F30 340i - Pt.3 - Cranking up the Power to Stage 2+

Part 3 of this series will finally bring us into some performance modifications! We'll be going in depth on the intakes, donwpipes, fuel upgrades and tunes available on the market.

There has been great debate over which is better; Stock Airbox or Aftermarket Intake System. The stock airbox is very well designed and proven to work very well for those on stock turbo. There are upgrades to the factory intake system to make it work much more efficiently.

For those who are unfamiliar, the B58 air intake path goes the following way: Intake Box (Filter) > Intake Coupler > Turbo Inlet > Turbo. Although it may seem like a short path, the OEM parts have built in resonators and muffling chambers which results in a reduced sound and obstructed airflow.

Upgrades to the stock intake system would be to do a Drop In High Flow Filter, Upgraded Coupler and Inlet Pipe.

Below is a side-by-side of the Upgraded Stock Intake System (Left) vs. Stock/Factory (Right).

The Upgraded Stock Intake System

Results are quite surprising. The BimmerPro Drop-In Filter was added first. Just with that upgrade, the Intake sounds were much more noticeable and you get a hint of that turbo flutter sound!

Next the BMS Intake Pipe Coupler and DINAN Turbo Inlet has been added. This resulted in a louder induction noise and turbo noises are much more noticeable even in the cabin. This combination is our best choice for stock airbox setups!

Aftermarket Intake Option: MAD

Now onto the aftermarket options. There won't be a huge increase of power vs the Upgraded Stock Intake system we just spoke about. The main benefits for having an aftermarket intake is mainly for sound and if you have an upgraded turbo.

* MAD INTAKE PIC

With the many choices on the market, it is important to pick the right intake. We opted for the MAD intake as this features a High Flow Intake Cone, Upgraded Coupler and a Heat Shield. The Heat Shield is very important as this will help keep the heat generated from the turbo away from the cool air pulled from the front scoop that is integrated from factory (M Sport Bumpers).

It is also worth noting that the Dinan Inlet Pipe will also be a good upgrade, as the MAD intake connects to the OEM Inlet Pipes.

Having had both of these setups on the 340i, the MAD intake does have much more of a wooshing sound and is much more audible compared to the Upgraded Factory Intake system. We did not notice any increase in performance vs the two.

Downpipes

Next we will talk about Downpipes. We want to start by saying we’ve tried almost every downpipe available for B58 on the Market.

This 340i specifically had 3 aftermarket Downpipes on it: VRSF 200 CEL Catted, VRSF 4.5” Catless and ARM 6” Catless.

The VRSF 200 CEL Catted is the best choice for those who want the extra sound, without the smell and all the while retaining a deep sound.

The VRSF 4.5” Catless does have a more immediate throttle response due to not having a catalytic converter in it. This in turn increases acceleration time, but leaves you with the infamous catless smell and a much louder tone (which we found raspy paired with the MPPSK exhaust).

The ARM 6” Catless is the best choice for our setup. It will flow the same as the VRSF 4.5”, however the 6” middle section tremendously deepens the tone (almost like the Catted) and pairs extremely well with the MPPSK. Watch our video here.

*TU PUMP PICTURE

Fuelling Upgrades

There are so many fuelling upgrades for the B58 and it really depends on what path you choose. We won't go in depth for the upgrades available, as that can be saved for a whole segment later on.

What we are focused on for this segment is getting the 340i to Stage 2+. For that, we will require a High Pressure Fuel Pump. There are many options on the market and we decided to go for the simplest option which is the TU Pump.

The TU High Pressure Fuel Pump (HPFP) is an OEM upgrade, as this comes from the GEN 2 B58s, dubbed TU. The TU Pump flows much more than the GEN 1 B58 HPFP and will allow for higher Ethanol Fuel blends.

Tunes

It is important to note that a Bench Unlock will most likely needed to be able to tune the car. For peace of mind and precaution, we replaced the spark plugs and injectors before the tune, as they will be working harder than before. 

There are many options for tuning platforms for B58, most commonly Bootmod3 (BM3) or MHD.

At BMG Performance, we sell both and can't objectively say one is better than the other. It will all come down to the user's preference in interface and also the tuner's preference if you plan on doing custom tunes.

In this case, we chose MHD for this build and loaded up the Stage 2+ OTS (off the shelf) tune. Bear in mind that Stage 2+ requires a minimum of 93 Octane for the MHD platform.

In conclusion, the modifications that stuck on the 340i are:

• MAD Intake
• ARM 6" Catless Downpipe
• TU High Pressure Fuel Pump
• MHD Tune

Stage 2+ is quite the power increase from the factory M Power Kit tune. With this amount of power, it is important that the rest of the car (suspension, tires, brakes) are in good condition and capable for this newly increased power level.

Stay tuned for more to come.