In these days I’ve been busy installing the turbocharger on my 320ci E46. The plan is to run a boosted m54B22 until an m54B30 will be ready to be swapped in. The Gt30 turbo will be limited to 0.5 Bar as I don’t know the limits of the B22 engine.

Let the build begin!

To start with, I removed both manifolds, front bumper, headlights, radiators, and such in order to have enough space to work on it. I also had to remove Camshafts cover and lower the pan a bit in order to remove the timing chain cover, which needs to be drilled in order to install an oil return fitting on it.

To remove this timing chain cover, you also have to remove cam pulleys and vanos system.. so it needs to be retimed after (you need the tool). This car is definitely HARDER to turbo than my previous project. I don’t want to scary you but this is a serious job and took me a lot of brain usage (and also reading of the workshop manual)

This is how much you need to strip your car in order to install a turbo.

In the above image you can see how much stuff I had to remove in order to work efficiently on the car.

I have to give you some advice:

  • Do not remove cam pulleys if you’re not at TDC on 1st cylinder (lock flywheel with a 8mm allen wrench)
  • Pay attention to not damage rear coolant hoses and timing chain cover
  • While you’re at it replace all the replaceable gaskets and stuff that might be worn
  • Remove CCV system and put a catch can instead

Small parts overview

In this picture you can spot the FTWL manifold I used which I bought from Alexander Hopwood of Hopwood Motorsport. Fitment was good, construction is also very good as it seems to be thick enough and welded fine. Future abuse will tell how stout it is, i’ll keep you updated.

As you can also see installed on it there’s a 50mm external wastegate with a 0.5 bar spring on it.

The injectors I’ve chosen are Bosch 0280158123 which are used by Porsche. These are 627cc/min at 3.5 bar fuel pressure. Pretty big if you ask me but these are cheap compared to other injectors. Only bad thing i’ve found about these, is that they’re load. They sound like small relays ticking all the time.

Gt30 knockoff

The chosen turbo is a GT30 knockoff. This features a t3 flange and god knows what else. Seems to be a replica of the Garrett gt3076 but on journal bearings instead of ball bearings.

The intake is made with universal kits, with some cutting, grinding and some brackets fabrication. Basically from the turbo outlet the charge line is 51mm (2″) then is increased to 63mm (2.5″) until the intercooler when it becomes 76mm (3″); stock 320/328 MAF (750kg/h i believe) and Throttle body is 76mm so the rest is all 76mm tubes and couplers. When using Audi RS4 MAF (1600 Kg/h) or stock m54b30 MAF (1024 Kg/h) you have to use 2 reducers 89mm->76mm (3.5″ to 3″) because these maf cases are 89mm. Anyway I started with stock MAF to get more confortable with the ECU before messing a lot with the software, putting a different MAF requires intensive recalibrations.

Oil return was made with An10 fittings and hose, with a bug welded into the timing chain cover. I would not put into the oil pan as in this engine it gets completely filled and my concern (also proved by some people) is that it will not drain and cause oil cocking on turbo seals

Turbo oil drain on timing chain cover
Downpipe fabrication

The only part that required a lot of fabrication is the exhaust. I decided to fabricate it all by myself using my Mig gas welder. It was a PAIN because i haven’t any lifter so i worked on jack stands and I had to work in bad positions, anyway it came out pretty well and it does sound good. It’s made all with 76mm stainless steel tubing and vband flanges. What I can tell you is that the exhaust sits low if you decide to go 1 pipe that big and if you actually have an RHD car (right hand drive) there will be the steering column in the downpipe way, so using a 76mm pipe will not be easy. I know somebody managed to do it but I believe you could also get well with a 63mm pipe.. Anyway I already fabricated a 76mm exhaust and I’m pretty happy with it. The first part of the exhaust is solidal with the engine: I modified the stock bracket that goes to the transmission. The second part of the exhast, is suspended with rubber hangers, using stock holes to fabricate some brackets to keep the rubber hangers up.

Second half of the downpipe, with bracket to transmission.
Exhaust bracket to hold the hanger to the chassis side

Car is ready, now what? ECU Tuning and gauges

After all the assembling, it was time to tell the ECU that we have bigger injectors and one blower that breathes… One post wouldn’t be clear and a lot of stuff must be done in order to get the car running well with all these mods.

To understand how the ECU works and what’s involved on tuning it, of course you must have a good background and also have a good reading of forums and this website

I want to say thank you to all the guys who spent a lot of time on writing the xdf and definitions files for us to tune by ourself these magnificents ms4x ecus. Also the contributors who wrote thousand pages on the forums for us to learn, thanks a lot again.

Ecu tuning is something delicate and requires you to understand very well how the engine works, what’s the air fuel ratio to target, how to avoid engine knock, ignition timing and so on, so if you’re unsure about something STUDY a lot or go to a professional.

To get it running well it took some hours but now it idles pretty well, runs great and has a very few things to address.

In order to monitor what’s going on into the engine I installed some gauges: of course my lovely Wideband, EGT (exhaust gast temperature) gauge, Oil temp gauge (not really needed as the engine already has one but this gives you immediate reading so Idecided to use it) and of course BOOST gauge!

Gauges with custom dash

Of course I also fabricated the holder with some sheet metal. Wideband is temporary as I use it to tune other vehicles so it will be removed when the tuning will be finally sorted.

Final observations:

Car runs pretty well but it’s certainly underboosting as the gauge only shows 200 mbar going in. It already pulls strong at that pressure and pulls about 550 Kg/h of air but I’m gonna troubleshoot it and turn up the boost. The only problem is that I had no time to work on it. I will post a video of it running very soon, stay tuned! Thanks a lot for reading and if you have any question feel free to contact me.