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stock cats on MAC ORP

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Old Jan 5, 2003 | 07:31 PM
  #1  
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Default stock cats on MAC ORP

I think I know what I want to get now after reading a lot of posts for a 2000 WS6

I need a emissions legal exhaust system (NY)

I was going to just get Mac headers with their y-pipes with cats, but it seems everyone is in agreement that their cats suck!

Can I just weld my stock cats into their ORP?

Thanks!

Tommy <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

PS are the Mac cats really THAT bad?
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Old Jan 6, 2003 | 07:44 PM
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Default Re: stock cats on MAC ORP

yeah, they really are. if you wanna get down to the nitty gritty, anything that moves the cats further from the engine than the factory placed them is illegal. on that note, that's just for visual inspections, assuming the person knows what to look for. as far as cats go, you can reuse your stock cats, but why not go with some high flow aftermarket cats and get the gains from them. i think carsound cats flow the best. another caveat: replacing your cats is also a legal no-no unless you have more than 50k on them or they are bad. (mine were bad <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> ) also, you can always gut your stock cats and weld a bullet into the i-pipe if you are just concerned about legality issues.

john
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Old Jan 6, 2003 | 07:51 PM
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Default Re: stock cats on MAC ORP

I actually don't care what they look like, they have to pass the emissions tests in NY. I've never had a visual inspection of any of my other cars for stock placement, but the emissions themselves must pass.

I heard the stock cats where not that bad, and if it saved me $250-300, I thought maybe it was ok to reuse the stock ones. Only 35k on them now...

Thanks for the info.

Tommy <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
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Old Jan 7, 2003 | 09:45 AM
  #4  
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Default Re: stock cats on MAC ORP

The stock cats aren't terrible, but as long as you're fabricating, why not get the MACs with offroad y-pipe (as opposed to their cat y-pipe) and put Carsound cats on it.
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Old Jan 7, 2003 | 09:48 AM
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Default Re: stock cats on MAC ORP

Anyplace that sells carsound cats for a good price?

This damn header install is starting to add up! <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

Tommy <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
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Old Jan 7, 2003 | 02:14 PM
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Default Re: stock cats on MAC ORP

If your going with headers you should come by and drive my SS with the FLPs with (3" intake and 2.75 output cats) before you decide....


...they bang like hell and there is still a slight burnt tar smell ....but anyway ...you would be able to get an idea of the before and after result of headers....

I was considering MACs early on but everyone said that mid-lenght headers are not very effective...for the money you pay for MACs ...you might as well go with full bore LTs....

I just had the emmissions done...these boys are really lazy about visuals and don't know what they are looking at anyway ...so don't worry...
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Old Jan 7, 2003 | 03:03 PM
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Default Re: stock cats on MAC ORP

Hi Robert!
I can get all complete MAC header setup with ORP for $499, which is much less expensive then a LT setup, and I can fit some cats on there easily... I've heard some good things about MACS and fot the price, thy seem great.
Anyways, I'm going to do a cam swap, pulleys, intake and tuning this summer, so I want to get the headers done first...
As for the banging, most people say you can adjust the pipes (loosen flanges and pry pipes away, and tighten back up)
Maybe you need to get MAFT to get real gains out of your LT, you maybe runing rich.
I have obd-2 scanner software. So I'll be more than happy to do some tests on your car if you want. I tried it mine last night, and you can log everything you need to get your tuning right on target.
Just tell me if you are interested.
Thanks!
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Old Jan 8, 2003 | 08:57 AM
  #8  
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Default Re: stock cats on MAC ORP

OK - I would be interested in scoping out my car with your A-Tap software ....Why don't you stop by this weekend....I will bring a laptop home if you need it...

If you can get the MACs for that price go ahead....

...there was a recent article of mods done to an F-body by the american institute of automotive enginers that contained a flow test table of the various cats....my recollection is that MAC cats were not very restrictive compared to others...when people say the MAC cats are bad do they mean they are restrictive or they just rust and blow up fast?
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Old Jan 8, 2003 | 09:02 AM
  #9  
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Default Re: stock cats on MAC ORP

Yeah, I bet we can squeeze about 10-20 more hp out of your setup, especially with your intake!

Maybe it would be a good idea if you bring a laptop since I borrowed one from work, but the screen goes blank if you hold it the wrong way, POS!

What day is better for you Sat or Sun? Both are good for me, the earlier the better!

Tommy <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

PS I think the MAC cats flow poorly and break easily...
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Old Jan 8, 2003 | 10:55 AM
  #10  
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Default Re: stock cats on MAC ORP

It does not matter to me ...saturday or sunday


...early saturday (8am or so??) works best I guess...
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Old Jan 9, 2003 | 12:06 AM
  #11  
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Default Re: stock cats on MAC ORP

How about I call you around 8:00 - 8:30 Saturday?

Hopefully we'll find the tuning all out of whack!

Tommy <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
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Old Jan 9, 2003 | 12:19 AM
  #12  
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Default Re: stock cats on MAC ORP

OK - lets go for it!

I assume if we find the pig is too rich my options are (i) a MAFT @ $275 or (ii) a $600 copy of LS1Edit...

Is this right?
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Old Jan 9, 2003 | 12:19 AM
  #13  
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Default Re: stock cats on MAC ORP

OK - lets go for it!

I assume if we find the pig is too rich my options are (i) a MAFT @ $275 or (ii) a $600 copy of LS1Edit...

Is this right?
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Old Jan 9, 2003 | 12:26 AM
  #14  
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Default Re: stock cats on MAC ORP

Yeah, those seem to be the options. MAFT is definitely the least expensive way to go.
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