[Transport3r]

Has anyone attempted to fit bigger twins to the N54 rather than the reworked stock housings? Is space an issue in our engine bay?

I'm talking about something like a Garrett GT22 or GT25 sized housing. I feel it might be the perfect middle between the tiny TD03 housings and the mythical big single setups.

thoughts?

[O HELLA BMW]

With $$$ anything is possible

[dlbrooks18]

I'm wondering the same thing, is it the space cause I would rather purchase bigger twins than rework the stock housings..

[quattrosaint]

Originally Posted by joshuo

Has anyone attempted to fit bigger twins to the N54 rather than the reworked stock housings? Is space an issue in our engine bay?

I'm talking about something like a GT22 sized housing. I feel it might be the perfect middle between the tiny TD03 housings and the mythical big single setups.

thoughts?

Wow I did not realize how small are turbos are that a GT22 is consitered a big turbo. They must be the size of a big mac.

[Transport3r]

Originally Posted by quattrosaint

They must be the size of a big mac.

more like a mcdouble lol

[FORCED AIR]

not even the size of a big mac...TD03 is a little turbo...most bikes run larger when they go turbo...but it does give us instant spool.

I to would be more interested in a larger twin setup to retain some quick spool characteristic. Possible even going to a sequential setup. I like our low and midrange.

[quattrosaint]

Originally Posted by FORCED AIR

not even the size of a big mac...TD03 is a little turbo...most bikes run larger when they go turbo...but it does give us instant spool.

I to would be more interested in a larger twin setup to retain some quick spool characteristic. Possible even going to a sequential setup. I like our low and midrange.

GT2871R's would be perfect if they fit. They will spool up very close to stock since they are twin scroll, dual ball bearing and not run out of gas up top. Just a guess but I could see 650 plus wheel hp with supporting mods.

[shock2314]

thats the turbo i run on my sr20det powered altima, great turbo, fast spool.

Originally Posted by quattrosaint

GT2871R's would be perfect if they fit. They will spool up very close to stock since they are twin scroll, dual ball bearing and not run out of gas up top. Just a guess but I could see 650 plus wheel hp with supporting mods.

[Brey335i]

It's the design of the engine and the tight space constraints that prevent an easy swap

[Transport3r]

Originally Posted by quattrosaint

GT2871R's would be perfect if they fit. They will spool up very close to stock since they are twin scroll, dual ball bearing and not run out of gas up top. Just a guess but I could see 650 plus wheel hp with supporting mods.

Would the twin scroll wastegate setup cause tuning issues though?
The It'll be like managing a twin sequential setup (if that makes any sense whatsoever lol )

[lamia2super]

ASR engineering turbos are char upgrades(garrett chars i think)

[ScorpionT]

Originally Posted by quattrosaint

GT2871R's would be perfect if they fit. They will spool up very close to stock since they are twin scroll, dual ball bearing and not run out of gas up top. Just a guess but I could see 650 plus wheel hp with supporting mods.

The 2871R is not twin scroll, they come in open T25 and T3 housings. Two of the smaller 49mm compressor versions would do pretty well, same for the 2860RS. The larger 51mm compressor versions would be overkill, sufficient for 800+whp combined.

Originally Posted by joshuo

Would the twin scroll wastegate setup cause tuning issues though?
The It'll be like managing a twin sequential setup (if that makes any sense whatsoever lol )

No, it wouldnt. Twin scroll setups are controlled no different than single scroll would be.

[plague]

someone needs to pull the trigger on this. i think AR design should approach a larger twin turbo upgrade. i know theyre working on the single turbo but id like to see this as well.... somebody.

[Trojan4evr]

well, sounds like ESS is comming out with a kit for N54. but yeah, space is a big problem.

[2Hip]

I have what I think is a stupid question but I'll ask anyway.

Is it possible to have 1 smaller turbo for lower RPM spool and a larger for high RPM spool?

Best of both worlds but I'd imagine the ECU would have a tough time managing the different boost levels.

[Transport3r]

Originally Posted by 2Hip

I have what I think is a stupid question but I'll ask anyway.

Is it possible to have 1 smaller turbo for lower RPM spool and a larger for high RPM spool?

Best of both worlds but I'd imagine the ECU would have a tough time managing the different boost levels.

It's not a stupid question at all! It does exist and is in fact quite common. In fact the N57 (335d engine) uses a setup like that. I'd say it is definitely possible, the hardest part would be to make sure the engine knows to not open both wastegates simultaneously?

[Ox11]

joshuo: iirc there were shops that attempted to go for the bigger twin set up, however space was the constraint. there is very little room to work with down there.. but hey maybe with enough time and money it may be possible!

[2Hip]

Originally Posted by joshuo

It's not a stupid question at all! It does exist and is in fact quite common. In fact the N57 (335d engine) uses a setup like that. I'd say it is definitely possible, the hardest part would be to make sure the engine knows to not open both wastegates simultaneously?

Thanks for the info. Keeping one existing stock turbo for the low-end and a slightly bigger turbo (if it will fit) for the top-end would seem to be a very interesting and cost-effective alternative if the ECU programming were to be created.

I know from my Suby days there was always a trade off with a single larger turbo but I love the idea of staggered turbos to cover the entire RPM range. Along time ago on the Suby board there was talk of a turbo/supercharger (single unit) that was supposed to be belt driven for low-end and exhaust driven with a clutch for high-end. Great idea and not sure why it's not used. I've definitely seen this done with two separate units.

[rader1]

Originally Posted by 2Hip

Thanks for the info. Keeping one existing stock turbo for the low-end and a slightly bigger turbo (if it will fit) for the top-end would seem to be a very interesting and cost-effective alternative if the ECU programming were to be created.

I know from my Suby days there was always a trade off with a single larger turbo but I love the idea of staggered turbos to cover the entire RPM range. Along time ago on the Suby board there was talk of a turbo/supercharger (single unit) that was supposed to be belt driven for low-end and exhaust driven with a clutch for high-end. Great idea and not sure why it's not used. I've definitely seen this done with two separate units.

EMD(formely owned by GM, now owned by CAT) actually use this same idea on their diesel locomotives. At low RPMs the turbo is driven by a gear set and then when there is enough heat to get the turbo spinning it would disengage from the drive gear. Ofcoarse there is a lot more room in the carbody of a locomotive to implement a setup like this, but the concept itself worked REALLY well

[Jeff@TopGearSolutions]

It can be done, but somebody needs to make a new exhaust manifold.

Aside from that connecting back to the hot side of the intercooler and use of oil and coolant lines is another thing. (if they are even used at all).

The real dilemma is fuel, as we can't support over 450WHP without methanol as a fuel band-aid.

Which brings you to the next upgrade needed which is likely secondary port fuel injection.

After that you will likely want an LSD to put the power down and upgraded axles so add that to the list

[Transport3r]

Originally Posted by Jeff@topgearsolutions

It can be done, but somebody needs to make a new exhaust manifold.

Aside from that connecting back to the hot side of the intercooler and use of oil and coolant lines is another thing. (if they are even used at all).

The real dilemma is fuel, as we can't support over 450WHP without methanol as a fuel band-aid.

Which brings you to the next upgrade needed which is likely secondary port fuel injection.

After that you will likely want an LSD to put the power down and upgraded axles so add that to the list

Of course this would go paired with all the necessary supporting mods, I was just wondering if anyone is thinking further ahead than RB's and ASR's, as good as these may be. I can't imagine, if people are fitting a GT35X with a monstrous manifold, how we couldn't fit a set of GT25's or GT28's

Maybe if the manifolds were to be designed as to bring the turbos down lower, there would be more space (since the engine is canted to the passenger side).

[FORCED AIR]

That is what I was thinking...one in place of the current two area and the second sitting lower where the stock primary cats are.