06 June 2011
When it comes to clutch selection, many enthusiasts overstate what torque they currently make and go all out insane when they speculate about future performance. I’m guilty of it myself having installed a triple carbon clutch that was rated for around double what my torque output was. But like many, I had high expectations that didn’t work out and that is where Exedy is making their big push with their Cerametallic multi-plates. These clutches have all of the clamping force benefits of a multi-plate but are for more realistic torque numbers for a fraction of the cost of carbon fiber clutches.
We recently talked with Exedy Brand Manager Evan Cline about what is new from the huge Japanese manufacturer. He walked us through several new twin-plate Cerametallic clutches for some of the hotter applications out there. “Traditionally, there was no multi-plate clutch for these applications,” Cline said. “The platforms were either too new or it was cost prohibitive to produce a carbon clutch for that market.”
The team got to work on producing a multi-plate that would benefit from Exedy’s ceramic and metal friction material. The clutch itself looks like a Hyper Carbon clutch until you pull off the trademark Exedy Purple on the forged aluminum clutch plate. The T5001 Cerametallic discs have a 6-puck design that offer extreme heat resistance versus some of the other materials out there. The discs are sandwiched between the billet steel plates to provide a huge amount of surface area for engagement. Depending on vehicle the center hub can be ordered either with a sprung hub for smoother daily driving or a solid hub for an all-out assault on the strip or track.
The unit is bolted together with high-tensile fasteners to ensure the unit will be intact under shock load. Contrary to some schools of thought, Exedy’s integrated flywheel is made from forged chromoly steel using the bare minimum of materials to remain lightweight. So there is no need to buy an extra lightweight flywheel and you know this one will interface well with the clutch.
The multi-plate clutch is designed primarily for one thing: harnessing big torque. But at the same time Exedy engineers gave it some reasonable pedal feel for every day driving as well. These clutches are not simple on / off switches but have an area of engagement that can be dealt with when navigating traffic and parking lots. The clutch features a patented strap lift design that even lifts both the main pressure plate and intermediate pressure plate for smooth release. At the same time, this is still a serious clutch. Yes, it may have some chatter on start up and will not be much stiffer than most of what is out there, but it is also easy to predict.
Recently added to the multi-plate Cerametallic family were four exciting applications. The Hyundai Genesis 2.0T Coupe, Nissan 350Z and Subaru Impreza STI get new HD units that are rated up to 535lb-ft of torque at the wheels. The Honda S2000 also gets a new HD unit that will handle 591lb-ft of torque at the wheels for those who have ridiculous custom turbo setups on their F20C 2.0L or the F22C 2.2L. Be sure to check their website list for loads of new applications coming out on a regular basis.