Downpipes, Cats, Catless, Bridge Pipes, AGAIN E63 W212




Most of the AWD downpipes are actually midpipes. OK. Yes. One can also see where they have to step down to connect to the smaller bridgepipes. Ok.
There are some real downpipes (bridgepipes replaced too) that are full size all the way to the turbo, and for AWD require different engine mounts, dropping the engine, etc.
My question is has anyone actually done a before and after dyno/track/anything Cat vs Catless? Or are pepole just ripping them out, creating smells and noise, with no extra power?
This thread has the fastest E63 cars in the world, some have stock cats. Look at the picture of the excel sheet that's posted - there’s a “Cat Deleted” column:
https://mbworld.org/forums/w212-amg/...-part-two.html
And this thread here @PeterUbers is making 730/780 thru stock cats:
https://mbworld.org/forums/w212-amg/...internals.html
Sooooooo
Should I bother doing anything about my stock downpipes if I'm keeping the stock turbos?!
I've been looking at midpipes - MBH and Kooks and Red Star and it hit me - research first. So I read through all these threads (and more!) and no one ever seems to have done a test before/after either dyno or track:
https://mbworld.org/forums/w212-amg/...-opitions.html
https://mbworld.org/forums/w212-amg/...downpipes.html
https://mbworld.org/forums/w212-amg/...e-install.html
https://mbworld.org/forums/w212-amg/...selection.html
Anyone have any real proof after all these years?
Last edited by I.T. Guy; Jul 20, 2022 at 09:50 PM.
Best Return on Investment Mods List
My heart wants Downpipes... logic dictates TCU + ECU Tunes.




There is a lot of great info in this older thread:
https://mbworld.org/forums/w212-amg/...turbo-car.html
Specifically
https://mbworld.org/forums/w212-amg/...ml#post6786153
And
https://mbworld.org/forums/w212-amg/...ml#post6788340
I decided to buy some used mid pipes to save money, since I'm still not entirely convinced. It'll be easier to get my money back from a used set if I decide to just put the stock ones back on.




Best Return on Investment Mods List
My heart wants Downpipes... logic dictates TCU + ECU Tunes.
BB Intake
Lighter Battery
TCU Tune
After I see what that all does "stock" I plan to go in for an ECU dyno tune. Because dyno time is pricey I'm trying to decide if I throw catless DP's on before the tune or not. If I don't have to I'm perfectly happy with the stock sounds and smells. I just don't want to leave too much HP on the table, that is what would sway me to do it, the HP. 20-30? Meh. 40-60? Ok you have my interest.
Last edited by I.T. Guy; Jul 25, 2022 at 04:19 PM.



