Hydraulic Clutch Conversion

We originally went with the Hasport K-Series mechanical clutch conversion. This is a mechanical lever that bolts in place of the K-series hydraulic unit (See pics of mechanical and hydralic below). It utilizes the CRX mechanical cable to accuate the lever and hence the clutch. It is not bad, a little ugly, and it takes up considerable room in the front of the engine, and with the Rotrex, intercooling, and full size radiator and plumbing going in, it was an issue. There are two ways, that we have seen, for going to hydraulic. The first is to go with a cable to Hydraulic adapter unit such as from Hasport or make your own cable to hydraulic adapter. Problem is, you still have the cable and now you have to find a place in the engine compartment for the master cylinder and adapter.

We came across an interesting product from Suja 1 Motoring called the Sonem EF Bolt-In Hydraulic Clutch Conversion. You can read some details on it and see some pictures on this thread. This is basically a bracket which bolts on to your existing clutch pedal assembly and mounts a stock Honda Master cylinder and fluid reservoir. It can make for a real clean setup, but there are a couple of things to be aware. First is you will loose the driver left side fresh air/heat duct as there is no room for it with the master cylinder under the dash. Not too horrible especially if you have removed your heater, we kept ours, necessary for our northern climate. Second, you have to weld a couple of washers on the "hook" at the end of the clutch with normally pulls the cable, but that is very easy to do. This allows for a clevis pin to be used to run the master. Third, and this is just the norm, it is a real PIA to work under the CRX dash. You need to drop the steering and fuse box at least, preferably the dash although we did it without removing the dash. So if you are going to go this route, install it when you have everything apart.

Haven't tried it on the road yet, we are about a month away from getting back on the road, but it feels good and it sure cleans up the engine compartment by getting rid of the cable and mechanical adapter.


First Impressions

We have been running the new hydraulic clutch setup for a couple weeks now including 2 autocross events. The feel is noticibly smoother than the mechanical setup and even with our new Clutch Masters ceramic FX400 it is easy to engage. The mechanical setup was a bit non-linear on pedal preassure, this setup is totally linear. We really like it and highly recommend going this way.



The master Reservoir locates nicely in the CRX, with some custom bracketing. The feed hose goes through the old cable hole, the hydraulic hose was snuck through the electrical pass through.
Top view, you can see the clevis pin on the "hook".
Sonem EF hydro kit mounted on clutch pedal assembly.
Stock hydraulic unit is much cleaner and compact.
Hasport mechanical clutch conversion, big, not pretty, but works OK.