[bk kid]

Hey I need some help on pipes. I would really like a pipe that stops before the wheel or at it. I have not seen any so I am looking into having a pipe set made. Do I have to have them equal length or will the power commander take care of that? Do I have to worry about back pressure other than torque? Is it okay to do the step up from 1"3/4 to 2 and 2'1/2 or stay at 2'. I know some of you can help. Thanks in advance.

 

[Painter]

Ok. Boy have I been here before! I chose the Viper 2 from Fuggin. Don't have them yet but ordered.

 

[Snuffdog76]

I was gonna say Fuggin too but not sure of the name of the ones that you HAVE to redo the intake or they will NOT work. They are real short and come down and end.

 

[FugginFabrication]

Fuggin Viper-2 Custom pipe (Shorter?)

BK Kid

Our Viper or Viper-2 pipes are as close to equal length as the bike will allow. If you are looking for something shorter than our standard collector length we can make you a custom length collector. The collector would turn-out at the end of the frame. I recommend the turn-out like the Viper-2 so that the exhaust is blowing away from the bike. As far as maintaining the back-pressure and torque, we can baffle the pipes to insure you get the right numbers. The baffling will not make the pipes sound any less and they may be somewhat louder. The cost for doing a custom version would be $50.00 more than our standard pipes.

We have been thinking about offering custom cut tips for our pipes, I will put some examples in another post soon.

If you are interested in ordering a custom set, please feel free to contact me.

Doug
Fuggin Fabrication
480/813-4474

 

[imwright1985]

Simplest way is trying to match equal length but if you can get flow rates matched (shorter pipe having a slightly wild bend creating slightly turbulant airflow) you have even closer performance for each pipe (fluid dynamics class helped out a bit with this, but some drafting programs like solidworks i think figure it out for you). I would try to avoid stepping the pipes too much though just because of the asthetics, needing multiple sized tubes, and 2" pipes are plenty of volume (I ran 2 1/2 on a corvette with over 400 hp no issues) unless your taking your bike over 100 hp its kinda wasted metal and less back pressure which people often overlook for helping generate torque and also helps the engine fire so starting cxan become difficult.

What i would do if you want bigger looking is to put a wider tip on it or do angled cuts. To balance it you could do a 2-1-2 pipe design like the bike originally had or a 2-1which would help compensate for planning oversights.

Also programming units usually are set as a table combining averages for the whole engine, not each cyl. when they get modded there are bumps you make through certain ranges in Throttle position and RPM for fuel, and timing compensation or step the entire table. which means you cant tune individual cyl's

Also dont forget to consider the exhaust is exposed so you need a nice finish on it (chrome or powder coat so check those prices to factor in too) these arnt sport bikes or dragbikes so

 

[RedspawnSilver]

Simplest way is trying to match equal length but if you can get flow rates matched (shorter pipe having a slightly wild bend creating slightly turbulant airflow) you have even closer performance for each pipe (fluid dynamics class helped out a bit with this, but some drafting programs like solidworks i think figure it out for you). I would try to avoid stepping the pipes too much though just because of the asthetics, needing multiple sized tubes, and 2" pipes are plenty of volume (I ran 2 1/2 on a corvette with over 400 hp no issues) unless your taking your bike over 100 hp its kinda wasted metal and less back pressure which people often overlook for helping generate torque and also helps the engine fire so starting cxan become difficult.

What i would do if you want bigger looking is to put a wider tip on it or do angled cuts. To balance it you could do a 2-1-2 pipe design like the bike originally had or a 2-1which would help compensate for planning oversights.

Also programming units usually are set as a table combining averages for the whole engine, not each cyl. when they get modded there are bumps you make through certain ranges in Throttle position and RPM for fuel, and timing compensation or step the entire table. which means you cant tune individual cyl's

Also dont forget to consider the exhaust is exposed so you need a nice finish on it (chrome or powder coat so check those prices to factor in too) these arnt sport bikes or dragbikes so

You gave a good text book version of what to do and made a good point as well, but on your first point, you forgot that if the pipes are angled towards the ground, such as the mayhem's or any other pipe that faces towards the ground is that you'll get that you'll get a few extra db from the sound reverberating off of the cement that you would a straight pipe out the back. So even if the pipes are not calibrated for a resonant frequency at the end of the pipes (which btw, might cancel out the sound if they are perfectly calibrated... to an extent of course), they may be louder and sometimes better sounding than a pipe that is perfectly calibrated with ... Just my 2 cents of course....