Hey guys, I have a question here as I've had my stock exhaust down and went for a custom straight pipe all the way from the stock down pipe to a custom muffler tip in the back without a single cat or a resonator or anything just a 2.5" stainless steel pipe and went with a HKS mushroom filter which made the blow off and turbo sound amazing but I do feel the torque is no longer there specially on really low rpms and it sucks taping on your pedal all the way down as you do feel a little power loss for some reason, any help here? You all are a bunch of cool guys with great cars and I do feel good being here..
Ps: it's the new n18 motor

I think that is to be expected. With just a straight pipe, you lose the backpressure, hence loss of low end torque. Most who do this said they can feel it via butt dyno but I don't remember if anyone actually dynoed it.

I just swapped my stock JCW exhaust on a Clubman to a custom 3" exhaust with Flowmaster mufflers. Subjectively I felt -some- loss of low end torque but due to the drone, I tossed a high flow resonator and the torque is back. And like I said, this is all butt dyno testing so can't say for certain(?)

So you recommend if I just add a high flow resonator? What exactly do you mean by muffler? Cause to me muffler is that outer tip which is only for appearance?

I'm not recommending anything as it really depends on your goals. We can get into a lengthy discussion about exhaust system but I'm not sure if you want that. I guess it depends on your overall goal. A free flowing, wider exhaust pipe is great at a higher rpm power band than a less free flowing exhaust. What we're really after is a certain gas velocity exiting the exhaust, rather than how "free flowing" an exhaust system is.

And you're thinking of exhaust tip, not a muffler. This is a muffler:

A good lengthy read on exhaust systems:

http://www.mustangevolution.com/forum/f312/t296628/

Bang on, Izzy is on point.

Omar,

I put a 3" straight pipe on my N14 JCW. I didn't notice any difference in torque output (according to my butt-dyno). I do notice the turbo spools up to the higher RPMs quicker. I also felt like I was faster/producing a little more torque around the 3000 mark (again, butt-dyno). I have yet to apply a tune to the car which is where I'm sure I will find the straight pipe to be beneficial.

Also, I forgot to add that the MINI's ECU does adapt air/fuel ratios(up to a certain point) so resetting the ECU and letting it relearn supposedly helps. Basically disconnect your battery and depress the brake pedal for 10 seconds. Reconnect and see if that helps.

I can't confirm if this really helps since I skipped it but it's free to try! :P

The pipe I got have no resonator no second cat no muffler no nothing and the link izzy posted says all about that loss I'm feeling (butt-dyno as well) so I'm thinking of adding a high flow resonator and a magnaflow muffler or something! Heard from some car tuning experts here that the mini's engine wouldn't last for too long after a tune, doesn't make sense I know and it's my first to hear such a thing but I wouldn't risk it as it would cost me something like 60,000 EGP which is approximately $10k

Your fine with the straight pipe. The cone filter will cause you to lose low end torque but high end power at high speeds. Either stick with the panel filter or get a tune and you won't notice the difference anymore.

Btw, lucky you didn't go with the 3" straight pipe cause you would have lost a little more low end power. But the 3" is really good at high end power if you track often or love speeding on the highway at 100+ mph.

Thank you Izzy, I'll try that and let you know.. Here is a bit clearer picture though

To be honest it feels great at high end power but whenever I go on the pedal all the way down it takes ages to shift to the next gear, I'll go with a tune and maybe a drop in k&n filter it fits perfectly like the stock one. I do as we'll hear some air leak or a sound close to that after driving when parked, been told that it may be the air seonsor and again not sure of that! Thanks for the help anyway

Actually I just talked to a buddy of mine who used to tune high end cars in regards to exhaust flow and backpress, etc. Velocity and flow is more important for V8s and up (hence the Ferrari example). Even with my 3" straight pipe I'm good in terms of exhaust velocity and keeping backpressure to a minimum. If you're sick of the exhaust drone then I would say go for the resonator and/or muffler. Other than that save yourself the money. As far as tunes are concerned I have not heard of people blowing their engines running on a tune. Maybe if you're running some stage 3/max output tune and driving it hard every minute of every day then you'll probably blow your engine. I would say don't worry about it. Get a tune (if that is your goal and desire for your car) and enjoy yourself.

Oh no man, I believe you. I'm doing my straight pipe 2.5" to my magnaflow muffler. But I was gonna give you a heads up if you tune, keep the cone filter in cause it makes the car flow better with the tune. Jerry at NM told me that.

Really? Study... Learn...