Great attitude and a good one. itll be interesting to see how this works out. In the end 1650 is a bit much for longer uneven primary tubes but maybe the collector will help make it all work. Just from looking at these there seems to be a lot of missing attributes of what makes long tube headers actually work and make power.
A lot of it will depend on how well the collector works or if its a real collector or not. After all just removing the cats is good for about 50whp or a little more from what some have said in the past so that alone we know helps.
The really big must do IMHO I would say is you need to do something with the outlet part. Iām not too sure on the size but it looks like 3" if thatās the case thats much too big you donāt want to have the collector go into a bigger dump area before going into a catback you want a bit of a neck down to with in a 1/4 of an inch or even 1/2 an inch of what your catback will be and then open back up to the catback. Its called a megaphone transition. Thatās something that you can do now to try and make up a little ground for all the other missing long tube headers needed components.
The Audi community has been let down and most shy away from longtube headers due to the past failures of others. But to be honest. All of the other failures all had the same MO and they just didniāt put the real work into the small details that make headers make power these too are missing a lot of what makes long tube headers a big power adder.
This has happened with the failure of headers for
RS4 long tube headers were made by hooker and one other company only made 10 more whp
S4 (china knock off not JHM)
B8 S4 I think it was euro code who made them they made Zero hp over stock manifolds with no cat
A4 3.0 super sprint made a set of headers and they resulted in a zero gain.
In the end this is great with the open minded attitude you have and hard work this can be either a win or a lesson for everyone to learn form. And maybe the V10 motors will shine with your current set up either way thanks for testing and letting us know. I think its a win either way.
