Hey guys, I need the knowledge of my fellow old school owners. I'm trying to figure out what clutch and flywheel to use on my Rx-4. I'm building a 13B 4 port with an Rx-8 e-shaft, S5 NA rotors, and S5 counterweights. I'm going to use a light weight flywheel of some sort. Just wondering if an S5 NA flywheel and clutch will fit properly with the stock 4 speed transmission in the Rx-4? My other option would be to get an RB flywheel to fit Rx-4, but will it bolt up to the S5 counterweight? Any advice will be appreciated. Thanks.

 

Those are two good choices.

The RB light steel flywheel should retain enough inertia for good driveability even starting on hills. It will require a bit more slipping though so choose a disc and pressure plate (225mm size) that allow slipping. Avoid any type of puck disc. You'll quickly learn to hate it. I don't even like HD discs with stock pressure plates because they really don't go together (driveability sucked, should have used a street strip pressure plate with it but then it increases pedal effort).

The S5 NA flywheel uses 225mm disc and pressure plates so you're fine there. It is slightly heavier than a light steel, but lighter than what RX-4s and Cosmos came with stock, which was 30 pounds (and only 215mm in size)! The S5 NA is like 24 pounds, right? The RB light steel is 13 pounds minus the counterweight, which is 4 pounds for a total of 17.

Yes an RB light steel will fit an S5 NA counterweight.

I'm currently debating a similar setup for my Cosmo. My rotating assembly is old school 13B so my choices are a 30 pounder, or a GSL-SE flywheel or an RB light steel. So far I've been using the GSL-SE and it's great but I'd like to try a camden supercharger and from what I can tell when I had it on the RX-4 with a GSL-SE flywheel, which is 26 pounds, it felt more like 30 pounds which I did not like at all. I wished I had gone with a light steel. Well now I have a chance to do it all over again, this time with a light steel flywheel so I think I'll go for it. The GSL-SE flywheel could go in my REPU since it's a truck and a light steel felt a little on the light side, actually. I honestly wish I could use an S5 NA flywheel in the truck, but I don't have any S5 rotating assemblies; I do have an S4 rotating assembly, but I want a moderate compression ratio around 9.0 to 9.2 instead of extremes of 8.6 and 9.4 of S4... unless someone could talk me into it.

Hmm... S4 T2 rotating assembly, S4 NA flywheel, stock disc and Daikin(exedy) FC pressure plate (for slightly more clamping pressure than FB but slightly easier pedal effort than a street strip from RB), 7" Camden SC, 2.5" exhaust, 3mm apex seals, all in a set of old school '74-'75 rotor housings in the REPU... I have to say I'm really liking the sound of that this morning.

 

The light steel flywheel and a HD clutch and pressure plate sound like a good plan. I'm planning on bridge porting this bad boy too with RB racing carbon apex seals. So there shouldn't be any clearance problems with the transmission bell housing if I run an aftermarket clutch and flywheel from an S5 NA.....
I currently have a fidanza alluminum flywheel and centerforce clutch and pressure plate on my FC. I have no drivability issues with it at all. I daily drive it in the summer. What I did notice was mad throttle response after installation though.

 

and I bet you rookie didnt even noticed that RPM drops as quick as it went up

 

is that you.... Wackey????

 

 

Actually, yes I did notice that but I don't really care. I got the flywheel and clutch dirt cheap. After a while though that small little difference just becomes normal anyway.

 

yes it does. may i ask tho what is it bout the rx8 shaft for ur decision to use it rather than, say, s4 shaft like i used?

 

The Rx-8 shaft is really cheap to buy brand new and since I want to use the Rx-8 stationary gears, I can order them with bearings already installed to match the shaft. It's also a bit lighter, but being it is so close to the rotational centerline it won't really have that much of an impact performance wise.

 

I prefer 4 puck over 6 puck or racing beat clutches. keep the pressure plate below 3K lbs and you should be fine

 

Go with a RB 4 puck sprung hub disc and you will have no problems. I don't know why people have a hard time driving them on the street. I drove my rx2 with a bridgeport with a 4 puck unsprung hub and had no problems. Like anything else, you just have to get used to it. I would stick with a lightened steel vs an aluminum flywheel if this is going to be driven on the street alot. Especially in alot of stop and go traffic.