excellent find, seems to work with alot of people...

ud better start a new thread on this subject.... would like too hear other mini owners experiences with this cel light fouler .....

 

i only have about 75 miles on the new header would the cat break down that soon

 

No, sorry to alarm you. It should be fine. My words were not chosen very carefully. It is simply what happens to metallic honeycomb style cats when they first get hot. They tend to settle in and will be fine. Just give it some driving time.

 

Updated. Anyone have any more details I need to add?

 

Yes, please edit and add the Stahl header. Pictures and details are on the Precision web site.
FYI The MTH header has 1 1/2" primaries, a 4-1 formed collector, and a 2 1/2" exit. $1000

 

So which of these headers is the quietest? And are these cats street legal (will they pass inspection)? Also, if the cat is not removable, and it goes (which it will at some point) do you all plan on just buying new headers at the same time?

Thanks for the very informative thread!

mb

 

No such thing - headers do not address sound, mufflers address sound.

The appropriate aftermarket cat should pass inspection.

The cat if "not removeable" (i.e. non bolt on section) would mean that it is welded onto the header. The cat could therefore be unwelded and a new on welded on.

 

You are correct, they do not address sound, but they do affect it. If you get a header that addresses the exhaust pulse, it will affect the sound. Just look at the Db levels from the exhaust shoot out from the dragon a few years back. All exhaust were about 10dbs louder with a header due to less restrictions.

 

so which one you all would get. I mean, what is the best HP producing header (I want more HP ) I don't care for price and I don't care for sound, I want a nice high quality HP producing header... so any experience or numbers?

 

1) While headers contribute HP, more noticeable is the TQ gain.
2) every vendor has the best, just ask them.
3) Headers run fron 200 bucks on up . . .
4) select your design 4-2-1 or 4-1. In a very summarized format a 4-2-1 is said to produce more midrange power and a 4-1 more top end. I am sure the pros here can really define what the two designs are meant to accomplish.

Remember $$ don't always equate to MORE HP or anything for that matter.

 

Yes, but I wanted to see out of experience which is the best. Torque is always good... if the 4-2-1 gives me more TQ then I want that and I want the best one. on a more personal note... how is the GIAC chip going with you?

 

i'm probably wrong but don't long primaries equal high peak but not necessarily the highest torque as would be gotten with shorter primaries ? also doesn't 4-2-1 offer more torque than 4-1 ?

 

Kind of. But in the world of "real" headers 28" is short! 4-2-1= wider power band.

 

cool

 

In sum, I am delighted with the GIAC.

See my post "ecu giac upgrade" which provides details and why I went this route.

 

Seeing as there are 2 header configurations (4-2-1 & 4-1), how come the 4-1 configuration is more popular for aftermarket?

I think there's only the Ultrik and OBX that are 4-2-1, whilst the rest are all 4-1.

 

4-1 is cheaper and easier to make. Stahl makes both types, has 28"+ primaries with three diameters to choose from.

 

Is there a way to tell which ones "flow" and scavange the best.... which ones are loudest and quietest..... are these designed in a vacumn or on a car.... is there any performance data? speaking as one who has seen several mods be less than what they were reported to be skepticism has enetered my lexicon...... why a Larini for $1000 vs and OBX? do we know "wall thickness" of the tubes?....what difference does that make.... has anyone done before and after dynos.....? if so with what other mods.....are you glad you bought the header..did it do what you wanted.....

This is really nice thread ... can we add some info.

the reason I ask is that I am really looking into the header market because the 62 has so much more capability that getting the exhaust to really flow with the 62 is very important to power production...... since no one has offered one up to let us try (yet... except Steve) and some are expenesive..... it is a little tiring/expensive to be a "beta" all the time..... what I am lookng for is something that has reasonable sound level with very good performance..... for reference, currently running the Megan with no cat and a Milltek cat-back....this setup is way too loud for the street.....

any help filling in the blanks is appreciated

 

Some general rules of thumb, As far as torque goes, Tri-Y will have the broadest torque range, followed by a 4-2-1, then a 4-1. The thicker the metal the more heat is retained in the exhaust, 16 gauge is kind of a standard, though some will use 20 to save weight or expense, stainless retaines more heat than mild steel but a ceramic coated mild steel will usually retain more heat than stainless. Inconel is the best for heat resistance and retention, it's what the F1 teams use, but by far the most expensive.

For a "62" kit I'd go the Stahl's web site and pick the kit that most closely matched your expected hp, probably the stage 2 or stage 3, get the 4-1 if you are looking for max peak power or the 4-2-1, if you want more midrange torque and are willing to give up a few peak hp and then I'd get it ceramic coated.

As my testing seems to indicate, matching the muffler to the rest of the system is the KEY to sound quality and noise level. To that end, I would begin with what ever Stahl supplied but be willing to either add in a resonator just before the split or be willing to try other mufflers in place of what they supply. If it was me and the supplied system was to loud the first thing I'd do would be to install two 5" disc Supertrapps.

 

All Stahl products for the Mini go through Precision. Even if you call them they will tell you to call me. 732-748-1964

 

but you'd be running this -illegal by federal law- setup on the track only, wouldn't you Spider? (nudge, nudge, wink, wink, know what I mean...)
I bet it sounds almost identical to my setup (!)
btw, did the fiberglass in the little Megan resonator turn to glass beads for you yet? Or are you running another pipe?
cheers,

 

Thanks for the input

 

I'd always thought "tri-y" & 4-2-1 were synonymous? If not, what features characterize the difference(s)?

 

this "track only" setup is coming off the car tomorrow

 

the elimintation of the pre cat is why the aftermarket headers are louder, and why they are all roughly the same amount of dB increase. Wall diameter will also affect loudness and sound. on a very small scale, thiner walls also mean larger ID, but not enough to worry about, but can shave the weight in almost half!

On a related note, just you boys wait until i get around to building my header, hopefully in the spring. I was going to build an ulta high rpm header, but a friend of mine just got me hooked on autocross, so my final design is still up in the air.

-Beecher