I'm working on a custom exhaust that is very similiar to the magnaflow system (using maganflow mufflers) but cheaper. Right now it is very loud inside the cabin, even during freeway cruising. I'm wondering how much quieter it would be if a resonator was added after the catalytic converter?

 

You really won't know till you try it, that's part of product development and its what many times causes good products to cost more money. Cheaper is not always the best price. If your exhaust performs really well compared to others on the market it will sell really well. Spend the extra time to do the testing, customers will come if the quality is there, price is never the first qualifying factor people use to determine a products worthiness. In fact price is usally the the third to forth point of a purchasing decision. You don't want the customer who makes decisions based on price alone, if you follow that customer you will wind up with a product very few people will want and many of those people will turn into very bad customers.
This is a enthusiasts market, enthusiasts want and buy quality performing products. Good luck with your exhaust system! :smile:

 

nah, this is just for me.
A local shop made it up for me today.
But from what i've read so far, a resonator quiets things down and the Magnaflow exhaust for the mini has one. Right now i'm running without one and it's hella loud. I'll throw one on tomorrow. This was easier than adding the resonator first and removing it if i didn't like it.

 

Oh, cool, good for you that is different! How far forward is the catalitic converter?

 

Well basically, it's almost identical to the magnaflow system that is currently available.
2.5" from the cat back (the cat is located way up towards the engine, still stock), two magnaflow mufflers, and mandrel bends.

The difference is mine is aluminized (cheaper), no resonator right now but that will change tomorrow, and instead of that straight pipe that runs behind the bumper inbetween the two mufflers with the tips coming out at a 90 degree angle....my pipes flow out of each muffler towards the center bumper cutout, and then each goes into a single tip with a nice smooth curve.

_________________

 

Sounds nice, the resonator should probably go in after the cat. But the best location after the cat would need to be tested. Can you engineer on doing a number of test different locations? There probably is a point of no return the further away you get from the cat but where that point is can probably only be idnetified by testing a number of different locations.

 

FWIW, I too have a fabricated exhaust, and after some evaluation, I can tell you, at least in my situation, having a resonator after the cat lowered the volume. More importantly, it eliminated a drone that I had, and just seemed to smooth-out the whole note... It also took-out some of the burbble that like I really like when backing-off the gas, but it's still there though

 

Having the resonator will help the noise, but also might affect the weight, reduce the power by adding backpressure and increase the cost.

For those wanting to do custom exhausts it is fun to do but your results may vary. Exhaust designs are not always as easy to do right as they might look and for the cost of fabrication on a one time project it is cheaper to get something that is already done. You may dyno the final exhaust and find that it barely gives any power over the stock exhaust although it might look nice or sound nice. In which case it becomes an appearance mod not a performance mod.

Be sure to post pictures of what your system looks like.

Check out the Rspeed MCS exhausts (two models for $600 each)- get some ideas.

 

Ok, it's done! :smile:
Here's some pics...
http://www.cooperspeed.com/forums/showthread.php?t=177
Sorry for the link, but the forum won't let me cross post pics and the nam gallery is too confusing.

Minihune, very good points. I definitely took a risk with the system.
This magnaflow resonator is a straight-thru design with just some dimples on the interior so it shouldn't really effect performance (cross fingers) and the butt dyno didn't notice any difference after installing it so that is good.
The main reason I fabricated my own was to save a few bucks. I have spent major $$$ on exhuasts in the past and I have had them fabricated before. The exhaust for my 2002 A4 was $1200 retail! I never noticed a difference with the aftermarket ones compared to stock when it came to power. So to me it just wasn't worth it if all i was looking at gaining was a better sound. But sound was my primary goal with better performance being secondary but a nice bonus. It did end up being a little more than expected because of the tight spaces under the mini. It was one of the hardest cars for these guys to work on. I almost walked away because it looked like there was going to be too many problems trying to find mufflers that fit. Now the only issue as far as performance is i never got a dyno before hand. :smile:

 

very nice looking exhaust. Can you estimate power/torque change?

 

>>very nice looking exhaust. Can you estimate power/torque change?

Thanks! Honestly.... no.

 

Any ability to post a sound sample? I would be curious to here it.


<A HREF="https://www.northamericanmotoring.com/albums/album04/Mini_X_2b1.jpg" TARGET="_blank">

 

d2mini,
Nice pictures and write up. Thanks for the link.

&gt;&gt;...very good points. I definitely took a risk with the system.
This is the problem with exhausts. You can do it custom but you have to be willing to compromise- loudness vs quietness, power gained vs unknown effects on power and torque (HP doesn't always parallel torque gains), Cost of custom vs mass produced aftermarket (some have fitment problems), weight of custom vs aftermarket, looks (custom-the way you want) vs limited designs and tips.

You'll have control over design- single vs double ( I thought you were mentioning about the lightness of single systems but you made a double- how much does yours weigh? The Milltek is about 31 pounds.) Which tips- your choice it's mostly subjective but some are harder to keep clean and looking good and some disturb the balance of the look of the rear bumper. What is the sound- not that you have that much control but once you hear it you can do as you did and modify a little to get the right sound. Power and torque gains- this one is tough and I would say that 5 HP and 4-5 ft-lbs torque is good but some exhausts do better in the mid to high rpm range.

The easiest MCS to check for a gain due to an exhaust would be ones that have Magnaflow, Borla Race, UUC or Miltek.
Don't drive at speeds with torque under 4000 rpm get into the 4500 to 6500 range to get the full effect. Add a pulley and you can really tell.

&gt;&gt;This magnaflow resonator is a straight-thru design with just some dimples on the interior so it shouldn't really effect performance (cross fingers) and the butt dyno didn't notice any difference after installing it so that is good.

It sounds like the resonator worked for you but with all those Magnaflow parts used and all that labor cost I am thinking you made yourself a once piece quiet Magnaflow. I'm not sure if you got equal power as the Magnaflow for the MCS. It's rather loud and does drone some and does have huge tips.

&gt;&gt;The main reason I fabricated my own was to save a few bucks.
Your exhaust costs $650 which includes installation (about $60-80 value)
From Webbmotorsports.com the Magnaflow adds about 10 HP, weighs 34 pounds and costs about $599- talk to Randy Webb. But there is shipping costs and those big tips (just cut them off).
:smile:

You can still dyno and just report what you got given the mods you have. We know from Randy and Eric Savage what a stock MCS would dyno at.

If sound was the primary goal and you are happy with that from an interior and exterior viewpoint then you are doing fine. If you got some power then great. If you really like the unique looks esp the tips then great. The problem is a one time product is not going to be cheap mostly due to labor costs. You didn't get stainless steel throughout so that is a minus but consider that the materials you did use helps with the mellow sound and by the time the exhaust rusts through you can get another exhaust that's better. Something to look forward to. Overall I'd say that if you enjoyed the process then you had an excellent time of it and have something beautiful to be thankful for.

Some pics-

 

exactly. they modeled my system after the magnaflow system. :smile:
My tips are huge too, they just don't &quot;trumpet&quot; at the end which wouldn't make any difference because either way the exhuast gasses are let out into the open air at that point. In the end i saved myself at least $100 and i got a system tuned to the way i like it. But ya, i would just need to find another MCS with an Alta intake and aftermarket exhaust to check the power. Eventually i should be able to get a dyno.
And in TX it should last the life of the car. When i was in NY on the other hand, i went thru exhausts every 2 years on the nose. doh!

Unfortunately though, nam seems to have a problem with me posting here with a sig to my cooperspeed site that i am part owner of. So i may not be posting any more of these kinds of helpful threads here anymore. It's a shame really. Oh, and sorry about those pics Minihune tried to cross post. We don't allow it due to bandwidth issues and personal gallery abusement. Many sites do that.

 

I noticed something interesting when I was on a British website. The miltec was priced cheaper than the Scorpion and Play Mini systems which are all made over there. if you do the conversion and keep in mind that we don't have to pay VAT, they prices are very good. I wonder how much shipping would be. I have had parts shipped England in the past and it wasn't bad.

http://www.minisport.com/new-mini-shop/products.html

 

I jsut did the currency conversion and the Milltec is $646.