My log of Alice's transformation into "my bike"

[Claviger]

Just using this to consolidate and preserve (for my own use mostly), the process of modifying my Z H2. (Pictures to follow from phone).

Thoughts as delivered:

Power is over the top. Kawasaki was insane to deliver this motorcycle to the public: it's flat out probably the most dangerous bike in stock form in the last 20 years, the previous bike being the TL-1000S/R. The Z H2 doesn't come with a steering damper stock, a horrible decision on a bike with a 57.2" wheelbase and 180whp/90ft-lbs at the wheel stock, with gearing fit for a 600 sport bike. It's not the most powerful stock bike, it's not the lightest stock bike, but geometry + power + weight + seating position = the net result of wheelie wheelie wheelie wheelie + wobble wobble wobble.

1 - First up is the steering damper installation, I bought a HyperPro RSC damper and fitting kit. Initial thoughts, huge help. It takes the high speed violent oscillations of the bar and turns them into manageable low speed oscillations. While not ideal, paired with wheelie control, I deem it acceptable. The root cause, KRTC setting 2, should still be avoided, either go to level 1 and accept the 1 foot hover wheelie or go to mode 3 and accept the reduction in torque but no wheelie; level 2 puts the wheel about 1" over the ground and skipping off bumps triggering wobbles.


2 - Next issue is weight. At 529lbs with only a 90% full gas tank, that translates to about 540lbs fully topped off. To address this I've taken a few routes some installed, some in the garage waiting for installation: ACF Protaper bar (-1.5lbs), rear peg mounts removed (-3.5lbs), lightweight steel rear sprocket instead of stock (-1.5lbs), tail tidy and reflector removal (-1lb), tool kit delete (-1.5lb). Remaining to arrive in shipping or be installed are: Titanium 2022 ZX10R exhaust + decat link pipe instead of stock stainless exhaust (-19.5lbs), LiFePo4 Battery (-6lbs), lighter fuel cap (-1.1lbs), various Titanium fasteners instead of Steel (unknown loss), full carbon bodywork, lighter rear Brembo caliper and carrier (-1lb), BST Carbon Wheels (-11lbs), switch to Michelin instead of Pirelli tiers (-1.5lb). Total weight loss potential resulting in a fully fueled weight of ~491 lbs once all items complete. As of today, I weighed the bike "over" full of gas, and it came out at 521 but much of the above list is not yet installed.

One brave soul has made a track only version of the Z H2, with a fully fueled wet weight of 458 lbs, but, that removes a lot of features like ABS to get there and I'm not willing to do so on a street bike. My ultimate goal is ~480lbs wet and fueled.

3 - Next most critical stock issue relating to performance is the gearing. Kawasaki decided the Z H2 should have short gearing internally and moderately long gearing on the front/rear sprockets using 18/46, the resultant top speed is 176mph (GPS), and an indicated 186 mph. The problem with this is just how short 1st, 2nd and 3rd are, they're not long enough to fully leverage the increased torque the engine produces compared to an NA liter bike. They enable too much wheelie potential resulting in KRTC cutting power to keep the bike from looping in the first 3 gears. To correct this I've switch to 18/43 gearing, and have a 19T front gear on hand which will be installed on Wednesday. Total gear reduction will be about 11 percent. The total gearing change results in the 5th peak speed being equal to the stock 6th gear peak speed, and the new 6th gear peak speed being 199.5 mph. This essentially shifts 6th gear into an overdrive role, meaning play will be done in 1-5 instead of 1-6, reducing the need for KRTC intervention in 1,2,3 and allowing the bike to actually put down the power it makes. While this wont help on a drag strip, it will help on the street; 1st gear is good to 88 mph, 2nd to 109mph, 3rd to 131 mph.

4 - Next issue is the intake temperatures. With a supercharger making 14.7 psi peak and no intercooler, the inlet air temperatures are unbelievably high, cruising down the freeway at 80mph the inlet temperatures are ambient + 50f. So in 90f weather, cruising inlet temps are 140f!! Now that's not so bad; but try and run 110 mph or higher for an extended period and you run into the issue. Averaging 123mph for a tank of gas, my inlet temps ranged from 170f to 220f! Imagine the timing retard required to keep 1 BAR of pressure safe with a 220f intlet temp on an 11.2 Static CR engine, jesus, no wonder the bikes drop 20hp as soon as ambient hits 90f vs 60f dyno pulls.

In order to fix this, an intercooler is necessary. Extreme creations to the rescue, they have an air to water intercooler with auxiliary radiator to help cool the charge temperatures; it's a 37f drop in inlet temperatures. This will be the first major modification to the bike I'll be making; targeting September to get it done. It also happens to be critical for flashing the ECU and making around 230whp on pump gas in hot weather. ECU flash and more power are not ruled out, but not my emphasis at this time; I simply don't see the need for 230whp on a bike that already struggles to put down 180 in the first 3 or 4 gears (weather dependent).

 

[Claviger]

Got my ABBA stand, nice piece of kit, allows both wheels in the air simultaneously. Had a snoop around the rocket to see if it could work, and the exhaust is in the way of the swing arm bolt so, unfortunately it looks like a nope. Shame, as it would be a great way to lift the heffer up for maintenance.

 

[Tal]

nice work!....your brain must be constantly ticking over with mechanical stuff!...how do you manage to sleep?!....i do admire your work and ability!

 

[Idaho Red Rocket 3]

Great info Rob. Hope all the plans pan out to get the weight down. Question about the inter-cooler. I am under the impression that air to water is the old way of inter-cooling. Now days most inter-coolers are air to air because of lower charge air temps. Or so they say. Is an air to air inter-cooler a viable option for the Z H2 ?

 

[Claviger]

Unfortunately it's not, the packaging severely limits the space available, so the air to water just works better.

Dropped for 1st Kawi service today. The new 43T rear sprocket is a great fit for the power band of the bike.

So looks like tomorrow a wave of parts get installed, wahoo!

As Tall guessed, I've been rummaging through the Kawi parts bin to see what can fit the Z H2 from the ZX10R. Looks like the magical BFF ZX10R front end is a near direct swap, but low priority as I find the BPF front end incredible.

Of more interest is the cylinder head which uses finger followers instead of buckets. It reduces rotating mass and would extend the safe valvetrain redline a good bit, to around 13800-14000. The accompanying ZX10R cams would be required as well, so I have more research to do, finding specs on this stuff isn't easy.

That leaves the bottom end, I need to find and get some hands on with stock pistons and H2 pistons so I can figure out what will work and what won't.

 

[Claviger]

Well I've found cam specs Turns out, Z H2 is undercammed from the factory to boost bottom end/midrange power over H2 and H2 SX.

H2 cams physically fit, but need adjustable gears to manually dial in timing.

Z H2
256 7.2mm lift 93 LCA
248 7.2mm lift 97 LCA

H2
264 7.7mm lift 95 LCA
260 7.9mm lift 100 LCA

This would create an interesting set of options:
-Time cams for H2 power band, biased towards 10k-13.5k. Will shift power from bottom to top, not my jam these days.
- Time cams for peak power at 12.5k, resulting in a good boost from 8.5k to 12.5k and a very mild boost below 8.5k.
- Balance the spread to peak at 13k and basically match stock low/mid performance.

None of this matters until piston situation is solved, stock pistons are the weakest link. If I go into the engine it'll be custom pistons to keep CR at 11:1 - 11.5:1 but gain the advantages of forged metal and thicker ring lands.

Looking at them, I'm thinking H2 inlet and Z H2 inlet cam as exhaust cam will be where I go if I do cams, keeps them fairly mild to retain street manners.

 

[Claviger]

First service report:
Fuel trims "within stock spec". Confirmation ECU can compensate for a slip on (and decat) with no retune required. Amazing how far bike ECUs have come from just 5ish years ago.

Everything else checks out, clean bill of health.

PS: I asked, dealer mode CAN view all sorts of fun parameters....max speed, % time spent at WOT, all the telemetry you can see on race bikes you can see on the Z H2: if there's a sensor, it logs it, goes for any Bosch IMU enabled ECU, so ....if you ride like an ass, the dealer knows

The only limitation is that it only records an (unspecified) number of heat cycles before overwriting oldest data points.

 

[Idaho Red Rocket 3]

Sounds interesting how they can nanny how you ride. Maybe overwrite might be a blessing ?

 

[Claviger]

Sounds interesting how they can nanny how you ride. Maybe overwrite might be a blessing ?

Yeah, I'm fairly certain it's a requirement or pending requirement for motorcycles by Uncle Sam., not sure if the law was passed on requiring it Cars do it already and are required to do so.
Posted that bit for the owners of the 2500 Rocket, they have an ECU that does exactly the same thing.

 

[ruzzle]

And I believe Triumph records every bit of that info automatically from your ECU at every dealer service and stows it all in the factory data bank.

Of course, they don't record whose bike it was from.......

Yeah, right.