I was wondering how much of a difference there is between mac mid-lengths and hooker/jet-hot longtubes. Right now the prices are great on the jet-hots, but I don't know if those would be right for what I need.

Car is stock for now except for nittos and subframes but eventual plans would be lid, ported tb, 3" true dual system (this summer hopefully), headers, and hotcam or similar mild street cam. I'll be running stock heads but I do think I'll run a 100-125 dry shot once the rest of the car is set up for it. How much of a factor would the longtubes be in allowing the motor to breath for the nitrous? Could I still hit my goal of around 375rwhp before the 100 shot with the macs? I want to go mild for now since on my budget I can't afford to start getting into the fuel system and such for a little while but if the longtubes are that much better I'd spring for the extra <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> .

I'm usually down at U of I in the southern illinois area, and cops love to bother us college kids with noisy rides so I'm thinking longtubes through true duals might be just a bit much...

 

I put down about 390 with a T1 cam and MAC's, an ORY and borla. I'm selling them now, and getting the jet hots or 1 7/8 headers and true duals. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

 

If you are getting a cam and doing Nitrous you're going to want longtubes! It's just the best way to go if you can afford them. You won't be able to tell that much of a difference until you do your cam/NOS, but I think that once you do you'll be happy to have them. The longtubes are an upgrade from the Mid-lengths. If you buy the Mid-lengths you might wish you had the longtubes and eventually upgrade them anyhow. If you buy the longtubes you will not wish you had bought the Mid-lengths. This is just my opinion. Good Luck! <img border="0" alt="[driving]" title="" src="graemlins/gr_driving3.gif" />

 

The long tubes aren't necessarily an "upgrade." More of a change than an upgrade. Go check out the article on LS1info.com. He puts MACS up against SLP long tubes and found that in the mid-range RPM's the SLP's had around 7 HP on the MACS, but on the top end the MACS had about 7HP on the SLP's. I wouldn't necessarily call that an "upgrade."

They're just a little different depending on where you want your power. Seems to be about the same overall HP in the long run, just in different RPM ranges.

 

Macs making more power over longtubes? Nope. MAYBE SLPs because they suck, but over FLP/Hooker/QTP? Not a chance in hell. They are definitely an upgrade.

Dope

 

Thank you guys for all the responses, that's pretty much what I wanted to hear. I'd like my power to be more in the lower and mid-range since I drive mostly street, so longtubes seem to be the answer to me. As far as the noise go if I ran 2 18" bullets intead of 12's, would that help cut things down a few db? How much would that restrict flow?

 

By "2 18" bullets" do you mean 2 on each side, like header-bullet-x pipe-bullet? I don't know you'll have enough room to work with.

 

Well,

The question wasn't necessarily based on MAC headers specifically (initially anyhow), just mid-length headers vs. longtubes. If mid-length's in general are so inferior to longtubes, why was the Colonel running Whisper mid-length headers on his 9 second race car? Cause they suck? Yeah. <img border="0" title="" alt="[Roll Eyes]" src="images/icons/rolleyes.gif" />

The point I'm trying to make is they aren't really THAT different. I just read about 2 guys on here the day before yesterday that had almost identical mods done to their cars, but one had Hookers and the other had MAC's on the SAME dyno SAME day they dynoed within 1 HP of each other.

Not to mention you could buy 2 complete sets of MAC headers with a Y-pipe and still be under the cost of a set of Grotts. <img border="0" title="" alt="[Roll Eyes]" src="images/icons/rolleyes.gif" />

 

Question regarding the bullets was reffering to 2 of them, sorry to not be clear. What I mean by 2 is not 2 on each pipe but one on each side. I was originally going to just use a pair of 12" bullets, but with the noise I considered moving to 18" instead. Hope that helps?

As far as the mid-length vs. longtube deal, is there anywhere I can read more about the differences between the two? Seeing a 9 second car run mids as well as the similar dynos are both pretty intruiging, especially because I'm considering lowering the car in the future. When you say they are simply different, where does that lie? Different power range? Which would be better for street and daily use?

 

I don't think the differance in sound for LT's and Mids would be that big of a differance. If a cop wants to bother you for having a loud exhaust, he'll do it whether you have mids or LTs.

Also your goal of 375rwhp, is this an A4 or M6. In an M6 375 should not be too hard to reach. Also what year car you have helps too, the 01+02 usually put out a little better #'s than the previous years.

Anyway I have an A4, my goal is around 350rwhp, I plan on reaching this with a ported TB, MTI clear lid, QTP LT headers, Corsa exhaust, FTRA.
I believe all that stuff should put me close to my #'s, I think the LTs will help the most

 

98 m6 trans am is what I'm running so I want to keep myself around 500rwhp or below with the nitrous before moving into a new fuel system.

 

Blk98,

Probably more people feel that long tubes give more power because they provide more in the middle RPM ranges, which is where most people drive their cars on the street.

Hence, they feel that their car has made more power than mid-lengths. This difference though I would be willing to bet is not over 10hp.

In reality on the dyno however, it may show nearly the same HP gain because peak HP is measured and not a "SOTP" gain.

I believe long tubes make a bit more power in the mid RPM range over MACS. MACS however are substantially cheaper and will give you nearly the same power and you won't have to worry about your car being lowered and scraping.

There are some long tubes that fit nicely underneath that will not scrape such as Grotts, but these are quite pricey.

 

Ah thanks very much for the clarification. I've been looking around and it seems I can get a new set of macs for around 350 which is excellent, and if the difference isn't huge in the mid-range then those seem to be the better choice for me.

I see you're in palatine, I live near there in Lake Zurich when I'm not down at U of I <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> . Could you recommend a good place to have the mac's flanges machined? I hear the ball joint at the end is a little restrictive with a larger exhaust system (I want to go 3" true dual soon as stated earlier).

 

Blk98,

Actually, I have a set of MAC's for sale, but the sale is currently pending. I've got them with the cat. Y-pipes brand new in the box.

If for some reason the sale falls through from other buyers, would you be interested?

--JF

 

If you'd be willing to sell just the headers without the y-pipe or cats then I may be interested if the price is right <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> . Let me know how things go with the sale.

 

I already sold the whole shabang. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

 

my thought is why short yourself now by getting mid-lengths when you're eventual goal will be better mated to a pair of longtubes.
longtubes will have better terminal velocity and can provide the additional backpressure vs a shorter style header to better accomodate the engine's firing sequence/ exhaust pulsing.
if you are wanting to slide a cam in you will feel a drastic amount of mid-top end power and even more on the bottle which will increase exponentially.

as for fitment i have the 1 3/4" grots with a full mufflex 3" y-pipe and still it all avoids the ground even with the pro-kit. just as long as you avoid such things as continental divides and black abysses, you'll be fine. hope this helps, best of luck. <img border="0" title="" alt="[Cool]" src="gr_images/icons/cool.gif" />

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by JF WS6:
<strong> If mid-length's in general are so inferior to longtubes, why was the Colonel running Whisper mid-length headers on his 9 second race car? Cause they suck? Yeah. <img border="0" title="" alt="[Roll Eyes]" src="images/icons/rolleyes.gif" />
</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Those mid-lengths were also 1 7/8" diameter primaries and had a 3.5" collector I think. Quite a bit different from the MACS with their 1 3/4" primaries (with poor welds inside the primaries), and the stupid 2.5" ball flange on the collectors.
If money is your main concern and you plan to get a true dual system, I was quoted $400 from MAC for just the headers. The Dynatechs are also $400 and you can get a very good collector from Hooker for $75 for BOTH sides instead of buying the $200 collectors from Dynatech. Of course if you have to have emissions hook-ups, it will be a pain. Maybe you can get FLP to sell you just the headers with the emissions hook-ups?
Just my $.02 <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />