brake master cylinder before for AUD150, roughly US100.

or as pointed above, you'll probably find it is off another model and available much cheaper than through a Japanese performance shop.

 

Rock Auto shows the stock FD slave bore to the 3/4" or 19.05mm.

So is there another slave out there that has a bigger bore? or is FEED just boring out and rebuilding FD slaves?

 

Doing a Google image search the only Mazda clutch slave that is even close to the FD's is .... the FD's. I think the pull type clutch makes it pretty unique.

I am betting they are getting parts from the OEM supplier (probably Tokico) and boring them out and installing larger pistons. Or having Tokico or some other parts supplier make them to spec for them.

In other words I don't think there's an easy way to just buy some other make/model slave cylinder and use it.

But, this part could very likely be replicated.

Dale

 

Anyone know what these FEED slave cylinder bore diameters are?

 

On the other hand its only $200 and you are supporting Fujita/Feed, an old school rotary company that has and is continuing to develop products for a nearly 30 year old chassis. Now that RHD Japan does Paypal I am onboard.

I like nothing more than watching Feed single turbo touge monster FD battling the RE Amemiya sequential twin touge monster on a Hot Version video.

 

How long does it take to get it from Japan tho?

P

 

In my experiences with RHD Japan, they are responsive and fast. The question mostly boils down to whether the vendor has the part available and are responsive themselves. If they do/are, you'll likely have the part within 2 weeks.

 

My experience with shipping smaller parts from Japan is they come over on an airplane which is usually a day slower or so than domestic air shipping (and I am assuming this is because of our customs inspections as the packages are usually opened).

With bigger parts like engine, transmission, door, etc that I have bought from Mazda Japan the parts go slow boat and it takes 2-3 months.

 

Or, you could support a rx7club forum vendor! We carry all Feed products and are able to get this part as well. I can order a bulk amount of them to save on shipping costs if there is enough interest!

 

I would be in for a group buy for it

 

Id order one as well.

 

Im in for a GB....

Jpr