MAC header install
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Teching In
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From: BERKELEY SPRINGS WV
MAC header install I have a few buddies that drive cobra's and all rock the MAC exhausts and we found out that they had them for the LS1's too so I decided to go ahead and try it out....I got the headers back and am looking to install them tomorrow since it's my day off..Has anybody done these or know what problems I can forward to running into? I am doing it on a lift though so I am figuring it should be too horrible....any info will help. Thanks guys
Great comparison you have there..... two different cars, two different headers, two different styles...
The Mustang guys usually run long tube Mac's, Mac only makes midlength headers for these cars. A longtube header would do much better, now and in the future especially. Did you get a y-pipe too? The stocker won't bolt to them.
I had Mac's on mine. Make good power but long tubes give a little more and sound less raspy. Good headers none the less tho. No real fitment issues. Check the welds inside the primaries, you may want to clean em up with a dremel. I recently switched to longtubes.
No point in rehashing the whole debate, you can skim the main issues here: https://ls1tech.com/forums/generation-iii-external-engine/613881-mac-vs-pacesetters.html
They go in fairly easily. I just pulled my coil packs and valve covers and dropped them in from the top. Sometimes you need to pull the steering linkage, sometimes not. I've only had to grind the casting tab on the block of one car to get them to fit, usually you don't need to but it's possible.
Honestly though, unless you got a great price you should have gotten LT's.
They go in fairly easily. I just pulled my coil packs and valve covers and dropped them in from the top. Sometimes you need to pull the steering linkage, sometimes not. I've only had to grind the casting tab on the block of one car to get them to fit, usually you don't need to but it's possible.
Honestly though, unless you got a great price you should have gotten LT's.
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From: BERKELEY SPRINGS WV
Yeah I got the MAC mid length headers , Y-pipe and exhaust as a package...total it was around 1300 but im just curious if it will sound as good on my car as my friends and yeah I know they run long tubes but like you said they only got mids for us...hoping to make a few sound clips if it sounds nice...if not im gonna have to pick a new exhaust haha. Just went out on a wing though and thought I would try something different than QTP and Kooks...
In short im obsessive compulsive and I have the MAC exhaust so I HAD to have the MAC headers...gay I know but it's a quirk of mine
In short im obsessive compulsive and I have the MAC exhaust so I HAD to have the MAC headers...gay I know but it's a quirk of mine
Last edited by DangerousCurvesZ28; Dec 12, 2006 at 07:33 PM.
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From: Tree-Hugging, Bug eating CALI'
I've had MACs, and two sets of QTPs.
On my car, the MACs were a PAIN to install. I won't get into a rant, but, AFTER they were in, there were no issues.
One set of QTPs went in EASY and there were NO clearance issues. Great power.
Last set of QTPs went in EASY, and I had to grind a bit (no big deal), and even better power.
I had to jack the motor up for the MACs, ever after removing the valve covers, and everything else. What a PITA. You'll get better ground clearance (IMHO) with the MACs (also considering the Y-pipe). I'd make sure that you keep an eye on their cats' though. I thought I remembered reading problems, in the past, with their cats'.
Good luck. I liked them.
On my car, the MACs were a PAIN to install. I won't get into a rant, but, AFTER they were in, there were no issues.
One set of QTPs went in EASY and there were NO clearance issues. Great power.
Last set of QTPs went in EASY, and I had to grind a bit (no big deal), and even better power.
I had to jack the motor up for the MACs, ever after removing the valve covers, and everything else. What a PITA. You'll get better ground clearance (IMHO) with the MACs (also considering the Y-pipe). I'd make sure that you keep an eye on their cats' though. I thought I remembered reading problems, in the past, with their cats'.
Good luck. I liked them.
Originally Posted by radz282003
I've had MACs, and two sets of QTPs.
On my car, the MACs were a PAIN to install. I won't get into a rant, but, AFTER they were in, there were no issues.
One set of QTPs went in EASY and there were NO clearance issues. Great power.
Last set of QTPs went in EASY, and I had to grind a bit (no big deal), and even better power.
I had to jack the motor up for the MACs, ever after removing the valve covers, and everything else. What a PITA. You'll get better ground clearance (IMHO) with the MACs (also considering the Y-pipe). I'd make sure that you keep an eye on their cats' though. I thought I remembered reading problems, in the past, with their cats'.
Good luck. I liked them.
On my car, the MACs were a PAIN to install. I won't get into a rant, but, AFTER they were in, there were no issues.
One set of QTPs went in EASY and there were NO clearance issues. Great power.
Last set of QTPs went in EASY, and I had to grind a bit (no big deal), and even better power.
I had to jack the motor up for the MACs, ever after removing the valve covers, and everything else. What a PITA. You'll get better ground clearance (IMHO) with the MACs (also considering the Y-pipe). I'd make sure that you keep an eye on their cats' though. I thought I remembered reading problems, in the past, with their cats'.
Good luck. I liked them.
Wow, my Macs went it smooth, without a lift. did have to grind a little of the casting block on the passenger side as well, but besides that it was easy. hell, the driver side header would fall straight threw if i wasnt holding it up.
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From: BERKELEY SPRINGS WV
Ok...the MAC's were the biggest pain in the *** to install...we had to lift the motor...take the oil filer out...it took 7 hours to take the old headers and exhaust off and get the new headers , ypipe, and exhaust on. And sadly I think I may change them again in spring. It sounds good but I personally dont think it's loud enough
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From: BERKELEY SPRINGS WV
Well I wouldnt have wanted it to sound exactly like their cobra's...Two different engines. Figured if they can make a cobra sound sweet then they could do the same for our cars
My Mac's werent easy to get in either. The passenger side went in easy from the bottom but there was no way I could find to get the driver side in from the bottom. That side went in from the top after the coil pack came off and the steering linkage was disconnected.
Installed my MACs in a tight, 1-car garage on ramps. Remove the coil packs, plugs/wires and passenger side VC and they should drop in from the top. The MACs were some of the best-fitting, easily installed headers I've ever seen. I don't know how you guys had any problems with them... For a few extra HP, clean up the welds and do "the collector mod" to remove the ball/flange. DO NOT use MAC cats. I re-ued my factory cats in the MAC pipe and still made 18-20rwhp.
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I am just getting ready to finish my mac header install... It has been a horrible experience. The drivers side went in relatively easily from the bottom.. the passenger side on the other hand did not. I ended up having to loosen the motor mount on the passenger side and jack up the engine enough to fit it up. What a pain! It better be worth it.
Originally Posted by keliente
Why??
When I first installed my MACs it took forever and I was in a shop with a lift. Installed from the bottom. Did the motor jacking thing as well. Broke a few plugs and so on. After I removed my AIR and EGR and relocated my coil packs, I was able to remove them from the top with no interference from anything. Had them out in about 15 minutes.
Originally Posted by Bird-Of-Prey
MAC cats don't flow very well at all. I believe they were found to be more restrictive than the stock converters.
When I first installed my MACs it took forever and I was in a shop with a lift. Installed from the bottom. Did the motor jacking thing as well. Broke a few plugs and so on. After I removed my AIR and EGR and relocated my coil packs, I was able to remove them from the top with no interference from anything. Had them out in about 15 minutes.
When I first installed my MACs it took forever and I was in a shop with a lift. Installed from the bottom. Did the motor jacking thing as well. Broke a few plugs and so on. After I removed my AIR and EGR and relocated my coil packs, I was able to remove them from the top with no interference from anything. Had them out in about 15 minutes.
As said though, the mac cats flow worse than stock.
