can you elaborate on the importance of the x pipe!!

i ask this because in the near future my car will be going in to have the stock headers replaced with the supersprint ones,

from there it will be of to the local mb body shop to have the c55 spare wheel well, heat shield and rear bumper fitted.

and after this the plan is to have a custom quad exhaust system made to replace everything from the headers back.

what kind of problems can i expect if any ? ,
is there any danger of me screwing up my car ? ,
would i be better of leaving the cats alone and just having new piping from the secondary cats back ?

i'm sure the shop doing my exhaust knows whats required, he's the same guy who did my resonator delete and specialises in stainless exhaust systems ,
i just want to make sure i get this right and not end up regretting it

thanks

 

hmm, I wonder if secondary cat delete on my 320 coupe would be ok...otherwise I'll just downgrade to a magnaflow exhaust

 

Well, an H-pipe will minimize back pressure by equalizing the exhaust pulses. The placement of the H-pipe is crucial. Like I said, the best place for my H-pipe was about 2 1/2 feet pass the primary cats. My mods are different and with the 100 cell cats, there is a good chance that your H-pipe will need to be closer to the front of the vehicle. If you can find a heat gun, you will be able to find the best spot. Just measure the heat off of the tubes until you find the magic spot. Your exhaust guy should know this trick....it's been around a long time.

An X-pipe does the same thing as the H-pipe, but it is more effective and less restrictive. The exhaust gases don't have to make a 90 degree turn, which is always good. The X-pipe is harder to place than the H because of its design. If you are going to do a custom dual 2.5" or 3" exhaust from the cats back, then I would suggest an H-pipe at a minimum. If you or your exhaust guy can squeeze in an X-pipe somewhere near the front, then go for it.

If you are not going to dual the car out, I would leave everything alone. The back pressure in the exhaust system can be your friend if you understand it. There are tools you can purchase to measure the back pressure and you can tune it accordingly. I will finish this project once I get my other mods done and post my findings.

If you want to move forward, read as much as you can on exhaust systems and back pressure. Here is a good article to start with.

Here is a link to an exhaust back pressure test kit.

I would treat the exhaust system on the C32 like any other area of the car. Don't install parts just because. Take your time and tune the exhaust accordingly. Measure your back pressure now and if you can't find a level of pressure that will provide more power, at least you will know what level has the most power and can adjust the pipes to get that amount back.

What may work for my car might not work well for yours. I lost 25HP when I started farting with the system and I was forced to figure out why. Don't make my mistake.

 

If I could design the system from scratch and $$ wasn't an issue, I would do the following (in order from front to back):

1. Port the Exhaust ports on the heads to match the headers
2. Purchase long tube or shorty headers with a 2.5" outlet (maybe 3")
3. Create a port matched down pipe with built in 100 cell cats
4. Add a flex section to the down pipe
5. Use same size Stainless Steel tubing to custom tuned X-pipe
6. Create a flanged section for easy removal
7. Add in two SS bottle resonators, one on each pipe.
8. Create another flanged section for easy removal
9. Use same size SS tubing from resonators to mufflers
10. Use free flowing non baffled mufflers with AMG tips.

There is nothing better than a SS exhaust that is easy to remove / work on.

Oh yeah...Don't use SS until you get the design figured out. SS can be expensive.

 

I played around with my exhaust a lot too. The setup that I ended up sticking with is

headers
factory primary cats
flex section on downpipe
SS piping
aftermarket 18" long 3" diameter resonator
no secondary cats
stock AMG muffler

I am very happy with the note.

 

Any update?

 

Sorry for bringing this back but