E46 330d 3 inch downpipe and 2,5 inch backsystem

[bjzwart]

My tuner is specialised in VAG and BMW diesel engines. out of a 1.9TDI, he manages to squeeze around 300BHP... So he figures the 3 liter BMW engines should be capable of around 400BHP. However, he strugles to get far over 300 bhp with that engine. He did however tune a 118d to the extreme for a circuit car and managed 286 out of it, which is not bad at all!!!

My personal target is not 400 bhp, but an 'easy 300'... So I thought every thing I could do to improve, I will. After the intercooler, the exhaust will get it's turn. I've bought a second hand 2,5 inch absorption silinced system with a teribly ugly tail pipe. So first thing was to have the tailpipe changed for a better looking one:

The stupid thing with the standard exhaust for this car is that right after the flexible element in the downpipe, the diameter is reduced versus the rest of the system; The outer diameter is 54 mm, which then goes into the 2,5 inch system which is about 63 mm OD. Since the exhaust gasses are hottest in the downpipe and cooler in the rest of the system and hot gasses need more volume compared to cooler gass, it is wise to start with a large OD exhaust pipe and then reduce as the gassess get cooled down. So instead of using the same 2,5 inch OD pipe for the downpipe, I made one up out of 3 inch.

First the old downpipe on the car (which I had made several years back):

Then it was time to remove it and start with the components that I had bought and made up allready.
I'll be using a hybrid turbo which has the same exhaust connections, so with the old turbo still in place, I made up the connecting pipe and welded the first bend of 3 inch on:

The connection to the rest of the exhaust is a very nicely made cone shaped piece of tube, with the bend to the downpipe attached. My muffler shop had a machine to shrink the diameter of the pipe, going from 3 inch OD to 2,5 inch ID over a length of about 40 cm:

Also, the flexible part is fitted, but not yet welded. This is how it connects to the upper part o fthe downpipe:

After welding everything up, I could nicely compare it with the old downpipe, by putting them side by side:

It's longer, because I didn't want to keep the strange bends in the exhaust where the OEM one connects to the downpipe. It's only there for the particle filter, which obviously was long gone!
The effect while driving is an even quicker spooling turbo, but regarding power output, I did not feel a huge difference (yet). It will come into it's own after the final remap!

 

[Nikhil]

Welcome bud! Look forward to reading the progress on this thread! 330cd I wish we got those!:inlove:

 

[Rayzor]

Looks hot, :inlove:
We dont get so much

 

[Dhp507]

Nice Work :bravo:.............what option did you go with for the hybrid turbo?

 

[bjzwart]

.............what option did you go with for the hybrid turbo?

You'll see in one of my future posts:=):
Next thing is the exhaust manifold, for which I have done some nice work as well...

 

[Nikhil]

where does it boost with the bigger down pipe and exhaust? has it reduced the lag? :=):

 

[Andy1GP]

Very nice that you can shape the 76mm to 63mm in once piece. Wish we could have that over here.

If you can please have before and after tests with the exhaust manifold. Very curious to see whether there are gains to be had at all. Is yours the Stainless or cast manifold?

 

[bjzwart]

where does it boost with the bigger down pipe and exhaust? has it reduced the lag?

There's no real change in the lag, but I notice when it starts spooling up, it gives the boost quicker; hard to explain... It really feels like it's less restrictive. The map in my car still is the original one (I know; amazing... I just love the mechanical stuff and figured it would be wise to do the map as a final icing on the cake). I can really image when there's a remap, the turbo wil have huge benifit from the new exhaust, because now, the pressure is just regulated as if it was stock. When it is tuned on a dyno for specificaly this car, the reduced back pressure in the exhaust system will influence the map, I guess.

The wissling noise has also increased a little. Inside the car, only during accelerating hard or when driving above 180 km/h, there's a difference in exhaust note. More deep, dark which I actually like :inlove:

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If you can please have before and after tests with the exhaust manifold. Very curious to see whether there are gains to be had at all. Is yours the Stainless or cast manifold?

Wow Andy, I've just gone through your E46 thread; awesome!!! I've learned some things as well.
Was there any noticable difference when removing the vacuum lines from the engine mounts?

Anyway, my current manifold is the stainless steel one, but due to the cracking issue (you know about it), I'm going for the cast one. My tuner has been testing tubular manifolds/headers versus cast ones on VAG engines and the only difference is a few more HP in the top range of the revs for the tubular ones; the cast ones had a much more flat and slightly higher torque curve, so they advise not to go for tubular headers. I wanted to go that route, but now chose to upgrade the standard cast manifold of a pre-facelift E46 330d.

Since I'll also be changing out the turbo to a different one, it's hard to tell the difference of the manifold alone; I don't feel like doing the work twice of first only changing the manifold, take it to the rollers and then change the turbo and take it to the rollers again... But I agree that it would be interesting to know the difference from only the manifold. For your piece of mind however, my tuner normally uses the E90 330d manifold on a tuned E46, since it's an improved one...

 

[Andy1GP]

E90 manifold you say... Hmm now you've got me thinking Reason I ask is there is someone on the forum that has loads of experience with the 330d's (netercol) and he has gone through all the routes getting the most of these motors. Hybrid turbo, swapping manifolds, 335d injectors, more boost etc...

We know the cast manifold is reliable but gives you less hp. I'm curious to see what the E90 manifold gives with the stock turbo. And you say you're using a different turbo, also want to see what that's going to be.

Vacuum lines I only did for piece of mind so I know there won't be any hidden leaks ever! Only need to concern myself with the turbo line now which is easily accessible.

Keeping the MAP sensor and charge temp sensor clean made a nice economical gain, and possibly hp gain.

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Oh and another thing to add I have the same downpipe+exhaust setup on my E90 and it's brilliant.

 

[DieselFan]

Have you also considered upgrade to 535d injectors? Not the cheapest upgrade but there are guys on overseas forums running 300HP with injectors remap and dp... What turbo upgrade are you looking at?

 

[spawn616]

The 3.0 injectors have a max output of 240ish hp for the e39 e 46 range so bigger injectors is a must if you want anywhere near 300.

I'm amazed that your tuner got 286hp out of a 118. The most iv seen is 260 from 123d .

Just don't kill your motor but if that does happen maybe look at the entire 335 engine as an option

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[DieselFan]

I would do injectors before turbo upgrade provided you already have the GT2560.

Netercol said he experience surge from the turbo with his hybrid. He then went to stock.

 

[Andy1GP]

I would do injectors before turbo upgrade provided you already have the GT2560.

Netercol said he experience surge from the turbo with his hybrid. He then went to stock.

+1

The GT2560V also has improvements within itself with later serial nmbers. So if get one from garret now it will be better than all previous ones.

 

[bjzwart]

The 3.0 injectors have a max output of 240ish hp for the e39 e 46 range so bigger injectors is a must if you want anywhere near 300.

This is correct for the M57D30 engine, but not for the M57TUD30, which the E39 never received. Luckily, I have the newer motor (M57TUD30), which in standard form can be chip tuned to app. 260ish hp allready.

This is the turbo that I will be using: http://www.turbodynamics.co.uk/shop/mdx537-stage-1-hybrid-turbocharger-for-bmw-330d-x3-p-4869.html

 

[spawn616]

Still do injectors.you can always modify your own turbo to produce more power.have you looked at holset turbos.i think he 35 might a bit big so he or hx 30

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[DieselFan]

The 3.0 injectors have a max output of 240ish hp for the e39 e 46 range so bigger injectors is a must if you want anywhere near 300.

This is correct for the M57D30 engine, but not for the M57TUD30, which the E39 never received. Luckily, I have the newer motor (M57TUD30), which in standard form can be chip tuned to app. 260ish hp allready.

This is the turbo that I will be using: http://www.turbodynamics.co.uk/shop/mdx537-stage-1-hybrid-turbocharger-for-bmw-330d-x3-p-4869.html

Please let us know how that turbo runs. I'm also interested in it.

 

[bjzwart]

In this and this post, I had promissed to give results of my search for power for my 330cd...

After my injectors had failed due to dirt, I had them changed to 535d ones, so my list of tuning upgrades now are:
- Larger front mounted intercooler DIY (also on this forum somewhere).
- 2,5 inch exhaust system
- 3 inch downpipe
- Cast exhaust manifold, flow improved
- EGR removed
- Swirl flaps removed
- 535d injectors
- Hybrid turbo

The result was pretty impressive. Especially without any programming. So on a standard ECU (the car had never been tweaked), it allready made 262 BHP and 538 Nm!!! That's with mechanical tweaks only!

After playing around with the ECU, it made 308 BHP and 676 Nm of torque. The graph from before and after:

I was very, very impressed!!! Driving is like mental with this hefty machine. My other car is a Lotus Elise, which almost seems slow;-)
At the traffic lights, I have never met another car that is quicker. Even the Porsches up till now were slower...

The only issue I have is that below 2800 rpm, the car vibrates like crazy when using all the power. I guess it's the rear subframe and diff. The DMF and clutch both have been upgraded to heavy duty items. Any ideas what it could be and what to do about it? My tuner says they all behave like this when tuned...

 

[spawn616]

maybe retune th lower part of the graph for better drivability i.e. less torque

but then you might also produce less hp

tuning a modded car like this isn't a couple of hours more like a few good days to make it like oem but that might run you out of a lot of dollars

also please include dyno vid and street driving vid or il report you and get you banned for teasing us :crazy laugh:

if you look on your graph your already making 350 plus torque at 1500 rpm so maybe try cut that down a bit or just switch off traction and buy tyres every day