nysid2007

Hi guys ~

Just wondering typical Long tube headers due to their length , you have to

remove the primary cat and secondary cat and stock H pipe.

Increased HP installing LT headers. But what is the HP increase if CATS

are not removed?? Maybe with sport CATs or something?

This whole HP increase is not just from removing the CATS right ?

nanayaw6

The bulk of the gain is from having larger primaries(runners), the collector being furthur down (helps extraction) and the elimination of the primary cats. I just don't see the secondaries causing much of a restriction especially when it comes to race cats. Of course I don't have before and after dynos to prove my theory but I can't for-see anything more than a 5whp difference with quality cats, if even that at all.

SterlingE55

Agreed. You can easily gain 40rwhp with LT's and high flow cats.

nysid2007

Hey Guys thanks for all the info ~!! I see that most of after market set ups

are Long tube headers with X pipe and end muffler. I was told that X pipe

is best when located close to the headers as possible. If I'm going to delete

the primary cats ~ Do you think its best to place the X pipes at where

primary cat goes in and then place just straight pipe where stock resonator

goes in ???


wow 40 rwhp???? Damn .!! My first performance tunes gonna be headers !!

do you think I should do the ECU at the same time or is it ok to do it later??

Cuz I dont think I have enough cash after headers + installation .

SterlingE55

If I were to do it all over again I would have done headers as a first mod. 40+whp and lower IATs.

Looks at this link:
https://mbworld.org/forums/w211-amg/...ders-must.html

This is why headers are worth 40+whp on these cars. It's perfectly safe to run your stock ECU with headers. They way the car is setup you'll have to put the X-pipe some what back in the system. There's simply not room to have it super close to the LT's collectors.

Here's some pics and vids of my set-up.
http://s1113.photobucket.com/albums/...erlingE55/E55/

Anything is leaps and bounds an improvement over stock.

nysid2007

chawkins2001

He does have an E63 not an E55, but a buddy of mine just installed MBH headers with an x pipe, and the car picked up over 40rwhp. If you delete or leave the secondary cats in place, it will not make much of a difference, less than 5rwhp.

I would recomend removing that factory mid pipe, and have a nice x or h pipe made or you could buy MBH's full exhaust back to the catbak. They guarentee 42rwhp or your money back, that is major right there brotha!

Another great product is American Racing Headers, major gains and top notch product.

nysid2007

Hey thank you for tapping in !! Totally forgot about the American Racing guys !

I will check them out as well. I heard their price is a bit more competitive

than the others. So headers that are available for E63 are

MHP , American Racing , EVOSPORT, Keelmann, Agency Power

those are about it right ?

SterlingE55

Haha whoops. I forget about the 63 guys sometimes. From what I've heard headers are a big and great first mod for the 63 as well. Hard to go wrong with LT's first.