HF cat and Muffler

Vinalero · 07-06-2008, 04:13 PM

I'm on my way to complete my exhaust set up and I was wondering which brand of Cat and muffler to buy. I'm gonna probly try a dynomax turbo muffler but for the High flow cat, I just dont know.

I dont want to get one with ceramic because I want it to last for a while.

I'd like to go 2.5 inch piping or even maybe 2.75 or 3 since I'm boosted now.

So what are your opinions on this?

01oldsgls · 07-06-2008, 04:18 PM

magnaflows always a good choice for a high flow muffler, and ive always ready 3 inch exhaust is good for boost, but im by no means an ld9 expert

YALEROYNOT · 07-06-2008, 07:59 PM

I have a 2.5 down pipe (3.4 no turbo) and a SS magna flow high flow cat and 2.5 pacesetter kit works well love the extra ummpph and the sound.

Alerosaint · 07-07-2008, 07:42 AM

I have a magna high flow cat and a vibrant str8t thru muffler sitting in my room...... all 2.5"

If you decide to go 2.5" the cat model number is 53006
Got it from here http://www.hottexhaust.com/

Spilner521 · 07-07-2008, 11:04 PM

Quote:

Originally Posted by Vinalero

I'm on my way to complete my exhaust set up and I was wondering which brand of Cat and muffler to buy. I'm gonna probly try a dynomax turbo muffler but for the High flow cat, I just dont know.

I dont want to get one with ceramic because I want it to last for a while.

I'd like to go 2.5 inch piping or even maybe 2.75 or 3 since I'm boosted now.

So what are your opinions on this?

Some people will tell you a 3" exhaust is too big even with a supercharger. Since the supercharger provides instant boost, exhaust scavenging at low rpms becomes much less important. With that said, a 3" exhaust will gain a little more power over the 2.5" piping, but it will be pretty loud, especially since there's no turbo in the exhaust stream to help keep it quiet.

I'd stick with 2.5" piping with a Magnaflow metallic high flow cat (part no. 59956), long resonator and large straight through muffler, like something from Magnaflow or Vibrant.

Alerosaint · 07-07-2008, 11:17 PM

Quote:

Originally Posted by Spilner521

Some people will tell you a 3" exhaust is too big even with a supercharger. Since the supercharger provides instant boost, exhaust scavenging at low rpms becomes much less important. With that said, a 3" exhaust will gain a little more power over the 2.5" piping, but it will be pretty loud, especially since there's no turbo in the exhaust stream to help keep it quiet.

I'd stick with 2.5" piping with a Magnaflow metallic high flow cat (part no. 59956), long resonator and large straight through muffler, like something from Magnaflow or Vibrant.

a"lot of my research came off of some of your posts...but im going 2.5....do you think its gonna yield good performance gains compared to 2.75" or 3"
...I already ordered the parts....what you think???...Im s/c up

Spilner521 · 07-07-2008, 11:25 PM

Yes you'll still make good power with a free flowing 2.5" exhaust and it'll be quieter than a 3" system.

Alerosaint · 07-07-2008, 11:30 PM

ok cause i got my cat, muffler and reso...just waiting for my header which is taking forever to come from coating....but i didnt want to get a dud exhaust system

Spilner521 · 07-07-2008, 11:45 PM

You'll be just fine, especially adding a header to a full, free flowing exhaust.

Alerosaint · 07-07-2008, 11:56 PM

cool...good re assurance coming from a turbo nut

Vinalero · 07-08-2008, 09:38 PM

Thx for the infos

is that it? :

http://www.hottexhaust.com/detail.asp?PRODUCT_ID=59956

Alerosaint · 07-08-2008, 10:54 PM

I wonder whats the diff between the 2.5 " ID 300 cell density Metallic Substrate Universal Catalytic Converter and the regular 2.5" cat??? Anybody???

spyhunter · 07-09-2008, 03:30 AM

My 3inch is very quiet.

Spilner521 · 07-09-2008, 08:52 PM

Quote:

Originally Posted by Vinalero

Thx for the infos

is that it? :

http://www.hottexhaust.com/detail.asp?PRODUCT_ID=59956

Yep that's it.

Quote:

Originally Posted by Alerosaint

I wonder whats the diff between the 2.5 " ID 300 cell density Metallic Substrate Universal Catalytic Converter and the regular 2.5" cat??? Anybody???

The regular Magnaflow cat is ceramic. You just mentioned you didn't want a ceramic core cat so I gave you the part number for the metallic core cat. The metallic core will handle super high exhaust temps better and may flow a little better, but I've been happy with my regular 3" ceramic Magnaflow cat.

I am swapping to a 3" metallic Magnaflow cat for my Eco engine, but then again, I'm aiming for quite a bit more power and flow than I have now.

Quote:

Originally Posted by spyhunter

My 3inch is very quiet.

So is mine, but we have a turbine in the exhaust path that helps keep the noise down.

Alerosaint · 07-09-2008, 09:39 PM

I got the regular ceramic one.... vinalero is the one who didnt want ceramic...but I did talk to the magnaflow cat tech and he told me the same thing you said that it flow better than the ceramic one...and he recommended that for the force inducted over the reg ceramic...ill try to see if a can get a swap or just purchase it and sell the ceramic on here

Vinalero · 07-10-2008, 03:52 AM

appreciated guys, thx

spyhunter · 07-10-2008, 06:37 PM

what's the purpose of a cat?

jayson_waltz · 07-10-2008, 06:54 PM

^because u only gain about .5 hp taking it off, so y be illegal? or if you are being serious, it takes a bunch of bad exhaust crap and basically turns it to harmless stuff like water

for a 4cyl, i'd have to say go with the 2.5. i'd think 3 would sound a bit shitty and wouldn't make a big hp difference with just a supercharger. now if you had a turb i'd go with the 3".

Spilner521 · 07-10-2008, 07:15 PM

Quote:

Originally Posted by Alerosaint

I got the regular ceramic one.... vinalero is the one who didnt want ceramic...but I did talk to the magnaflow cat tech and he told me the same thing you said that it flow better than the ceramic one...and he recommended that for the force inducted over the reg ceramic...ill try to see if a can get a swap or just purchase it and sell the ceramic on here

Eh, I knew it was one of you, I was just putting the part number out there for anyone

You'll be fine with the ceramic core cat, but it's up to you if you want to swap, every little bit of flow helps. Like I said, I've had it on my car since day 1 with boost and I've been very happy with it.

Quote:

Originally Posted by spyhunter

what's the purpose of a cat?

I'm not a big fan of cats actually. I'm a dog guy myself. I have two

spyhunter · 07-12-2008, 08:47 PM

Quote:

Originally Posted by jayson_waltz

^because u only gain about .5 hp taking it off, so y be illegal? or if you are being serious, it takes a bunch of bad exhaust crap and basically turns it to harmless stuff like water

for a 4cyl, i'd have to say go with the 2.5. i'd think 3 would sound a bit shitty and wouldn't make a big hp difference with just a supercharger. now if you had a turb i'd go with the 3".

I gained more then .5 taking my cat off.

Actually my exhaust setup is probably the straightest of anybody with an n-body.

Log manifold, turbo (side note: wastegate dumps into the atmosphere instead of being recirculated back into the exhaust, teehee.), 2.5 downpipe into flexpipe, into 3inches into Apex'i N1 can, which is closer to 3.25inch.

Sounds awesome.