Awsome! in place of your secondary cats did you just replace them with straight pipes? I've got 2 spare cylinder shaped mufflers that are straight through but very small, I was thinking to maybe put them in place of the cats incase its to loud (since I've already deleted the resenator) I'd hate to start getting a drone

 

With cut outs, you don't need to do anything to your existing exhaust, since you just redirect to an open pipe....really is a cheap racing set up...

 

Mmm thats the route I wanted to go Doc, but I'm not sure what the loss of back pressure will do to my performance, Rob ran with his open but I haven't seen anything where he's run with his normal exhaust who knows he may have gone quicker?

I do remember reading on the forum here awhile back that supercharged cars dont need any back pressure. I cant seem to find the thread though.

 

yes in place of the secondary cats are just straight pipes. then the x going into the y pipe into a single to the muffler. for me the x eliminated almost all the drone. a tiny bit at 2000 rpm but hardley noticable

 

Ahh found it.

quote from Rob @ Needswings.

"yes that is a straight dump tube off the manifold, torque is not a problem with them, i was runnign a very similar setup when we went 11.9's @ 119.8mph. actually we ran that with exhaust cutouts in the downpipe but these will flow a little better and also give the ability to drop the entire catback and both downpipes off the car, im guessing around a 100 pounds of weight savings

For a forced induction car the best exhaust is NO exhaust, this is as close as we could get while not burning the car down"

 

I have watched everyone who has ran header, straight thru exhausts, set ups to cat deletes, resonator deletes....without much of a change...some say a 4-10hp increase, but I just don't see it...but, you ask about changing your exhausts to this direct approach...and I am just saying for a direct approach, the cut outs are a cheap fix...whether they work for you or not, it certainly won't cost you much to find out....not saying here, which is best or not....I will do a resonator delete just because of the weight, no other reason, and if I gain something, then grt...good luck either way...

 

when i had mine setup as secondary cat delete res delete with x pipe and the free flowing ansa i noticed a definate drop in power! cant explain it but when the amg muffler went back on the power returned. at 3000 to 4000 rpm it just seemed to struggle a bit

 

Maybe the stock muffler gave you just enough back pressure for it to all work well.

I guess I shouldn't complain to much we've been blessed with cars that came out with a pretty perfect exhaust system from the factory. Seems as theres little to nothing we can do to help it performance wise. Other then sublte changes e.g. res, cat delete

 

i couldnt agree more. now you have that extra edge with your muffler centered in the middle you can run the dual inlet dual outlet oval muffler like a magnaflow or other brand and get a true dual exhaust! unfortunatly for me it looks like ill never have that little bit extra

 

Haha it would be nice to add the magnaflow but it will just be a constant drone I'd imagine now that I've removed the resenator.

I've seen the R170's underbody I'm sure you can run a dual set up, will just take abit of customizing and abit of $$$$

 

With just the muffler removed i was making 356RWtq with 178 pulley intake and tune. that was on the eurocharged dyno.

 

True "Factory" Mopar Cut-outs.

::: MoparMax ::: A Trend in Racing - Marco DeCesaris '62 Motor Trend Ramcharger Dodge - 12/2/08

 

Rear muffler or resenator?

 

unfortunaltly the slk32 amg doesnt have enough room between the area were the spare tire is supposed to go and the rear suspension. the re is less than 4" of space. not enough to fit 2 2.5 tubes and no room to bend the tubes to fit into a dual inlet and dual outlet. been trying for 2 months with every setup known . just aint gonna happen!

 

All stock just took off the muffler and ran a Y splitter out the back to turn in back into dual. So resonators and and cats still in place.

 

Awsome, how does it sound? any drone?

 

If I were to try cutouts, could I put them on before the cats, or would they have to go after the first cats due to the O2 sensors? Thanks

 

after..........

 

Thanks doc.... That is what I was thinking.

 

Pick Rob's brain on this one...it's not something I would do, but I know if has been done...