E46 330i Automatic - M54B30 Turbo

[dburt86]

6870, now we are talking

[PEI330Ci]

Seeing how the 6466 spools with your manifold, 6870 wouldn't be all the laggy. For under 750whp tho, Id choose the 6466 or its just wasting powerband.

0.84 a/r or 1.00?

[NOTORIOUS VR]

0.84 a/r or 1.00?

What's your goal for WHP? I don't believe a .84 would hold you back much or at all even @ 700 or so, the precision turbine wheels flow well.

[Butters Stoch]

0.84 a/r or 1.00?

1.0 is what I'm using. I wouldn't go smaller unless I had smaller displacement. Say under 3.0.
I did a ton of thinking about the 1.0 vs the .84.

I think the .84 is good for small displacement high rpm applications.

[pbonsalb]

How about a 0.92 IWG 9174 or 9180 with EWG as well? The best response of an 800 rwhp turbo.

[PEI330Ci]

What's your goal for WHP? I don't believe a .84 would hold you back much or at all even @ 700 or so, the precision turbine wheels flow well.

500 wheel torque

1.0 is what I'm using. I wouldn't go smaller unless I had smaller displacement. Say under 3.0.
I did a ton of thinking about the 1.0 vs the .84.

I think the .84 is good for small displacement high rpm applications.

How about a 0.92 IWG 9174 or 9180 with EWG as well? The best response of an 800 rwhp turbo.

But will it fit.

The E46 is different than the E36....I'm having an issue getting the GTX30 to fit.....

[chikinhed]

The EFR 9180 is huge compared to the GTX3582R and almost double the weight.

[PEI330Ci]

With a GTX3582R GEN2, I would be using the same turbine housing size and compressor housing size. None of the pipe work would have to change.

[pbonsalb]

It would be nice to not change much with the turbo swap. The driving time versus working on the car time ratio has to be balanced. For 500 lbs rwtq you have some good options in the 62mm size with 0.82 back housing.

[wazzu70]

Be the first to try the GTX3584RS? Might fit similarly which is a bonus.

[Butters Stoch]

Be the first to try the GTX3584RS? Might fit similarly which is a bonus.

Very expensive for the goals.

[someguy2800]

This isn't exactly a budget build.

[Butters Stoch]

I get that. But poor choice of turbo for goals. Those are like a 6862 and rated for 1000hp high pressure applications. It will make the power, but will have less power under the curve.
Maybe just grab a 6262/6466 or reg 35r and gold plate the compressor housing. That will meet goals, more power under the curve and cost the same. Win win win.

Any mid frame precision, Garrett will be PNP for what he has, exception will be removal of coolant lines with the precision. Although an 8374 iwg would probably be the best choice. But most work.

[NOTORIOUS VR]

A GT3582 should be able to do 500 wtq almost to 7k, I would assume the GTX would do it easier.

For a bolt on swap that would be the best bet to me.

But honestly, if I had to buy a new turbo these days I'd go with BW. They're solid units with great designs... not even the EFR line, but even their AirWerks line S300-E has some serious potential with minimal cost.

[PEI330Ci]

Be the first to try the GTX3584RS? Might fit similarly which is a bonus.

I contacted ATP, and they have a twin scroll 1.06 A/R housing for the GTX3584RS.

I suspect it's exactly the same housing that I have on the car right now, but machined for the larger turbine wheel.

[pbonsalb]

Dont do a 1.06 for 500 lbs rwtq.

[PEI330Ci]

Why do I think I need a bigger turbo?

The data below is from an approximately 13 minute test drive. I'm looking at mass flow through the engine,(Where I've done a rough calculation to show HP and Tq) inlet manifold pressure, and exhaust manifold pressure.

Overview of the test drive:



Zooming in, we see that at 4300 RPM, inlet manifold pressure equals EBP:



Zooming in a little further, the graph below covers 186 samples of EBP at a sample rate of 10 Hz:




Here are is the same "186" sample period shown as estimated HP and Torque vs EBP:



The "+" curser marks the point at 4300 RPM where inlet manifold pressure equals EBP.

What the data shows is that mass flow per combustion cycle plateaus at 4300 RPM, and then exhaust back pressure increases with RPM. In other words, I've hit a choke point of this combination at 15 PSI, and 4300 RPM. Above that point, the engine is not really making more power.

This parallels what my seat of the pants driving experience has been. The turbo spools up to 15 PSI of manifold pressure, then it feels like the engine lays over as RPM increases. Running off just the WG spring, or approximately 11 PSI of boost, the engine felt a lot stronger up top. While I don't have a fair apples to apples comparison run at the drag strip, I ran 118 MPH with the engine running "Full" ignition timing at 11 PSI of boost. When I turned the boost up to 15 PSI for the last trip to the track, the engine felt weaker up top, and I only ran 114 MPH. This was probably a combination of less timing due to the increased manifold pressure (Ignition map) and also knock control reducing timing.

In short, the engine has been recording more inlet manifold pressure, because there was an exponential exhaust restriction above mass flow of 2200 lb/hr.

Here's what all 13 minutes of driving looks like:

[PEI330Ci]

To be clear, I can get 4000 lb/hr of inlet mass flow, but it takes 30 PSI of exhaust back pressure to do that. Pump fuel isn't happy with that...

Another interesting thing is that I tried to advance cam timing at higher RPM, and the engine felt slower.

When I was tuning just on WG pressure (Approximately 11 PSI), the engine's VE keeps increasing above 5000 RPM. I honestly think that this engine isn't even getting to hit peak torque before back pressure becomes an issue.....

The GTX30 is probably a good 8-10 PSI/400hp turbo for this engine, but it's a choke point above that in my opinion. I also think that the T4 twin scroll is probably a waste on this turbo.

[PEI330Ci]

Dont do a 1.06 for 500 lbs rwtq.

Can you explain that please?

[PEI330Ci]

This is the data from my last trip to the drag strip running 15 PSI target manifold pressure:

[pbonsalb]

Because you can make 550 lbs rwtq with a 0.82 GT3582R on an S52 on pump gas plus meth at about 24 psi tapering to 21 psi at peak rwhp. Responsive and does the job. Even more adequate for your 500 lb goal. I would not leave response on the table using a bigger housing.

[PEI330Ci]

Because you can make 550 lbs rwtq with a 0.82 GT3582R on an S52 on pump gas plus meth at about 24 psi tapering to 21 psi at peak rwhp. Responsive and does the job. Even more adequate for your 500 lb goal. I would not leave response on the table using a bigger housing.

I can't find anything but a 1.06 A/R T4 Twinscroll housing for the GT35. Are you sure you're not thinking of a T3 divided housing?

[PEI330Ci]

I've got a line on a GTX4088R, which I'm told is an 800rwhp turbo that's at full boost by 4600 RPM.

The turbine housing options are 0.85, 0.95, and 1.06.

Looking at RPM being used at the drag strip, I don't think 4600 RPM would be a problem:

[NOTORIOUS VR]

Define "full boost"

If the GTX4088 comes on anything like my 4094R I think it will be hard to beat...

[PEI330Ci]

Define "full boost"

If the GTX4088 comes on anything like my 4094R I think it will be hard to beat...

It depends on context.

Here's the full comment from him:

"35r is lit hard at 4000. 4088 is more like 4600, but it hits easier and
doesn't explode the tires. So it depends on your goals."

I'm also looking to throw some nitrous into the mix, so having a turbine/housing combo that can flow a bit more is a benefit to me in the long run.