I have the stock clutch right now and im changing it really soon. I have some questions as to what I should do. I am only going to add cams and a fuel pump on top of the mods I already have So ill be somewhere around 315-330whp area. Im gonna stay with the stock pressure plate and clutch housing. What is a good clutch disk that i can use with the stock housing and just get a little more grip than stock?

 

the organic clutch discs that the popular vendors use (ACT, Exedy, etc.) as a stage one upgrade disc won't hold any more power than the stock disc. The extra holding power comes in with the fact that the pressure plate (I think what you're calling a clutch housing) is upgraded to a higher clamping force that the sell with the organic disc as a package. So I'm a bit confused by your statement of using the stock pressure plate AND clutch housing.

The stock clutch has a pressure plate, a disc, and a flywheel. The stock disc is an "organic" material. If you want a replacement disc to hold higher torque than stock does, you can't go with the stage 1 organic discs offered by the vendors, you'll have to step up to a puck style disc, which I think at a minimum will be cerametallic????

My question is..... why not go with the organic disc and heavier pressure plate? The clutch peddle will be a bit heavier, but the stock driveability will be maintained. If you go with a puck style disc, you'll give up driveability. For your level of anticipated mods, I don't see the logic?

 

so your saying that if im goingt o change the clutch disk to anything other than the stock disk i should change the clutch housing aswell but if im going to keep the stock dick then keep the stock housing?

 

I think he is saying that if you want the holding power for your mods you have to get a different housing, that is where the clamping force comes from. You will lose driveability if you just stick a puck style disc into the stock housing. If you want the holding power you can still run an organic disc but have to upgrade to a different housing. Hope this helps.

 

let's talk in terms of what most vendors will talk in that sell clutches....

The EVO clutch has a pressure plate, a clutch disc and a flywheel. The pressure plate has a spring diahpragm that is rated in clamping force. The higher the clamping force, the "heaver" the clutch peddle will feel. Which makes sense because it's going to take more effort from your foot the engage the clutch.

Most vendors, sell a stage I upgrade (the cheapest upgrade and first natural step) for slightly modified street cars. The stage I kit usually consists of a new pressure plate with a high clamping force, but still use an organic disc material on the clutch disc that will be very similar to stock. It will engage smoothly, and be very street friendly, the clutch peddle will just be a bit heavier. The stage one packages get there extra "holding" ability for increased power levels due to the fact that the pressure plate has a higher clamping force, not because the clutch disc has a higher coefficient of friction. Some stage I packages also come with a flywheel, but that won't effect the clutch's ability to hold more power.

When you step up to stage II, this is when people start talking about racing clutches vs. street clutches. the clutch facing material will usually change to something that isn't organic, but usually a cerametalic material. This material will have a higher coefficeint of friction, and by more "grabby". This disc by itself will hold more power, but won't be as streetable as an organic clutch material like they use in the stage I clutches. It will be hard to slip and get a smooth, everday street start like you normally drive. It will chatter, it will hit hard, but it will hold the power. It really is meant for the track, where you're doing 5k rpm launches and don't care too much about pulling away calmly from a red light. With work, you can master this type of disc for street use, but it just won't be as streetable as an organic disc. You'll need to be careful here, because some of these discs are "unsprung" center section, which makes engagement that much harsher.

So you could get a clutch disc made of cerametalic material, that will fit with your stock pressure plate, and it will hold more power than the complete stock setup. But it will come at a price of driveability. Or, you can get an upgraded pressure plate (i.e. higher clamp load) and an organic disc which will hold more power than a complete stock setup, and maintain driveability for the street. Your clutch peddle will feel heavier, but the engagement will be smooth and just like stock.

Hence my recommendation to go with a aftermarket stage I clutch instead of just a high coefficient of friction style disc. ACT, Exedy, RPS all make a stage one street setup that I think would be your best bet. IMO.

 

omg, i love your write up, i was actually looking to get a clutch soon as well and wasn't sure what to go with. I do have one question for you, does the flywheel make any difference other than weight? i'm still pretty new at this and love the way you write dubbleugly01, any imput at all will be greatly appreciated, thx

 

flywheels are a different topic.... They won't won't allow you to hold any more power. The stocker is steel, and some say it doesn't dissipate heat well. The aftermarket flywheels will be either aluminum (for lightness) with a steel insert where the clutch disc rides, or chromemoly. Some people will tell you that both of these types of flywheels are more prone to warp than steel. Each has it pros and cons.

The stock flywheel weighs around 13#'s or so, the lightweight aftermarket are as light as 10#'s. Not much of a difference IMO, and not worth the extra coin for weight savings alone. But if they dissipate heat better, they may be worth it. I haven't seen any definitive evidence that says the stock flywheel doesn't dissipate heat well, other than some photos accompanied with those of an exploded/overheated clutch disc. And again, IMO, for a clutch disc to get that hot, it's driver error, not the flyhweels fault.

I just bought a Stage I ACT setup, with a new stock flywheel for my car.

 

Nice write up. I just did a stock clutch in my car and I hope to get 60K out of it. Next time I might spend the few extra dollard for an Exede twin plate.

Even the stock clutch gives my leg a workout at 60 miles a day. My eclipse had such a softer clutch. I could almost push it down with one finger!

-E

 

Ok after your amazing write up I decided that i will stay with my stock pressure plate and just put a new stock disk in being that my mods dont call for more than a stock disk nor do i feel like spending the money on one when I'm gonna sell the car soon. Thank you very much for you write up and I hope your a mod one day. Lol
Tom