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peak power
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Posted by: allaboutHP

would a z400 with a pc slip on, 160 mj, a uni filter with no air box lid have as much peak horsepower as a 400ex with the mods in my signature?

Posted by: montyjcm

Unless it was a poorly built 440, I doubt it.

Posted by: Billdog350

I would have to say it would depend on the compression on the 440. I have heard of people putting a weisco piston or the stock base gasket in a 440 and keeping the compression close to stock (low). In that case, I would say the 440 wouldn't be too high on power.....but if you're running 12:1 compression on the 440 with race gas and a good cam...then you should be higher than the slightly modded z400. Remember that the stock z400 starts with approx 3 hp more than the stock 400ex. Airbox lid and jet gives you another 2 hp across the band...and the pipe would be another 1-2 hp. That puts you in the mid to upper 30's for rear wheel hp on the z400...which is about what I'm hearing that normal 440ex's are putting out. If you remove your base gasket or replace it with the DRZ one on the z400, and do an intake cam, then I'd say you'd almost definitely be higher on power than the modded 440ex. Does anyone have dyno charts or seat of pants experience to confirm or deny>?

Posted by: ExRacer02

I have a kfx 400 that I trail ride with and a 416ex that I race. The 416 is cammed 12:1 Je 39mm FCR, and all the other goodies the only thing stock in the motor is the crank and the flywheel. My kfx has a full Pro Circut pipe kn filter with pro design intake and jet kit. Me and a friend raced them and my 416 pulled it all through the gears and beat the kfx pretty bad. But I'm not knocking the kfx I really like that bike and have seen one built by Terry Pope of turtle racing ( he builds motors for John Natelie) that would flat spank my 416.

Posted by: Billdog350

ExRacer, you proved my point. You're running high compression...which SHOULD beat a stock KFX. However if you were running 9.2 or 10:1 compression it would be a different story.

Posted by: montyjcm

Yeah, he was also running a fcr 39mm carb, which would up the hp quite a bit.

Posted by: allaboutHP

the compression is 11:1 and its not cammed. does anyone know the exact horsepower numbers of these quads, i thought it was 29 for the z and 27 for the ex but i guess i was wrong.

Posted by: Billdog350

Rear wheel hp for z is around 33 and the 400ex is around 27-29. I have seen a few dyno charts from places doing both on the same dyno.

11:1 on the air cooled honda is max for pump gas. You can get 12 out of liquid cooled z/KFX before you need race gas.