kooks headers with flowmaster AT, want to maintain 3" - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

black79ta · 04-20-2013, 04:10 PM

I am thinking about getting Kooks 1 7/8" x 3" LT's with cats. what i want to do is get their 3"x3" catted connection pipe. I have the FAT catback already installed. To maintain 3" dia all the way back, I would have to cut off the 2.5" neckdown portion of the FAT. In a perfect world i would then use a band clamp to attach the 3"dia cat to the 3"dia FAT pipe.

HAS ANYBODY DONE THIS BEFORE???

thanks

black79ta · 04-21-2013, 10:05 AM

Anybody?? Bump??

Iam Broke · 04-21-2013, 10:53 AM

I used a pair of 3" X 9" Vibrant race mufflers to eliminate the neckdown and they kinda look like HFC's. Might be an option on your setup. Straight through 3" ID in/out. Sometimes 3" exhaust is a bit smaller after mandrel bending ect. so you might have to cut 4 reliefs in the connections and use aluminium strips for shims with Accuseal clamps or have them welded.

black79ta · 04-21-2013, 06:16 PM

thanks for the reply Iam Broke. i am thinking it is worth it to maintain the 3" diameter all the way through, but am trying to figure if I want to go thru the hassle...thanks for your input.

kevin1106 · 04-21-2013, 06:29 PM

Just FYI, if you get headers and the FM AT CB, your car will have a ton of drone.... I sold mine cause of this....

black79ta · 04-21-2013, 07:26 PM

yeah it had a loud drone with just the catback below 2000rpm, before i pulled the muffs off and ran straight pipes. with straight pipes the drone is at 3000rpm, driving me nuts. what cat back did you end up with?

MarylandSpeed · 04-21-2013, 08:57 PM

Kooks makes a full 3" mid pipe..it is special order, and takes a while to get however. As you noted, it would require custom work to fit your flowmaster. Personally, I would not be too worried about the neck down. There are a lot of people pushing crazy HP through full 2.5"
catbacks here.

ZWA SS · 04-21-2013, 09:51 PM

I had couple pipes welded in to maintain 3". Cut the necked down portion off the catback.
Had I known 2.5" vs 3" wasn't needed unless making crazy power, I would have skipped the catback.
Buy with my longtubes and AMT catback, I really enjoy the sound. I like loud and the drone doesn't bother me.

black79ta · 04-23-2013, 07:25 PM

I ORDERED MY KOOKS!! 1 7/8" with 3" x 3" cat pipes. from JDP motorsports, got a great price! i am going to cut off the 2.5" end of my flowmaster AT catback, weld on a 3" extension then clamp to the 3" cats. I appreciate the suggestions from you all on this forum.

kevin1106 · 04-30-2013, 06:17 PM

Quote:

Originally Posted by black79ta

yeah it had a loud drone with just the catback below 2000rpm, before i pulled the muffs off and ran straight pipes. with straight pipes the drone is at 3000rpm, driving me nuts. what cat back did you end up with?

I put the ZL1 Corsa CB on my old SS... No drone... I purchased the same exhaust for my new ZL1 cause I know it drone free...

black79ta · 05-02-2013, 10:35 PM

I bought some 304 SS tube, I am going to practice tig welding stainless this weekend.my kooks and cats probably wont arrive for another week. I will only need about 12" of tube but had to buy a 10' section. if the welds turn out crappy i will not post pics...Kevin, i am going to run what i got, go from there. My main gripe about the Flowmaster AT is it is not loud enough.

black79ta · 05-05-2013, 09:15 PM

Here are my practice welds, the top weld was the first worked my way down. 3rd weld is the best, i think i am ready when the kooks and cats arrive. The hardest part was trying to make an exact square cut.
Name: IMAG0782.jpg
Views: 325
Size: 127.4 KB

Name: IMAG0782.jpg
Views: 325
Size: 127.4 KB

black79ta · 05-14-2013, 09:07 PM

MY HEADERS ARRIVED!! hopefullly I will have time to put them on this weekend. You can see thru the cats, I wonder how see thru the Green Cats are.
IMAG0785.jpg

litle88 · 05-14-2013, 10:31 PM

This is how mine sounds with those same headers Choke masters and no cats.

http://youtu.be/vw2PsWCsx8g

http://youtu.be/vw2PsWCsx8g

04-20-2013, 04:10 PM	#1
black79ta Drives: 79 transam with 582cid dart motor Join Date: Jun 2010 Location: missouri Posts: 529 View My Garage	kooks headers with flowmaster AT, want to maintain 3" I am thinking about getting Kooks 1 7/8" x 3" LT's with cats. what i want to do is get their 3"x3" catted connection pipe. I have the FAT catback already installed. To maintain 3" dia all the way back, I would have to cut off the 2.5" neckdown portion of the FAT. In a perfect world i would then use a band clamp to attach the 3"dia cat to the 3"dia FAT pipe. HAS ANYBODY DONE THIS BEFORE??? thanks __________________ 2010 Camaro (inferno orange, 2SS, RS and such) cat backs, catch can, CAI on the way 79 Transam, 582 cid dart motor 779hp 315's out back 40spline gdaxles tko tranny

04-21-2013, 10:05 AM	#2
black79ta Drives: 79 transam with 582cid dart motor Join Date: Jun 2010 Location: missouri Posts: 529 View My Garage	Anybody?? Bump?? __________________ 2010 Camaro (inferno orange, 2SS, RS and such) cat backs, catch can, CAI on the way 79 Transam, 582 cid dart motor 779hp 315's out back 40spline gdaxles tko tranny

04-21-2013, 10:53 AM	#3
Iam Broke PHAT B33 Drives: 2012 TF3 Camaro 2SS/RS M6 Join Date: Jun 2012 Location: Dark of the Moon Posts: 1,460 View My Garage	I used a pair of 3" X 9" Vibrant race mufflers to eliminate the neckdown and they kinda look like HFC's. Might be an option on your setup. Straight through 3" ID in/out. Sometimes 3" exhaust is a bit smaller after mandrel bending ect. so you might have to cut 4 reliefs in the connections and use aluminium strips for shims with Accuseal clamps or have them welded. __________________ Another 1 of 371 '12 T3 LS3 M6's built.

04-21-2013, 06:16 PM	#4
black79ta Drives: 79 transam with 582cid dart motor Join Date: Jun 2010 Location: missouri Posts: 529 View My Garage	thanks for the reply Iam Broke. i am thinking it is worth it to maintain the 3" diameter all the way through, but am trying to figure if I want to go thru the hassle...thanks for your input. __________________ 2010 Camaro (inferno orange, 2SS, RS and such) cat backs, catch can, CAI on the way 79 Transam, 582 cid dart motor 779hp 315's out back 40spline gdaxles tko tranny

04-21-2013, 07:26 PM	#6
black79ta Drives: 79 transam with 582cid dart motor Join Date: Jun 2010 Location: missouri Posts: 529 View My Garage	yeah it had a loud drone with just the catback below 2000rpm, before i pulled the muffs off and ran straight pipes. with straight pipes the drone is at 3000rpm, driving me nuts. what cat back did you end up with? __________________ 2010 Camaro (inferno orange, 2SS, RS and such) cat backs, catch can, CAI on the way 79 Transam, 582 cid dart motor 779hp 315's out back 40spline gdaxles tko tranny

04-21-2013, 06:29 PM	#5
kevin1106 Drives: 2015 ZO6 3LZ Stage 2 A8 Join Date: Nov 2010 Location: La plata MD Posts: 2,299 View My Garage	Just FYI, if you get headers and the FM AT CB, your car will have a ton of drone.... I sold mine cause of this....

04-21-2013, 08:57 PM	#7
MarylandSpeed Account Suspended Drives: 2012 ZL1 & 2010 2SS/RS Join Date: Jul 2009 Location: Maryland Posts: 3,378	Kooks makes a full 3" mid pipe..it is special order, and takes a while to get however. As you noted, it would require custom work to fit your flowmaster. Personally, I would not be too worried about the neck down. There are a lot of people pushing crazy HP through full 2.5" catbacks here.

04-21-2013, 09:51 PM	#8
ZWA SS BowtieBelle's SS Drives: 2010 Camaro SS Join Date: Jan 2012 Location: Perry, ok Posts: 1,074	I had couple pipes welded in to maintain 3". Cut the necked down portion off the catback. Had I known 2.5" vs 3" wasn't needed unless making crazy power, I would have skipped the catback. Buy with my longtubes and AMT catback, I really enjoy the sound. I like loud and the drone doesn't bother me.

04-23-2013, 07:25 PM	#9
black79ta Drives: 79 transam with 582cid dart motor Join Date: Jun 2010 Location: missouri Posts: 529 View My Garage	I ORDERED MY KOOKS!! 1 7/8" with 3" x 3" cat pipes. from JDP motorsports, got a great price! i am going to cut off the 2.5" end of my flowmaster AT catback, weld on a 3" extension then clamp to the 3" cats. I appreciate the suggestions from you all on this forum. __________________ 2010 Camaro (inferno orange, 2SS, RS and such) cat backs, catch can, CAI on the way 79 Transam, 582 cid dart motor 779hp 315's out back 40spline gdaxles tko tranny

05-02-2013, 10:35 PM	#11
black79ta Drives: 79 transam with 582cid dart motor Join Date: Jun 2010 Location: missouri Posts: 529 View My Garage	I bought some 304 SS tube, I am going to practice tig welding stainless this weekend.my kooks and cats probably wont arrive for another week. I will only need about 12" of tube but had to buy a 10' section. if the welds turn out crappy i will not post pics...Kevin, i am going to run what i got, go from there. My main gripe about the Flowmaster AT is it is not loud enough. __________________ 2010 Camaro (inferno orange, 2SS, RS and such) cat backs, catch can, CAI on the way 79 Transam, 582 cid dart motor 779hp 315's out back 40spline gdaxles tko tranny

05-05-2013, 09:15 PM	#12
black79ta Drives: 79 transam with 582cid dart motor Join Date: Jun 2010 Location: missouri Posts: 529 View My Garage	Here are my practice welds, the top weld was the first worked my way down. 3rd weld is the best, i think i am ready when the kooks and cats arrive. The hardest part was trying to make an exact square cut. __________________ 2010 Camaro (inferno orange, 2SS, RS and such) cat backs, catch can, CAI on the way 79 Transam, 582 cid dart motor 779hp 315's out back 40spline gdaxles tko tranny

05-14-2013, 09:07 PM	#13
black79ta Drives: 79 transam with 582cid dart motor Join Date: Jun 2010 Location: missouri Posts: 529 View My Garage	MY HEADERS ARRIVED!! hopefullly I will have time to put them on this weekend. You can see thru the cats, I wonder how see thru the Green Cats are. IMAG0785.jpg Attached Images __________________ 2010 Camaro (inferno orange, 2SS, RS and such) cat backs, catch can, CAI on the way 79 Transam, 582 cid dart motor 779hp 315's out back 40spline gdaxles tko tranny

05-14-2013, 10:31 PM	#14
litle88 V8 Lounge member #2 Drives: 2001 Ws6 Join Date: Sep 2009 Location: Burbank,IL Posts: 6,373	This is how mine sounds with those same headers Choke masters and no cats. http://youtu.be/vw2PsWCsx8g http://youtu.be/vw2PsWCsx8g __________________ 2001 ws6, 40k miles, Ls3 416 stroker, short block built by PER the rest by me. LPE Ls3 heads milled to 12-1 comp, FAST 102, NW 102, kooks 2", dual DMH cutouts, Magnaflow C/B, BTR cam + springs. Full UMI suspension.