I know what the logical answer is here, but will the factory Warrior headpipe choke down a modified engine? I have installed a 446 big bore & stroker kit, its ported & polished with larger valves, and has a 84 grind Webcam. I had been running a Curtis Sparks slip-on and had a 366 JE bore kit before with good results. Ive always been told the Warrior headpipes were almost as good as the aftermarket ones. Just want some more opinions. Thanks!

 

My understanding has been that the stock pipe is good enough for just about any engine mods. For the longest time, there wasn't even that many headpipes available for these machines. That was because the stockers were good enough. It wasn't till the companies realized that people will spend the extra$$$ just to have an aftermarket headpipe. Just because it's chrome, titanium or just painted steel, if it's an aftermarket headpipe, people will assume that it's better, which isn't always the case. Yes, there are headpipes available for the warrior that DO improve flow, increase performance, etc. Is it a significant increase over the stock pipe? NO. The majority of any gains you'll see are achieved via the muffler/silencer. I have read that the stepped design of the Big gun headpipe works well on this machine.

Keep in mind that this applies only to the warrior. If you look at the stock headpipe on lets say a 300ex for example, you can see the difference, their's are about 2/3 the size of ours. Adding a headpipe to one of those will result in a dramatic increase. Another example is the 400ex, although it is a twin pipe design, there are issue's with their stock pipes as well (too small in dia., plus the issue with the welds on the inside restricting flow). These are non-issues with the warrior pipe.

I'd be happy with your Sparks slip-on, no need for the extra headpipe, that is unless you have the extra cash to burn or just want it to look pretty.

 

I like the Sparks slip-on, but its getting old and I know it needs re-packing and it doesnt sound like a Sparks anymore. Sparks doesnt make a pipe for the Warrior anymore, so I plan on going with the HMF system. I just dont want to spend the money on the full system if its a waste of money, because I dont have it like that.

 

The factory head pipe is quite large and flows a lot of air. It's a little large for the stock motor.
If I were building a motor like this I would contact Mikey Dunlap (he's the guru of all warrior engine builders) and talk to him about this.

 

Yeah, I bought the 446 kit from Mickey. I shouldve asked him then, I guess. JASONP, how did that timing advance key work for you? I was thinking about getting one for mine, but didnt know if it was worth the trouble of installing it or not.

 

Yeah you have to buy a flywheel puller which is like $40 dollars. Then a gasket. So it's really much more price mod then you think... but if you can borrow one from your Yamaha dealer that would work. I told myself with all that trouble I'm going to have the flywheel machined by duncan racing to be lighter so that's $75 dollars right there. Honestly, I'm doing all this stuff at once to my bike so I have no idea what every little thing I did to the motor helped or not. I can only go by what my engine program tells me and as long as I've put the right numbers in then it's actually quite close to being relistic. We used these in school (UTI) before we dyno'd are hot rods and I was impressed. The programs like the teachers said was within 15 percent. Anyway yeah, it's just like advancing the timing in a car to get every last hp out of it. A lot of street rods I built and engines at school you had to run better gas to get away with increased timing... which help add throttle responce and hp.

 

Does that program tell you how much horse power you should make? Im just curious. I cant get all that high tech, I just do a little something to the engine, then go race somebody. I do know with all the mods I had, which is about what you have, I could beat 400EXs with big bore kits in a drag race. They gave me about all I could stand, tho.

 

It's right around 28 or so. I used it more for what cam should I pick out for my riding style. It helped me see how each cam I put in gave me a different power band and how much peak HP/Torque and average. I'm not really worried about how acurate the HP numbers are, like how much I will have after the mods. I looking for how it effects the power band and Torque of the engine. Does that make sense?
That's impressive, beating 400 ex's moded!

 

Im impressed with the way you designed your engine for your needs. It does make sense. I was proud of my old Warrior when I beat those 440EXs! After that race, I jumped all over a stock Raptor 660 and a modded Yamaha 450 while I was feeling cocky, but that was a big waste of my fuel![img]i/expressions/face-icon-small-blush.gif[/img]

 

Just for fun I went out and raced my friends on a modded up yzf 450r and banshee when they where over. I had a pipe, and a carb kit open air box. They had them piped and lids off the air box and jetted. I was left in the dust. I mean it was bad. Pretty funny. Those bikes are on a whole nother level when you get just a few mods done to them. Personally if I had that much power I'd kill myself and we are always riding in woods so we are always backing up. They had to pick there bikes up and move the front ends around. So I mean yes the warrior is a dated design but personally I love mine, like what it does and just looking for a little more uhmmp on the bottom end in mid range and I'll be happy!