GpZ550 Turbo Clutch Upgrade

The OEM clutch can't handle the power in 4th gear at full boost.
I'm creating a hybrid clutch basket using a 2013 zx636 basket and the oem 550 basket. The 636 clutch pack, hub, and pressure plate will be used with the hybrid basket.

The 636 clutch only uses 3 clutch springs but it has ramps built into the hub and pressure plate that create additional clamping pressure when higher torque is applied. The harder it's stressed the harder it grabs.

Here are pics comparing the 2 clutches, showing removal of the gears, and showing the material that will be removed from both basket so they can be welded together.
The center section of the 550 clutch basket is retained along with the rubber cushions and the drive gear. The 636 outer basket section with fingers will be welded to the 550 center section. Height of the 2 clutch packs with pressure plates vary by only .4mm (.017") so there shouldn't be clearance problems under the clutch cover.
Note: the 636 plates and basket are smaller in diameter than the 550 BUT the clutch pack has 1 additional friction and steel plate.

Clutch baskets are at a shop waiting to be machined and welded together.
Fantastic "gem" of a shop manned by an old timer genius and his genius son.
I spent 2 hours at his shop learning about all the projects he's done over the years and all the Companies and institutions he's done work for including DOD and NASA.

He's not doing it for the money. Only charges $75/hr. Total job should take about 3 hrs. Not bad for something you can't buy. His Son took one look at the 636 clutch basket and immediately said, that's a Kawasaki.

I want to work there. I'll do it for free.

Impressive.

garylbishop wrote:
Clutch baskets are at a shop waiting to be machined and welded together.

Did you have any pics of the clutch basket Job, (before, after and why you have to do)?

very cool. I may be doing something like this on my KZ750 twin. I was smoking the stock clutch bad with 150% more power on the last engine and with the new engine I hope power to be 200% over stock. I don't think the stock clutch has a chance even with stiffer springs.

Scirocco wrote:

garylbishop wrote:
Clutch baskets are at a shop waiting to be machined and welded together.

Did you have any pics of the clutch basket Job, (before, after and why you have to do)?

look at the first post. It has "before" pics of the 2 clutch baskets.
When I get the completed basket back from the Machine Shop I'll post a few pics.

Here are 2 additional "before" pics that show the relative final dimensions of the 2 parts being machined. Almost the entire center of the 636 basket will get removed and the outer diameter of the 550 basket will be turned down to match.

still waiting for the machine shop to rework the 636 clutch basket. I'm in the queue but they had lots of work ahead of me.

Finally got the 636/550 hybrid clutch basket back from the fabricator.

636 outer basket stitch welded to 550 back plate. 3 long welds, 3 short.

I'm happy with the results. Welding oil soaked cast aluminum can be difficult and sometimes down right impossible.
Puddle randomly blows out. Cosmetically challenged but functionally strong.

Center boss of 636 pressure plate sits slightly taller but the backside of that boss, where the clutch PULL bearing sits is at the same height.
The clutch on the left in the picture is actually from a ZL600 . I need to pull my ZX550 clutch off to directly compare with the new Hybrid.

The 550 clutch has been removed and the hybrid basket with the 636 center hub, clutch pack, and pressure plate has been installed to take measurements and pictures.

The outer edge of the basket needs trimming to clear the inside of the 550 clutch cover.
The material that needs to be removed for clearance is marked and can be seen in the attached photo.

The 636 center hub will also sit a bit further into the basket once some material is removed from the backside at the hub's bore.
The entire clutch pack remains the same height/thickness but it will sit further in the basket. Moved in about the thickness of 1 friction plate.
The outermost friction plate will be installed with it's tangs inline with the other 7 friction plates. Normally it would be installed in a separate set of slots machined into the outer ring of the basket. Most slipper clutches incorporate a separate set of slots to hold the outer most friction. Since my clutch pack will sit further inside the basket, I wont be able to use those separate slots and a portion of them will be machined off when I trim the basket for clearance.
Not a problem though. The clutch will still function as an assist and slipper clutch.

A few more pics..
The 636 center hub needs material removed at it's center on both sides.
Removing from underneath allows the hub to sit lower in the basket.
Removing from the topside adjusts the total length of the splined center, allowing the retaining nut to fully thread onto the transmission shaft.
The areas to be machined are marked and can be seen in the pics.

Also installing ZL600 primary and clutch basket gears. 28/63.. Up +2 teeth on the primary gear and -2 teeth on the clutch basket gear.
The 550 has 26/65 gearing.

The 636 clutch, like other slipper clutches, has 1 double thick steel clutch plate made of 2 steel plates loosely riveted together with spring steel separators to expand them apart slightly. I opted to drill the rivets, separate the 2 plates and use just one of them in the clutch pack. That reduces the over all clutch pack height by 3mm allowing the pressure plate to sit lower in the basket. More clearance under the 550 clutch cover. It also reduces the spring tension so the 3 threaded spring towers need to be shortened by 3 mm in order to restore spring tension.

Pics show the reduced clutch pack and the steel plate that was removed.
One pic shows the reduced height clutch pack and basket mounted on the 550 engine.

Next time,hit the "insert all button", to right show up your pics in your next post please. :whistle: :whistle: :whistle: