New Clutch, Flywheel and HFC

The new clutch, flywheel and high flow cat arrived last week but with very little free time the next few weeks, I had to call in reinforcements in the form of Robert Thorne to get Bumblestook up to speed asap. Thankfully, Robert was kind enough to fit me in today and got the car sorted in no time.

Thorne getting ready to drop the transmission - 4-20-2019
(Also reunion with the The Big Bad Wolf) 

The first order of business was to inspect the Berk high flow cat which I was suspecting was the cause of my power loss. While the cat had seen better days, the inside wasn't collapsed or blown apart so I really don't think it failed. However, since I already got a new EVS Tuning 63.5mm cat, I figured it would be a good time to swap it in anyway. The pictures aren't in chronological order. Obviously the new cat went in last since the transmission had to go out which also meant moving the engine around. What I need to find is an HJS 200-cell core like the one in the STU Cayman and have Robert make me a high flow cat that is going to for sure be much more reliable and better flowing.

New EVS Tuning HFC (top), Old Berk HFC (bottom)

EVS HFC installed - 4-20-2019

This is not the first time Thorne's dropped an S2000 transmission. He had lots of really cool shortcuts to get the trans out without dropping the subframe or the header saving a ton of time. I won't go into those details here but not having to do that meant saving time and more importantly not upsetting my alignment.

Driveshaft, Transmission, Clutch and Flywheel off the car

One of the surprises we got when he removed the driveshaft was a bunch of transmission fluid spilling out of the output shaft flange cavity. That's supposed to be dry! Thankfully the flange of the output shaft and the drive shaft is so tight that it never leaked on the outside so the fluid was contained in that space. Turns out, when we replaced the output flange from AP1 to AP2 last year, the little O-ring, must've still been stuck to the old flange. It's not obvious that you need an O-Ring here since there's yet another teflon ring that goes on top of that. Thankfully Robert has spares of everything and this was quickly remedied by him stealing the O-ring from one of his spares. The part number is 91301-PCY-003 for future reference.

Output flange with missing O-Ring

Now we got to inspect the clutch and what we believe is the real cause of the power loss. The clutch must've been slipping a lot. It's totally worn down all the way to the rivets on the flywheel side of the friction disk. This clutch has only seen about 3000 miles in total but most of those miles were very hard miles and I'm sure the years of ProSolo launches did not help. I went with a new OEM friction disk because it's more than capable of holding down power. Even the turbo guys use this. The springs were also beginning to rattle a lot but at least they were still in place.

Heavily worn old clutch. 

New OEM friction disk

As for the old 11.5 lb Competition Clutch flywheel, well it had its share of hot spots probably from those crazy high RPM launches. This time, I went with an OEM AP1 14lb flywheel. I think it's the perfect street performance flywheel. It's just the right weight to make it easy to drive on the street while still being light enough for quick acceleration and heel-toe. You also can't beat OEM quality. The car is "almost stock" after all.

Old Competition Clutch flywheel

New AP1 Flywheel installed with new bolts and washer- 4-20-2019

As is always recommended when doing a clutch job, the release bearing guide was also replaced along with a new throwout bearing.

New Release Bearing Guide

New throwout bearing

I did have Robert reuse my ACT HD Pressure plate. In hindsight I probably should've gotten a new one since I've already gone through the trouble of buying all new parts but it's too late now. The condition is "ok", not horrible but also not excellent. We'll see how it holds up.

Car all done  4-20-2018

I will say though what a massive difference the car feels now! Although I am still taking it easy to break the clutch in, I can already feel it grab so much better. Even at part throttle, accelerating in 2nd, I can feel a massive difference in acceleration. There's no doubt in my mind the power loss was fully attributed to the bad clutch. I'm super glad I got this taken care of now because I'm going to be able to go the S2k Takeover of NYST next month will full confidence that everything is as it should be.

Here are the OEM part numbers for everything replaced including their current prices from Majestic Honda. I compared this against the last time I bought OEM parts and these prices have gone up quite a bit in the last few years. I should probably buy another set to keep as a spare for the future.

Part Number	Part Name	Price	Quantity	Total
22100-PCX-005	Flywheel	$314.41	1	$314.41
22200-PCX-055	Disk, Friction	$172.89	1	$172.89
90429-PCX-000	Washer (38X88X2)	$13.00	1	$13.00
90011-PCX-B01	Bolt (12MM)	$4.50	8	$36.00
90034-689-000	Bolt, Twelve Point (8MM) (Tokai Trw)	$5.81	9	$52.29
22810-PCY-003	Bearing, Clutch Release	$157.00	1	$157.00
21103-PCY-003	Guide, Release Bearing	$34.02	1	$34.02

Overall I'm super happy with the results. Big thanks again to Robert for the clutch save (pun intended). Even just hanging out at the shop and checking out their cars there was a lot of fun. It was also cool seeing The Big Bad Wolf again. The last time these two cars were this close was back in our days competing in BSP. What totally different directions we've taken our cars since then.