Here are my dyno numbers with the obx-racing headers installed. We used the oem-kat, please notice the before run was at 28°C and the after run was at 56°C!
My configuration: 2003 MCS, 56,5mm pully, mth ecu, beru spakplugs, k+n CAI and remus exhaust.

 

aaaarrrrgggghhh matey..... METRIC !

 

Nice gains across the board there And with twice the ambient temp.. EVEN BETTER When you say you used the OE cat, you had it welded on? Do you have any pics of this system??

Who wants to bet Bush will try to get rid of the metric system cuz he cant understand it?

 

Thanks for the posting.....

Matt

 

To convert metric units:
1 kW = 1,341 HP ; 1,3557 Nm = 1 lb ft
Yes we had to cut the oem header and weld on the cat to an connection tube.
I have the OBX header from sparktec on ebay.com for only $ 175,- !
Here are some pics of the header:

 

Curious, how does this header differ from the Miltek - in operation and marketing? Are they both a four-into-one? How clean is the merge-collector
in the OBX? The gains seem very real world, thank for posting.

 

The OBX is a 4-2-1 header, the Miltec is a 4-1 type. The mechanic told me he expect better gains when the 4 primary tubes are smaler in diameter (36mm instead of OBX 40mm). The OBX header is a 1:1 copy of the supersprint. The fitting was 1a. Does anybody know if i get more gains with a 200 cpsi metallic cat?

 

I'm surprised to see about 10 Nt-M torque gain so uniformly across the rpm band; I would have expected to see some peaking behaviour from the header tune. I suppose this means the improvement is simply due to less restriction, not tuned lengths?

 

Interesting observation jlm



MadMick, I'm a little confused. Your mechanic stated he would have expected better gains from smaller primarys, but the OBX according to your post is 40mm and not 36mm. Did you mistakenly switch around the sizes or are you unhappy with the dyno results? Personally I think the results are impressive as headers can move power around yielding gains so not usefull day to day.

 

Very interesting results! Kudos for doing before and after dynos.

 

@MEB:
The mechanic means with smaler primaries i.e. 36mm the exhaust velocity is higher and the peak hp gain must be bigger. He told me that an modified oem header (just the pre-cat removed) has better gains than my obx header?!
Some more pics:

 

So, if one wanted to leave the pre-cat inplace - for obvious EPA reasons - your header provides an improvment over the 'completely' stock unit??? Or, if one wanted to simply remove the pre-cat from the stock header - all other things equal - the stock header sans pre-cat would perform better than the OBX??? Just confirming with different words.

 

My mechanic said:
Simply remove the pre-cat from the stock header - all other things equal - the stock header sans pre-cat would perform better than the obx.
I´m quite happy with the results of the obx header.
I dont believe the mechanic but i try to get another dyno graph from a friend with that modification.

 

Ha! Here's MadMick's pic with jlm's Supersprint pic below it:

 

Really nice to see! I thought header upgrades for the MINI provided only marginal performance differences up to this point. How does the actual driving performance feel now?

 

You can feel quicker throttle response and and faster upspooling. At daily driving you can use one gear higher due to the bigger torque at lower revs. The engine pulls harder at any rev. The sound is more deeper and when you close the throttle you can here nice popping and nice bangs when changing gears under hard acceleration.
Its quite a big gain for the money! For $ 175,- plus an hour of work you wont get better performance

Sorry for my bad language but I´m writing from germany

 

haha, thats better english that most of us use! I have noticed everything he has mentioned with the Miltek, but its 4x the price

 

Would their Cooper header be worthwhile for me to buy? I already have an R Speed exhaust and Pro MINI intake, so the header seems like the next logical choice. My only concern was the EPA stuff in Ohio, but if the OEM cat can be welded on, that should satisfy the EPA testing, wouldn't you think?

 

The check engine light is not on and here in germany you will pass all emission checks when using the OEM cat and precat removed. The precat is only installed due to the homologation by bmw where the car must haver propper emission values right after starting the engine a -7°C. You will go to the emission checks with a nice tempered engine so the precat is not necessary while the main cat is well heated.

 

Installed this header yesterday with the help of a welder buddy, I used the factory CAT. $165 + shipping from ebay. Cheaper than the HP Racing CAT-less header I tried and reviewed in the reviews forum.

Ladies and gents, this one is a winner in ALL respects. The fitment is PERFECT. In laying the header gasket on the flange, every primary and bolt hole lined up perfectly, no grinding or adjustment necessary. The primary holes in the flange are flush with the inner primary tubes themselves providing a nice smooth flow for exhaust. To make it fit with the factory CAT, one needs only cut the CAT off the factory header behind the weld bead (cut between weld bead and CAT). Cut as close as you can to the CAT to maintain pipe diameter consistant with the header adapter. Its attached to a Borla Sport exhaust.

While I've never seen the Supersprint in person, I'd bet the farm that the OBX is same quality. Its beautiful, and precisely manufactured. Noise level - which made my previous header a non-starter: I can't tell a difference between the OBX and factory header -- a good thing in my book! Needless to say, I'm thrilled with this buy/install. If you're considering a header, you can't go wrong with this one!

Next up, larger injectors and some fuel management... longer term, a ported head.

 

The price is MUCH less than others! It appears that these guys are in SF, according to eBay, and the phone number on their website...

Speaking of which, there is no info about the MINI header on their website:

http://www.obxracingsports.com/perfo...22&subCat2ID=1

Can someone confirm the size (diameter) of the tube where the cat is attached? If like the SuperSprint, it's 2.5" or 63.5 mm. Stock is 2.25"...

Thanks.

 

Tony, as measured with my calipers.... the inside diameter of the adapter is 2 3/8", the OD is 2.5". I believe the factory exhaust will be a loose fit inside it. However, if you use the factory CAT, and cut it off to the rear of the weld bead, the pipe to the CAT tapers out in this area. Cutting here will give you a 2.5" OD-to-2.5" OD to butt-weld against. I also test fit an aftermarket CAT with 2.25" in/out pipes (actual OD of this CAT was 2 3/8" ID was 2.25"). It was a nice snug fit... you could easily use a clamp to secure it, and then find a way to tie the rear of the CAT to the exhaust. It would mean cutting out the factory flanges, but would work well too. Or, you can use a pipe stretcher/expander to get a comfortable slip-fit with either the factory CAT or aftermarket CAT.

Hope that helps. Any other questions, I'll do my best to answer.
cheers!

 

BluMiniMe, thank you! A few us have catbacks that are 2.5", thus my question... I fabricated mine, and the center pipe is SuperSprint, with resonator, 2.5". The price of SS's header is substanially more though...

I was thinking of using an ATP stainless steel race cat that I believe jlm and possibly (I forget) Andy are using:

http://www.atpturbo.com/Merchant2/me...egory_Code=MDP

Actually, I think it's this one:

http://www.vwturbo.com/products/details.asp?id=48&cat=8

I might call these guys and see if I can visit them, and see it up close. And if I like it, save on the shipping Please do give us your drive impressions as well. You shared that sound is unchanged, but then with the stock cat, that doesn't surprise me. Thanks again.

 

yep, the second one. no probs after a year or so and I passed an emissions sniff.

 

fantastic. i believe you coated your supersprint header also. if so, just the outside, and did you coat any part of the cat as well? i'm gussing not...

jlm, from what you can see of this header, what's your honest input? thanks.