EJ hydraulic clutch pedal box on EA81 car

[LeoneTurbo]

So I'm going to EJ-turbo my EA81 Wagon. I would really like to convert it from cable clutch to hydraulic clutch, but... Will it fit? I will be using an Impreza pedal box and I know I would have to drill three holes (one big two small) to fit the clutch master cylinder to the firewall, but has this been done before? If so, any advice? Or pics?

[rguyver]

when i did my brat i had to custom build a peddle set out of the WRX and the brat, lots of cutting and welding , i also had to move the hydro master in more so it was shorter on the shaft , redrill the pin for the leaver and relocate the throttle cable , i built a jig that simulated the firewall so i could weld the peddle set in the proper location . not an easy task and i dont know of any EJ peddle set that would bolt up with out major mods .

[idosubaru]

i see no reason why it wouldn't fit on US cars, yours surely shouldn't different. they still have to be placed around all the same components that exist on a clutch cable car - and hydraulic/cable clutches were offered on the same chassis vehicles - like legacy's. which makes sense, subaru wouldn't want to retool things if they didn't have to - much simpler to make it applicable across entire swathes of product.

 

fitment shouldn't be an issue at all. maybe you can look at a picture of two, or find one, a quick glance should tell you a lot?

 

given the frequency of hydraulic clutch repairs, failed MC's, failed slaves, failed hoses, i'd consider this a downgrade. which is very telling since hydraulic stuff is typically much newer than cables which come in all the older stuff. i realize there's other considerations, just thought i'd let you know.

[LeoneTurbo]

I'm only considering the hydraulic setup because I'm afraid a cable will break due to the stronger pressure plate I would like to use (engine torque will be est 190 lb-ft). If a cable can hold that extra force then consider this topic closed.

 

[renob123]

I'm only considering the hydraulic setup because I'm afraid a cable will break due to the stronger pressure plate I would like to use (engine torque will be est 190 lb-ft). If a cable can hold that extra force then consider this topic closed.

 

 

I'm interested in this as well. I'm betting the answer will be yes, it can hold it, but it'll be very stiff, and you may need two feet to push it down:)

 

Jacob

[idosubaru]

gotcha, i figured you had a good reason.

 

that's beyond my skill set, but my guess is that cables are fine. folks have been swapping high power engines/parts for years with cable clutches.

[GeneralDisorder]

Cables were used for many years on things MUCH larger than Subaru's. It's all about leverage and if the force required is higher then a different ratio fork is used to change the pedal pressure required. Fundametally, a cable is no different from a solid bar connecting one point to another - it's just flexible is all. The cable itself has nothing whatsoever to do with the feel of the clutch - it's all about the ratio's of the lever's in the system.

 

Hydraulics CAN change the feel depending on the ratio of the sizes of the master and slave cylinder pistons. Personally I feel that in the specific case of Subaru's many of the earlier cable clutches were more reliable than the hydro's and personally I don't have any problems with the way they feel. Many cars use Hydro because of the location of the transmission and how bad the cable routing would have to be - if even possible - for the location of the fork. You see this on Nissan's, etc where the slave cylinder is actually under the car....

 

Subaru originally went with the Hydro's on the turbo's - this was an obvious choice for the pull-type clutch they use as the slave could be mounted on the transmission side instead of trying to route a cable looped around under the manifold in order to pull on the fork from the engine side. Why they went with the pull-type clutch on the turbo's is beyond me but given that they did, the hydro clutch was the obvious answer to the cable routing problems they created with this choice.

 

Eventually someone realised that they could save a lot of money by only building the hydro pedal assemblies and just putting the slave on the engine side of the fork. At least I'm assuming that's what happened - also the deal with the pedal pressure and the higher clamp force clutches comes into play with the larger, more powerful engines Subaru is using since the switch. It made sense to go hydro instead of having really large ratio forks to ease the pedal pressure for the ladies

 

GD

Edited September 2, 2010 by GeneralDisorder

[LeoneTurbo]

Thanks for that, especially that last sentence

[idosubaru]

Thanks for that, especially that last sentence

yeah he's a piece of work isn't he? !

 

might want to consider new parts on the slave cylinder and hose. not sure if it's only some years, but they require frequent replacement and are typically done at the same time.

[rguyver]

they never made any Hydraulic clutch trans SUBARU prior to 1990\91 so i dont know what car you have seen that has a EA engine and hydro clutch ?

 

the EA cars are a lot smaller and the peddle set from a impreza or legacys. will not fit , the 4 bolts for the booster are the same but that's it , the part that bolts up under the dash is different and the throttle cable mount is not part of the peddle set on the EJ cars .

 

 

i see no reason why it wouldn't fit on US cars, yours surely shouldn't different. they still have to be placed around all the same components that exist on a clutch cable car - and hydraulic/cable clutches were offered on the same chassis vehicles - like legacy's. which makes sense, subaru wouldn't want to retool things if they didn't have to - much simpler to make it applicable across entire swathes of product.

 

fitment shouldn't be an issue at all. maybe you can look at a picture of two, or find one, a quick glance should tell you a lot?

 

given the frequency of hydraulic clutch repairs, failed MC's, failed slaves, failed hoses, i'd consider this a downgrade. which is very telling since hydraulic stuff is typically much newer than cables which come in all the older stuff. i realize there's other considerations, just thought i'd let you know.