S55 M3/4 Prototype BMS exhaust photo, video and dyno - PRODUCTION VERSION PICS!!

[BuLoOoSki]

Sounds very throaty, but I bet the drone is awful

[Blindside_137]

That sounds is fantastic

[Mike@N54Tuning.com]

Originally Posted by BuLoOoSki

Sounds very throaty, but I bet the drone is awful

The next prototype of the catback will have the merge from 2-1 closer to the dps allowing for a longer run of aluminum and space for a 3rd resonator to cut down drone.

[DangerousTacos]

I'm excited to hear more about this. Each time I finally decide on an exhaust... Someone else announces they are working on something promising.

[m3less]

Sounds great! Need a driving video so we can hear it under load.

[Apollo_1092]

I'd hope they have a valve option since they have products that control those and I like having the ability of being able to control the sound of my exhaust.

[TurboSid]

Agreed on Valved exhaust. Especially if it utilizes factory hardware and has just the bracket integrated

[///M ARMY]

According to Terry, mostly likely will not have valved option.

[hotrod2448]

So the production version will be aluminum or is that just for prototyping?

[BMW M4 PWR]

I'm all in for a genuinely inexpensive and lightweight exhaust option, for me it's gotta beat just keeping the stocker with valves open via JB4... a valve'd exhaust will increase the complexity and hence the cost/price... there's enough valve'd options out there already... but valve'd and truly cheap don't go hand in hand...

[AM4ZING]

Burger Motorsports is awesome.... SO much contribution to the F8x platform and top quality parts with insanely good customer service! Good shit

[BuLoOoSki]

Originally Posted by Mike@N54Tuning.com

I saw that, but as stated, "it will cut down drone" which means there will still be some drone, and I'm willing to be that it will still be an obnoxious amount of drone.

[JamesGames]

Cant wait for the exhaust..!!

[JsGarageCo]

Thats some big power on stock turbos.

[A1PericoM3]

This should sound very similar to my setup. AA midpipe with custom muffler delete's. I have no drone issues. Sounds amazing!

[Bowser330]

Originally Posted by JordanKohler

Thats some big power on stock turbos.

On stock downpipes too!

[Reach]

Stock downpipes really don't seem to rob much power. I love it.

[BMW M4 PWR]

Originally Posted by Reach

Stock downpipes really don't seem to rob much power. I love it.

At the boost level in question you bet ur ass there's at ~20wheel hp left in it... that'd take this car to 580/580 hp/trq at wheels on *stock turbos* & bolts...

[Boss330]

Exhaust sounds really cool

But why do you use STD (or SAE) correction on all dyno results? You are aware that the S55, and other modern turbo engines, aren't supposed to have correction added to the dyno results?

Adding correction on these engines usually just inflates the numbers and doesn't show the correct number. The DME has allready corrected for ambient, altitude etc. Adding SAE/STD correction is a "double dipping" in correction factors and provides a false number...

BTW, this is not particularly aimed at BMS because every tuner and dyno operator seems to be doing it...

[BMW M4 PWR]

Oh Jesus Christ here we go again

Put simply, its the correction everyone uses on the dynojets, which CANT be altered by dynojets operator... so for example, an SAE figure on an M3 on one dynojet can be accurately correlated with another M3 at a different dyno / different day but SAME SAE correction factor. The delta between them is as close to accurate as you can get... as long as you use the machines same scalar (SAE vs SAE or STD vs STD)

There's more to why correction factors are still applicable to modern sophisticated self corrected turbo motors (albeit not as much as N/A motors) but frankly, that's a novel I don't care to the write a dissertation on, along with the BS back and forth for a WEEK by every "Sunday engineer" on here... and particularly on the Saturday before Christmas... (Damn soccer moms are violent in the isles of the malls, watch out! )

Just remember, the ONLY two things that matter in posted dyno results. #1) The correction/scalar being used, and #2) that it's a FIX'ed correction/scalar that can't be altered by the type of dyno. (Generally dynojets) ...then and only then do you have as close to "apples to apples" as you can have when comparing different cars...

[Reach]

Agreed. We're not all dyno'ing on fancy hub / chassis dynamometers, so SAE corrected dynojet (whp) numbers are about the best real-world results we can use to compare all of our apples and oranges.

[Boss330]

Originally Posted by BMW M4 PWR

Oh Jesus Christ here we go again

Put simply, its the correction everyone uses on the dynojets, which CANT be altered by dynojets operator... so for example, an SAE figure on an M3 on one dynojet can be accurately correlated with another M3 at a different dyno / different day but SAME SAE correction factor. The delta between them is as close to accurate as you can get... as long as you use the machines same scalar (SAE vs SAE or STD vs STD)

There's more to why correction factors are still applicable to modern sophisticated self corrected turbo motors (albeit not as much as N/A motors) but frankly, that's a novel I don't care to the write a dissertation on, along with the BS back and forth for a WEEK by every "Sunday engineer" on here... and particularly on the Saturday before Christmas... (Damn soccer moms are violent in the isles of the malls, watch out! )

Just remember, the ONLY two things that matter in posted dyno results. #1) The correction/scalar being used, and #2) that it's a FIX'ed correction/scalar that can't be altered by the type of dyno. (Generally dynojets) ...then and only then do you have as close to "apples to apples" as you can have when comparing different cars...

Are you saying that Dynojets can't show uncorrected WHP? If so I did not know that...

Regardless, applying SAE/STD correction to these engines actually mean that you can't compare from one dyno to another, unless the dyno's are next door to each other and have the exact same ambient conditions... Because there isn't such a thing as a "fixed" correction... The whole point of correction is that it varies according to varying altitude and ambient conditions.

If you have one dyno at sea level and one at 2300 feet the SAE/STD correction will be very different between the two dynos. Same with ambient temps and intake temps, if they are different then the correction will also be different.

Those correction factors are there for one thing, to equalize measured power on engines that is affected by these varying conditions. For a engine that self corrects for this, correction adds a false value.

Let's say that you take a F8x and dyno it on three different dynos on different locations. At different altitude and ambient conditions. The uncorrected whp will be the same at all three dynos, since the DME adjusts boost etc to compensate for these different conditions. But if you add SAE/STD correction, you end up with three different HP numbers (because correction factors are different, see explanation at the end of the post).

Now, let's say you dyno a E9x M3 on three different dynos on different locations. At different altitude and ambient conditions. The uncorrected whp will be different at all three dynos, because the engine power is affected by these different conditions. But if you add SAE/STD correction, you end up with three similar HP numbers (because correction factors are different in order to cancel out differing conditions).

So, on a traditional engine you NEED to add correction to be able to compare. On a modern engine you must NOT add correction to be able to compare.

And, this is not "just a Sunday Engineer" statement. But something that is stated in the SAE and EU standards and explained in more detail here (by MAHA engineers and respected German Magazine Sport Auto):

http://f80.bimmerpost.com/forums/sho....php?t=1206686

http://eur-lex.europa.eu/LexUriServ/...12:0046:EN:PDF

2.3 Power correction factors
By way of derogation from paragraph 5.1 of Annex V to UNECE Regulation No 85, when a turbo-charged engine is fitted with a system which allows compensating the ambient conditions temperature and altitude, at the request of the manufacturer, the correction factors α a or α d shall be set to the value of 1.

Here, correction factors as per ECE 85 is defined:
http://www.unece.org/fileadmin/DAM/t...es/R085r1e.pdf