There are two main types of clutch used on Subaru’s – the conventional ‘push to release’ clutches used on all naturally aspirated Subaru’s, and the ‘pull to release’ clutches used on turbo Subaru’s. See the web site of Subaru’s OEM clutch manufacturer, Daikin, for an excellent explanation of the differences between the two types of clutch (and lots of other useful clutch information). Both types can be used with an RJES bellhousing, but a different kit is required for each, as the clutch release mechanisms work differently.
There are two types of push clutch, which are not compatible with each others’ flywheel– the single mass and dual mass flywheel versions.
There are two types of pull clutches which are not compatible with each others’ flywheel – the 225/230mm and 240mm versions.
Both push and pull type clutches are also available in different sizes / ratings. For all clutch types, make sure the Subaru clutch pressure plate you get matches your flywheel. For the majority of cases this will mean using the following:
a. A single mass flywheel from a naturally aspirated or turbo Subaru with a clutch of 215, 225, or 230mm diameter. See Subaru Flywheel Types for more details.
b. A 225 or 230mm clutch pressure plate. Both push (nat asp) and pull (turbo) types are suitable, but you must use them in conjunction with the correct RJES Bellhousing kit.
Push to Release Subaru Clutches
215mm Subaru Push to Release Clutch:
The 215mm clutch was used on some 1.6 and 1.8 engines. It is interchangeable with the 225mm ones, and could be used in a conversion (with the 215mm clutch disc from a late 1.6 type 1 engined or 1.7 or 1.8 type 4 engined bay window bus). However one of the bigger Subaru clutches would almost certainly be a better idea. These clutches are located by two 6mm dowels on 120 degree centres, and fit any single mass flat face Subaru flywheel.
225mm Subaru Push to Release Clutch:
The majority of naturally aspirated Subaru engines use a 225mm diameter clutch disc. The size refers to the outer diameter of the disc (or driven plate). These clutches are located by two 6mm dowels on 120 degree centres, and fit any single mass flat face Subaru flywheel.
Pull to Release Subaru Clutches:
225mm Subaru Pull to Release Clutch:
The majority of turbocharged Subaru engines which come from the standard turbo models (i.e. not the WRX, GT, RS, or STi models) use a 225mm diameter clutch disc. These clutches are located by two 6mm dowels on 120 degree centres, and fit any single mass flat face Subaru flywheel. Standard ones are OK up to about 240 bhp.
230mm Subaru Pull to Release Clutch:
The majority of turbocharged Subaru WRX engines from 1993 onwards (but not those from all WRX STi models, see below) use a 230mm diameter clutch disc. These clutches are located by two 6mm dowels on 120 degree centres, and fit any single mass flat face Subaru flywheel. Standard ones are OK up to about 280 bhp. Many aftermarket uprated clutches are also 230mm.
240mm Subaru Pull to Release Clutch:
Subaru WRX STI’s from 2001 or 2002 onwards use a 240mm clutch to help handle the increased power. They also use a unique design of flywheel, which does not have a flat face. The pressure plate is a ‘push’ type, as with all the turbo Subaru’s but this is also specific to the 240mm clutch. There is no 240mm VW clutch disc which can be used for the conversion, and to the best of our knowledge there are no suitable discs in use on production cars. It will be necessary to use a special clutch disc with the 240mm pressure plate. We can get suitable clutch discs made (to order). The maximum bhp for these clutches as standard is not known. Please e-mail if you know. Many aftermarket versions of the 240mm clutch are available.