hooleyboy

Do day I went down to Dyno comp at ask about the CP They claimed there is no way to install it wrong so bla bla bla Rich the owner is a good friend of mine and We ran some dyno's and then at the spur of the moment chopped out the secondary cats on my C55. I have before and after, same day dyno runs. All I can say Is the car sound is 10000 times better than just the res-delete. I would highly recommend doing this mod it made my car sound so mean almost like an exotic Lambo or ferrari. It sounds so crisp and monstrous. Any way the removal of the secondary cats in a c55 yielded about 19wtq and 13whp. After i installed these wheels I deff seeing a lose of power at the wheels on a dyno. anyway Here is the Dyno


sound video... update no lawn mower this time

http://www.youtube.com/watch?v=o2a9yc-lzf4

jturkel

wow those are pretty impressive numbers for just deleting the secondary cats. i had no idea it would clear up that much hp and tq.

genome

you know i always wanted to do this. i know you are in arizona, but would you happen to know if i can do the same and pass cali smog?

i vaguely remember reading its not.

oh and.... link to sound?

im very curious on how it sound now.

jturkel

i read somewhere that an SL55 with race cats, deleted secondaries, and deleted resonator passed emissions in CA

hooleyboy

I'm not sure I think it should pass emissions they all told me there i would pass no problem. I will get a link to the sound. The Sound wont be as good as the car was in dyno mode and that shuts of the stupid rev limiter when its in park (I think) I will go do it give me a few mins. I think I have a before audio clip too.

rploaded

Since all of the sensors are in front of the 2nd cats, I would not think it would effect any test using the OBDII system.

As for sound, it does clear up some noise. I am resonator and muffler free after the first cats.

Well I do have a hollow flowmaster welded in to pass inspection. I even ditched the little mini mufflers at the tips and just welded the tips on to a new section of straight pipe. Stock look, far from stock sound.

I have vettes, old hotrods, older muscle crowd generations pull up next to me and say how big of a V8 is in that thing......

hooleyboy

The sound is up on you tube. click the link in my first post.

TruTaing

wow. That is a HUGE gain....

thats a mean soundin lawn mower :P

SilverBulletAMG

Holy crap! That sounds awesome and the dyno is amazing. Who would have thought that would yield such a gain!? Impressive.
Did you completely remove the front cats and just run straight tube in place?
I wonder what that does for our supercharged 3.2s?

EDIT: I was was thinking you removed the primary cats. Still surprised at the results of the just removing the secondaries. The 3.2 doesn't seem to gain squat from doing much of anything with just the rear cats and resonators removed. Most likely true for the front.

hooleyboy

I was on the dyno and they were looking under the car saying I could free up some power if i removed the secondary cats so I trust Rich at dyno comp and we chopped them off and repiped them with a 2008 M5's exhaust! complete with heat shield. Kinda bad a$$ i must say. We called over to Renntech and asked the engineer there if this would gain anything and he said "it sure will." and IF i went total custom exhaust with magnaflow mufflers the Renntech engineer said i would pick up about 10-20whp on top of what i just gained. So custom full exhaust is coming soon! If there was high flow main cats for this car i bet i would get 30whp total

jturkel

i thought that deleting the secondaries didnt do much for C32s besides weight reduction, though i could be wrong.

great sounding exhaust btw!

Eleventeen

You thought right. Not worth the bead of weld required. In fact, removing the primaries doesn't do much either (not if the car is nearly stock anyway). If only I had a time machine, I wouldn't be on my second set of after market cats thinking about just how good the AMG cats are from the factory.

rploaded

I did want to mention that deleting the secondary cats did void all of my emission system warranty and everything south of the combustion chamber. I was BL on those parts from the dealer. Don't think when you roar into service they are not going to peak. Just a FYI.

Does sound cool though.....

My .02

jturkel

i dont think they make high flow main cats specifically for the car, but im sure universal magnaflows can fit and would yield some gains.

hooleyboy

My exhaust has been chopped cut and rebuilt so... I know im SOL on that not but i dont care to much about it.

hooleyboy

Kleemann i thought maid hiflow cats but i cont think it will fit with my evosport headers. I will be looking into some options though

rploaded

If you really want to free up some more noise and about 3 hp, ditch the muffler/resonators right before the Exhaust tips.

Tack weld an x-brace to the twin tips to keep the angle and gap equal, and cut from muf/res. Then make a custom y-pipe to fit and weld back to straight pipes. Then you will get the sound and 3 free ponies while maintaing the stock AMG tips.

Enjoy and sweet looking ride.

hooleyboy

we were thinking of chopping the 2 inch pipe the leads into the exhaust and doing some custom fab work to feed it with larger pipe. We were also thinking of getting some magnaflow mufflers that are duel tip and chipping them off then welding the AMG ones back on... for looks of course

rploaded

I am expecting my car back from the shop mid next week, I can take some pics of what we did if your interested. It looks factory from the outside and sounds mean as all hell.

hooleyboy

Do it up.

c32used

Sweet!

hooleyboy

He11 yeah.. hay when you get knocked down you gotta get back up!

S5LorinserF1

did you delet the resonator also??


how do you think it will sound on a 500 motor with evosport headers, and my custom magnflow exhaust

hooleyboy

It would sound nice i bet. Hay can you take a pic of your mangaflow exhaust? and what muffler his you use and did you use an after market main cat? If so to any of those could you let me know. I got a new video going up with out the lawn mower turn your speakers up it sounds killer.

New video No lawn mower

http://www.youtube.com/watch?v=o2a9yc-lzf4

S5LorinserF1

i have the 14816 mufflers.


there perfect size, and sound is great already. my car gurgles already without the resonator delete or sec cat delete yet.


cant wait for appointment at shop next week for header install and straight pipe from secondarys to magnaflow mufflers.

hooley boy ill get pics for you soon