I've been dewlling on this mod for a while now, after seeing posts and hearing Mad Dog's vid I could not wait anymore.

I made some phone calls and found the muffler and an installer that would pop this in today. I am picky about the look of my 540 so I wanted a clean install with no peaking tips.

I bought the muffler from the good folks @ Greyhound Auto Parts
Boca Raton, FL 561-367-0373

Spoke with a lady by the name of Mary she actually got under my car and made sure that it would fit. Even though she is into mustangs she is ok in my book. It also helped that she was HAWT!! (god I hope she does not read this)

Then took the car over to the Mad Hatter muffler shop in Davie, FL 33314 (954) 797-9152‎ and had it installed by Kevin (the owner) He did a supurb job.

Sorry for the crappy pics I only had my phone camera with me.

here are some more pics

mandrel bending would have been a good idea... most good shops do it... and also one piece piping...

:buttrockCool, looks nice. Any chance for some videos so we can hear the beast?

So what do you think about how it sounds? Which magnaflow is that? What costs did you incur?

the thing that stops me from doing this is you actually loose both hp and torque when you do this....the exhaust may be big and heavy and not very loud but it is perfectly engineered for our cars...

mandrel bending would have been a good idea... most good shops do it... and also one piece piping...


+1 on mandrel bend

Looks like too many kinks/twists....you might lose some power there :)

Spoke with a lady by the name of Mary she actually got under my car and made sure that it would fit. Even though she is into mustangs she is ok in my book. It also helped that she was HAWT!! (god I hope she does not read this)



magnaflow pics are pretty commom, i rather see pics of the hawt lady who was willing to go under your car

Nice.

Now lets hear that sucka!

So what do you think about how it sounds? Which magnaflow is that? What costs did you incur?

It sounds just like Mad Dogs video. That is what drove me over the edge to get one.

the thing that stops me from doing this is you actually loose both hp and torque when you do this....the exhaust may be big and heavy and not very loud but it is perfectly engineered for our cars...

So far I have not felt any lag in shifting. Power is still there and that sweet 4th gear torque still thrusts you into next week.

+1 on mandrel bend

I agree the mandrel bend would have been a smarter choice. (hindsite is 20 / 20) :)

Looks like too many kinks/twists....you might lose some power there :)

Not sure about any power loss due to kinks.


magnaflow pics are pretty commom, i rather see pics of the hawt lady who was willing to go under your car

If I go back I may have to ask her to model for me. :)

Nice.

Now lets hear that sucka!

I can record it but is sounds just like your vid. Thanks for posting it. I cant wait to see the pics of your sweet ride's underbelly. lol

It sounds just like Mad Dogs video. That is what drove me over the edge to get one.


I can record it but is sounds just like your vid.

I left the OE resonator on - and only removed the rear boob tubes.

Yours has to sound different.

dyno the car, swap the exhaust and dyno it again...you will see a loss in power because of the decrease in back-pressure...

I left the OE resonator on - and only removed the rear boob tubes.

Yours has to sound different.

I'll try to record it this weekend.

dyno the car, swap the exhaust and dyno it again...you will see a loss in power because of the decrease in back-pressure...

I'm sure someone has a stock dyno run so taking it off wont be needed.

As for any loss in power I may have at this point? I didnt feel any at the foot so...

I have already installed the Zionsville Raddy and this temp exhaust. My next plan is the Wheel well cut out, m5 bumpers and then a full on m5 exhaust. This is all prep work till I get the Dinan SC installed.

the SC will make it a moot point...

You're losing power on this mod. Not so much with the muffler itself, but the excessive kinks and crush bent piping. Your flow is worse now than what it was with the OEM stuff. You have not felt it because you lost a ton of weight.

Who cares if you lose a few hp/lb-ft...the fact that it actually sounds like something other than silence makes it feel a lot faster. It makes the car so much more fun. A nice feeling shifter (545i shifter, M3 shifter, etc) and a great noise alone make 540s so much better to drive, even if it is now .05 secs slower to 60.

the thing that stops me from doing this is you actually loose both hp and torque when you do this....the exhaust may be big and heavy and not very loud but it is perfectly engineered for our cars...

Where are you getting this from?????

The Cat and headers are the primary source of back pressure on the exhaust system. Removing the headers WILL cause a reduction in performance as an engine does need some amount of back pressure to operate at peak efficiency and power but this is only over the length of a set of Tuned headers, after that everything is reducing performance by adding restriction and reducing flow. Removing downstream restriction WILL NOT reduce performance, it generally wont add anything unless you also open up the intake and port the head. Every single after market exhaust out there has lower back pressure (is freer flowing) than the stock exhaust, by your reckoning everyone of them will reduce performance and frankly that idea is just flat out WRONG.

please post a sound clip...

well i have a good friend of mine who has a 530i, and he had a Magnaflow cat-back exhaust system installed, and he decided to go with 2" madrel single piping from the cat back, and he had 2 pipes all th eway back with a similar 2 mufflers at the end. he saw approxiamately 10.3hp and 13.2tq gain over stock. the place that did his specialize in bmw performance, and they told him to go with smaller piping whne u change the exhaust system out on due to the loss of back pressure...So i am planning on have the same type of exhaust work done on my 528i...so from my point of view, i would recomend this type of setup!

It should sound different than Mad Dogs and I'm sure it sounds much better. Congrats on taking the step and thanks for posting pics.

I say, if the cars power band is roughly the same as it was before, it's all good. While we all would like to have 10 more hp, I'm not sure you could feel the difference anyway unless you really had your foot in it.

It seems to me, the weight loss on these exhaust mods compensates for the loss of back pressure so the "actual power gained/lost" is essentially a wash over stock and you have better sound. It's really a no-brainer and as long as you are happy, that's all that matters anyway.

well i have a good friend of mine who has a 530i, and he had a Magnaflow cat-back exhaust system installed, and he decided to go with 2" madrel single piping from the cat back, and he had 2 pipes all th eway back with a similar 2 mufflers at the end. he saw approxiamately 10.3hp and 13.2tq gain over stock. the place that did his specialize in bmw performance, and they told him to go with smaller piping whne u change the exhaust system out on due to the loss of back pressure...So i am planning on have the same type of exhaust work done on my 528i...so from my point of view, i would recomend this type of setup!


:confused:confused:confusedUHHHHHH OOOOOKKKKKK.

You do understand that two 2" pipes will flow more air than one 2.5 inch pipe and at a lower pressure, don't you?

You do understand that the gains your friend saw were due to improved flow(i.e. reduced back pressure) allowing the engine to breath better and produce more power by reducing the power required to squeeze the exhaust out through the restrictive factory exhaust?

This is pretty basic performance improvement 101/kindergarten type stuff here guys.

You never lose hp and torque by reducing backpressure, you lose it from reducing exhaust velocity either with piping that is too large, non mandrel bent tubes, etc. The stock 540i exhaust is tuned all the way back to the resonator with specific varying exhaust diameters to increase velocity and flow. Changing one piece without swapping out the entire exhaust throws it all out of tune.

backpressure myth

there is no thing as "lack of backpressure"

there is a thing as " lack of siphioning" when your exaust is too big or too small for current rpms

simply put when your at low rpms smaller pipes would have more power but when your at higher rpms bigger pipes are better...so where do you want the gain?

the incredibly stupid part of all of this is that none of this means a hill of beans for like 98% of the cars on here. If we were designing race cars then maybe these points would be of any consequence but alas on cars equipped with cats its all really pretty much pointless.

the incredibly stupid part of all of this is that none of this means a hill of beans for like 98% of the cars on here. If we were designing race cars then maybe these points would be of any consequence but alas on cars equipped with cats its all really pretty much pointless.

You would not care whether your car is running so poorly that its down 35 lb/ft of torque and 25 whp in the midrange vs. stock?:dunno If not, then just take a 3" hole saw/drill and start putting holes in the exhaust until it makes the noise you desire.

I like my whips to perform AT LEAST as well as stock. I hate the idea of spending the money/time/effort to mod a vehicle so that it performs substantially worse than stock in a category as fundamental as engine output/acceleration.

You would not care whether your car is running so poorly that its down 35 lb/ft of torque and 25 whp in the midrange vs. stock?:dunno If not, then just take a 3" hole saw/drill and start putting holes in the exhaust until it makes the noise you desire.

I like my whips to perform AT LEAST as well as stock. I hate the idea of spending the money/time/effort to mod a vehicle so that it performs substantially worse than stock in a category as fundamental as engine output/acceleration.

I would love to see some numbers to backup this assertion that you are making. We have already been offered data to refute this so pony up, lets see what you got.

I would love to see some numbers to backup this assertion that you are making.

You wanna see some numbers, huh?

You mean like recent, back to back, same day, same dyno, same car, stock vs. resonator delete, type of numbers?

That's asking a whole helluva lot, but here ya go:

Check-out post No. 68 in this thread:
http://forums.bimmerforums.com/forum/showthread.php?t=766366&highlight=dyno

You got anything similar to show that deleting the resonator does not creat a loss - other than theory/rhetoric?

:D

You wanna see some numbers, huh?

You mean like recent, back to back, same day, same dyno, same car, stock vs. resonator delete, type of numbers?

That's asking a whole helluva lot, but here ya go:

Check-out post No. 68 in this thread:
http://forums.bimmerforums.com/forum/showthread.php?t=766366&highlight=dyno

You got anything similar to show that deleting the resonator does not creat a loss - other than theory/rhetoric?

:D

Careful being quite so smug Mad Dog, I read the whole post and you were right on board the theory/Rhetoric band wagon until you got the dyno runs. I was as surprised as anyone that the tuned portion of the exhaust extended beyond the Cats. Earlier in this thread someone reported improved performance from an exhaust change and that was what I was reffering to.

Elimination of exhaust restriction is a tried and true and in most cars very successful way of improving performance so its not like I pulled this one out of my ass. I guess its good that I decided to leave the dog leg in on my exhaust mod.

Careful being quite so smug Mad Dog, I read the whole post and you were right on board the theory/Rhetoric band wagon until you got the dyno runs.

Huh?

What are you talking about?:dunno

I never posted in the thread until after the dyno results were in.

Please direct me to the post (any post, anywhere) where I espoused removal of the resonator, or said reducing back pressure is ALWAYS a good thing, or otherwise rode that band wagon?

In my expereince modding BMW's, I have found that opening-up the exhaust is typically fruitless for a street-driven car, unless you have SERIOUSLY increased the volumetric efficiency of the motor via cams/intake/manifold/tuning or gone FI. Low/mid losses are commonplace when opening-up an exhaust on an otherwise stockish BMW motor.

I have heard many folks who I consider "in the know" (including people who build 540 exhausts and dyno the results) tell me that the 540 is very dependent on the resonator and muffler/silencer for its phenomenal low/mid torque/power.

Notwithstanding the above, the MASSIVE losses (w/ ZERO gains) established by the dyno results in that thread are still shocking to me. It is by far THE worst loss I have ever seen via an exhaust mod. Given the absence of a similarly reliable dyno result to the contrary, I can't imagine why anyone would even consider/suggest the mod.

You wanna see some numbers, huh?

You mean like recent, back to back, same day, same dyno, same car, stock vs. resonator delete, type of numbers?

That's asking a whole helluva lot, but here ya go:

Check-out post No. 68 in this thread:
http://forums.bimmerforums.com/forum/showthread.php?t=766366&highlight=dyno

You got anything similar to show that deleting the resonator does not creat a loss - other than theory/rhetoric?

:D

It's a little more complex than your implying.

In the case your siting, he deleted the Y-resonator along with the secondary silencer muffler and replaced them with a crimp-bent 2.5" pipe.

The OEM system uses 2.5" pipe TO the Y-resonator, then 2.75" pipe AFTER. So, basically, he replaced a section of large pipe with smaller crimp-bent pipe. I'm not surprised he lost power.

I'm not saying exhaust necessaryily gives extra hp. But before I started spouting this around like it was gospel, I would want to see a test where the pipe was replaced with a pipe at least as big as OEM.

I would also like to see numbers with the y-resonator in place, but the oem mufflers removed (and replaced with 2.75" mandrel bent pipe or larger).

It's a little more complex than your implying.

In the case your siting, he deleted the Y-resonator along with the secondary silencer muffler and replaced them with a crimp-bent 2.5" pipe.

The OEM system uses 2.5" pipe TO the Y-resonator, then 2.75" pipe AFTER. So, basically, he replaced a section of large pipe with smaller crimp-bent pipe. I'm not surprised he lost power.

I'm not saying exhaust necessaryily gives extra hp. But before I started spouting this around like it was gospel, I would want to see a test where the pipe was replaced with a pipe at least as big as OEM.

I would also like to see numbers with the y-resonator in place, but the oem mufflers removed (and replaced with 2.75" mandrel bent pipe or larger).


Your theory MIGHT have some credibility IF he had sufferred the huge losses in the top-end of the powerband.
However, the car performs like stock from 5.2k rpm to redline. This totally contradicts the idea that the modded exhaust is restrictive and strangling the motor's flow. To the contrary, the dyno indicates its flowing exhaust gas at a similar velocity to stock at high rpm.

Its in the 3.2k - 5.2k rpm range where flow velocity would appear to be stifled - that's not a function of too small piping or crush bends (which would actually boost that area of the curve, if anything).

When considering a systems' flow rate, more goes into it than pipe diameter and crush vs. mandrel bends. Do you have any idea how restrictive the OE resonator and boob tubes are compared to "straight-through designs"?

Do you know what kind of resonance they may create and what kind of impact that may have on performance? Why do you think there is a rubber "vibration absorber" on the OE exhaust across from the inlet to one of the "boobs"?

Do you know why the OE intake and exhaust incorporate helmholtz resonators? Do know how their resonant frequencies and/or that of the intake manifold may affect performance?

Why do you think BMW engineered such a complex exhaust system? Certainly could have made a simple quiet exhaust for MUCH less dough.

You think ripping all that heavily-engineered stuff out and replacing it w/ straight pipe (and straight-through mufflers/resonators) is an enhancement for an otherwise stock motor?

You go from a highly-engineered, high-tech, complex, tuned set-up, to a low-tech, generic set-up based on guesswork (or at best hypothesis) and think THAT will enhance performance?

I suspect the OE exhaust is tuned to significantly boost gas velocities in the mid-range rpm, while at the same time being of sufficient size to support good flow at higher rpm.

I have no doubt that the "straight through" 2.5 inch crush-bent cat-back design that was dyno-tested to lose power/trq. has lower mid-range gas velocity than the OE's complex 2.5/2.75 inch design. Increasing the pipe diameter coupled w/ straight-through designs will only allow the gas velocity to drop even further.

I cant believe you guys are using that dyno thread as your evidence. It seems to me that dyno/dyno user had some issues. I think we need a dyno day at a reputable shop so we can compare similar cars on the same day in similar conditions.

Your theory MIGHT have some credibility... Do you have any idea... Do you know... Why do you think... boobs... Do you know... Do know... Why do you think... You think...

I suspect the OE exhaust is tuned to significantly boost gas velocities in the mid-range rpm, while at the same time being of sufficient size to support good flow at higher rpm.

I have no doubt that the "straight through" 2.5 inch crush-bent cat-back design that was dyno-tested to lose power/trq. has lower mid-range gas velocity than the OE's complex 2.5/2.75 inch design. Increasing the pipe diameter coupled w/ straight-through designs will only allow the gas velocity to drop even further.

I'm really impressed that you can draw so much from one graph, of one car, modifying multiple vehicle components at one time.

I know enough about exhaust tuning to keep my foot out of my mouth and not look like an a$$. I have a solid understanding of harmonics, resonance, pressure, turbulence, etc and how they can affect flow.

I can even carry a competent conversation about suspension and shock absorber damping characteristics using a whole bunch of other neat graphs and words like velocity, damper, linear, progressive, anti-squat, axle-path, transition region, knee, volumetric flow rate, shim stacks, etc. I simply prefer to spend my time being helpful, or explaining myself rather than trying to make others look incompetent.

I'm not saying your wrong, or trying to pick an e-knife-fight. I actually agree with a lot of what your saying about BMW engineering and the stock exhaust (particularly the y-resonator). I do not agree, however, that the exhaust cannot be improved. Engineering, like life, is a series of compromises.

recall that most of us choose to make exhaust mods to improve the sound of the car not to improve its performance.

I'm really impressed that you can draw so much from one graph, of one car, modifying multiple vehicle components at one time.

I simply prefer to spend my time being helpful, or explaining myself rather than trying to make others look incompetent.

I'm not saying your wrong, or trying to pick an e-knife-fight. I actually agree with a lot of what your saying about BMW engineering and the stock exhaust (particularly the y-resonator). I do not agree, however, that the exhaust cannot be improved. Engineering, like life, is a series of compromises.

1. I do not draw my conclusions based solely on the before/after dynos. As I stated previously, I have spoken to people who have played around w/ modifying 540 exhausts and have dyno'ed various different configurations. Their learned opinions are consistent w/ the dyno graphs in the thread.

2. My posts were not an effort to make anybody look incompetent. I don't know the answers to half of the questions I asked in my prior post. They were rhetorical in nature - simply to illustrate the complexity of what we're dealing with.

3. I never said the stock exhaust could not be improved upon. However, for an otherwise stock motor, the stock exhaust is not leaving a whole helluva lot on the table. Maybe 5whp to be gained w/ the right muffler vs. the boob tubes? I think Dinan advertises this w/ his muffler.

well i have something to add in here...

before my exaust the obc(and calc's after the pump) came out to 19 mpg average(26ish hwy)

after my exaust the obc(and the calc's after the pump) came out to 21 mpg average (28ish hyw)

since my motor is breathing better it should have more power

i have had the same driving habits for a long time with this car so that is not a concern and my type of driving is about 25% hard 50% city 25% hyw

so this is real world numbers that i will back up 100% and beleive they are more acurate that a before/after dyno run in the same day

a note: my exaust is different than most since i ran 2.25 pipes from the cat back to two 14815's with a x-pipe between

Do you know why the OE intake and exhaust incorporate helmholtz resonators? Do know how their resonant frequencies and/or that of the intake manifold may affect performance?


Not to add flame to the fire, but I just wanted to point out that helmholtz resonators are for noise cancellation and affect permformance about as much as the rock wool or fiberglass in an absorbtion muffler.

Lol. Why not go in to exhaust scavenging as well! After all we are talking about race engines, aren't we??? Lol.
Nice new exhaust mate. I will be going a similar route in a couple of weeks - in part because a full exhaust system (with cats) from BMW costs £2500. Toooooooo steep for me!