Jeff20B

iTrader: (13)

So the general concensus here is that I should pull the 12A and drop in the 20B then?

That being the case, I want to talk about clutches! It's gotta be 225mm because I'm keeping the stock tranny... for now. When I go turbo is when I'll up it to 240mm with all new stuff and a T2 tranny. For now the '81-'83 tranny, with its big gears, should be more than enough on stock tires as long as I don't abuse it.

I think I should go aluminum for the flywheel because Mazdatrix recommends it for fuel injected engines. Did I just say fuel injected? Well, yes, but in bold. MegaSquirt for the win! More on that later.

Let's talk clutches. Ok, assuming I'll have an aluminum flywheel, whether Racing Beat, Fidanza or Spec, which clutch package or individual components should I get? Bear in mind the car will be used primarily for the street with some sprirted driving on occasion. Therefore I'd like to avoid puck clutches if I can.

I also don't want a super heavy pressure plate. Something as stiff as my REPU with its stock (actually heavy duty) pressure plate would be acceptible. If I had to compare, I'd say the REPU pressure plate is somewhere between RB's street strip and race pressure plates.

I think RB's race pressure plate is a little stiff for daily driving, just to give you an idea of what I don't want.

I've looked into various clutches available for '83-'88 (or was it '83-'92?) 225mm clutch kits. The clutches I (and you) should avoid are:

XTD and Centerforce.

People who use XTD stage 2 and also stage 3 and various Centerforce kits end up having to replace them far sooner than they ought to. I will avoid these clutches.

Spec

Next up on the list is Spec brand clutches. It appears the most people who've had problems with Spec clutches are if they used stage 1 which has a full faced organic disc. I think the pressure plate in the stage 1 may be the weakest of all the stage as well. Appearantly the rivets fail in iehter the disc or the poressure plate. I can't recall which.

As for Spec stage 2, 2+, 3 etc, I think they work fine for nearly everyone. When you get up to the higher stages, you're usually driving pretty hard, and other more respected clutch companies like ACT and Exedy appear to have similar failure rates as the stage 2 and up.

ACT and Exedy

This brings us to the upper echelon of clutches and pressure plates: Exedy and ACT. Nearly everyone uses ACT pressure plates it seems when they've done major mods to their cars. I've heard of some failures here and there. ACT is more expensive than the others, until you get up into the double discs and stuff, but they're only available for turbos and FDs so blah.

Exedy is probably the very best stock style stuff you can get, and they have a few upgrade options to boot. If I needed a full faced organic disc for any reason, I'd get Exedy.

Jeff20B

iTrader: (13)

So there you have it. My take on clutches. Now I wonder what I should get.

What have you driven? What do you like? I briefly drove a 1st gen with an ACT heavy duty pressure plate and a 6 puck sprung disc around a small parking lot and thought the pedal effort was pretty high. It was kinda like the RB race pressure plate in effort, but more grabby. Too much for me, but if I had a chance to drive it more, maybe I'd change my mind? I'd have to work my way up to it I suppose.

Maybe the Spec stage 2+ would be a good starter clutch package on my way up to an ACT HD with 6 puck for when (if) I go turbo? Hmm...

orion84gsl

iTrader: (5)

as long as you dont abuse it? your putting a 20B into your FB and you don't think you'll abuse it? You must have a light right foot. Mine is made of lead. So far I've only driven a stock clutch that needs bleeding so I can't help you there.

Jeff20B

iTrader: (13)

That's the thing. You have to almost abuse a 12A to get it up there. A 20B would not have to be driven as hard.

That's what I want; an engine that you don't have to scream to get tire twisting torque. It's like comparing a low boost 20B to a high boost 13B. One will run longer and have better driveability, yet both have the same peak HP.

fatboy7

I've tried both the Spec Stage II and the ACT Heavy Duty w/6-puck on my 13BT powered 85.

The Spec pressure plate was really light feeling for a performance clutch, almost stock effort. The ACT requires a bit more effort, but I wouldn't say that it is unstreetable, though perhaps not what you're looking for.

As far as the SPEC kevlar faced disk, I was very dissappointed with it. I broke it in nice an slow, but it still didn't hold. After driving the car around for awhile tuning at 6psi, I bumped up the boost to 10psi and it almost immediately started to slip. Problem with kevlar faced clutches, is that once it starts to slip and heats up significantly, its characteristics further degrade to where it slips at almost the hint of torque. I wouldn't go with the SPEC stage 1 or 2 for a 20B, even stock.

After the engine went (only 3k mi on the JDM transplant), and I pulled it to rebuild, I replaced the SPEC with the ACT 6-puck. No more slipping problems, and as the clutch heats up it actually grabs harder. Due to my situation changing, my 7 became my daily driver for over 2 years. While I've been told that puck types aren't streetable, it doesn't take that long to get used to its sharper engagement point and compensate. I like nice smooth shifts, and push-offs--it really wasn't that hard to accomplish once I got the hang of it. When my 7 got off daily duty and my A4 daily driver is also a manual, it is a bit of an adjustment to get back in the 7 with its "race" clutch, but it comes back quickly.

I've known a few cars with Exedy clutches with good results--if I were trying to stick with the 225mm flywheel, I'd probably go with one of theirs. Though I were you, I'd go with a TII tranny now, while the engine is out. The larger size of the 240mm flywheel alone increases the torque handling a bit, and it widens the possiblities for clutches and flywheels.

Jeff20B

iTrader: (13)

So for a full faced disc solution, I should go with Exedy? That sounds like a good idea.

The Spec stage 2+ has a carbon/kevlar composite material. Do you think it's worth the rist?

I'd prefer a lighter pedal, and I know the 240mm stuff can handle more torque at stock pedal effort. Hmm, I'll just stick with stock 225mm for now since I have access to several 1st gen trannies.

As for the pressure plate, if I have access to that RB Race pressure plate, I'll hop in and give it a few pushes to see how it feels to me now that I've been driving my REPU around, which has a heavy duty pressure plate as OEM. Also a full faced organic disc that is actually quite grabby, yet it gives you great control while hauling or towing. I like it. If I could replicate that, but with an aluminum flywheel, I'd do it in a heart beat.

Still thinking... Thanks for the info.

Siraniko

iTrader: (13)

Carbon/kevlar is good and much better than the ferodo IMHO, and it wot hurt the flywheel. In fact, thats what I have in my FB (yeah, teh one collecting dust) with aluminum flywheel and 2500 lbs dual diapram pressure plate.

Jeff20B

iTrader: (13)

Carbon/kevlar is good you say? That's good news.

That pressure plate turned out to be a street strip. It's similar in pedal effort to the REPU. Just a little heavier. I bet I could drive it and not hate it in bumper to bumper.

dj55b

iTrader: (2)

I bought the XTD clutch almost a year ago, haven't installed it yet but looks decent quality for the price. Where did you read the bad s tuff on that clutch jeff? And by far sooner than it should wear, how long exactly would that be. If It can get me atleat a year or two at the very minimum, I'll be happy with that. I just hope it doesn't like chatter or anything. The reason i opted for it, is to try out the karbon kevlar material. If Anyone is interested I can snap some shots.

Siraniko

iTrader: (13)

The carbon kevlar is a lil bit more expensive that the RB street strip. Thats the advantage of living in Socal, I can go straight to the RB's clutch builder (as far as I know) and I dont get no mark up. In fact, I can get anything made which includes t/o & pilot bearings and flywheel resurfacing for $250 t/-. In addition, I can get a stock items with better clutch linings than el cheapo, kragen etc etc. It only takes a couple of hours for them to make it.

Jeff20B

iTrader: (13)

dj55b, you'll probably get a few years out of your XTD. Don't dump it at high RPM or otherwise abuse it.

I want a clutch that I can dump at high RPM whenever I want and not burn it. I'm still debating between RB, Spec and ACT.

dj55b

iTrader: (2)

for the 130ish $ paid for it ... I can't really complain now can I. I will be investing in most likely an ACT one later on. But would like to still retain the Carbon Kevlar Familly

FirebirdSlayer666

iTrader: (3)

Jeff, I got the RB strip/street clutch for my FB and I've loved it. It really grabs hard and feels great. For the price it's a great drop in clutch

Jeff20B

iTrader: (13)

My friend has the RB street strip pressure plate and HD disc in his supercharged FB and it grabs well and breaks 'em loose in gear. It's definitely on my list of possibilites.