i have a 2001 honda 400ex that im building up to a 440ex with stage 2 hotcam, hotrod connecting rod, k&n filter and jetting, how much horsepower will i make with these mods?

also, how much power does porting add?

 

with the 440 kit you might be pushing what my stock scrambler is pushing,pretty sad huh?

 

Stock hp is about 26-28, I believe. I would say if you did the 440 kit, a cam, and a good port & polish job you could easily get 10+ ponies. I mean they say a stock YFZ is getting 45hp, so you gotta be somewhat close, right?

 

I would say around like 38.

 

you won't have the same horsepower as the yfz. i talked to someone with a decked out 440 that couldn't keep up with a stock yfz. he said he had more torque, but that yfz keeps revving and revving and in the higher gears he was left behind by a couple atv lengths. why are you wanting the stage 1 cam? are you wanting this mainly for trails and not speed? you will probally notice a difference with a port/polish if you go to a good engine builder. you would probally notice much more difference if you put on a fcr 39 though. i bet your horsepower will be less than 40.

 

Dirt wheel magazine said that the yfz have only 36.5 hp and a modified Z-440 have 38.5

 

Hp isn't everything. But it sure is fun.

 

Torque is everything. [img]i/expressions/face-icon-small-happy.gif[/img]

 

Maybe torque over a broad range of rpm/s? But torque is not everything or would be using diesels.

The longer you can extend the peak torque range (say maintaining 80% of peak torque) the more useable power you will have. If your torque peaks at say 3700 rpm's but dies off quickly after that say having only 60% of peak at 5500 rpm/s, and someone else reaches a little lower peak torque at say 3600 but maintains up to 80% of this torque up to 6500 rpm's, the second bike will have a lot more useable "power" than the first. The first will require a lot of shifting to stay close to the peak range.

 

not sad at all, the scrambler 500 weighs almost 600lbs with an auto and the 400ex weighs only 400, power to weight ratio is everything