11 Bravo

iTrader: (3)

Just took them out of the box. The coating on them doesn't look that good, some seems to have rubbed off just during shipping, but maybe it just got rubbed and turned a darker color. The welds arent the best, but I don't think the header will come apart lol! I can see the metal to remove to port them, looks easy and I'll do it tomorrow. They would look sweet if I used the dremel to smooth out some irregularities and got them Jet Hot coated but I'm too impatient-they are going on next week. Questions- I recived 6 header bolts and nuts. Shouldn't I have 12 or are 6 stock manifold bolts supposed to be reused? Will header wrap keep the compartment a lot cooler? If so, I may wrap them with it. I really wanted some SLP's, but these won't scrape or bang and cost me $608 total w/ orp, 02 sensors, and shipping.

jmX

If you got 6 bolts and nuts, those aren't "header bolts"...header bolts dont use nuts since they screw into the head.

Those are probably the bolts that connect the ypipe flanges to the collectors, as well as hold the 2 ypipe pieces together.

I doubt you need headerwrap...had my normal non-jet hot coated macs installed for a very long time and I never noticed any heat issues under the hood. For the most part it seems like the coating myth is bollocks, but thats just my personal uninformed opinion based on personal experience.

11 Bravo

iTrader: (3)

[quote]Originally posted by jmX:
<strong>
Those are probably the bolts that connect the ypipe flanges to the collectors, as well as hold the 2 ypipe pieces together.
</strong><hr></blockquote>


Now I'm feeling stupid <img src="images/icons/smile.gif" border="0"> Duh!

Benjamin Russick

iTrader: (1)

Yes, they are the flange bolts for the three piece Y-pipe. I threw them away and got some nicer ones. The install is a snap, but if you have any questions...give me a holler. I installed both sides from the top. No engine jacking, no grinding...didn't even remove the starter motor. You will lose a little torque down low, but they really shine up top! Good luck!

GregM

Install is a B*TCH! Getting the stock stuff off was extremely difficult on my 98Z. The headers were a pain to get up into the engine bay, but once you got them lined up, they went on a lot easier than the manifolds came off. Good luck with your install!

GregM

jmX

The macs go in from the top. They practically fall in once you take the valve covers off (a 10 minute job).

The macs are easier than the FLP's to install for this exact reason.

Gary

[quote]Originally posted by jmX:
<strong>The macs go in from the top. They practically fall in once you take the valve covers off (a 10 minute job).

The macs are easier than the FLP's to install for this exact reason.</strong><hr></blockquote>

- HA !!!, you tellin' me that the passeger side just "fell in" with the valve covers off ??? Are you sure you installed MAC's ? <img src="images/icons/smile.gif" border="0">

Wicked Ls1

[quote]Originally posted by jmX:
<strong>The macs go in from the top. They practically fall in once you take the valve covers off (a 10 minute job).

The macs are easier than the FLP's to install for this exact reason.</strong><hr></blockquote>

So then you really didn't have to jack up the car, just to put on the new y-pipe? If you can just drop macs in, then you must have just pulled the stock headers right up and out of the engine bay <img src="images/icons/rolleyes.gif" border="0">

Kilroy's 99 TA

I'm lucky, my engine is already out of the car, I think installation will be a snap!!!

J'sRamAir

The way you install MACs will vary from model year to model year...probably true for all headers. Some go from the top, some from the bottom. I don't remember the instructions for each year.

Bill

My advice would be to be patient, have them jet hot coated and do the porting like you plan. I would have the outside welded around each tube. The MAC factory coating will look like crap in a few months.

As far as install, you guys must be much better than me, nothing seemed to drop in and it took a long time. I just switched to Grotts and lost some low end torque that was sweet with the MACs. I hope my top end pull is worth the change on a heads/cam car. FYI- The Grotts are so much quiter than the MACS. I miss that loud rumble and resonance many complain about on the MACS. It had a killer sound.

bigSS

[quote]Originally posted by Bill:
<strong>The MAC factory coating will look like crap in a few months.
</strong><hr></blockquote>

Yeah, did you see that picture that was posted a couple days ago! Crap! <img src="images/icons/smile.gif" border="0">

Benjamin Russick

iTrader: (1)

Uh, the MACs pretty much did drop in once everything was removed. I've heard horror stories about jacking the engine, grinding off parts of the block, etc., but none of that is needed on a 2000 Z28 anyway... The driver's side is a breeze, but the passenger side valve cover will need to come off.

98blackSS

Installed mine from the bottom. Wasn't aware of the valve cover removal method. I had to grind off the casting blocks on both sides to make mine fit up in there. Not fun laying on the garage floor either doing this either. <img src="images/icons/grin.gif" border="0">

PaiN

Tip... do everything you might want to do...now. Don't get impatient.

Coating...thats for you to decide, but I will say Mine have been jet coated for well over a year, and pretty much look just as good as the day they went into the car.

Popular mods that work well with the MAC's.

1) port them at the flanges. This should really be considered a MUST DO. Might have to weld em on the outside...although I didn't on mine, and they have held up fine.

2) Clean the ports on the colector side of the header. These can be pretty fugly as well.

3) The 2 bolt flange for the header to y-pipe connect sucks. Chop that off, and weld a 3 bolt header flange on it. You can pick these up from Jegs cheap.

4) Modify the y-pipe. cut off the ends that mate with the header. Weld in a flowmaster conical reducer , and weld a mating 3bolt header flange on the end of the conical reducer. The y-pipe will now mate to the 3 bolt flange on the header ( if you installed em ), and has a much smoother flow transition to the y-pipe.

5) On the far end of the y-pipe you'll notice the two 2 2.5" pipes flow into a pipe that is not 3". Pickup a flowmaster y-collector (2 2.5" into a 3" ) this is a really well built collector, and when you install it you will remove a bottle neck there, and also it will mate correctly to most of the aftermarket cat-backs.

just some ideas.

jmX

Oh boo hoo, they'll look like crap. <img src="images/icons/tongue.gif" border="0"> They are exhaust pipes people....who cares?

Anyways, Wicked Ls1, yes, the car had to be jacked up of course to remove the ypipe. I personally just think its easier to pull something from the top than lay on the ground and do it from underneath. While the macs took 10 minutes to remove, the FLP's took 15 to get bolted up and in place...so neither were exactly difficult. One just required more time with my back on the pavement.

Benjamin Russick

iTrader: (1)

Pain: Those are great tips! My weld were actually pretty good, so I didn't touch them. Since I had a custom Y made for using the stock cats, I already did most of the stuff you mentioned. Since my car is a weekend only vehicle, I didn't coat my headers. I plan on long tubes eventually, so it made no sense.Very good advice!

11 Bravo

iTrader: (3)

Pain, thanks for the advise. Question: The end of the y-pipe measures 2 5/8. Will that mate correctly with my pipe on the Borla cat back? I know Mac y-pipes are famous for not fitting correctly, but I've also heard the new ones have been fixed. If it won't fit, then I will order the Flowmaster Y collector, it does look nice. I can't find the conical reducer in the Summit catalog, guess I'll check Jegs. And, I am going to use header wrap. My hands will thank me someday <img src="images/icons/tongue.gif" border="0">

PaiN

[quote]Originally posted by 11 Bravo:
<strong>Pain, thanks for the advise. Question: The end of the y-pipe measures 2 5/8. Will that mate correctly with my pipe on the Borla cat back? I know Mac y-pipes are famous for not fitting correctly, but I've also heard the new ones have been fixed. If it won't fit, then I will order the Flowmaster Y collector, it does look nice. I can't find the conical reducer in the Summit catalog, guess I'll check Jegs. And, I am going to use header wrap. My hands will thank me someday <img src="images/icons/tongue.gif" border="0"> </strong><hr></blockquote>

Not sure about the new ones, but the older ones I got my MACS in um early 2000... definately did not mate my Borla correctly.

I'm not even sure Jegs had the conical reducers in their online catalog. I called them and asked for them 3" to 2.5" You need 4 3bolt header flanges, two conical reducers, and a good set of header flange gaskets. I had a lot of people recommend the copperseal ones.

I really need to snap some good photos of my setup to put online <img src="images/icons/frown.gif" border="0">

Also it looked like sort of a Bi$%h to weld all that stuff up and make it fit correctly. Not an easy job unless your experienced which I'm not...so I let someone else do it.

Jorday

I agree that the MAC y pipe doesn't work right with the intermediate pipe because the MAC collector was way too small. I ordered the 3' collector that was mentioned earlier. It was kind of a pain getting it to fit right...ended up having to shorten the intermediate pipe by a few inches and replace some of the bends in the y pipe to get it right. I also put some bullet mufflers in the y pipe to quiet the raspiness due to the off road pipe.

FWIW, I've had my MACs on and off the car a few times and I always install the passenger header from the top and the driver header from underneath. Drivers side goes in from the bottom with the plugs out and the oil filter off on my car.

later

Jordan