After looking at pics of the cat on the stock exhaust again, I dont know if option 3 is going to be possible...bummer.

 

I basically know very little about aftermarket MINI parts, seeing as how I don't have a MINI yet, but I kinda need to chime in with my two cents, OBX products tend to be in the cheapo/budget range of parts for other cars, especially Hondas and the Ford Focus. Their quality tends to not be the best.

That said, I didn't read all 8 pages of this thread, and if you guys have good luck with 'em, then more power to ya! But if you are wondering why the OBX is less expensive than others, well, it's designed that way.

 

Coming from the Honda world I hear you loud and clear Jared! After looking at the dyno for this header and then looking at the price (sub $200 shipped vs $600-800 + shipping) I couldnt find any reason to buy it. The welding looks well done, although I havent checked fitment yet. I think for the money its a very competitive product

 

The reason I bought the OBX clone (and I had two issues with mine), was that the price from the "usual suspects" for mini parts suppliers charge so frigging much for a header, with or without cat. The Pilo stuff is coming closer. For my mustang, I got a good set of headers for it for ~$400, and that's both sides! I don't know if the parts prices are high for the Mini because it's
a) sold as a luxo-comact, and they expect us to be able to pay.
b) parts are from small companies, and they just don't make many.
c) larger companies just charge more because of the channel costs for a small volume product.

Probably a bit of all three, but when a header with cat can cost over $800, OBX baby!!!!

Matt

 

I guess you have a point. for $200, if it ends up being a piece of crap, who cares? better than spending $700 and having THAT be a piece of crap

 

We have a winner!

 

I find that on the stock header, the pipe leading to the cat is non-magnetic, as well as the flared ends of the cat. A magnet sticks to the cylindrical portion of the cat. So, I would guess that flared portion of the cat is stainless, which is where the the OBX will be welded.

 

Excellent, Glad to hear that!

Andy's comments earlier about VW's with CAT's that were to large. I think he was referring to them flowing to much with not enough differential between the two O2 sensors causing them to set codes. I built a system once for a 2 liter double over head cam running without a resonator, way to loud. I put a glass pack in to act as a resonator, it killed the high frequency and sounded nice after that. If doing it again I would buy SS Res.. I found these nice SS resonators and other exhaust parts here;

[size=2]http://stores.channeladvisor.com/vertexnow/Resonators/Vibrant/?sck=54376669[/size]

I'm going to use two of these size=2]http://stores.channeladvisor.com/vertexnow/Items/TAS-250?sck=54376669[/size][size=2] on the OBX provided socket and one on a made up coupler flange at the other end of CAT which attaches to my Magnaflow flange. This way if the CAT goes south I can easily replace the CAT.

[/size]

 

So if thats the case you still need to make sure that they are using a stainless spool to do the welding, otherwise your weld will still be poor. I haven't taken off the stock header yet so I wasnt sure, I only assumed that they used mild steel. Thanks for that bit of insight!!

The best part though is from the dyno sheets listed...its not a piece of crap

 

I called JetHot and got a quote for $150 plus shipping. I had it done on a 428 CJ motor and no problems so far. I went with what worked before. I just need to figure out the cat part. If there is no benefit of changing over stock or marginal gain, I'll stick with that, but the stainless to mild steel issue is something that concerns me. I had a failure on a joint on another car, I'm sticking with all the same material somehow.
Keep the faith.

 

I'm not sure which comment you are referring to, but I don't think there is anything wrong with using a cat that is too large or that flows too much. The problems occur when the cat is either not able to do as good a job of cleaning the air as the stock one, or it relocates the O2 sensors in such a way that they no longer have the same geometric relationship to one another. For some reason, this change in positioning can cause an otherwise functional cat to be perceived as failing by the ECU.

 

I installed the OBX header also and when I talked to a tech. at Magnaflow they did warn me about using a cat that was too big (flowed too much).

 

Looks good....I meant the header, not your foot.

I think im going to do that myself....Good stuff. ....I know this prob has been debated b4 but, is there any difference with or without a cat?

 

What was the tech's warning?

 

I find that hard to believe.....the only purpose of it is for emissions and nothing else....putting a cat which is bigger than the oem size isnt gonna do a thing but prob give you a different exhaust tone and even clean your HC reading even more.

 

The catalyst needs to hit a "light off" temp where the conversion efficiencey is high. Very large cats with very small motors will take longer to strike, and you may throw a code with a cold motor.

Matt

 

Somewhere earlier in this post, two owners gave different model numbers of a Magnaflow cat they were going to use with the OBX. I called Magnaflow and talked with one of their technicians. He asked the size of the MINI engine and said that one of the cats should work fine but the other was much too big (too much flow) to work properly. I accepted this without asking him why.

 

But isnt that whole point of having a heated O2 sensor.

 

The heater in the O2 sensor isn't there to heat up the cat. It's there to heat up the O2 sensor itself so that it operates within its operating window.

 

It flows air like a 3 litre NA motor. Something for a V6 is appropriate....

Matt

 

Yep, and the supercharger eats some power too. Airflow for a normally modded ~200 bhp MCS (pulley, intake, exhaust) is roughly comparable to a 250 bhp n/a engine.

 

about 25 hp to the SC, if I remember correctly.... Makes you wonder what other parasitic losses of power are around that can be replaced with electic motors (like our power steering system....)

Matt

 

I saw an electric water pump somewhere, but it was super expensive. Electric accessories still cause loss from the increased current draw from the alternator, but how much I don't know. You would probably have to increase the output of the alternator, also.

Steve

 

Dr. O just confirmed for me that his CAT was lighting off. From his post and yours I think we all understand the concept.

 

uses an electric pump. Lots of cars do. I can get one for my Mustang that keeps the serpentine belt by having a dummy pully for about $450....
I've seen a kit that uses the 6 series electric pump for over a grand, but if it gets you 15-20 hp, better hp/$ than lots of stuff.

Matt