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And for those who kept saying do a supercharger, I have a feeling I will be wishing I would have listened. With my goal being to preserve as much of the stock sound and sound quality as possible, a supercharger really may be the only way. I have a feeling the turbo log header, although its cast iron, it may introduce that crappy ticking sound that you get with headers and may introduce all kinds of other noises. I had to learn with my other car that its not only the factory mufflers and resonators that provide a factory sound quality but also all the other pieces, including the cast manifolds and thick cast header merges and other pieces. I even think the heat shields the bolt to the stock manifolds even provide some attenuation of exhaust gas noises coming out of the exhaust ports.
Are you talking about like a non EPA approved aftermarket cat? or something else? I know GESI makes one like that, that is not EPA approved but they don't put a HP rating on it.
turbos like heat, having a cat before them is a ever present source of heat in my opinion. Getting rid of the unburnt fuel smell? what better men’s cologne is there?
look at rx7s and how Mazda used a thermal actuator ( I think) to help with emissions. It just was an area that the engine heated and helped to reduce emissions
turbos like heat, having a cat before them is a ever present source of heat in my opinion. Getting rid of the unburnt fuel smell? what better men’s cologne is there?
look at rx7s and how Mazda used a thermal actuator ( I think) to help with emissions. It just was an area that the engine heated and helped to reduce emissions
Yeah you would think given the extra combustion that occurs in the cat heating up the exhaust.
Does anyone know if the GEN III LQ9 exhaust manifold flange is different from the 6.2 GEN IV flange. I know mine has different flanges between the drivers and passenger side exhaust manifolds from what I can see so the answer is probably yes. I am going to make a trip to LKQ tomorrow where there is ample and plentiful all you can take GEN III GMT800 stuff, and even some escalades and denalis. And the escalades and denalis are 100% guaranteed to have the motor missing for very convenient and easy access to the exhaust downpipes haha. People litterally camp out around here and wait for them to put out the Escalades and Denalis and they instantly swarm them.
Since I've got good clean pipe now I recently ordered, I could technically go ahead and start to make a downpipe either by trying to make one with no cats and put one big aftermarket cat behind the turbo and see if I can get a stock flange from the junkyard tomorrow like I was talking about above, I want to avoid cutting my stock one and using it if I don't have to and can keep my stock one intact.
Or I can keep trying to go with my original plan and cut my stock exhaust at the crossover pipe below the transmission pan and leave the drivers side manifold and cat untouched. Even if I cut my stock exhaust at the downpipe. One of the obvious problems would be that the passenger side cat is like a 2.5 in inlet and outlet, so when I try to run the 4in pipe out of my GT45 it would be going into a 2.5 in cat inlet then going into the 3.5 in or whatever size it is stock exhaust after where the y merges. Because of that I just don't think it is feasible. The stock crossover also routes further back by the transmission pan, when I could build a crossover way up closer to the front of the truck and have a much shorter crossover than the stock pipe.
Sorry everyone for being stubborn and thank you everyone for everyone's advice as well.
I did go ahead and order a GESI 4in inlet/outlet 4.5 in body "Ultra High Output" single cat supposedly rated at 850 hp. I am worried that I may not get good light off and temperature to make it effective though.
Also as a side note, I had a LQ9 Escalade with this exact same looking leak. I did oil pressure sensor, cam sensor, oil pan gasket, oil cooler gasket, and more I think and I still had this same stupid leak. I ended up selling the Escalade. Now I have this truck and it looks like the exact same leak. I was so confident changing the oil pan gasket would fix it but it appears not:
I know some people have said they have fixed leaks but they continue because there is residual oil trapped in places so not sure if that is the case here but I don't think it is. When I had the oil pan off I did look up at the back side of the flexplate and torque converter to try to see if there was any oil looking like it was coming from the rear main seal and everything looked dry so I don't think its that thankfully, but I may have to pull this motor just to find this stupid leak.
Crank position sensor o ring would
be my next guess
header flanges are the same
Thanks Arthur they are the same, I walked around LKQ for like 2 hours knowing there had to be a flange or manifold laying on the ground, I didn't want to crawl in the dirt and mud and get the real miserable junkyard experience. I found a right and left manifold with the flanges attached, but LKQ wanted almost $100 for both which I expected. So I sawzalled the flanges off and luckly brought kroil to get the nuts off, and then I only had to pay $4 for both side flanges.
Unfortunately I pulled the passenger side manifold off and starter and pulled the crank sensor out and the oring seems fine, and I can't see any visable oil looking like it is leaking from the hole:
One thing I haven't checked which I should have already checked is the oil pressure sensor o-ring, I think I remember this being a common leaking place. I think you can buy just the oring on ebay I think.
Judging from the picture above it may still have been the oil pan gasket, just looking at the wet places where there is dirt build up from oil parallel with the oil pan gasket flange. I just have heard oil can get trapped in a bunch of different places and appear that its still leaking when its not.
09-09-2021, 10:31 PM
