back preasure my arse, WB E-SERIES

[key4202003]

i have this slip on and the packing is about done. so one day i decided to take all the disks off the slip on, and basically run it straight piped. all i can say is i would not go back to the disks, because it revs sooo much faster, and sounds better i think! if anything it is better for the engine to rev faster, and expell the gasses faster too. i have not read anywhere that says the 400EX needs to have the back preasure, or the valves will warp... i say B.S. but if anyone has tryed this or says its bad not to have back preasure, PROVE ME WRONG!! oh buy the way it is jetted perfectly, with a 42p and 152m clip on 4th slot (one up from middle) and has air box lid ON, with K&N and stock header modification. its 14f 39R sprockets, and has 20x11-8 Champion bead locks,w/Razr tires. AND IM 190LBS. I LOVE MY BIKE

[key4202003]

sorry thats my other bike

[whiteflash]

i bet it really loud, i'm sure your neighbors are loving it!!

[stc416rider]

they do need back pressure to run

u will f up ur motor

[2004exrider]

You do not need backpressure, back pressure just controls where you get your power, bottom, mid, or top. The only reason you will burn up a valve is if its not jetted properly, if you have an exhaust leak where the header mounts up (because its letting in air around it and will make the exhaust gases hotter), or if you dont have on an exhaust and the valves are constantly getting hot then cooling down.:)

Jimmy

[key4202003]

fur sure jimmy you got the right idea, at first i was timmed to try, first i just had the headder, and man was that a rafter rattler!! i think i woke up my dead dog on that trip to the dirt hills. i was too lean, and then when i put the slip on with the disks off and lid on i was perfact! i think that is the biggest problem with everyone doing there own jetting, just slap a huge main on and everything is fine, but when i messed with the clip, what a more refined power band i had. mine always burped in half or so but screwing with in was a total plus, i wouldn't go back unless i had a HMF, just a success story, H*LL YEAH

[smokinwrench]

Originally posted by key4202003
but when i messed with the clip, what a more refined power band i had. mine always burped in half or so but screwing with in was a total plus, i wouldn't go back unless i had a HMF, just a success story, H*LL YEAH

Seems to me you finally got your machine jetted properly and are finally feeling good power for the first time. Its just amazing when you get it jetted correctly and you have power completely throughout the rpm range.

[key4202003]

FUR SURE!!! i totally recomend doing this mod to anyones quad with the E-SERIES WB.

[400exrider0004]

post a picture of your bike!!!!!!!!!!!!

[key4202003]

it says its too big off file, i have no idea how to make it smaller, hows my BIG bike look?

[smokinwrench]

Originally posted by key4202003
FUR SURE!!! i totally recomend doing this mod to anyones quad with the E-SERIES WB.

No, what I'm saying is that you finally got it jetted properly. I'm saying that if you put the disks back in the pipe you won't find any loss of power and just maybe you might save yours and some other peoples hearing.

[phildogg]

Originally posted by smokinwrench
No, what I'm saying is that you finally got it jetted properly. I'm saying that if you put the disks back in the pipe you won't find any loss of power and just maybe you might save yours and some other peoples hearing.

I wonder would it be any louder then my hmf ? which is basicly a free flowing pipe you can see straight through it. just wondering.
phil

[400exrider0004]

WOW!!!!!!!!!!! I just took the discs and spark protector off my WB slip-on and all i can say is WOW!!!! It revs much faster is sounds awesome!!! I can wheelie much easier and it runs great!!! Thanks so much for your idea!!!

[key4202003]

told ya!! i would say the hmf would sound better cause its a tuned exaust, but i say power is the same.

[JR3]

Originally posted by stc416rider
they do need back pressure to run

u will f up ur motor

then i woudl ahve lost my motor last winter wen i ran the e series with nothing on ti for 1 month and thats riding it for 3 times a week like the 1 guy said back pressure just puts ur power certain places

[Bigun55]

lol ive been runnin my wb like that for about 5 months and its doin fine. Love the way it sounds and the way it runs.

[MAD450r]

Never had an issue with it that way. It did get much louder but with the noise came a more broad power delivery. My 416 hangs with and can beat stock 450r's.
As for noise with the e-series with no end plate or disk's its still quieter than my 450r with sparks exhaust.
http://www.imagestation.com/picture/sraid179/pb99233c33d366c5ea63499d38ee0284c/f317f45f.jpg

Sorry this one is a bit dark was at work in the warehouse.
http://www.imagestation.com/picture/sraid185/p705416cafdcc9e94beb921f047b5a40d/f266acb9.jpg

[400exrider0004]

here are some pictures I took after I took the discs off. It runs great and I love the power delivery throughout the powerband!!! It sounds great also!

[400exrider0004]

2

[400exrider0004]

last one

[stc416rider]

without the disks there is still back pressureinside thepipe

the disks help it have more

[smokinwrench]

This all seems funny to me. Buddy of mine has a 05 TLD Predator with a W/B slip on. He had it on the dyno with and without the disks. It made almost 1.5 more hp with the discs. I know its not a 400ex but it should still have near the same results.

i had a white bros on my 400ex no disks n turnt in to a shorty n it did rev fast. sense i sold it i made my one pipe n it looks cool n gaves me way more top end power but i lost some botom end.

[JR3]

U should buy there turn down end cap and put it on instean of havin nbo cap at all.

[stc416rider]

so if i cut my stock and take out the baffle

wont it be like all urs

[2004exrider]

kinda, its just not gonna have the same tone. The eseries still has packing lining the inside i belive (someone correct me if im wrong) so yours will just be really loud.

Jimmy