125 HP?

I got tired of my old car projects and am really enjoying working on a bike for a change. I have a couple of questions:

What modifications would I need to get around 125 crank hp from my 79 KZ1000?

What is the rule of thumb for percent hp loss to the rear wheel on a chain drive bike?

Thanks, this forum is great!

Post edited by: caffcruiser, at: 2006/09/29 09:45

Ah-ha Caffcruiser. I've gone that route on cars before and it is fun till the bottle runs out. I know you are poking fun, but I'm looking for typical N/A "engine mods" so the power is always there. "no officer, those aren't NO2 bottles, they are aerodynamic saddle bags".

have you thought about turbocharging? or just a big bore motor?(or both?:evil: :evil: )

Take a look at www.oldkawman.com . He has some interesting and (I think) accurate info on HP gains with different mods. Porting, pipes, cams, big bore, high compression pistons, etc. A KZ1000 is limited to less than 125 HP due to overheating issues on the street. Your goal is probably reachable for track use.

How far up Blue Ridge are you from GA?

125HP? My 400cc Honda four is speced as 56HP@10,750RPM. 11.5:1, 4 valves/cyl, 32mm carbs. Rev limiter at 12,500 RPM ;-) It's pretty quick for a small bike.

Biggest gain comes from getting more mix in and exhaust out and increasing the temp delta(increasing compression). Reasonable displacement increase(not beyond the point where cooling capacity is reduced) wouldn't hurt. Adding oil cooler will help with increased heat dissipation requirements. This is armchair advice as all the engine building I've done has been of the 'repair/rebuild' type. No hotrodding.

hey wireman, tell the guy what you have builtB)

Duck, I'm on the Blue Ridge Pky about 5 miles south of the Va border.

The 83 GPZ1100 I had once upon a time was "rated" @ 120 hp and had no heating problems. It had the power level I'm looking for.

I guess I'll just live with the mild cam upgrade, bigger carbs and pipe until it needs freshing up. Then I can go with the 1075 kit, cams, porting, etc.

Losses through the chain drive anyone?

A bike rated at 120hp will typically make 100hp at the wheel. That's not drivechain losses though, that's marketing

I've opted to got with the 12:1 WISECO 1075 kit. Like to run on steet pump gas. Sunoco Gold but not a VP or something.

Romspaceknight, how do you like the kit? How does it run? Does the head flow cause it to run out of breath on top end?

Post edited by: Exitpupil, at: 2006/09/29 22:24

andoman wrote:

Take a look at www.oldkawman.com . He has some interesting and (I think) accurate info on HP gains with different mods. Porting, pipes, cams, big bore, high compression pistons, etc. A KZ1000 is limited to less than 125 HP due to overheating issues on the street. Your goal is probably reachable for track use.

I would suggest you look elsewhere than the Old Kawman.
My GPz1100 is rated at 120hp stock, what's the difference really between it and a KZ1000 regarding overheating?
I have an 1170cc big bore kit with the compression upped to 10.25:1. No overheating issue here.
I think 125hp is easily done. Porting, carbs, exhaust...APE Jay is probably the guy to set you up.