Bung question

[gobble]

I'm taking the advice of many and am re-testing my air/fuel pre-cats. To do so, I'm going to temporarily install the Dali cat replacement pipes. I have the Anytime exhaust which has a bung welded near the front of the pipe that connects to the cats.

Can I simply use the Anytime bung with the test pipes installed or should I weld another bung into the Dali pipes in order to get as close to the heads as possible? Will two feet make a difference?

 

[NSXTech]

To answer the q from a purely technical perspective, yes. Thats why they are always in the manifold. For our purposes, the differances are probabally not measurable.
That said, I would do the bung-
1- its cheap
2- most accurate is best :wink:
3- the test pipe will be more versatile for future use
or make it more sellable, or borrowable to someone else

My .02
MB

 

[gobble]

Will I run a different air/fuel ratio with the cats off compared to when I put them back on? Assuming that removing the cats makes the exhaust flow better, would I get more air in the mixture with the cats off? I would then think that the mixture would fatten up a bit when I put the cats back on. If so, how much? Anyone else consider this?

 

[NSXTech]

That is a big assumption. Dyno tests show that no improvement in power is gained by removing cats, on the NSX. Therefore, no (measurable) change in flow or a/f can be anticipated.

MB