Obviously BOTH is the easy answer, but let's say, for whatever reason, that you had to choose between a Header OR a Cat-Back. The goal is simple: everyday, around town performance.

 

Cat-back Exhaust. From what I have read a header is mostly benefical at high revs. Something you won't be doing around town

 

If it was me, I'd go for the cat-back first. The car will not only run and sound better, but it looks nice to have anything other than the stock tips behind the car.

 

Cat back is the obvious choice here. Get it first.

 

I would do an inexpensive header and 1-ball modification. This is a great exhaust system.

PS - The header 4-2-1 design to compliment your TQ.

 

You guys recommending CATBACK - how many of you are running a header as well?

 

I'm not running a header due to the cost to hp ratio and the added noise. I wanted more exhaust noise but not as much with what comes from a header and exhaust.

 

catback only as well. For the type of driving I do (daily driver + occasional auto-x) this is sufficient for my needs. High cost per hp and effenciency at 5000+ rpm of the header makes other mods more important to me.

 

The reason I asked is how can one share an opinion if one doesn't have both experiences. There is no doubt in my mind that a header/1-ball beats hands down performance wise any just CatBack system.

just so you know -

While the header did add some additional noise (deeper) it added very little. I would suspect that with your exhaust system (which I really like by the way) it would add some but very little noise - good noise at that.
I agree w/ the cost /hp ratio until headers became available for 200 bucks. At this level it becomes much more interesting/viable for daily street.

 

I just got a Gtech and I'm still learning how to use it but at some point I'll post results but I need to weigh the car first. But so far my highest torque reading have been between 4-5000rpm.

 

It's mostly myth that a catback makes any real power on our car. ::you can all gasp now::. Become friends with some MINI tuners and ask them straight up: is a catback gonna get me power? The answer, sadly, is a laugh. The catbacks give noise [some nice noise] and a little power [5 whp MAYBE], but anything more is just promises. I've seen a lot of very exaggerated, "fortuitous," dyno data around some manufacturer and vendor sites, and the bottom line is all the same. Don't expect more than 5 whp from any catback, and even then those full 5 ponies will come at the top end, when your car is breathing best.

On the other hand, headers. There are a lot of myths here, too. First off, 4-2-1 does not necessarily breathe better down low, worse up high, although Alta seems to say so . IT's just not so simple. In fact, in a properly designed 4-2-1 header, cylinders can be paired so that exhaust gases from one cylinder are released while the other is still firing, allowing the gases from 2 cylinders to be smoothly released [4-2-1]. This also allows a tangible negative pressure in the header [from pretty uniformly increased velocity of gases through the tubes] to "suck" exhaust out of the open exhaust port [believe this called "scavenging" but I'm blanking on the term, sorry]. Bottom line: a 4-2-1 can make you some power AT ALL revs. Properly designed, it will make less turbulence, and you will make more power at any rpm [I've been reading about this!]. Most people really really like the kick in mid-range power from the OBX, for instance. You can get more than 5 whp out of a good header on our cars [with a cat]! Of course it may not net the 10 hp that people throw around, but claims often don't pan out...

Strictly speaking performance, there is only one answer to me: get a header. But, you won't get that kick in VHP [visual HP, credit to FTR] from a header, unless you make it a habit of running people over . There's my [pretty founded] opinion.

 

I don't have a header yet because I'm going to stay in G Stock for another season and headers aren't legal. BUT even on a street car, I would still do the cat-back first.

 

I agree with Bahamabart... Header & One Ball or other low budget exhaust.

If "ONLY" one, I'd go with the catback first. That's just personal opinion because I think the stock S design configuration sucks.

 

- I found a difference from 4000 on up from my OBX w/ stock cat recycled.

- couldn't agree more.

The only reason I swapped out my 1-ball for a Catback was exactly for VHP (I wanted sexy tips) and more AHP (audio HP) which I got but I can't say that I got more HP (okay I got a little).

 

Sock,
You're leaving out the part about the length of the tubes and their effect on harmonics and how the ideal lengths change with RPM. 4-2-1 is optimized for a particular powerband and is not as simple as matching cylinders. Keep reading.

 

Not as simple, yes, but I'm not gonna write a book's worth of stuff here. It's not _necessarily_ more complicated, though! Suffice to say there's a ton of engineering in a properly designed header. BUT, everything I'm reading says that 4-2-1 is the best for us. Period.

However, it seems to me that you're neglecting to realize that both header configurations involve lengths of tube that can and should be tuned! The effect of tuned lengths applies to _both 4-2-1 and 4-1_. I did not really leave out a valid difference, since it's a common factor, not a difference.

If there's more that you feel needs mentioning, please mention it. Thanks!

 

Let’s not forget paring considerations in a 4/2/1,1&4/2&3, 1&3/2&4, 1&2/3&4.

 

Yup, Keith. As you know and are suggesting, the idea is to pair cylinders which are 180 degree opposite, so that one cylinder in each pair is releasing gases at a time. Not sure which is which on our cars, since I haven't looked into custom designing one, but yeah....

 

Reasons I brought this up are several: 1) prices for decent headers are looking pretty reasonable, 2) most catbacks are, IMO, fairly pricey, and 3) I'm not too interested in either AHP or VHP ... What I really want is improved performance at a reasonable price.

 

Although this might be true, when considering between the too, I seem to see many ppl say there is no point in adding headers without doing the head because the real gains are when you put the whole package together. The same as adding a TB when its just a bigger pipe feeding a small pipe. Thats not to say you will not get some HP. Rather, its to say the real benefit from it comes after the head.

I've heard this from multiple threads here as well as from MINI mechanics.

 

Yeah I went thru this logic as well, and ended up with the OBX header and stock cat. I haven't regretted it. Same as Ingsoc, I concluded that cat backs are mostly about sound and tip design. With the OBX header, though, there is noticably more torque, especially in the 2500-4000 range. This is really the way to go for improving everyday driving fun. Sound changed very little, once I bent the heat shield so it wasn't touching the header.

 

I had this all done for less than $400. Blows the doors off the cat back. If you don't believe, look at this https://www.northamericanmotoring.co...80&postcount=1. Gains accross the RPM range.

And the sleeper look too! This is by far the best bang for the buck on exhaust improvements. You can step up to a higher flow cat for about $60 (magnaflow 94166 at Performance Peddler, www.performancepeddler.com), but the sound will go up a bit.

All that for less than the price of most cat back systems.

Matt

 

Guys, I have the same Q as Ozbone. I can only choose either one; the header or the catback. It seems like the milltek catback and MTH header is around the budget, where MTH header is slightly more expensive. IMHO, it looks like the header will give more power and torque if we were to compare with a catback (any brand).

I test drove a JCW with mini mania manifold and it's awesome. It wasn't that loud in the cabin. I was planning to get just the catback but after the test drive, it makes me confuse.

Which combination is worth doing:

1. MTH+One ball
2. OBX+One ball
3. Any Catback+stock Manifold.

Should we get a new CAT or the stock is good enough already?

 

Don't buy the MTH header. At best case, honestly, the premium pays for the needless shipping from Germany. At worst case, it costs more for what is almost surely no extra power. I'm sure it makes power, just no more than the Milltek or such additional headers.

My vote goes for the OBX [I've heard that it requires a little modification and/or a stud instead of a bolt when fitting]. The others seem just way too expensive for what seem to be marginal if any gains. The OBX is 4-2-1, which is probably the best solution from a config perspective.

Regarding the cat, the stock is perfectly fine and probably robs little significant power. Some people purchase others, like the Magnaflow unit above [DrO's post], just so that they don't have to hack up their stock header, but if you're fine doing some surgery it's perfectly good to use the stock cat...

 

Why do you say don't buy MTH. There are thread about it somewhere and it sounded like it makes a good HP with special MTH for it. MTH cant make any HP with the Milltek Header so this is one of the reasons why I'm confused. I have MTH but it doesnt work with Milltek.