[mapleridge]

So....I finally got a chance to have my car dyno'd. 2.5L N52. Canadian 323i. This was done on a dynocom. What the hell is up with my car? Everyone else's cars read close to factory numbers or better depending on their mods. Given they were all different models. I dyno'd at 146.5hp and 157tq. Factory crank HP is 200 and 18Xlbs of tq.

My mods are a euro intake and a catless exhaust. piping diameter is 2.5 to 3". 1 HP2 muffler and a dynomax vt4 muffler.

Could my exhaust really make me lose 40hp and 3Xlbs of torque? Only comparison I have is Dimsums baseline dyno of the same car coming in at 18Xhp and 17Xlbs of torque.

[BRAISKI]

Its always good to dyno the car first when its stock so you have a base line.

[Oo=[][]=oO]

Hi Mapleridge,
I noticed your printout from the dyno says "2007 323i" which is the N52B25 producing 130kW or approx 170hp. @ 5,800rpm. and was only brought in for Canadian marketing of a fuel efficient 4 door sedan. It was over 12% more fuel efficient than the M-54 that it replaced, and it was at that time rated the highest hp. per kg of any 6 cylinder engine producing approx 86hp. per litre, and almost 1.25hp. per kg of engine weight.

That engine differs from the current (2011 E-90) motor that is rated at 152kW or approx 200hp. @ 6,400rpm.

I've read that the drop in effective hp. could be a result of the removal of the variable resonance system and variable back pressure muffler.

Hope this helps, Tom in SW Ontario.

[Zebra99]

I definitely agree with the above. Back pressure is a necessary evil on an NA motor. I say you either put on catless with lower diameter exhaust. Maybe 2.5 all the way back or you cat your current system.

Also, since you're mistake on the rating, you're really only losing 10-15whp.

Sry to hear dude, hope you figure this situation out.

[Dr. G]

A 3" exhaust is pretty big for what you need to flow, plus your motor needs that back pressure to make some torque. Your torque curve looks a bit funny, have you seen any other dynos of the same car to compare it to? If so I would look for a significant variance in low-mid rpm torque to see if you are indeed losing power due to loss of back pressure, 10-15 would be very reasonable, 40hp I don't think so.

[mapleridge]

I took my info from here.

http://www.auto123.com/en/bmw/3-seri...rid=1070800101

[mapleridge]

Originally Posted by Oo=[][]=oO

Hi Mapleridge,
I noticed your printout from the dyno says "2007 323i" which is the N52B25 producing 130kW or approx 170hp. @ 5,800rpm. and was only brought in for Canadian marketing of a fuel efficient 4 door sedan. It was over 12% more fuel efficient than the M-54 that it replaced, and it was at that time rated the highest hp. per kg of any 6 cylinder engine producing approx 86hp. per litre, and almost 1.25hp. per kg of engine weight.

That engine differs from the current (2011 E-90) motor that is rated at 152kW or approx 200hp. @ 6,400rpm.

I've read that the drop in effective hp. could be a result of the removal of the variable resonance system and variable back pressure muffler.

Hope this helps, Tom in SW Ontario.

This confirms what you say.

http://www.getcarspecs.com/bmw/2007-bmw-323i-sport

[Oo=[][]=oO]

Mapleridge,
This motor is still a workhorse and there are tons of Eurospec addons to really pop the output without getting inside the head or block. Many European sites (won't mention because they are not sponsors here) have sport racing bolt-ons and chips that are supposed to be "offroad" use only.

Balance the respiratory system to maximize efficiency!

I design turbines, generators and alternative energy systems that rely on maximizing the kinetic energy in flowing wind. I am working on a simple bolt on induction system that will stabilize pressure (high) on the intake side by using a series of Turbonator type impellers encapsulated inside a sealed airbox. By creating a computer model to scoop and divert air from a larger cross-section, we will effectively increase volume, pressure and consequently "flow".

if the airbox is not sealed, the increased airflow and pressure would dissipate and the benefit would be lost......this is a common problem with many add-on air systems.......yours included.

You need to avoid creating a turbulent flow within a stable airmass. A large volume of stable, constant pressure and prefferably cooler, dense air is the secret to untapping your engines potential and filling those 76mm tubes you are running.

Remember I said "balance the respiratory system" that means intake and exhaust. imbalance on either side of the equation will not deliver any results and possibly reduce power over the stock configuration.

Have a look at this pic and tell me if your stock exhaust was full dual tubes all the way to the cat? Do you have a pic of your new exhaust set-up?

I will keep the post updated on any progress in the new forced induction we are working on.

Hope this helps, Tom in SW Ontario

[mapleridge]

Originally Posted by Oo=[][]=oO

Mapleridge,
This motor is still a workhorse and there are tons of Eurospec addons to really pop the output without getting inside the head or block. Many European sites (won't mention because they are not sponsors here) have sport racing bolt-ons and chips that are supposed to be "offroad" use only.

Balance the respiratory system to maximize efficiency!

I design turbines, generators and alternative energy systems that rely on maximizing the kinetic energy in flowing wind. I am working on a simple bolt on induction system that will stabilize pressure (high) on the intake side by using a series of Turbonator type impellers encapsulated inside a sealed airbox. By creating a computer model to scoop and divert air from a larger cross-section, we will effectively increase volume, pressure and consequently "flow".

if the airbox is not sealed, the increased airflow and pressure would dissipate and the benefit would be lost......this is a common problem with many add-on air systems.......yours included.

You need to avoid creating a turbulent flow within a stable airmass. A large volume of stable, constant pressure and prefferably cooler, dense air is the secret to untapping your engines potential and filling those 76mm tubes you are running.

Remember I said "balance the respiratory system" that means intake and exhaust. imbalance on either side of the equation will not deliver any results and possibly reduce power over the stock configuration.

Have a look at this pic and tell me if your stock exhaust was full dual tubes all the way to the cat? Do you have a pic of your new exhaust set-up?

I will keep the post updated on any progress in the new forced induction we are working on.

Hope this helps, Tom in SW Ontario

my stock exhaust is the exact same as your pic. I am going to have to chuck it back on. Only variable that I can see screwing things up is the exhaust.

Also, I can't believe I had a completely different engine and output. See Dimsums, thread stating he has the same engine and the numbers on his dyno.

http://www.e90post.com/forums/showthread.php?t=382656

doesn't make sense just yet.

[Zebra99]

Build dates could also have something to do with it. But your major loss is definitely exhaust side.

[mapleridge]

its totally the build date. When I checked last I believe I was 01/07. It looks like I have the engine from the 2006 323i producing the lowest output. Now the question is what the hell gives the other model an additional 30bhp.

no doubt the exhaust has to go.

[Oo=[][]=oO]

Don't solve a problem by reinstalling the original set-up that was the reason for your unhappiness!

Send me a quick pic of the underneath of your car right now and we can plug the figures into the computer and tell where the main problem exists.

A stated volume of exhaust gas moving through a set diameter of tubing has specific calculable characteristics for flow, force and pressure. When you reduce or restrict the diameter or impinge flow with baffles or media to arrest sound, there is an increase in back pressure, a corresponding increase in the restrictor pipe pressure and as a consequence of this process, the stated volume of exhaust gas must increase speed for the volume to exit the system at an equal rate. Simple flow dynamics.

You could unbolt where you removed the cat (i assume you cut the duals and added some SS flanges to feed the HP2 and Vt4?) and run 73mm or 2.5" flex sections to your Vt4 dual inlet dual exhaust muffler. We can't go catless here in Ontario as you have done, but this simple test will equalize the tube diameters and eliminate the 3" sections you are using because they are probably a major cause of your problem. When you see the difference on the dyno, you can pull out the flex sections for a couple of simple pipes.

The build date in 2007 is not so critical since the evo dates were all in 2004. The main reason for the lack of HP is the factory tune and valvetronic settings. The octane should be 91 min, look for a chip, seal the intake better, equalize the exhaust piping and you will get the 30+ HP you crave.

Id love the pic and i will get you some answers, but the one thing nobody has mentioned is the age of the vehicle, the condition and the number of clicks on the clock........they are all power robbers!

best of luck, Tom in SW Ontario

[engotski]

^ we need you in vancouver, east has one too many brains lol

[mapleridge]

i bought the set up from detailaddict. it is custom made.

http://www.e90post.com/forums/showthread.php?t=693547

those are all the pics i have right now. wife is out with the car. How could I better seal my intake?

[Gen_E92]

so who else dyno'ed?

[mapleridge]

Originally Posted by Gen_E92

so who else dyno'ed?

Gavin. 350bhp 38x wtq. M54 Z4 21xwhp. 94 750il 28xwhp. e92 335is can't remember the numbers. stroked s2000 250whp 17x wtq. e36 m3 turbo'd.550whp 570wtq.

I went for a ride in the e36 and experienced space shuttle travel. That thing was a monster.

[Oo=[][]=oO]

Thanks Mapleridge, Tom here.
Now I'm really confused...the pics I saw on the link appeared to be an LCI E-90 with an aftermarket Chinese black polycarbonate narrow M-3 style rear bumper and diffuser.

Also, the explanation of the tubing and how it swages from 2.25 up to 3+ inches in a series of steps is the absolute death blow to performance.

Every action needs an equal and propotionate re-action in the opposite direction.

If you throw a baseball with all your might, you will propel the ball as far as you possibly can by transferring all your energy into the ball......if you do the same thing with a sponge ball, you will blow out your arm and shoulder.........this is exactly what you are trying to do with this progressively diminishing load or back pressure with your trumpet pipes.

You described them as a "work of art" but never let form supercede function......

Bottom line, the pics and description I saw don't resemble a 2007 N52

As for the intake, sealing it is only beneficial if you can maintain a high pressure zone in the airbox. This is achieved by delivering more cfm's of air into the system than the sum of the cfm's being consumed by the entire induction system inclusive of the pre-chamber and intake box storage area.

This is what a forced induction system accomplishes, it pressurizes pre combusted air in a containment vessel that floods the combustion chamber when the intake valve opens. Superchargers do it by spinning impellers driven by the engine, turbos do it by spinning impellers driven by exhaust gasses...we are looking at developing a bolt on simple system that increases pressure by channelling a larger cross section of avaliable airflow into a conical restrictor that is fitted with a two stage Turbonator canister impeller that will ensure the airbox is overcharged with available pressure. If the airbox is not sealed this pressure will bleed out and there will be no appreciable gain in volumetric efficiency of power.

[PepE92M3]

Originally Posted by Oo=[][]=oO

Thanks Mapleridge, Tom here.
Now I'm really confused...the pics I saw on the link appeared to be an LCI E-90 with an aftermarket Chinese black polycarbonate narrow M-3 style rear bumper and diffuser.

Also, the explanation of the tubing and how it swages from 2.25 up to 3+ inches in a series of steps is the absolute death blow to performance.

Every action needs an equal and propotionate re-action in the opposite direction.

If you throw a baseball with all your might, you will propel the ball as far as you possibly can by transferring all your energy into the ball......if you do the same thing with a sponge ball, you will blow out your arm and shoulder.........this is exactly what you are trying to do with this progressively diminishing load or back pressure with your trumpet pipes.

You described them as a "work of art" but never let form supercede function......

Bottom line, the pics and description I saw don't resemble a 2007 N52

As for the intake, sealing it is only beneficial if you can maintain a high pressure zone in the airbox. This is achieved by delivering more cfm's of air into the system than the sum of the cfm's being consumed by the entire induction system inclusive of the pre-chamber and intake box storage area.

This is what a forced induction system accomplishes, it pressurizes pre combusted air in a containment vessel that floods the combustion chamber when the intake valve opens. Superchargers do it by spinning impellers driven by the engine, turbos do it by spinning impellers driven by exhaust gasses...we are looking at developing a bolt on simple system that increases pressure by channelling a larger cross section of avaliable airflow into a conical restrictor that is fitted with a two stage Turbonator canister impeller that will ensure the airbox is overcharged with available pressure. If the airbox is not sealed this pressure will bleed out and there will be no appreciable gain in volumetric efficiency of power.

Excellent!!!

[Iceburg]

Originally Posted by Oo=[][]=oO

Thanks Mapleridge, Tom here.
Now I'm really confused...the pics I saw on the link appeared to be an LCI E-90 with an aftermarket Chinese black polycarbonate narrow M-3 style rear bumper and diffuser.

Also, the explanation of the tubing and how it swages from 2.25 up to 3+ inches in a series of steps is the absolute death blow to performance.

Every action needs an equal and propotionate re-action in the opposite direction.

If you throw a baseball with all your might, you will propel the ball as far as you possibly can by transferring all your energy into the ball......if you do the same thing with a sponge ball, you will blow out your arm and shoulder.........this is exactly what you are trying to do with this progressively diminishing load or back pressure with your trumpet pipes.

You described them as a "work of art" but never let form supercede function......

Bottom line, the pics and description I saw don't resemble a 2007 N52

As for the intake, sealing it is only beneficial if you can maintain a high pressure zone in the airbox. This is achieved by delivering more cfm's of air into the system than the sum of the cfm's being consumed by the entire induction system inclusive of the pre-chamber and intake box storage area.

This is what a forced induction system accomplishes, it pressurizes pre combusted air in a containment vessel that floods the combustion chamber when the intake valve opens. Superchargers do it by spinning impellers driven by the engine, turbos do it by spinning impellers driven by exhaust gasses...we are looking at developing a bolt on simple system that increases pressure by channelling a larger cross section of avaliable airflow into a conical restrictor that is fitted with a two stage Turbonator canister impeller that will ensure the airbox is overcharged with available pressure. If the airbox is not sealed this pressure will bleed out and there will be no appreciable gain in volumetric efficiency of power.

Tom for member of the month!

[mapleridge]

Originally Posted by Oo=[][]=oO

Thanks Mapleridge, Tom here.
Now I'm really confused...the pics I saw on the link appeared to be an LCI E-90 with an aftermarket Chinese black polycarbonate narrow M-3 style rear bumper and diffuser.

Also, the explanation of the tubing and how it swages from 2.25 up to 3+ inches in a series of steps is the absolute death blow to performance.

Every action needs an equal and propotionate re-action in the opposite direction.

If you throw a baseball with all your might, you will propel the ball as far as you possibly can by transferring all your energy into the ball......if you do the same thing with a sponge ball, you will blow out your arm and shoulder.........this is exactly what you are trying to do with this progressively diminishing load or back pressure with your trumpet pipes.

You described them as a "work of art" but never let form supercede function......

Bottom line, the pics and description I saw don't resemble a 2007 N52

As for the intake, sealing it is only beneficial if you can maintain a high pressure zone in the airbox. This is achieved by delivering more cfm's of air into the system than the sum of the cfm's being consumed by the entire induction system inclusive of the pre-chamber and intake box storage area.

This is what a forced induction system accomplishes, it pressurizes pre combusted air in a containment vessel that floods the combustion chamber when the intake valve opens. Superchargers do it by spinning impellers driven by the engine, turbos do it by spinning impellers driven by exhaust gasses...we are looking at developing a bolt on simple system that increases pressure by channelling a larger cross section of avaliable airflow into a conical restrictor that is fitted with a two stage Turbonator canister impeller that will ensure the airbox is overcharged with available pressure. If the airbox is not sealed this pressure will bleed out and there will be no appreciable gain in volumetric efficiency of power.

lol. I am following you on a general scale but it looks like my specific problem has gone out the window....It's not as simple as you thought heh.

I have an 07 323i. Built 01/07. I did an LCI rear end conversion with an m3 rep bumper. The exhaust is a custom made piece by a machine shop. While he was no expert in exhaust systems and the science behind it he is a very skilled fabricator. The initial dyno's of the system showed an increase in hp and tq on the dyno so I was going for form and function. The results on my vehicle were a surpise to me, hence the batman catch phrase. Add to it, the fact that I had my engine output all wrong and that should about explain it. The system is 2.5 dual pipes that go into a y pipe right before the pictures in my thread, then the rest is there for you to see. it's 3" pipe going into the final muffler and two 2.5" outlets.

Still think you can help? Only solution my minimal experience favours is throwing the stock system back on and deleting the secondary cats on that. It is already designed to maximize back pressure and taking out cats should let it breathe easier. I'm open to suggestions and info about how they boosted bhp on these engine to 200hp and 218hp respectively in Canada and Europe.

[dassub]

That was actually the first car I test drove 4 years ago, and my butt dyno was telling me the same thing! Ended up in a manual 325i instead (the 3 litre improved my butt dyno experience enough).

I think I've said butt dyno a few too many times in this post, but meh!

[jim.e.]

Originally Posted by mapleridge

lol. I am following you on a general scale but it looks like my specific problem has gone out the window....It's not as simple as you thought heh.

I have an 07 323i. Built 01/07. I did an LCI rear end conversion with an m3 rep bumper. The exhaust is a custom made piece by a machine shop. While he was no expert in exhaust systems and the science behind it he is a very skilled fabricator. The initial dyno's of the system showed an increase in hp and tq on the dyno so I was going for form and function. The results on my vehicle were a surpise to me, hence the batman catch phrase. Add to it, the fact that I had my engine output all wrong and that should about explain it. The system is 2.5 dual pipes that go into a y pipe right before the pictures in my thread, then the rest is there for you to see. it's 3" pipe going into the final muffler and two 2.5" outlets.

Still think you can help? Only solution my minimal experience favours is throwing the stock system back on and deleting the secondary cats on that. It is already designed to maximize back pressure and taking out cats should let it breathe easier. I'm open to suggestions and info about how they boosted bhp on these engine to 200hp and 218hp respectively in Canada and Europe.

based on what Tom said...you have a mismatch in piping all over the place which is resulting in lower gains than expected.