I have a Milltek header and have put on exhaust wrap sealed with silicon spray from the four exhaust primaries down over the pre cat, the sport cat and to the end of the header. Should I bother with the wrap? Should I not wrap the entire header and do only a portion? Will the wrap increase heat so much on the header (stainless steel) that it will reduce the life of the header to less than a year and cause it to crack prematurely? Does the wrap melt into a hard casing that is too hard to remove once it is burnt in? Or can I remove it if I want to later?

Anybody with experience? Thanks- please post your opinions.

And by the way the Milltek installed gives definitely a much louder exhaust note- to my quicksilver- much deeper and much louder. And there is definitely more power to be had from 4000 rpm in 4th gear. I figure peak torque is about 4000-6000. There is some at 3500 or so. There is a little exhaust rattle. And maybe a tad of droning that was not a problem before. Nothing major.

Initially the wrap did burn and smoke a bit- nearly forest fire like if near dry grass. Now it is mostly like smoking a cigar in your car but not much visible smoke with the windows down.

 

Thanks for sharing minihune. Alas, I think maybe the header is not for me.

 

>>I have a Milltek header and have put on exhaust wrap sealed with silicon spray from the four exhaust primaries down over the pre cat, the sport cat and to the end of the header.

DON'T WRAP YOUR CATS! They get hot enough as it is - they'll fail for sure if you wrap them. I would wrap up to 6" from the cat

 

some of the special high-temp ceramic coatings are suited to blower/turbo exhausts where the temps can get very high. as I recall, claims of about 400 degree reduction to outside header temperature were made for a coated header. this has got to help the metal and under hood temps, but the heat that would have soaked out through the metal is being retained in the exhaust stream, so that poor cat is getting a shot!

 

>>>>I have a Milltek header and have put on exhaust wrap sealed with silicon spray from the four exhaust primaries down over the pre cat, the sport cat and to the end of the header.
>>
>>DON'T WRAP YOUR CATS! They get hot enough as it is - they'll fail for sure if you wrap them. I would wrap up to 6" from the cat
Thanks I call pete at stratmosphere and eric at helix13 about this.
Milltex doesn't recommend any wrap-they have not done testing on it. Hotter means it could adversely affect the steel and increase brittleness and failure even with stainless steel. so it is really unknown.
If you do wrap then you can do it from about 1 inch from the start of the primary pipes and down to the collector near the first O2 sensor then stop. No wrap any further. I will do a mod on my wrap and adjust accordingly. I will keep the early part of the header wrapped for now and cut off everything around the first O2 sensor on back.
Thanks

_________________
ALOHA

 

OK, I removed all of the wrap past the first O2 sensor so the sport cat is bare.
Then I did a little driving around in 3rd and 4th gear in the 3500 to 6000 range.
Very good power and keeps pulling past 6000 rpm. It's really best in the 4000-6000 range so mid and high range.
The MINI is very smooth and drivable shifts nicely the the promini short shifter that I added. Got the M7 Plasma booster and still waiting on the Pilo ignition upgrade set I ordered.

Now for all those who think that the header makes little power and no gain on the dyno- you should drive my MCS. I think you will be pleasantly surprised and the Milltek works just fine with the lightweight Quicksilver exhaust that I have. I was a bit worried how the two would work together with having the right amount of backpressure and about loosing power at low rpms but everything works great. I also have the madness intake and 61mm throttlebody so that all helps some.

Later down the road I'll add the pulley and some sort of ECU once it becomes clear what are the best choices.
Thanks all that wrote on this thread. I'm very happy with my partially wrapped Milltek exhaust header and the loudess I am beginning to get used to so it is not at all bad or too loud. And I tried to get it to drone on the highway from 60 to 70 mph but it did not drone. It was actually pretty quiet at 60-65. More like purring. Nice.

Time to turn the big stereo back on! This MINI is great fun.

 

Take a look at the variable exhaust system on the new Buel motorcycles. At low RPM the have an "automatic adjustable plug" that restricts flow and helps low end troque while at higher rpm moves back and allows better flow. This is a pretty cool idea that appears to work well. IF your exhaust sysem is tuned for high rpm flow, low back pressure, then low end torque will be hurt. if it is tuned for low end torque then high rpm performace will suffer. The trick is to find the right balance for the way you drive the most (or hope a Buel like system is developed for the MINI so we can have the best of both worlds) :smile:

 

Tomorrow I will take out the MINI and check out the low end torque- see if I can detect any sluggishness. I haven't so far. Definitely mid to high range power.

One other note is the weight. Stock header is about 14 pounds and the Milltek was 15.
The stock header is quite restricted with short very bent primaries that lead to a collector which is tiny/crimped (less than 2" or close) compared to the Milltek (looks like 2.5&quot. The stock header has a pre-cat (another bottleneck) and a much smaller more restrictive cat. It sure looks as though a better design is possible.

 

>>And by the way the Milltek installed gives definitely a much louder exhaust note- to my quicksilver- much deeper and much louder.

Minihune-

Can you describe the sound a little more?

Where are you noticing most of the increase from? the rear, underneath or the header location itself?

J

 

>>>>And by the way the Milltek installed gives definitely a much louder exhaust note- to my quicksilver- much deeper and much louder.
>>
>>Minihune-
>>
>>Can you describe the sound a little more?
The exhaust note is deeper throatier or lower in tone than before. Quite a bit louder esp around 40-45 then it calms down and gets quiet at about 60-65. If I were to compare the noise to a friend's MCS with Mini Mania header with sport cat and Magnaflow I would say that his is louder by a bit.

>>Where are you noticing most of the increase from? the rear, underneath or the header location itself?
The noise is coming from the rear at the tailpipe. But you can hear it pretty loud from inside the MINI at certain speeds like 40-45. Even with all of the windows closed. And I have sound deadening heavy in the doors.

If I stand at the bonnet closed or open I hear the engine idling but as I walk back to the rear I hear the deep exhaust note. A completely different sound.

Tonight I went for a drive to test the 1000-3000 rpm range and it was good in first and second gear. Hard to imagine how much better pick up I could get from a pulley. My MCS pulls pretty good and smoothly from 2000 to 3500 rpm in 1st through 3rd gear. It doesn't bog down or hesitate. There is no lag or dull spot I can find. Then when you get to 4000 it really takes off rapidly. Everything is working great.

 

Thanks for the response Minihune. Sounds good.

I wonder how it would be with my Borla street exhaust? Not even sure if it is compatible or not.

 

I have a friend that has an MCS that has a Mini Mania header with sport cat and regular Borla street exhaust. He is doing well with it and has added power. In fact he suggested that I get a header. His exhaust is a little louder as well.
Overall it should work OK. He has a large typhoon K&N intake. Again we don't have separate dyno numbers for each type of exhaust. You might check around in your local area for MCS owners that have the headers and then see what exhaust they have.