blkfrmla925

does anyone have any info on the mac mid length headers for ls1..any power results,install problems,track gains,track losses,problems etc
any help here would be appreciated
thanks again
patrick

WILWAXU

iTrader: (6)

They're a good header for the money.

get_sum

AWESOME header. I have a set of MAC's without any coating in an offroad pipe variety <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> The install was flawless except for the passenger side spot where they pour the block or whatever. The passenger went in from the bottom and the driver side from the top. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> If you get the offroad pipe you'll need a pair of plugs for the rear 02 sensor bungs (a Advance Auto Parts..oil plugs.. part number????) On the passenger side you have to grid about 1/2 inch or so off the engine pour spot (as prviously mentioned). The toughest part I had was taking the damn coil packs off <img border="0" title="" alt="[Sad]" src="gr_sad.gif" /> I would also invest in some stage 8 header bolts (thunder racing has these) and Pearcy's aluminum gaskets (Summit has these). If you get those you'll have absolutely no leaks at the heads whatsoever. I have recently (this past weekend) heard of a product that fits around you collectors and other ball and socket joints that keeps them from leaking. I saw it on the show TRUCKS! (on TNN).

Anyway good luck with the install. Oh yeah, my time with the headers and Loudmouth was 12.94 @ 110.5 on stock tires

Ragtop 99

iTrader: (7)

I had MACs. Good power for the money (although some true L-T like hookers are now pretty reasonable), but they sound suck-*** with an ORP due to a nasty rasp in the 2000 - 2500 rpm range.

blkfrmla925

thanks guys...do you have any actual track differences in e.t's from with out the macs.to with the macs..dyno numbers will help too
thanks in advance
patrick <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

BYE RICE

iTrader: (2)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Ragtop 99:
<strong>I had MACs. Good power for the money (although some true L-T like hookers are now pretty reasonable), but they sound suck-*** with an ORP due to a nasty rasp in the 2000 - 2500 rpm range.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Yes they do!
I heard you can install a real collector in place of the ball flanges & it'll mellow it out.
I went 12.79@ 111.8
When used in conjunction with an '02 intake & '01 LS6 cam.I left my rear o2's installed & switched 'em off with Edit.I had to have the drivers side portion of the Y-pipe re-bent for ground clearance.No biggie.

<small>[ December 16, 2002, 10:55 PM: Message edited by: BYE RICE ]</small>

John02SS

iTrader: (47)

A friend of mine just installed a set here in Pensacola. Really woke the car up! Install wasn't bad at all. We are trying to set up another dyno day the 1st Saturday in Jan. We will have dyno # then.

John

CRCWS6

I had my macs installed about 6 months ago. also installed mac y-pipe with high flow cats. I didn't do the install myself, so i can't help with that. After install, the car pulled much harder than stock. Track times went from 13.4 or 13.5 down to 12.90 to 13.00 during the summer. My best of 12.7 was in much colder weather a few weeks ago. Excellent mod, i highly recommend it.
Almost forgot-the only problems i've had since instaling the macs is oil consumption. My car now goes thru a quart of oil/600 miles. Nobody seems to know why; not my install guy or the dealer. Might have something to do with the o2 sims.

<small>[ December 17, 2002, 04:45 PM: Message edited by: crcws6 ]</small>

Tally TransAm

iTrader: (17)

i gained 21 hp and 20 ftlbs with mine on back to back dynos

ryan

<small>[ December 17, 2002, 12:40 PM: Message edited by: Tally TransAm ]</small>

LS1 JAY

Before Macs with just a Whisper lid...
60FT: 1.976
1/8: 8.44@85.61
1/4: 13.04@106.67

With Macs & O/R pipe...
60FT: 1.901
1/8: 8.32@86.29
1/4: 12.88@107.61

Best mph of 107.70

My car is a fully loaded '99 SS A4 with NO weight reduction & the stock converter.

Weather was similar but a little worse on the 12.88 than the 13.04

Lane

iTrader: (1)

With true duals, you can't beat MAC's IMHO. I've NEVER lost to a long tubed car with similar mods.

Check my sig for track times. Stock internals. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

Damian

iTrader: (89)

Mac's are worth every penny. You can put a little time and about 50 bucks at the muffler shop, and they'll flow almost like longtubes......Port the primaries on each header, and have 3 bolt flanges welded in the place of the ball flanges. You'll be set, and ridding the flanges gets rid of 95% of the rasp. I have a custom 3 inch y-pipe paired to my Macs, and it sounds just like any other longtube LS1 I have ever heard...

Josh