How well do your piped and jetted ex's run against a z/kfx? Saw a race between the 2 on the weekend. It seemed like the ex wasnt running to its full potential. The kfx smoked him. I raced the ex later that day and stayed with him the whole way, he beat me by half a bike length. Thats why i'm thinkin the ex wasnt running that well. I thought the ex could have easily beaten me. It not a rider problem either, these guys have been riding for years and can do just about anything.

 

I would think it would come down to the riders, seeing that a stock Z has 3 more HP than a stock EX, and a pipe adds about 3-5 HP to the EX.

 

I don't think any pipe ads 3-5 HP on an EX... more like 1-2 hp

you'll probably need a cam and piston along with a pipe, to beat a Z...

and you'll need a big-bore kit, with a port & polish on top of all that, just to run with the Raptors, Predators, and V-Forces...

my guess anyways

 

DSAPP is right on the money

 

Some dynos I was looking at even showed a peak power loss of up to 1 hp with an aftermarket pipe on a stock 400ex.

 

A piped,jetted and filtered 400ex wont touch a bone stock z400. Its not a killer but, its not a race either.
Peak hp is sometimes sacrificed for the power to come on stronger. If you are talking about a top speed race then yes we want to talk about peak hp. But in a drag, point a to b its not about peak hp.
440 kit in ex (Nothing radical, but the run of the mill 440), with a mild cam, ported, polished, hard rockers, bigger valves and springs is about one length faster than a stock z400 in a 500 yrdish race.

 

two of my buddies raced a brand new 400 ex vs. a Z. . .neither were jetted or anything .but the z killed it. . .even without jetting or pipe. . whatever. . .the ex I don't think will win. . now the 440 in the ex. . .thats a different story!!

 

What are you smok'in? I never had a chance to race a piped Z when my EX was stock. But now with only a 416 piston and cam I've killed more piped Z's than I can count. One length in 500 yards!?! Just in 100 yards, I'm usually already four lengths ahead and pulling away fast.

 

<FONT color=#0000cc>"What are you smok'in?"
</FONT>High Grade......
Why would I make **** up. I own a z400 a 400ex, my brother has a 400ex stock, a 440, a 250r and we race them all the time. Come watch if you want.
<FONT color=#0000cc>"I never had a chance to race a piped Z when my EX was stock..... "
Obviously you don't know what you are talking about, I have had the race you haven't.</FONT>

 

I think it could depend on who did the work to the bike, the clearences between the piston and the cylinder could be tighter in one or one may have been broken in differently then the other making the power different. even small things like spark plugs make differences in power. When they were raced what were the engine temperatures. remember the z400 is liquid cooled and the 400ex is oil cooled. the liquid cooled definately keeps a cooler motor. Engine temperature makes a big difference too... theres alot of things to think of. My friend raced his stock, but pretty used, 400ex against his friends brand new and stick z400 and was right with him the whole length.