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Mac Headers and flowmasters

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Old Dec 20, 2002 | 11:43 AM
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Default Mac Headers and flowmasters

I just bought a set of mac headers and ory. I'm also getting a catback to install at the same time. I had a flowmaster catback on my last SS and saw a .2 gain from them but that was the only mod to the car besides a lid and FRA(and 4.10s). My question is will I see gains from both the headers and exhaust or will the flowmasters restrict the flow of the headers? I dont care if i only pick up .1 from the flowmasters because im getting them due to their deep throaty sound that i like a lot. My car will just be a bolt-on car with no internal motor work. I would also like to know how this setup sounds? Does it have a lot of rasp? Is it really deep bc thats what im looking for. Right now my car has a lid and FRA and I ran a 13.1 at 109. I'll be happy if i can gain .3 and 2-3mph with this setup. Is this possible?

Thanks
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Old Dec 20, 2002 | 04:57 PM
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Default Re: Mac Headers and flowmasters

I have pretty much the same setup you're thinking of doing. When i had my flowmaster installed, i didnt get the cat-back 'cause the pipe between y and muffler on the ws6 is a bit bigger than non ws6 cars. i didn't feel any difference with the flowmaster on above stock.
When the mac ml header were installed, i gained about 3-4 tenths(depending on weather). the combo sounds great. there are certain rpm's where it gets a bit raspy, but that's why i got it. car pulls much harder after the macs
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Old Dec 20, 2002 | 11:09 PM
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Default Re: Mac Headers and flowmasters

I'm sorry, but the Flowmaster will rasp like all he!! without cats on an LS1(same with many other exhaust). It honestly sounds that bad IMO. Of course, that is just the nature of this motor without cats.

You want your Flowmaster to still sound good, have your stock cats(or highflow one's) welded into the Mac y-pipe. The sound will still be deep and clear. And if you need the extra flow, just slap a cheap cutout on your I-pipe for the track.

Mike
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Old Dec 21, 2002 | 12:50 AM
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Default Re: Mac Headers and flowmasters

Are there any cat-backs for around the same price as flow masters that have little or no rasp with an ORY? Or is any cat-back that you put on there going to have rasp do to the fact that there are no cats on there. If so, would the flow masters still have a deeper tone than say... Borla, Whisper, Magnaflow, etc.? Because if they are all going to have rasp I am still going to stick with the flow masters.
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Old Dec 21, 2002 | 02:51 AM
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Default Re: Mac Headers and flowmasters

I like the way my freinds ss sounds with oryp and Hooker cat back. cant beet the flow either.
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Old Dec 22, 2002 | 12:04 AM
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Default Re: Mac Headers and flowmasters

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Nice SSer:
<strong>Are there any cat-backs for around the same price as flow masters that have little or no rasp with an ORY? Or is any cat-back that you put on there going to have rasp do to the fact that there are no cats on there. If so, would the flow masters still have a deeper tone than say... Borla, Whisper, Magnaflow, etc.? Because if they are all going to have rasp I am still going to stick with the flow masters.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">But see, that just depends upon you. Personally, the Borla, LM, Flowmaster, Random Tech and cutouts rasp horribly without cats. All the other systems rasp too but not quite as much. If you want that deep Flowmaster sound, just run cats with your headers. I don't see why that should be a problem for you? If you must use an ory, go with something like the Magnaflow, Hooker, or SLP 20TL cat-back.
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Old Dec 22, 2002 | 02:26 PM
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Default Re: Mac Headers and flowmasters

I have these same headers and went with the off road pipe into a Mufflex cat back 4 inch single hide away outlet with 02 sims. It looks like a sleeper from behind. Fits perfect without rattling the hell out of the interior when ideling, but when your on it, sounds deep and strong. Great performance gains over the flowmaster, that the Mufflex system replaced. There are some sound clips on www.mufflex.com <img border="0" alt="[Burnout]" title="" src="graemlins/burnout.gif" />
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Old Dec 22, 2002 | 06:34 PM
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Default Re: Mac Headers and flowmasters

No cats using a flowmaster(s) and zero rasp. Look at the sig. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
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Old Dec 22, 2002 | 11:34 PM
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Default Re: Mac Headers and flowmasters

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by redrumss:
<strong>No cats using a flowmaster(s) and zero rasp. Look at the sig. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Thats because you have a true dual set-up using an X-pipe which pretty much eliminates the rasp(no cats) associated with a single exhaust(Y-pipe) set-up on an LS1. Trust me, Flowmaster(like most other exhaust) rasp like hell without cats using the factory exhaust set-up.
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Old Dec 22, 2002 | 11:43 PM
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Default Re: Mac Headers and flowmasters

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by 2000LS1Z28:
<strong> </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by redrumss:
<strong>No cats using a flowmaster(s) and zero rasp. Look at the sig. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Thats because you have a true dual set-up using an X-pipe which pretty much eliminates the rasp(no cats) associated with a single exhaust(Y-pipe) set-up on an LS1. Trust me, Flowmaster(like most other exhaust) rasp like hell without cats using the factory exhaust set-up.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">He's right. I had that setup (American Thunder catback with ORY) and it rasped pretty bad between 2100 and 2500. It was almost embarrissing at times it was so bad. I also had SLP 2OTL which did not rasp really at all, but after a while I got sick of how it looked with my TA rear bumper. Now I have a Bassani catback with an ORY. Sound is perfect and looks/fit/quality/flow are all excellent. It's pricy though, so if you're looking for cheap, good flow, and good sound with an ORY I'd say to a Hooker catback.
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Old Dec 22, 2002 | 11:45 PM
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Default Re: Mac Headers and flowmasters

Btw, just to clarify, the mufflex site is www.mufflex-performance.com . And personally, the GMMG exhaust dont sound bad, but some ppl say its pricey (cant remember off the top of my head how much) site is www.gmmginc.net
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Old Dec 22, 2002 | 11:48 PM
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Default Re: Mac Headers and flowmasters

Oh, and www.ls1info.com has some cool sound files aswell if you wanna hear what some of the other things sound like. they've got just 'bout everything
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Old Dec 23, 2002 | 09:35 AM
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Default Re: Mac Headers and flowmasters

Good catch. Quality control sucks on sunday after a six pack <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />
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