yes, there is a cat inside that weird shaped heat shield thing, right after the first o2 sensor dave is wrong I'm not sure he's ever opened up one of these oem headers I cut mine at the weld, removed the first cat, and welded it back together. The 2nd cat is still in place this is what the first cat looks like, it was a ***** getting it out. I cut the weld in a different spot from this pic, so the shop could weld it back together. I had to drill that bastard out, it took me an hour the stuff is tough as nails. car is louder now, but no where near as loud as the catless header I have
Cheeze Whiz... can't y'all share info without being a bunch of asses. Oh yeah, not some of these folk involved. #SadVerySad
I forgot to mention, I own a DB meter, I did test my catless and it was 100db at 25' with no load just hitting 4500 rpm, one of the places we autocross has a 90db limit, 90 vs 100 is a huge difference. when I pre-cat mod my JCW I'll take a before & after DB meter measurement, it's definitely louder but I cant say how many db it is
Well I guess you don't know what you don't know! So with my setup I had them cut off the second cat, the one I knew about, and they welded a piece of pipe to the front of it to make up the difference between the header and the exhaust. So I only have one cat.....well I have two cats one we call kitten because its so small and the other we call George because we thought it was a boy when we named it, but really I like our dog the best but I digress. So my exhaust setup is don't laugh a OBX header (yes I know now I don't want to hear it) one cat, WMW exhaust with resonator. The sound never drones is nice and mellow and at WOT it sounds great! Don't preach I promise I will do something about my cheep header.:biggrin5: I hope this helps.
My sons Mustang has a very nice exhaust with no cats. I put headers on it, you have not lived till you put headers on a 03 Mustang GT, I don't know if it was louder but it did seam to make the sound a little deeper. I would think it depends on the exhaust system. Here is Halo and kitten The cat likes the dog but does not make her louder but some times cat pesters dog This does cause the dog to be louder. So I guess it really does depends on the setup.
My 06 JCW did not have that pre-cat BS. Also just because you add a header will Not make your car louder. You have to add free flowing Mufflers. OEM and other mufflers will muffle the sound and make it sound stock. That's why they are called "MUFFLERS" you dim wits.
That is "...LOUD ass BLOWN out mufflers". Heh, come on Dave, at least spell check your insult attempts.
I'm not sure why you are falling on your sword, but I did not change my mufflers and it's a hell of a lot louder with just a header change. I'm taking off my factory 06 JCW header in a couple weeks I'll report back what mine has
At this point I don't give a rats ass because I have an RMW street header mated to a Milltek and it's not that loud at all.
Not how it works silly. If it was they would not be called "MUFFLERS". How stupid :mad2: people are is amazing.
No Dave, that's not how it works. Way way back when I was in engineering school, we had a lab about silencing the exhaust on internal combustion engines. The school had an old Chrysler slant six on a dynamometer that we could make changes on and record the results. Anything we changed from the exhaust ports to the muffler changed the sound level of the exhaust as measured with a Sound Pressure Level meter or Decibel meter, including the exhaust manifold. We found that a muffler lowered the sound pressure level the same amount given the same inlet pressure. One kind of muffler reduced the sound pressure level by 50 decibels another only 30 db. Everything we did changed the sound even the length of the pipe after the final muffler. So yes, changing the type of exhaust manifold changes the sound level at the outlet of the exhaust system.
"... all this science I don't understand Its just my job 5 days a week ... Rocket Maannnnnn" That song always pops in my head when I hear technical arguments over nothing. Continue.
But lets not forget a CAT will muffle just a little. So if your going from stock setup to header and removing a cat it will be a little louder. If you keep the cat then I don't know. I'm with Rocket man!
Rocketman: A curmudgeon who has diarrhea of the keyboard and thinks that the merits of a person's statement can be judged by post count and how much money they've spent, and who comments on everything he reads, even though usually all he has to say is "your car is not an R53, therefore it sucks and this thread is irrelevant", or "Your parts are not RMW, therefore they are crap and you are a cheapskate". When he answers a question often he's right but sometimes he is wrong. And he'll shout down or shut down anybody who dares to contradict him, and the people who know better don't say anything because either 1) he amuses them, like the weird uncle you see every year at the holidays, or 2) they know what happens when you argue with a fool, or 3) his fan club will rush to his defense and join him in confusing the nature of the question and attacking the credibility of the poster. And the OP ether gets the wrong answer or never knows what is right, and walks away from the thread in disgust. And apparently this is all a good thing.
All - There is lots of good information on this thread. However at this point it is moved to pointed and personal attacks. Our community is know to be open and civil in our discussions. Lets return to the core topic and what we are here for, to discuss MINI's. If the personal attacks continue, we will moderate the thread and potentially the users who are producing the negative post. If you have any questions or concerns, please PM me directly. Thanks, M/A Team ::This is MINI Country::