I thought I would make this thread to try to help folks new to the M235i platform and that want to know how to make it faster. I've learned some useful information through some personal experience and communicating with Terry of BMS both online and in person. Many of the info here would have been helpful to me 6 months ago. I'll try my best to improve the post as well.This thread will only be about the piggy back tunes.
The first decision I suggest you to make is whether or not you are getting or plan to get a downpipe down the line.
Path #1: "No Downpipe!"
You may want to consider this path over the other for the following reasons:
- Best HP/dollar value or "Bang-for-Buck"
- Very easy to install or uninstall mods for dealer visits
- Don't have to touch the Catalytic Converter
- Lower chance of getting codes or lights on the dash
- No need to update or tweak your tune
What you need:
Dyno charts show 323whp and a whopping 365wtq! This will be about 30 more whp and about 35whp over stock, not bad for a few hundred bucks.
This is a very comfortable setup as the car will be making power well within its capabilities. Just choose a plug and play tune such as the BMS Stage 1 or the aFe Scorcher, both popular and very similar products with similar results. The Dinan Stage 1 may also be something to consider if you value your warranty as Dinan offers a factory-matching warranty, but expect to pay an extremely large premium for this.
You can pair one of these tunes with its respective intake for power and a lot of sound. I've personally had the BMS Stage 1, the more popular of the two, with the BMS F30 intake. Additionally a catback or axelback exhaust of your choice could be added for pleasure but not power gains.
Stage 1 Tune Options
BMS N55 Stage 1:
http://burgertuning.com/N55_Jb_BMW_P...nce_Tuner.html
aFe Scorcher:
http://afepower.com/shop/details_new...rtno=77-46304&
Dinan Stage 1:
http://www.dinancars.com/product/d44...ries&mid=1183/
RaceChip:
https://www.racechip-usa.com/chiptun.../M-235i-240kw/
Even more STG1 choices:
http://www.2addicts.com/forums/showthread.php?t=1110399
Intake Options
BMS Intake:
http://burgertuning.com/F30_335_F32_...ke_filter.html
aFe Intake:
http://afepower.com/shop/details_new...rtno=51-12202&
Dinan Intake:
http://www.dinancars.com/product/d76...ries&mid=1183/
Injen:
http://www.x-ph.com/injen-short-ram-...-335i-435-n55/
Path #2: "I want a Downpipe!"
Why you would want to take this path?
- Even more power
- The effective use of E85 Mixes and Race Gas
- Awesome spooling sounds from being catless
What you need:
- EWG N55 F series BMS JB4
- Your choice of a downpipe
- An Intercooler (Recommended)
- A Chargepipe (Recommended)
Now this is where things can get more expensive and risky as you can push the car closer to it's limits. With addition of a downpipe, the car will no longer have a "bottleneck" effect going on due the elimination of the restrictive factory cat. The turbo will be able to run higher boost and spool much quicker for a gain of 40-80whp and 50-90wtq more over stock depending on tuning and fuel.
Pick up a downpipe such as the Evolution Racewerks 4in Catless DP, fitment was spot on for me. I've heard that Shifteck isn't bad either and also made in the USA; VRSF is made overseas. The new PDU downpipe looks to have a fantastic design. I would *personally* advise against catted downpipes. Save your money here because chances are you won't pass smog anyways, and if you do then the downpipe isn't very effective.
You will also need a BMS EWG JB4 for F series in addition to the downpipe. The M235i is equipped with an Electronic Wastegate that is also found in 2014+ 335i and 435i, therefore the "EWG Specific Board" should be used. And to my knowledge, the JB4 is the only tune that will allow for EWG control. The JB4 will tune the car to be able to take advantage of the downpipe as well as automatically clear the light that will occur from being catless. Additionally, the JB4 will allow you to run different "Maps" and fuel for different power applications. Such is the reason why I advise against spending the extra money on a JB4 unless you go with a downpipe, you would only be using Map 1 which has practically the same gains as the BMS Stage 1 (or other Stage 1 tunes I mentioned) but you add the complications of user adjustments and firmware updates.
Do not pass on the USB datacable as you MUST
datalog your car with this setup to make sure that your car is running optimally, and yes you will want a USB extension cable. Also purchase the $35 "
EWG Harness Adapter", this is currently under upgrades but should be considered necessary because it lets you consistently hit target boost. Without this, you will be only able to effectively run Map 1 or 2 on the JB4. You will also need the recently released "
F Series OBDII CANBus Interface" upgrade because all updates now will be using an OBDII Firmware. FlexFuel wires are standard now on JB4's currently sold.
Some nice upgrades to have are an intercooler and chargepipe upgrade from ER. I suggest going with ER as their chargepipe best fits their own intercooler. Map 7 in the JB4 is the most aggressive tune for the car and pretty much warrants these two upgrades. The intercooler helps makes a little power, cooling, endurance for turbos + engine, and just all around beneficial. The chargepipe (CP) will not give you gains but under Map 7, the stock plastic CP will eventually see failure. There have been instances of stock N55 cars with failed CP. The way I look at it, being able to run Map 7 should be the reward of doing these upgrades. Familiarize yourself with the difference Maps
here.
Lastly, taking this path will require you to be a more active and knowledgable than the the other path. The JB4 firmware for our cars I still consider as beta since there is much more room for improvement, N55 F series cars are running very lean. You will need to be in touch with what's going on on N54tech and be prepared to run into codes. If you've made it this far in the post, then you can see how much more involved and nuanced this path is. Isn't it crazy how one downpipe warrants so many more upgrades? Though I can say that it is a very rewarding experience
Tune
BMS JB4 (Choose EWG option to get the EWG Specific Board):
http://burgertuning.com/N55_JB4_F_ch...BMW_tuner.html
http://www.burgertuning.com/N55_JB4_upgrades.html
Catless Downpipes
Evolution Racewerks:
http://www.evolutionracewerks.com/node/213
PDU:
http://www.performancedesignunlimite...tless-downpipe
Shifteck:
http://www.ebay.com/itm/Shifteck-N55...1fd94c&vxp=mtr
Fabspeed:
http://www.fabspeed.com/bmw-m235i-f2...pass-downpipe/
VRSF:
http://www.vr-speed.com/vrsf-ceramic...0-f32-f33.html
Intercooler and Chargepipe
ER IC and CP:
http://www.evolutionracewerks.com/catalog/212
Now that you know what it takes, hit up the vendors
