Hi friends. I know that maybe this question have been asked many times, but I need your advice for my specific setup, that I know is the same as some users here in JBO.

After some research and questions about my future exhaust, personally I will prefer going with a 2.25” cat-back instead my previous 2.5” idea, due to my needs. Ok, looking around I select the RK Sport 2.25” Single exhaust cat-back that will be coupled with a GMPP SC and a RK Sport 4-1 header.

The problem is that I heard that the RKSport cat-back sometimes is raspy; when it is cold; could be quiet down using a resonator, etc, etc, etc, etc….. I really prefer a deep and mellow sound, and I know that some people here have solved the problem with great success.

Then for this special case or setup (SC+ RKS 4-1 Header + RKS Single cat-back) I know that a good resonator in a good location could make the trick. But which one? Brand? Size? Location? One or two? My idea will be using a Dynomax Race Magnum Muffler 18” (case long) x 4” (round) exactly after the downpipe, where the gasses are hottest. In other cases I had great success with resonator, but was bigger engines.

Again, clips will be great, but I prefer specific comments of real success and precise info of the solution. I appreciate your simple comments without doing a great debate about this topic.

As always, thanks a lot for you support and patience with me.

Thanks,


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ELIOT. Now.....boosted.

have you thought about just buying a muffler and having them custom bend piping from the header back? megan racing makes amazing mufflers and are not raspy in the least bit.

I would also suggest that with a Super Charger you should go 2.5 but thats your preference



LE61T PTE6262 Powered

Thanks for your advice QBE, but I am looking max performance at mid-range rpms. My car is 90% daily driven 10% racing, that is the reason I prefer maintain at 2.25". Also I notice that the header set-up my powerband a little, then the 2.25" will support best HP number around the 3000-5000rpms. Also 2.25" exhaust can support 200WHp and low boost (8-9psi) easily of course with a free flow exhaust, retaining excelent torque.

After some readings here in JBO and other sites, friends advice and some calculations, 2.25" exhaust seems to be the way to go. If you want maximum performance, up to 250WHp or more, 10-12psi or more, 2.5" is the way to go. Inclusive remember that the climate in my country is hot, SC doesn't like it. Also remember that the EcoTEC SCed is runing 12psi of boost and use an MP62 supercharger, then excelent gains are obtain from a 2.5" cat-back.

About the resonator, RK Sport, recommends me to go, at least, with a 18" resonator. I am looking at it. Comments are welcome about the selection of it.

Thanks,


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im using the pacesetter header , high flow cat , and rkcrappy catback , all 2 1/4" tubing

its louder than loud while accelorating , its ok at cruise

id start with a 18-24" resonator , then move to the muffler

the worste part of the rkcrappy muffler is 2 1/4" inlet and 2 3/4" outlet

for a muffler is use a 18-24" which ever will fit best , and you want to make the outlet section as long as possible it will help controll some of the buzzing

I just thought I could save you some money with my thoughts.

check customtubesinc.com they can supply yrice, I pa size piping mandrel bent at a decent price, I paid 160 shipped for just my pipes, 3 inch diameter, yuo could have them,s end you just pipes and have a shop through in a resonator/hangers/muffler and be done with it



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i sorta got that set up. but a 45inch resonator / no cat. ( summitracing.com)

man it sounds sweet. i been through it all for set ups and i love this one the best.

my rk muffler got stolen, so i tried a few different kinds, and my current dynomax one i like.

I have RK 4-1 header, hi-flo cat, can't remember the length of my resonator and a Magnaflow muffler and all 2.25" stainless, and when I'm on it, it's raspy as all hell and I hate it!!! I think it might be the muffler itself on it's last days, think it's coming apart inside it's like 4 years old now at least.





14.330 @ 96.37mph

Jake
Which dynomax did you go with? Was it the super turbo one? What other kinds did you try and why did you not like them?

Edited 1 time(s). Last edited Wednesday, August 09, 2006 7:51 PM


FORGET GIRLS GONE WILD WE HAVE GOVERNMENT SPENDING GONE WILD!

ya i have the 2.5inch super turbo one. was not too much $.

i tried just the header/ cat and rk single cat back(magnaflow muffler), that i was told sounded" dirty". i hated it.

then a 2.5inch 18inch resonator ( well dynomax small glass pack thingy)and a twister style (internal twist) muffler. - bad

then quieted it down with a dynomax muffler, still sounded bad, but not as bad.

then i ripped out my cat- (header, 18inch resonator, dynomax muffler) backfired like a gun shot when i shifted. and loud and raspy, that was annyoing

then i put in a 45inch resonator (thrush i think, got it for 40$ at summit)and i love it. i am not going to change it ever again.

I have a pacesetter header thru a magnaflow cat then to a 27inch resonator to a can style muffler......... it was really raspy and crackly before the resonator. Personally if you want something not loud with a nice growl.... go with the longest resonator you can fit under your car then to a dynomax super turbo muffler...... from what everyone sez on here those are supposed to flow well and be very quiet...... thats what im planning on using when i boost......... but for now im switchin back to stock

Is there any sound difference between resonators or are they all about the same? I know the length makes a difference. The longer the better.


FORGET GIRLS GONE WILD WE HAVE GOVERNMENT SPENDING GONE WILD!

I have installed part of my 2.5" exhaust parts in a truck of a friend. I am talking about Dynomax Race Magnum Bullet resonator 12" long and a Magnaflow 18" long muffler in a 1994 Grand Cherokee V8 5.2L. The sound is just amazing!!!!! At idle or cruise you barely notice the exhaust, but when you floor it, god!!!! nothing sounds as good as an american V8.

Anyway I think the whole trick is the muffler / resonator location, muffler internal temps and and type of sound absorbing material. In the truck of my friend the muffler is under front seats, so it get hot quickly. Also remember that Magnaflow's muffler has a first layer of SS mesh packing and after that fiberglass the main sound absorbing material. SS mesh is used to improve heat support and avoid burn the fiberglass. Personally I think that Dynomax sounds mellows than Magnaflow's but maybe it will last less, because I think only uses fiberglass material. These are only ideas.

Following the recommendation of QBE, I have contacted Custom Tubes Inc to make and special cat-back for me. I will let you tuned.

Regards,


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ya, 45inch is the biggest you can fit under there. basically right from the down pipe, to the first bend around the gas tank.

hey dude my buddy joe has the gm supercharger on this z24 and he was running a 27" cherry bomb glass pack and a magnaflow wide open series muffler with no cat a it sounded real deep and very pissed off when he got on it.


k5 ftmfw!!