S54 swap questions and concerns

[jink0619]

The 044 is overkill unless you're going for lots of power, I believe it is E85 friendly too. This is my choice for the N54 swap since I'd like to take advantage of E85 mixe.

The in tank pump will become the Latter pump, then to the surge tank with 044 pump, then to the N54

Some that has this setup in their m3 with either a rebuilt s14, euros50 or s54 hasn't had any issues. So I'm gonna give it a try if it's overkill like u say, then I'll replace the intank with a walbro255 and delete the external pump.

I've been waiting for someone to swap an N54 into our cars, this will be very interesting.

[the imitator]

The 044 is overkill unless you're going for lots of power, I believe it is E85 friendly too. This is my choice for the N54 swap since I'd like to take advantage of E85 mixe.

The in tank pump will become the Latter pump, then to the surge tank with 044 pump, then to the N54

[jink0619]

Bosch 044 Fuel Pump Specs:

Bosch Part Number: 0580254044
Minimum Current: 12 Volts
Operating Pressure: 72.5 PSI (5 Bar)
Minimum Flow @ Outlet: 80 GPH (300 LPH)
Fuel Pump Location: In-Line
High Temperature Reduction: 8 GPH (30 LPH)
Weight: 1030 Grams (2.27 Pounds)

I will be using this and th stock intank pump for my setup.

[dmjensen]

Make sure the pump you use has the proper fuel volume rating for the s54, I can't remeber the spec for Mcars but out regular cars it's 1 liter per 30 seconds.

[jink0619]

very useful info Nando thanks, give me an update when you get results. When preparing for this swap I've done a ton of research but it's always the little things that gets you stuck and scratching your head for answers. I'm hoping to have everything covered in this thread so that anyone wanting to do this swap will have all the info available and thanks to all you guys sharing your knowledge, we can make it easier for the next guy.

[nando]

the pressure is controlled by the regulator, not the pump.

When you increase pressure, volume decreases. The first question is, is the pump identical? The second, more important question is - can the pump flow enough volume at 5 bars? I have the feeling the answer is yes.

It makes sense to me that they would just make one type of pump for many different models instead of continuing to manufacture the same pump from 30 years ago. The car won't care if the pump can actually flow a lot more volume at a higher pressure than it needs, pressure is controlled by the regulator and volume by the injectors so it works out to be the same.

anyway, I just wanted to put it out there as a potential option for people doing a swap like this. I could very well be wrong, but we will see. :)

[jink0619]

Hmmm that's very interesting, but with it looking identical will it perform the same, cause it could be lower pressure for the e30s. I do wish I had a late model tank so I'm able to go single pump, things would have been so much easier.

[nando]

the bosch pump is probably overkill, but that would work.

I posted this in another thread - but a while ago I got an E46 M3 pump to retrofit into my original fuel pump carrier (I have a late tank/single pump). I finished it but never put it in the car - well, I went to do that last weekend, and when I pulled the pump I had in the car (which I bought brand new just a couple years ago), I realized they'd updated the pump carrier and sock on the newer pumps. the E46 M3 pump would have been a direct fit into the later pump carrier & E30 sock. In fact, the E46 M3 pump and the updated E30 pump look identical - so I decided to just leave the new pump I had in the car and not use the M3 pump. We'll see if it holds up to 5 bars, I have a hunch it will be fine because it's likely the same pump anyway.

[jink0619]

I believe the M3, as well as early E30s, had a dual pump system, where the in-tank was a low-pressure (high volume) lift pump, and the second pump underneath the car was the high pressure pump.

I don't think the car will run right if you put a high pressure pump in the tank, while retaining the E30 high pressure pump.

I am not sure what the solution to your problem is, because I'm uncertain as to how the pump plumbing is in early cars.

After farther research, there are some options I can go with that will allow enough fuel pressure for the s54@5bar. This is just for cars with Duel Fuel Pumps, The late models just need to replace the intank pump.

1-keep intank stock and replace external pump with a inline Bosh004 or walbro
2-replace intank with a high pressure pump and delete external pump
3-replace early model gas tank with late model and convert to single pump

I'm going with option 1, because the intank pump is used as a lift, lifting up fuel for the external pump, I'm deciding to leave it alone and replace the high pressure external pump to a inline Bosh004 which is a direct fit. Now just hoping for no fuel starvation and finally headaches over and can continue with swap.

Edit* Im wrong about the Bosh004 being a direct fit, you will need to find two fittings one being an 8mm 5/16" and 18mm 1/2" I found them on EBay.

[jink0619]

Thanks for the responses guys, man what a headache!!! I really don't want to replace the tank to go single pump. So if I can't put a high pressure pump intank, then would replacing the external pump with something with higher pressure work? I think walbro makes an inline pump so what intank pump could work with it?

[328ijunkie]

the 318is has a single in-tank pump though

the dual pump setup is actually more efficient but it seems like they have more starvation issues due to how the tank is designed.

Sorry meant to say 318 retains early/small tank, although does have single pump

[nando]

the 318is has a single in-tank pump though

the dual pump setup is actually more efficient but it seems like they have more starvation issues due to how the tank is designed.

[328ijunkie]

E30 M3 and late model 318s are just like <=87 325i/e's Little POS lift pump (high flow low pressure) in tank and high pressure low flow external where late models have fuel filter...

[nando]

unless you want to swap to a newer tank and single pump, it might be better to get a new stock lift pump and use a higher output external pump instead.

you could use the high output internal pump + a stock high pressure external pump, but that would be way overkill. Essentially what that will do is make the external pump a lot more efficient and it will flow a lot more fuel than you need.

[FredK]

I believe the M3, as well as early E30s, had a dual pump system, where the in-tank was a low-pressure (high volume) lift pump, and the second pump underneath the car was the high pressure pump.

I don't think the car will run right if you put a high pressure pump in the tank, while retaining the E30 high pressure pump.

I am not sure what the solution to your problem is, because I'm uncertain as to how the pump plumbing is in early cars.