For anyone questioning the effectiveness of MAC headers on a stock engine, this post if for you. I've always had great results with them, back in 1999 I made 21 rwhp with them on a stock 98 motor. Also seen several 20+ rwhp gains. Slapped a set on a buddy's car the other night and went to the dyno this morning. Car is an 01 T/A..

Base (before headers) - 331

After Headers- 357

Cars mods:
-Lid
-Magnaflow Catback
-Macs w/ ORP

Car doesn't have a pulley or ported TB yet.

Just thought i'd share this for those considering MACS. For a stock internal car, they are the absolute BEST bang for the buck out there. He only paid 200 bucks for these things lol. Also, to clarify for those who don't undertsand why I said "Unmodded"....These Macs did not have ported primaries, still running the 2.5 collector, and ball flanges all over. Once the flanges are improved and a 3.5 collector is put in, I expect to see a couple more HP out of them.

On another note, the Magnaflow catback sounds like musical viagra without cats

 

I wonder why I don't see more results like these? Incidently, what kind of torque did it make? I would laugh too, at anyone who bought uncoated headers. Hell, I laugh at Jason for it all the time.

 

I just got my used, custom coated MAC Headers and ORY...for $340 !!!!
I thought they'd make a nice bang/buck item .....

Cobrats on your numbers...!

 

Andy, plenty of guys making 20-22 rwhp with Macs. Hell I did it almost 5 years ago. Just about everybody back then was making 18-22 depending on the car. Dont remember the TQ #

Thanks brother, but see the sig. Headers came a long long long time ago for me. This was a friend's car

 

So basically no gains with lt over mids huh?

 

I would not say that (assuming you mean on a stock motor). LT's will GENERALLY make more low-mid TQ than the MACS, even on a stock motor but the peak will be about the same. However, i've seen some guys go from MACS to an LT and gain nothing. Just depends on the car really.

26 rwhp is a one off thing I "think". The most i've seen out of Macs was my own, 21 rwhp. However, bang for the buck you can't ****** beat 'em. Hell, you can buy Macs for 200 bucks these days. Spend half the money, and make within 1-3 HP of an LT on a stock motor. If I were still stock internal and had no plans of changing, I wouldn't even bother running LT's.

 

Was the car dyno tuned for the Macs or was it just a regular dyno run minus a tune?
I could definately see those gains on a stock motor if they tweeked some areas with a dyno tune.

 

Wow that's good for MAC's. I gained 14rwhp with ported primaries.

 

Mine were ported with a Dremmel tool (Dremmel bit #9903). It took about 45 minutes of work on each header and a lot of minute metal shards were pulled from my fingers. If you port your Mac primaries out this way make sure you have some needle point tweezers and a strong magnifying glass. Also, be sure to wear a plastic apron. That stuff is embedded in my clothing.

Anyway, the inside diameter of these 1 3/4" primaries measured 1.64" after I ported them out. When I cranked up the car after installation, it sounded great through the Borla exhaust. My car picked up unbelievable power after ditching the JBA shorties and the Random Tech Y-pipe for the MAC Mid-length headers and MAC ORY. MAC's IMHO are THE best bang-for-buck. My cam FINALLY gave me the lope that I wanted at idle. MAC's are awesome for the money.

 

Good to hear the MAC's making such great numbers, I have been seriously considering them. And would jump all over a set of them for that price.

 

exact opposite....Macs will make the low to mid torque over LT's...depending on tube diameter as wel....itll most likely be the same down low...but becuase of the extra breathing the LT's will show more up top

 

And he is right, the macs worse low end power, has to do with the length, which is y people like long tubes. People with higher reving motors dont mind the mids cause they top end power is just as good , if not better- ( could be worse than long tubes ) but the Mids make great power up top.

 

Nice gains.


When people talk about 'porting the Macs', is it just the 8 primaries that they're referring to or is it the collector (ball flange) as well?
And if doing the collectors and cutting off the ball flange what usually takes their place in holding/sealing the Y pipe to the headers?

 

How much was your time and skin worth?

 

I don't think that is the case. 1) because none in their right mind would throw a half *** header at a WAO motor, and 2) because any streetable, high revving motor will need every bit of torque and power down low to make up for the shift in the powerband.

 

Porting MAC's refers to the primaries only. Changing the collectors is something completely different. Another good mod for the MAC Y (or any other Y) is to have a Flowmaster collector wedled in. QTP does this on all of their Y's (look at their website for pics).

 

i dont think anyone can say macs dont make power, just LT's make more


yes i know its not stock internaled...

 

I would definetly not rag on a 21-26hp gain from headers only . The particulars are of interest, though. A 21HP gain is outstanding on any motor, but the torque is an equally important factor. I think uncoated headers are a poor investment, just as I think examining gains wihout reference to torque are a poor comparison. I'm not saying you would leave this measurement out for any reason; that would be pretty pointless, not to mention below you. I'm just saying I think this aspect is pertinent to value of the header, coated or uncoated.

FYI: Buying uncoated headers is like porking a girl that you know has the clap.

 

I needed power/speed for improved times in the 1/4 mile Even MORE SO I wanted quick pickup/power on the street. What it came down to for me was (1) stainless headers and ORY OR (2) Mac's, ORY, and TC for the same price. I chose the Mac's, ORY, and Yank SS3600 (total cost = $1,289.00 includung tax and shipping charges). All-in-all, IMO, it was the right decision for me because my goal was to get into the 11's ... not to make numbers on a dyno. I don't think I would be even close to 11's with just LT's ONLY. If you have the extra money, who in their right mind wouldn't have chosen LT's?

One thing was surprising, though. My temp guage still ran well under the mid-point of the guage. It didn't even budge. Before the header exchange, I had ceramic coated JBA shorties ... doesn't look like the HTS coated MAC's brought the engine temperature up to any noticeable difference.

For people who rag on MAC headers, everybody can't afford everything we want. Someday I will have LT's, but, not until I can afford a nice set of stainless ones. When I do, it will probably be stainless FLP's and not the cheap LT's. Also, after doing a lot of searches here, it looks like most of these folks (who are ragging hard on MAC's) don't seem to have experience with actually using the MAC's. The people who HAVE HAD the MAC's seem to have a tendency to think they are OK and a good investment for power if you need the best power for the least amount of money.

I'd be interested in hearing from more people who have actually used 1 3/4" MAC's WITH FULLY PORTED PRIMARIES (who are now users of LT's) to weigh in on their difference in ET's. Did LT's give you significantly better 1/4 mile times than the MAC's w/ORY?

 

How much power difference cuold there be between the Macs and LT's with the Macs having the ported primaries and ball flange collectors?