I'm switching from a V&H ProPipe to a SuperTrap Supermeg on a bike fitted w/ a T-max Autotune. The O2 sensor bungs on the V&H are about 1.25" long, so the sensors do not poke into the interior of the headers. Conversely, the SuperTrap bungs are about 0.25" thick nuts welded onto the header pipes, so the sensors poke way into the headers. What about this? It seems the V&H design is much better, because it does not disrupt the exhaust flow.

 

The total mass of the O2 sensors protruding into the pipe are not going to obstruct the exhaust flow. Go get a leaf blower, turn it on, and then stick about 1" of a pencil in front of it to see how well it blocks the air flow !! You'll get the idea.

 

Sensors need to be in the active exhaust flow for the most accurate readings. The sensor response will be lazy if pulled out as you described on the V&H system

 

I have a SuperTrapp Supermeg on my bike, albeit without the O2 sensors installed. Knowing where they are on each pipe I doubt if the high velocity inferno coming out of the exhaust ports at umpteen hundred degrees is going to even notice them!

 

When you ask a reputable tuner about this, he will tell you that the tip of the O2 sensor absolutely needs to be in the exhaust stream to work properly. What you are describing is partly why some head pipes make for an easier and better tune than others. This is one thing to consider when deciding on a head pipe to use. This is also why the stock Harley head pipe works as well as it does.

 

think you got that backwards. with the v&h, the sensors are not going to get as accurate a reading as the supertrapp.....

 

Thank you all. Helpful responses. I posted a similar question elsewhere and all but one response said the same thing: for accurate readings, the sensors need to be in the exhaust flow, and the resulting obstruction to that flow will not affect performance.