High Flo

[Timw286]

Will replacing the 2 cats closest to the motor with a pair of high flow cats make any signifigant change to power/noise? I plan doing that in conjunction with either magnaflow/flowmaster mufflers but don't want to waste the money if it won't be noticeable. :burnout:

[tbone]

Just remove the second set of cats along with Magnaflows and you will have perfect sound.

[fastblackmerc]

Any change will affect the exhaust note.

I'd remove the 2nd set of cats and just use 2 hi-flo cats.

[SC Cheesehead]

Replace the first set of cats with high flow units, and remove the second set of cats, will pick up some power as well as slightly increase the sound volume.

Should be good for about 5-10 hp.

[Marauderman]

Will replacing the 2 cats closest to the motor with a pair of high flow cats make any signifigant change to power/noise? I plan doing that in conjunction with either magnaflow/flowmaster mufflers but don't want to waste the money if it won't be noticeable. :burnout:

Check our meet this Saturday in Columbia in the Carolina Marauder Forum. You can here mine to decide. I have removed cats with magnaflows and unrestricted 2 1/2 in to 3 "deleted tips---

[slickster]

The results in HP order:
1.Flowtech Warlock (open) 374.2 hp/ 333.1 tq
2.Bassani Real Street 373.7 hp/ 333.8 tq
3.Hooker Maxflow 373.5 hp/ 333 tq
4.Borla XS 373.3 hp/ 332.6 tq
5.Magnaflow 372.8 / 332.5 tq
6.MAC 372.3 hp / 331.5 tq
7.Flowtech Afterburner 372.3 hp/ 330.1 tq
8.Hooker Aerochamber 372.1 hp/ 330.4 tq
9.Bassani 372 hp/ 333.5 tq
10.Spintech 371.6 hp/ 332.2 tq
11.Edelbrock Performer RPM 370.9 hp / 331.3 tq
12.Borla XR1 370 hp/ 334 tq
13.Flowtech Terminator 369.5 hp / 331.3 tq
14.Dynomax Ultra Flo 369.4 / 333.2 tq
15.Flowmaster 369.4 hp / 331.8 tq
16.Flowtech Warlock 366.3 hp / 325.3 tq
17.No muffs 365.2 hp / 330.1 tq

Sound Off in Quietest to Loudest (Decibels):

1.Borla XS, 80db at idle, 90db at 2,000 rpm, 110db at WOT.
2.Hooker Maxflow, 80db at idle, 90db at 2,000 rpm, 120db at WOT.
3.Magnaflow, 82db at idle, 91 at 2,000 rpm, 114db at WOT.
4.Flowmaster, 82db at idle, 93 at 2,000 rpm, 115db at WOT.
5.Flowtech Warlock, 83db at idle, 92 at 2,000 rpm, 112db at WOT.
6.Dynomax UltraFlo, 83db at idle, 94 at 2,000 rpm, 113db at WOT.
7.Borla XR1, 83db at idle, 96db at 2,000 rpm, 118db at WOT.
8.Bassani Street, 83db at idle, 96db at 2,000 rpm, 120db at WOT.
9.Edelbrock RPM, 84db at idle, 93db at 2,000 rpm, 118db at WOT.
10.Bassani Real Street, 84db at idle, 96db at 2,000 rpm, MAX. (120+db).
11.Flowtech Afterburner, 86db at idle, 94db at 2,000 rpm, 115db at WOT.
12.Flowtech Terminator, 86db at idle, 94db at 2,000 rpm, 119db at WOT.
13.Hooker Aerochamber, 87db at idle, 94db at 2,000 rpm, 114db at WOT.
14.SpinTech, 87db at idle, 97db at 2,000 rpm, 116db at WOT.
15.MAC, 87db at idle, 98db at 2,000 rpm, 119db at WOT.
16.No Muffler, 91db at idle, 103db at 2,000 rpm, MAX. (120+db).
Keep in mind without rear cats it will be louder. This test car was not a mm

[MOTOWN]

I honestly think that list is misleading at best! there are a number of variables that will effect how a muffler performs on a given vehicle

[fastblackmerc]

I honestly think that list is misleading at best! there are a number of variables that will effect how a muffler performs on a given vehicle

I agree... too many variables....

[bugsyc]

Where in sc are you located????

[SC Cheesehead]

Where in sc are you located????

I'm gonna guess he's at Shaw AFB, about 40 miles east of Columbia.

[ctrlraven]

Replace the first set of cats with high flow units, and remove the second set of cats, will pick up some power as well as slightly increase the sound volume.
^This!

I've seen a few people remove the 2nd set of cats, replaced them with high flow ones and then left the 1st set of cats in place.

I went with Magnaflow 200 count 2.5" small cats with a downtube connected right off the factory exhaust manifold.
http://a2.sphotos.ak.fbcdn.net/hphotos-ak-snc4/62504_1271884655760_1789212029 _546482_7823424_n.jpg
http://a7.sphotos.ak.fbcdn.net/hphotos-ak-snc4/62504_1271884895766_1789212029 _546487_1804050_n.jpg
http://a3.sphotos.ak.fbcdn.net/hphotos-ak-snc4/44269_1283225459273_1789212029 _565438_6463086_n.jpg

[SC Cheesehead]

^This!

I've seen a few people remove the 2nd set of cats, replaced them with high flow ones and then left the 1st set of cats in place.

I went with Magnaflow 200 count 2.5" small cats with a downtube connected right off the factory exhaust manifold.
http://a2.sphotos.ak.fbcdn.net/hphotos-ak-snc4/62504_1271884655760_1789212029 _546482_7823424_n.jpg
http://a7.sphotos.ak.fbcdn.net/hphotos-ak-snc4/62504_1271884895766_1789212029 _546487_1804050_n.jpg
http://a3.sphotos.ak.fbcdn.net/hphotos-ak-snc4/44269_1283225459273_1789212029 _565438_6463086_n.jpg

^^^^ Seems to me that would defeat the purpose of the high flow cats. One set of cats, those being high flow, are the way to go (as we've noted).

In my case, I've got FRPP shorty headers connected to a Cobra off-road Mac Pro-Chamber mid pipe that was cut and sectioned to accomodate a pair of Magnaflow 94316 high flow cats.

http://www.mercurymarauder.net/forums/attachment.php?attachmentid=24 033&d=1301761386

http://www.mercurymarauder.net/forums/attachment.php?attachmentid=24 034&d=1301761487