BerBer63

The resonantor has a crossover pipe, the xpipe theory doesn't make sense.

AMS Performance

There is a crossover in the resonator but its tiny by comparison and its essentially a tiny H-pipe. For the amount of gas volume & velocity you are talking about for a high revving 6.3L V8 its honestly not sufficient at all.

Super, you can still keep the current setup but just install and X-pipe, install it as close to the tranny/headers as possible right where the two exhaust pipes comes closer together and you should be able to pick up more power. The X-pipe should also help smoothen out the sound as well and quiet down a bit of the resonance

For a frame of reference... on an almost stock W210 E55 AMG, the X-pipe alone made 8wheel HP above 5000rpm up to the 6000rpm redline on the dyno (and that's on a much lower powered, lower revving M113 V8 so imagine on the high revving 6.3L AMG V8).

SMP

Chubbs, don't be so stubborn ........we've already covered this once before ....... the secondary cats have a cross over as well. When removed, there should be an X-pipe instead. That little H-like cross over at the resonators is not only too far back, but also too small to balance the exhaust.

Super: Not only will the X-pipe show some gains, but it will also make the exhaust sound more refined.

AMS Performance

SMP is correct, the crossover in the resonator is essentially purely for noise cancellation (which is exactly what the resonators job is in the first place). Its simply too small to provide any legitimate power gains of any kind.

Don't expect crazy power from the X, however I wouldn't be surprised if the gains were 10-12HP above 5krpm, better than nothing over the previous setup that's for sure.

superlubricity

I'll certainly try the X-pipe in combination with the primary cat delete pipes.

Note: When I replaced the secondary cats with the X-pipe originally, I saw little/no gains up top. -> https://mbworld.org/forums/c63-amg-w...-2010-c63.html

BerBer63

I'm ready to be made a believer. Make me believe in the X super.

RStevens63

I agree with putting the crossover as close to the in this case manifolds as possible, but you really can't compare the exhaust needs and requirements of two completely different setups. Displacement is different, valve count is different, valve/seat area is different, cams are different, exhaust from factory is different and on and on. Also factor in normal pull to pull dyno variation. The X may help but I'm not so sure it's a panacea.

EUGENE-Taiwan

I don't know if the MB ECU as smart as the M3 are.

but the O2 sims don't work on my car !!!!!!!

mechanical or modules ones.

if you really want no headaches I would get a tune cat delete tune.

its the safest and no pains in the long run.

nice job with the report!

SMP

I think he just used an example. I was talking about what I run on my CLK63 BS, since the engine in the C63 is the same. The only real difference between the two cars in exhaust set up is the resonators are much smaller in the Black Series and the diameter of the pipes are 2.75" compared to 2.5" in the C63.

superlubricity

Stock primaries and GT PRO X-Pipe are back in place. Car is civil again.

Back to the track on Wednesday night.

Will work on the Cat-less Downpipes/X-Pipe combo in a couple weeks.

RStevens63

Thanks for the great info!

RStevens63

Keep it coming please.

avengerboater

Mmmm. Such interesting scenarios and possible data. Thank you, supes, for providing us with all these info.

Sincity

Eagerly waiting.............

AMS Performance

SMP is correct again, different setups vary I was merely providing a frame of reference.

I will say, that X-pipe is not the best ever, it could be improved upon, the merge is a bit smaller than it should be and its not a smooth curve but a sharp joint. You want the merge to be a smooth crossover to allow the gasses to mix properly then exit quickly without any sort of obstruction. Many of the Xs on the market don't do this properly. Designing the perfect X isn't easy but its still a decent X. The magnaflow ones are actually pretty good at this, but they just look cheap and are stamped (but they get the job done, only downside is the pipes are spread too far apart so they don't fit that well).

I bet you the X will make significantly more on a long tube setup. The stock OEM manifolds are the major bottleneck in the system and as a result it can't make the gains above 4k it normally could if it had more airflow to work with. Sometimes you have to remind yourself that proper exhaust design is a balancing act of multiple bottlenecks and sometimes by eliminating one... you run right into another. So just b/c it doesn't make gains on that specific dyno, does not disprove its functionality or efficacy.

Hope that helps.

lap time

Hi!! I am new here. Just wanna say Hi to everyone. After browsing through, i just find this forum is very intereting with lots of useful & good advice!!! Thanks for all the contribution.

Thanks for the updates Superlub!! Looking forward to more.

I am about to track my c63 in Aug and here is some info. about the mod.:

1) i have deleted the middle cat. (sorry, i dont know the exact term for this part, can someone tell me pls). But after it is done, it became a lots louder n feels smoother, so I like it. (approx. US 400)

2) MHP ECU flash ECU + TCU (see attached for the dyno results after flash). Feel free to advice or spot anything unusual, thx.

Since cant attached extra photo, will continue in next post.

BerBer63

You removed the resonators not the cats.

lap time

3) i am considering for this exhaust (c photo) or should I just try GT PRO X-Pipe + header? (any advice??)

4) does anyone who has engine oil + gear box temp. problem when you track your c63 coz i heard a few friends already complaint about being able to do 2-4 laps MAX (in China). That would be a HUGE concern for me, to be real honest. So i will consider the DTM style front bumper w larger holes + adding direct water spray to the cooler (still discussing w my garage about how to do this)

5) anyone has any problem when tracking c63 e.g. temp., brakes? btw, mine has the AMG performance package.

Cheers & thx guys.

lap time

thanks chubbs (sorry for ignorance).

BTW, currently i am using Bridgestone Re011, i love it (compare w Toyo 888 and Yokahama AD 08 before).

BerBer63

Maybe start your own thread at this point?

superlubricity

OK, back on track . . . literally. Here's some more data.

My car has 1) Kleemann K1 Tune, 2) PLM Manifolds, 3) Evosport Pulley & 4) Nitto Drag Radials. The driver (me) is 6'3" and 230-lbs.

07/21/10 - w/ Catless Downpipes (No X-Pipe) & 1/4 tank of gas
07/28/10 - w/ Stock Primary Cats + GT PRO X-Pipe & 1/2 tank of gas
Note: I'm not a huge fan of drag racing in the summer (high temps & humidity) but these week-to-week conditions are pretty close for comparison's sake. The DA corrected numbers tell the best story.

Anyhow, there is definitely some power to be had with the catless down pipes at the top end. It's not a HUGE gain, but there is something there. At the end of the day I don't think it's enough for me to chase after. I may still try a new X-Pipe w/ the catless downpipes but I'm really leaning towards just getting a set of Long Tubes and calling it a day. I need to figure out sound control as anything catless is just too loud during cold start ups for me and my neighbors.

With cooler air and/or a diet I'll be comfortably in the high-11's as-is. LT Headers (and the gobs of torque they make) should easily push me to mid-11's. If I can find a day where the DA dips into the negative thousands I'll be in for a nice treat regardless of my setup. Fun times ahead!

More to come . . .

PetroC63

Excellent data as usual super.

It looks like some of your torque returned with the cats and X-pipe
setup which is reflected in your 60' times. Obviously, horsepower
is down a little with this setup.

Maybe some MBH long tubes w/cats as a compromise. That is the
combination I'm leaning towards.

Sincity

Bhamg's setup with MBH headers and cats sound really good and easy on the ears. Different story when he opens it up.

Not a fan of racing in the summer? Our low temps are hotter than your daily high.....ugh!

superlubricity

I'm A-OK with adding cats to the mix if they attenuate the sound to an acceptable level and are easily removable. I've heard the 300 cpi cats on nrgy's MHP headers. It's still a bit too aggressive for my taste for daily driving/cold start. I might just add my own 400 cpi cats using v-bands for a quick swap to whatever solution I end up with.

You don't get cold starts in the summer in Vegas.
The humidity in the summer's early evening is the killer up here.

Sincity

Touche.

It is strange hearing a Benz sound like a muscle car.

EDIT: Have you spoke with James @ ACGSD about the Cargraphic headers? Price is better than what is currently out there and mates with stock secondaries or your GT Pro X.