DP is nearly done, spending many hours getting it aligned just how I want it for the following exhaust to aim so I can eliminate as many bends and lessen the ones it has to have.
Porting every step of the way to ensure the cleanest flow possible, every bend a true bend and not cheated, flared out the bend out of the cat as the hole was bigger than the pipe, it would of been weldable but left a major step causing a loss of efficiency, turbulence, etc. I spend an hour with a tiny ball peen hammer and anvil to get it just right and then after welding in place another 45 minutes or more smoothing out the transition with a die grinder.
Top is mine, middle is ATP which is a great DP and bottom the pathetic stock one.
Outlet on mine is a bit bigger than the others, one more thing to help flow better, how much it helps, or could even hurt in some ways, I will let the engineers ponder that issue
Other side to see the sensor bung below the cat.
Though hard to tell by the pictures buy bend between cat and flex coupling is absolutely spot on correct for the best flow and the area mentioned about that is very well ported.
I have to build an SS heat shield as the 5" diameter cat is a a bit to close to some wiring and plumbing but I knew that was going to happen, I have some rolled SS on hand just for that reason.
Weights:
10 lbs 7.1 oz, stock with heat sheil
05 lbs 8.1 oz
07 lbs, 11.8 oz without heat shield, it will weigh just a few oz so around 8 lbs.
Welding, issue there, ran out of the right gas for SS and regular gas for MIG is pretty hard to work with so just tacking it all together but had to fully weld one section so I could still get to it and port it properly, ended up not pretty but dang solid which is more important and can barely be seen when under the car anyway.
The attention to detail takes many times longer to build a part and it is just not feasible for shops to do this unless a few made for hard core racers with a big race budget, i.e. full sponsorship or just quite wealthy. Gains from it, of course, huge, probably not but I love making the best parts I can and do not consider my normal hourly rate when making my own personal parts, it is to fun!
Again, if you notice the crappy weld, I just have to eat that one, the rest will be far better.
I will finish this up in the AM and the exhaust should go 2-3 times faster so might be all done by tomorrow evening.