buy exhaust or not

[Hondarider427]

A few of my friends have pipes on their 400ex's and i can beat one of them top end and acceleration. I only have 18's when he has 20's and we are dead even top end.(he only has a slip on)
My other friend has a full system and I can beat him acceleration but he beats me in top end by a little.He has 20's also. I was woundering if a pipe will make my quad wind slower because i like fast reving motors.

[400exrider707]

:huh A pipe will in no way shape or form make you quad rev slower. UNLESS! you dont jet it properly. A pipe with proper jetting will give you some more power, and if you do an air filter with open lid, pipe, and jetting it will really wake that 400 up. Also those 18" tires are why you dont have the top speed. Also there is no way that your quad with 18" rear tires is outrunning a piped 400 with 20" rear tires, unless either one of you has different gearing.

[397ccEX]

400exrider707
Hes got it all right

[Metzroth]

I'm guessing by the name of your thread you were contemplating buying an exhaust. If your wondering if it is worth it...yes. I've ridden 400's with and without pipes... big differences. You'll see even more of a difference if you do the mods the other guys suggested. (You guys helped me finalize my decision bout airbox lid off BTW). But I just recieved my HMF header and I am ordering the silencer with the inlet made for there header soon so I will keep you updated on the difference.

[Hondarider427]

thanx for the input
it helps a lot

[Zeke]

If you put agood aftermarkeet pipe on anything it will always make it performe better. but only if you have the right jetting. It seems like you are a better rider than them to if yours is all stock with 18's in the back.

[Metzroth]

I'm not trying to flame but i dont think because he has 18's he is a better rider. Am I wrong? I agree, no matter what aftermarket pipe you buy you will get better performance as long as you jet your carb right. You can get your carb rejetted for about $35 or just do it your self in 2 hours or so. It will only take you this long the first time. Stick with any of the 3 I mentioned earlier and you will be happy with your gains. Pipes will not make you have a higher top speed. It will just get you their quicker. If I were you I wouldnt even try to get top speed out of it. I'm thinkin of going down a tooth on the front. I hear it really makes a huge difference. It will give you less top end but you will accelerate really fast. I have a MPH calc and dropping one tooth on the EX takes away about 4 MPH in 5th gear at 8,000 RPM. So for 4 MPH you get madd acceleration. That will give you a top of about 55. Your top now should be somewhere around 59. If you want the calculator for yourself its nice to have. "The Quad Calculater by Gabe Ellett". If your trying to estimate what your top will be in all gears (it shows 1st throught 5th top speed and Feet per minute at certain RPM so its nice to have.

[cals400ex]

adjust the throttle cables on all of the bikes. if you have a bunch of slack in it, the carb isnt even opening up all the way. there is no reason why your bike should be faster than the other two. jetting is important too.

[yellowWB400ex]

All i know is that i beat you. Thats all that counts!!! It doesnt matter what you do. You dont have the money. ;)

[400exrider707]

Originally posted by Metzroth
I'm not trying to flame but i dont think because he has 18's he is a better rider. Am I wrong? I agree, no matter what aftermarket pipe you buy you will get better performance as long as you jet your carb right. You can get your carb rejetted for about $35 or just do it your self in 2 hours or so. It will only take you this long the first time. Stick with any of the 3 I mentioned earlier and you will be happy with your gains. Pipes will not make you have a higher top speed. It will just get you their quicker. If I were you I wouldnt even try to get top speed out of it. I'm thinkin of going down a tooth on the front. I hear it really makes a huge difference. It will give you less top end but you will accelerate really fast. I have a MPH calc and dropping one tooth on the EX takes away about 4 MPH in 5th gear at 8,000 RPM. So for 4 MPH you get madd acceleration. That will give you a top of about 55. Your top now should be somewhere around 59. If you want the calculator for yourself its nice to have. "The Quad Calculater by Gabe Ellett". If your trying to estimate what your top will be in all gears (it shows 1st throught 5th top speed and Feet per minute at certain RPM so its nice to have.

I had a 14 tooth on for a while and it was awesome for SX tracks where it was really tight. I could out accelerate my buddies Z and we had the same mods. But he DEMOLISHED me on top end. We both had same tires on back. I would be tapped out in 5th and he would go blowing by me like half throttle in 4th!!!! And he also weighs 100lbs more than me! I did some engine mods and went back to stock gearing and its sooooo much better. But if your doing tight racing or woods racing then do it!

Also just to clarify. Even if it does take you 2 hours to do a jetting. Dont be intimidated cause it only takes like 5 minutes to do the actual jettting to the carb, the rest is pulling off everything in the way and putting it back. Maybe 1 hour for your first time and then you should be able to bang it out in like 30 minutes I would say. I guess it depends on your mechanical ability.

[Hondarider427]

Originally posted by yellowWB400ex
All i know is that i beat you. Thats all that counts!!! It doesnt matter what you do. You dont have the money. ;)

I said you beat me top end you idiot. I didnt say that i had you top end i was saying that i had rhode top end and acceleration and i had you acceleration but not top end. pluse i have money dick, any day you want to race a normal 1/8 mile drag its on.:)

[cals400ex]

Originally posted by Hondarider427
I said you beat me top end you idiot. I didnt say that i had you top end i was saying that i had rhode top end and acceleration and i had you acceleration but not top end. pluse i have money dick, any day you want to race a normal 1/8 mile drag its on.:)


how much money you got? if it is enough, i might have to come race you. :blah:


your post was pretty funny. i about lost it when you called him a dick.


adjust your throttle cable and you will get a nice gain if it isn't adjusted. a bone stock one will easily pull on a piped, filtered, and jetted one if it isn't adjusted properly.

[MSL]

I don't care what pipe you get jetting is very important! If you dont jet it correctly your quad will run and sound like crap. A piped and properly jetted 400 EX running 20's will beat a bone stock 400 EX running 18's on top end and thats a fact, either your buddies quads are not jetted correctly or your full of ssshhhhiiiiooootttt!!!!:bandit: