[UncleFester]

Many of you BMW N52 owners are interested in increasing power, without moving to an N54/N55. I’ve received a lot of good info from this site, and hope to give back with some documentation of the power modifications I did.

The Car:

2009 BMW 328i, 6 speed, Sport & Cold Weather packages (minimal options)

Modifications:

Step 1, November 2012: Installed Active Autowerke tune. No baseline stock dyno, but the “pre” dyno in Step 2 should serve as the “post” for this mod. Result: better throttle response, slightly more power.

Step 2, December 2016: Bimmer Performance Center (BPC) installed a 3 stage intake manifold and performed a dyno tune. Results from pre and post dyno runs are included. Result: significant increase in power. DISA valve transitions were a bit more abrupt than I anticipated.

Step 3, July 2017: I installed Active Autowerke headers and BPC performed a dyno tune. Results from pre and post dyno runs are included. Results: noticeable increase in power, DISA valve transitions reduced, rev limiter increased.

All dyno runs were conducted on BPC’s dyno, with stock exhaust.





A few additional comments:

Suspension vs. power? This car has received suspension mods, too, but they’re more difficult to report on objectively. I think suspension mods are more valuable on the track, and the power adds more fun on the street.

Are the headers loud? With a stock exhaust, they’re very stealth. If you modify the exhaust they can get stupid loud.

BPC? Very knowledgeable and very helpful! They’re enthusiasts.

https://www.youtube.com/watch?v=LZSS8u-s88A

[rick100]

240 , nicee!

[tlow98]

Great info and appreciate the nice post. I’d imagine that’s a pretty sprightly car now.

I imagine your stock whp numbers are pretty close to that AA tune but of course every dyno is a bit different and the differences add up.

[6ixSpd]

Thanks for the well articulated information!

Your car seems right in line with what is to be expected with the trifecta power combo on the N52 (header + tune + 3SIM). 40whp is a big gain on these little cars. That's almost 25% more power than stock!

[desertman123]

Originally Posted by UncleFester

Step 2, December 2016: Bimmer Performance Center (BPC) installed a 3 stage intake manifold and performed a dyno tune. Results from pre and post dyno runs are included. Result: significant increase in power. DISA valve transitions were a bit more abrupt than I anticipated.

Does it feel like ur hittin vtec brah?

Also are you considering the MILVs?

[CobraMarty]

Originally Posted by desertman123

Also are you considering the MILVs?

Great work.
Doing dyno work to document results, A+!!

Any air intake work?
Charcoal delete, aFe filter? EURO intake? PI? aFe air box?
Silicone intake hose?
Intake air scoops? They do help at highway speeds.

All that's left is mid pipe cat delete, PE, MILVs.

MILVs will add +10rwhp and +10rwtq across the rpm range.

[cpie168]

Sorry but what is MILV?

[desertman123]

Originally Posted by cpie168

Sorry but what is MILV?

http://www.e90post.com/forums/showthread.php?t=1329840

There's a fair bit to read through, but basically it's as close as we'll get to an upgraded camshaft. (Correct me if I'm wrong) They modify the eccentric shaft angle and in return, adds more intake valve lift.

[Volasko]

Originally Posted by cpie168

Sorry but what is MILV?

The final frontier in getting more power from our N52's other than the more commonly known mods for our cars!

[UncleFester]

Originally Posted by desertman123

Does it feel like ur hittin vtec brah?
Also are you considering the MILVs?

No VTEC surge, Brah! Felt more like a stutter in the torque curve. Pretty much gone now, so I’m happy.

I haven’t been tracking the MILVS developments. Just went back and educated myself. Looks promising.

Although I posted on power mods, I’ve actually put more money and effort into suspension improvements since I started tracking the car last year. Improve the car … track the car (improve the driver) … improve the car … track the car (improve the driver) … The cycle of mods and track time has been a great learning experience.

Originally Posted by CobraMarty

Any air intake work?
Charcoal delete, aFe filter? EURO intake? PI? aFe air box?
Silicone intake hose?
Intake air scoops? They do help at highway speeds.

Charcoal delete. The euro intake looks nice due to ease of filter access, if nothing else.

[CobraMarty]

On my son's 328 when we replaced stock intake with the EURO intake, I made a crude flow bench with a shop vac and CFM flow meter and IIRC the EURO intake did flow like 10% better than the stock intake. Maybe it adds 3-5hp over stock and 2-3 over charcoal delete. My 328 commuter I did a charcoal delete and aFe dry filter and the expensive EURO intake is still on the shelf.

The MILVs, they are indeed like adding a 'performance' intake cam. They add just over 1mm of lift and 2-3* duration.

The valvetronic is a linkage nightmare. Not really but there is an intermediate rocker arm which connects the intake cam to the valve stem. The eccentric cam changes the intermediate rocker arm position/fulcrum and therefor the actual lift of the valve. One end of the intermediate rocker arm has a roller which rides on a slightly sloped support. It's position on the support also determines the valve lift. It is this support that I modify to give more lift at 80-100% throttle position.

Installed with the proper adjustment in the tune, they add +10 rwhp and +10 rwtq across the whole rpm range. About the same amount as adding headers again.

[rick100]

Originally Posted by CobraMarty

On my son's 328 when we replaced stock intake with the EURO intake, I made a crude flow bench with a shop vac and CFM flow meter and IIRC the EURO intake did flow like 10% better than the stock intake. Maybe it adds 3-5hp over stock and 2-3 over charcoal delete. My 328 commuter I did a charcoal delete and aFe dry filter and the expensive EURO intake is still on the shelf.

The MILVs, they are indeed like adding a 'performance' intake cam. They add just over 1mm of lift and 2-3* duration.

The valvetronic is a linkage nightmare. Not really but there is an intermediate rocker arm which connects the intake cam to the valve stem. The eccentric cam changes the intermediate rocker arm position/fulcrum and therefor the actual lift of the valve. One end of the intermediate rocker arm has a roller which rides on a slightly sloped support. It's position on the support also determines the valve lift. It is this support that I modify to give more lift at 80-100% throttle position.

Installed with the proper adjustment in the tune, they add +10 rwhp and +10 rwtq across the whole rpm range. About the same amount as adding headers again.

Headers is more like 20 whp . Same as 3 stage intake.

10whp is still a decent number.

250whp should be doable with ur mod and headers / 3 stage combo

[CobraMarty]

Headers- +13-16hp (240-227/224) and +8-9tq (224-215/216)

These are PEAK differences. Different rpm will have more or less gains.

MILVs- +8hp (238-230) and +8tq (233-225)
On BPC turbo N52 engine- +25hp (474-449) and +32tq (477-445)

[rick100]

Originally Posted by CobraMarty

Headers- +13-16hp (240-227/224) and +8-9tq (224-215/216)

These are PEAK differences. Different rpm will have more or less gains.

MILVs- +8hp (238-230) and +8tq (233-225)
On BPC turbo N52 engine- +25hp (474-449) and +32tq (477-445)

still twice as much gains compared to MILVs

your statement was "almost the same as headers". There are dynos showing 20 whp gained. so roughly 15-20 whp gained.


Milvs are still a very interested mod for sure, probably the third one in the list of gains in the list behind headers and 3 stage intake for now. I'm still wondering if 250 whp , would it be possible for FBO ( with MILvs)

I m subscribed to your thread , waiting for more results .

[CobraMarty]

And I am pretty sure that testing of the MILVs by BPC were with an original +0.5mm lift and not the current version with +1.0mm additional lift.

The additional +1.0mm intake valve lift does make more power.

My butt dyno is a bit old and crusty and is not rpm calibrated.
Just saying that the gain with the MILVs is almost like adding the headers again.

And on a $/hp gained, it's a tossup.
Headers, 3IM, MILVs, tune.
Add in PI, PE, secondary cat delete, silicone intake hose, intake scoops.

[atmosphericM]

Thanks for sharing. Too bad you didn't have a base-line, pre-AA tune, but oh well.

I am guessing you're "too old" for an exhaust or something like that. But I'd love to see this progress with an exhaust and possibly intake, and then of course a final dyno. 250hp is the mark, let's goooo!

[UncleFester]

Originally Posted by atmosphericM

I am guessing you're "too old" for an exhaust or something like that. But I'd love to see this progress with an exhaust and possibly intake, and then of course a final dyno. 250hp is the mark, let's goooo!

That accurately describes me.

I do have a PE muffler on it now. It's loud above 3k rpm. Great on the track so I can hear the engine with a helmet on and the windows open. A bit much for the street. I have no plans to remove the secondary cats and resonator. (note: the BPC YouTube video I linked has the stock exhaust.)

I'll be sure to include dyno runs if I move forward with the MILVS ... for science ... and the children

I'll admit, the "250 Challenge" is difficult to ignore.

[CobraMarty]

Originally Posted by UncleFester

I'll admit, the "250 Challenge" is difficult to ignore.

You'd be the first!!

[tlow98]

Originally Posted by UncleFester

That accurately describes me.

I do have a PE muffler on it now. It's loud above 3k rpm. Great on the track so I can hear the engine with a helmet on and the windows open. A bit much for the street. I have no plans to remove the secondary cats and resonator. (note: the BPC YouTube video I linked has the stock exhaust.)

I'll be sure to include dyno runs if I move forward with the MILVS ... for science ... and the children

I'll admit, the "250 Challenge" is difficult to ignore.

You're in a great position with BPC, since they're the most qualified to work with the MILVs and their re-tunes are so reasonable.

All this is very insightful and really appreciate your efforts. I've been through the dyno/tune/dyno/tune process on a previous car so I understand where you're at! Also, agree on the louder exhaust mods - no thanks. That's the area of least gain and highest annoyance. Do you happen to have a tune only vs tune/3SIM/headers graph? Should show a big transformation!

Now, if I could just get my damn valve cover to start leaking...the MILVs would be purchased and installed.

[6ixSpd]

I wish BPC was local, I'd get a full dyno tune late-winter in a heartbeat.

I'm installing the 3SIM on Friday and aiming to get headers around XMas followed by MILVs shortly after. By spring, I want my 328i to be a different animal.

It's pretty much stock right now, except for the AFE sealed intake and a Magnaflow muffler with resonator deleted. I sorely crave more power out of this car, I hope I can get another 40whp/tq. It would be a HUGE bump and a great iteration of BMW's last N/A inline 6 - a culmination of decades of perfecting this platform in my eyes.

I've always said a 280-300 crank HP N/A E90 6MT RWD would be the best damn daily driver, it's too bad BMW never made it. This will be the closest thing I can get to that dream, before shifting my mod-budget/focus back to the M3

[Bob@BPC]

Originally Posted by UncleFester

That accurately describes me.

I do have a PE muffler on it now. It's loud above 3k rpm. Great on the track so I can hear the engine with a helmet on and the windows open. A bit much for the street. I have no plans to remove the secondary cats and resonator. (note: the BPC YouTube video I linked has the stock exhaust.)

I'll be sure to include dyno runs if I move forward with the MILVS ... for science ... and the children

I'll admit, the "250 Challenge" is difficult to ignore.

250rwhp? Been there, done that

Project Alice before the turbo

MODS
- auto to manual swap
- BPC Tune DUH
- full custom exhaust & AA header
- custom cold air intake
- N54 intake manifold & Throttle body

[CobraMarty]

Tada!! 258rwhp!!

But you did trade some TQ for HP with that N54 IM + TB.
For a racecar (258hp/220tq), great, for a daily street car (238hp/233tq), not so great.

Really want to see 3IM + BPC tune + headers and exhaust + CAI and bump up the TQ.