exhaust question...(fabrication)

[halfwit]

ok. i have an idea. first off, im 20 yrs old, have a decent car, jsut bought a house, and have this bike.... so i dont want to drop 1000$ on a full exhaust sytem, but i dont like the idea of catalytic converters on my bike (weight, restriction ect) so i have an idea, and wanted your input.

i want to take the factory header off, cut it right before the cats, merge the two pipes together (want single side exhaust), then jsut route it right where it goes factory (where a slipon would install) by the right side rearset.

then buy a slipon, or jsut a muffler (im confused on what kinda muffler or slipon i can get that is single sided, but will flow enough since i merged the two pipes)

and whamo! i have a "full" (the differencein the aftermarket head vs mine cant be more than 4 hp) exhaust.

any ideas/help/why i shouldnt do it?

 

[Fate]

If you have the know how, that would be really interesting. Not much input on how it will work, but sounds cool

 

[halfwit]

thanks, im actually thinking of using the truck tip (flowmaster looking angle cut tip) but with a resonator (some fiberglass and metal grate) to quiet it a little, i like that look alot more than the muffler.

either way, ill have some pictures up within the next few weeks..

also jsut got allthe decals off, lowered the front(soupys) and lowering rear soon as i get my link in the mail... bmc street filter in also.

 

[In10SS]

How bad could it be? Depends on what you use for a model.  A free flowing exhaust is always a plus, but there are a lot of other factors that effect engine output. Primary tube length and the configuration of the collector (4:2:1 or 4:1) can dramatically impact your torque curve right where you normally ride. You would have to use mandrel bent stainless in like 3 different sizes, a jig to notch the pipes, a good welder to put it all together and a lot of planning & measureing time.  You will lose torque and gain maybe 3 horsepower.  It won't match the flow of any aftermarket exhaust because the primary tubes are still stock diameter.  You will lose some weight though.  My opinion?  1)Shorten your stock cans and open them up a little (do a search on this) and leave the rest alone until you can buy the exhaust you want. or 2)just do the truck can thing you were talking about on both sides until you can afford the one you want. There are a couple of decent exhausts out there for about $800 which isn't bad at all. I do applaud you for keeping your finances in order!

 

[halfwit]

How bad could it be? Depends on what you use for a model.  A free flowing exhaust is always a plus, but there are a lot of other factors that effect engine output. Primary tube length and the configuration of the collector (4:2:1 or 4:1) can dramatically impact your torque curve right where you normally ride. You would have to use mandrel bent stainless in like 3 different sizes, a jig to notch the pipes, a good welder to put it all together and a lot of planning & measureing time.  You will lose torque and gain maybe 3 horsepower.  It won't match the flow of any aftermarket exhaust because the primary tubes are still stock diameter.  You will lose some weight though.  My opinion?  1)Shorten your stock cans and open them up a little (do a search on this) and leave the rest alone until you can buy the exhaust you want. or 2)just do the truck can thing you were talking about on both sides until you can afford the one you want. There are a couple of decent exhausts out there for about $800 which isn't bad at all.  I do applaud you for keeping your finances in order!

thank you for the helpful advice, as of right now i did the "truck" exhaust, and it isnt as loud as i thought. very bearable. so ill just keep it like that til i break down and bu yan exhaust! thanks!

when i do get ready, i am still going to make my own, but worst come to worst i buy one..or it works and i pat myself on the back..lol

 

[freponyryd]

What about using the full stock headers, gourging out the cat, putting a cap on one of the outlets(the chain side), and putting the short tip on the other side? would it negatively effect the back pressure? If one side isn't flowing at all it should retain some back pressure and with the open element short tip it could possibly flow enough air to make a positive gain.. I'm no exhaust guru but in my warped sense of mechanics I like to think it could work.

 

[halfwit]

What about using the full stock headers, gourging out the cat, putting a cap on one of the outlets(the chain side), and putting the short tip on the other side? would it negatively effect the back pressure? If one side isn't flowing at all it should retain some back pressure and with the open element short tip it could possibly flow enough air to make a positive gain.. I'm no exhaust guru but in my warped sense of mechanics I like to think it could work.

the problem i had with that idea was , if there are two mufflers (and two pipes) one pipe must not flow enough. so if i capped off one side, i dunno if the single pipe would be big enough to flow all the air. i realize its only a few inches that the pipe would be small before my tip, but at high rpms/ speeds where there is alot of air, i think it would have some sort of an effect.

 

[freponyryd]

I thought the same thing, but with it being short it might not hinder the flow too much.

 

[ToXSicK RoCKeT]

What about using the full stock headers, gourging out the cat, putting a cap on one of the outlets(the chain side), and putting the short tip on the other side? would it negatively effect the back pressure? If one side isn't flowing at all it should retain some back pressure and with the open element short tip it could possibly flow enough air to make a positive gain.. I'm no exhaust guru but in my warped sense of mechanics I like to think it could work.

the problem i had with that idea was , if there are two mufflers (and two pipes) one pipe must not flow enough. so if i capped off one side, i dunno if the single pipe would be big enough to flow all the air. i realize its only a few inches that the pipe would be small before my tip, but at high rpms/ speeds where there is alot of air, i think it would have some sort of an effect.

heres my

im also a mechanic by trade, but anyways..... I do know that suzuki did not put 2 mufflers on because it "didnt flow enough with one". it's do to sound regulations and EPA crap. as far as you needing "BACK PRESURE" to make hp, THAT IS A OLD TIME WISE TALE!!! it has been proven time and time again the LESS back presure the MORE HP AND TQ. NOW, with that being said, there is alot of R&D that goes into header design, you have tube length, diameter,cyl filling, scavenging, ect...... I personally think if you are going to do the low budget exhaust(and i also commend you for your financial priorities , hard to do at your age

). I would do what was recommend previously and gut the cat, cut and block one side, and go with a slip on or meg tip. Not to say this will help hp/tq(prob will hinder it if anything, will sound better

) but if your gonna go through with it thats my

, for what its worth. please keep us updated, would like to see how it turned out.

 

[halfwit]

 

[BULLETB]

I Have a set as decribed in my above post,for sale. Anyone interested?

 

[BIKE DUDE]

I got my full Yosh R77 for 725.00 and........one r77 slip-on will probably run a least 300-350 and your plan will require a lot of time and materials plus some skillful fabrication so it might not be cost or time effective.

Just bite the bullet, shop around and get a real full system. JMO