First thing I did before fitting the header was deleting the MTH-standard file, loading the OEM file and take the Cooper for a run. It felt just like I had two MacDonald-sized passengers in the car. Then I loaded the new MTH-tuner file, resat the ECU and took off again. After some initial stumbling, the familiar MTH-crispiness and highrevs was back. Noticeably better powerband than stock, even if there still were no actual power gain over 6.2K. There were also an increase in low and midrange power that actually is better felt than I had expected. The engine sound became a bit louder too ( no not pinging!)
Back in the garage, I fitted the header. Gawd- that is one beautiful little thing. The fit is OEM and the finish is all I expected from a German manufacturer - perfect. The job took about 2 hours. (Thanx to Randys how to)
New start up. No leaks. Warm-up and pedal to the metal. 30 km of forcing the ECU to understand it`s controlling a race engine And at last I got exactly what I wanted, an engine that increases its power output all the way to redline without falling off the last 500 rpms. At last! OMG that feels good! Now I don`t have to buy that Schrick cam after all...

Tormod

 

Good to hear a positive review!

 

Sounds great!

Could you describe the sound change?

I have replaced a cust iron manifold on my 2000 Miata with RB stainles tubular headers and thought that it was the best mod for the money ( around 10 hp and 10 lb/ft for $400).

But MC already has tubular manifold, so most of the changes, I think, come from the less restrictive cat. It should make the exhaust louder, but, I hope not by much.

Leon

 

Heh. That was a tricky one. Describing the sound change - well more engine sound. If you have ever tried to retard and advance the ignition manually on a gasoline engine you will hear the difference. Advanced ignition gives a more defined and louder sound. I could probably describe it in Norwegian, but not in English - sorry. And now the header contributes to the sound also, so I ain`t gonna hear the difference again.

The OEM header seems very restrictive at the collector base. The new one definitely is not. I doubt you would get the same effect from just replacing or removing the OEM Cat.

My 90`miata had OEM tubular manifold. So it is cast iron nowadays? Too bad.

Tormod

 

Thank you for responce.

Only 99 and 2000 Miatas had cast iron manifold, therefore, they benefited the most from headers. Some people even installed OEM tubular headers from later year models with good results.

I am all for this mod as long as it doesn't make the car much louder.
I drive most of the time in the sity and don't want to scare people.

Leon

 

This Header alone makes less noice than an aftermarket Catback or CAI. I doubt you will hear any difference under 4K. I have also opened up the restrictive back box, which adds a certain raspiness.

 

It does look gorgeous doesnt it...for a header anyway !

Ive supplied one to the cooper rallycar i sponsor, along with a tuner file...expect that to fly !!!!!!!!!!!!!!!!!!!!!!!!!

 

Hi, Sounds like you really like the header & your perception is that it improves performance.

Questions:
Did you dyno your MINI at any time prior to instalation?

If you believe there is improved power/torque where would you say you're feeling improvment - rpm wise?

I too like the look of this header, but I know that it's a 4-1 & that means it'll take higher rpm before it really becomes effective (as opposed to a tri-y). From photos I see that there's no pre-cat & the primaries appear longer (due in part to the lack of the pre-cat). This should improve torque... but I suspect its probably in the 4k + rpm range.

Now that I've told you why I'm asking what I am can you give further impressions/experiences? Thanks.

PS IMO a tri-y (like the OBX) should offer better lower-mid torque/power. I figure if I pair it with my Magnaflow or a similar 'open' exhaust that affords better breathing at high rpm I should end up with more even power distribution.

Thoughts?

 

No. I have not dynoed the Cooper, and I never will. A chart witch confirmes the actual rwhp from a 1.6 litre athmosperic engine will probably send me into a heavy depression.

Anyhow. Low and midrange torque got an undisputable boost from the tuner file. No doubt about it at all. This is a gain you actually feel, and not that placebo gain you get from removing the airfilter or adding a CAI . The header didn`t add anything under 4K as far as I can say - but it sure didn`t remove power either. My concern was that the Cooper got asthmatic over 6K , and that issue is fixed with the header. Now I am actually rewarded for my redlining.
I am pretty sure that you will not get an even powerband with a header designed for low or midrange torque. Software did enough of that. You may have a lack of power at high rpms. This little non FI-engine has to compensate the lack of torque with rpms in order to go fast anyway.
Without FI, we are bound to live with less torque than the Cooper S and diesel trucks.

 

If you look at the stock header, there's a funky restriction around the first 02 bung. Look on the OBX header thread, and people running with the stock cat get good power (about 10/10). So there's less restriction in the pipes, and no pre-cat.
Also, if you look at the bends etc on the stock cat, they're sharper because they have to hit the collector closer to the car.
It's a pretty good stock cat (the ones on the 5.0 ford that I got would make you laugh. from the factory there are all these bend dimples, pour (not so little) motor was just choked by the exhaust.... At least for it, an excellent set of headers doesn't cost much.

Matt