[Jeff20B]

Dave, I have a used 215mm CF DF disc and p-plate that look to be in decent shape, plus an old style RB light steel flywheel that lacks the clearancing for 225mm pressure plates, so it can only be used with 215mm plates even though the friction surface extends out to 225mm. I also have a new 225mm RB SS p-plate, HD disc and light steel flywheel that has these 225mm clearances. Lastly I have a CF 215mm p-plate by itself, a stock 215mm clutch disc and an aluminum flywheel (again lacks clearances but the steel friction surface extends out to 225mm and I got away with a 225mm disc and a 215mm pressure plate - it had a funny 5mm lip of disc on the outer edge hehe - didn't cause any problems).

I need to get my REPU running soon and a new engine will be built for use with the 5" SC and -10 pulley. It will be expected to tow a load no heavier than a GSL-SE complete car on a trailer or a VW baja with one of those front beam tow hitch things. My friend tows stuff like this all the time with his '77 REPU and the 7" SC as described above. His clutch setup consists of a 225mm SS p-plate, 225mm HD disc (it shudders a lot, I'm sorry to say, but grips just fine) and a light steel flywheel. The tranny is a '76 5 speed and the rear end gearing has got to be the tall '77 3.9 set because it just seems to be geared a might bit taller than what I would consider to be ideal.

My REPU is a '74 but apparently has the same rear gear ratios as his '77 because when we drive the same speed in the same gear, our RPM sounds the same. I too have a '76 5 speed (it has the far spread between 2nd and 3rd and 5th is short). It drives a lot like his '77 due to the rear end. A high idle makes it hard to creep along in parking lots because it feels like you're in 2nd gear sometimes.

I'm asking for opinions on which clutch/disc/flywheel combo I should use. The engine and intake are already known. The tranny and rear gear ratios are already know. The exhaust is just an RB collected header for REPU (they don't make them anymore) into a single 2" system routed through two RE glasspacks. This keeps velocity high for good low RPM performance. I assume the -10 pulley will kick in soon and then run out of breath right around when the exhaust becomes a bottleneck. The engine ports will be small stock '76 Cosmo size for maximum low end. R5 side plates. Stock exhaust port timing (they close early compared to GSL-SE for less overlap and less wasted boost out through the exhaust system).

I thought about using the CF DF and the old style light steel flywheel in the REPU because I want relatively easy pedal effort, due to the REPU's shorter pedal travel, but my friend's REPU has decent effort like how mine did with a dead stock REPU clutch setup (the disc was worn down to less than 7mm and was stiffer and more grabby than it should have been). I hated the stock 30 pound flywheel with a passion. If I were staying NA, I'd have gone with a GSL-SE flywheel, but I feel the SC will add a bit of rotational mass+drag so it will make the light steel feel heavier. My bro's RX-4 had a GSL-SE flywheel with the SC and it felt just as heavy as it did with the stock 30 pound flywheel, but while NA felt lighter and matched the tall '78 3.636 rear gears quite nicely. If we would have known this about the SC during the planning stage we would have gone with a light steel. It worked out for the best though because the SC came off the RX-4, but I don't want a repeat in the REPU since I plan to keep the SC in it. So light steel all the way.

Do you think a CF DF would stand up to years of REPU usage? Or would I be better off with the SS p-plate? I don't think the HD disc would be ideal since my friend's shudders so much. I have a good used stock 225mm disc ready to get. Does the CF DF disc shudder like an HD disc? I heard the dual friction discs don't last long. Any input you can add is greatly appreciated.

Last but not least, I have a 1st gen that needs a clutch setup as well. It's getting a 13B while I gather funds to build an NA 20B. No plans to upgrade the tranny or rearend. I'd rather have the tires slip than break drivetrain components all the time. So 225mm is the maximum size I can go until I'm forced to upgrade to T2 components. I wish I knew more about the holding capabilities of RB vs CF, you know? All I have to go on is what others have said about them.

Do you think a CF DF could hold between 250 and 300HP behind an NA 20B? Or should I plunk the CF DF into the REPU? I sort of wanted to max out the clutch setup for the 20B, including the 225mm HD disc, since shuddering wouldn't be an issue in a 1st gen, and it is kind of a spicy meat ball, you know? but would entertain the CF DF since the car is lightweight and it's getting a 13B first anyway. The truck needs a good relible clutch setup that will last for years, and so far, despite the shuddering, the RB setup has worn well in my friend's REPU. I figure I can cure the shuddering with a stock disc. Well, I've rambled long enough. Thanks for any input.