Originally Posted by havasusteve03Beast
Thank you for your assistance on this. Yes, the flanges dont help and I understand that. Unfortunately, I have to have them to switch back and forth between your CATS and OEM CATS at smog time. This was the easiest way of doing it. I am going to grind away at some of the unnecessary metal in the meantime.
I noticed you didnt comment on the area where the header pipe joins the collectors; can you check with your engineers to see if this is an acceptable amount of gap? It is the only area at this point that I could see any difference being made.
By the way, I love the Supersprint headers, love the way they make my Beast sound. I and oters would sure like to get them to fit more flush though.
Thank you again for your assistance.
Steve, the first thing the shop guys noticed from the photos, is that they believe that the collectors actually must be slid in, even further. They feel like the 4-1 collectors may not be bottoming out against the 8 primaries' ends yet.
However, this is a speculation, based solely upon the amount of the enlarged (step up) pipe section they can see, sticking out from the floating, 4-hole flange plate.
I believe you when you say that you already have pushed the collectors all the way in; but there still my be some way to go, regardless of the resistence you feel when forcing the collectors further in.
The pipe junctions may have an overlapping section sticking, or seizing, in some place, which keeps the collectors from slidind all the way in.
Anyway, I will do some more dimension checks on the headers jigs, as well as on the original project blue-prints, to make sure that the production headers are still within spec.
Speaking of the flanges you have added, I perfectly justify your goal, about the ease of switching the cats back and forth, with the minimum effort; but a slip-on connection would be less obtrusive in terms of ground clearance, although the removal certainly would not be as easy and straightforward, as with the 2-bolt flanges.
When designing exhausts, the slip-on and the flange connection systems both have pros and cons, depending on the individual area of the exhaust.
An additional plus of the slip-on over the flange system, in this particular place, is that it allows fine tuning the overall lenght of the exhaust system, between the individual sections, while the flanges limit the entire exhaust to a fixed, non-adjustable and very rigid position.
If you find out that your cats actually put a tension on the headers collectors, and pull them backwards, you should have them checked, cut-off and re-welded into a more correct, neutral position.
I will get back to you with more infos, as soon as the checks are done.
Have a nice weekend.