Very little resonance. Maybe a hair in the low RPMs when going up hill, etc.

MHP makes some great products and I'm sure their ECU tune is great. Thanks for sharing.

Ha, stay away from my undercarriage.

I have not tested the pipes in conjunction with headers as we just witnessed, we actually did not know what to expect, but to be honest I am happy with the results, not as happy as I'd like to be (I'm always looking for more power), but it was great to get a 3rd party involved in testing. BUT you guys need to understand that this car has PLM manifolds as well, we have only tested with stock manifolds.

RE: the main cat change up, we're working on it, so far I'm not at the point were I want to talk about it, but should be soon, so Super, let's keep in touch, and thank you for your unadulterated review!!

I don't want to take this too far off topic and I appreciate the feedback, but there isn't any solid data to support that claim. I know you had a dyno done after you had your cats installed, but there were many variables/conditions that had changed (Different day, colder temps, fresh ECU re-flash, etc.) You would also need many similar before and after runs to get consistency before comparing. I always do at least 4-pulls before and after and I throw out the lowest numbers so after numbers are not inflated. Even you were questioning where the small difference in power came from, starting with post #58. -> https://mbworld.org/forums/c63-amg-w...capable-3.html

Thanks, Brian!

True; lots of variables in dynos, especially when done on different days, etc. Since they typically see gains in other cars with high-flow cats (and even the C63 AMG with this amazing oem stock exhaust doesn't have high-flow cats), I would still like to think that the high-flow cats yield some gains in the ~ 5-10WHP range, but we would certainly need more before/after dynos from other MBW members for proof.

The newer 6.3L secondary cats aren't as bad as the old M113 5.5L secondaries. On the older M113 NA V8s you get 10HP/12TQ easy @ wheels on a loading dyno w/ just second cats (even more w/ cat delete). So its not fair to compare apples & oranges.

Although the primaries may be more restrictive, they too are probably a big improvement over the old M113 V8 primary cats which are pretty bad.

With that said it did give alot more low end to mid range torque (which is more important than HP on the 6.3L V8s anyways). If the X-pipe was slightly redesigned to not have any sharp edges at the X itself you may be able to make even more (similar to the magnaflow style X-s where its more of a smooth crossover, than an actual X-shape). This is just a suggestion, by no means knocking it, its a good product but there's always room for improvement (albeit probably not that much, maybe a few more HP)

great post

Good insight AMS. Much appreciated.

Still waiting for AMS to announce their C63 headers.

It appears that the proposed no-cat downpipe/Xpipe to resonator would be a direct bolt on with no cutting required. Is that a true statement?

(That would be ideal and make the switch back to stock a breeze.)

That depends on who makes it. If GT PRO comes up with a solution, they'll likely mate it and bundle it with their X-Pipe so it would be a bolt-in solution.

The beauty of this would be they could sell it in several modular configurations.

I have a guy who might be able to make a few of these up. He did some work for me on a previous car, and it was great.

If one of you can post a pic of the primary cats configuration -something that shows how they connect to the manifold, what the bends look like after the manifold, and where the second flange would need to be placed- I can show it to him and see if he is interested.

j_woody, awesome, I can do better than that. I can bring you and your buddy the actual pipes. I have a complete set in my garage.

Let's chat!

I'm interested!

Take good care of them pipes, mmmkay?

Yes, a multitude of modular solutions are ALREADY in the works, from the LT's, Single X, Double XX, MD Cat pipes, there are a lot of things in the works.

HURRY!

LOL, I'm working as fast as I can in a shop that is not fully functional..(just had to take the lifts down due to the concrete issues, we had to dig a 3 ft hole to pour concrete footings). Also, when I release a product, I want it to be perfect, so I vacillate over the details..it's just my way..

Nice review and great power!!

What are "MD Cat pipes?" From stock exhaust manifold back?

Superlubricity---Just wondering why your slowy putting a puzzle together, this mod that mod this mod that mod. Wouldn't just make more sense if you just do what your buddy Avenger did, and just get the MHP longtubes and get it over with?. Or are you trying to find other sources of power for a cheaper price than MHP's pricing. Just seems you already spent a tons of money on dynos and miscellanous mods. Just asking

I, for one, appreciate what he is doing. He is creating choices for us. For me, it is difficult to stomach the cost of what vendors are charging for LTs.

I agree, and appreciate what he is doing also, but im just saying, putting all of his mix n match mods togther plus labor pretty comes out to the same price as MHP or close enough? Or maybe I am missing something. I mean he has the K1-$1500, PLM manifolds-$2500, X-Pipe-$600, plus labor and more mods coming. Its great that he has the time and ***** to all this, and thats very cool, but i was just curious