Hi everyone!

I've recently put back my resonator(I had mendrel bent pipes) because I felt the engine had no power before 2000rpm. But now I am kinda regret about what I did because the car is a bit slower on the highway and the engine is not as throaty at higher rpm

This had made me thinking about other ways to improve the performance of the exhaust system:

1) remove the second set of cats and replace with straightpipes and keep the stock resonator
2) change the second sets of cats to high flow cats and keep the stock resonator
3) replace the resonator with magnaflow X pipe and keep the stock cats
4) X pipe with high flow cats
5) X pipe with no cats

Also I would like to know what exactly does X pipe do? are the stock cats very restrictive? what would be more noisy: remove the cats or remove the resonator?

cheers,

 

I have been down the same path.
By resonator -do you mean the mid-muffler after the 2nd set of cats? If so this is a straight through item that has very little restriction,even though it is fairly large. You will see better HP gains removing the cats. The cats are supposed to be pretty good, but higher performance cats will net around 5hp. The biggest improvement is relacing the exhaust manifold. This is worth around 25hp. I have no experience with an X pipe. I assume this is a crossover pipe that takes advantage of exhaust system pulsing.

 

Our headers will be available in about 3 weeks.

 

Some new products coming from SuperSprint for W210 E55:

http://www.mitcom2.com/supersprint/a...dello=mer21020

 

K-AMG-E, so what have you done to your car? What has been the ultimate combination?

 

You say you had mandrel pipes installed when the resonator was removed? Does this mean you changed from a Y-pipe configuration to a true dual?

The reason I ask is a Y-pipe and an X-pipe perform a nearly identical function... scavenging. The placement of the merge is important for torque generation. The factory location is good. Removing this will reduce low RPM torque. Replacing it with a better flowing merge (either X or Y) can give you both low rpm and high rpm power (torque x rpm = power) Pipe diameter is important. Too large a pipe will reduce low rpm velocity and reduce scavenging. Too small will reduce high rpm flow (stock).

The stock cats are mildly restrictive although not horribly and due provide some muffling (not much but some). I would keep the cats and go to a 3" ID resonator in the stock location with a Y-pipe from Burns Stainless. Not the cheapest, just the best. http://www.burnsstainless.com/Crosso...rossovers.html