[G30M]

Originally Posted by SwankPeRFection

Pretty much correct. There’s simply not enough exhaust volume to move two larger turbos, depending on size of course. A nice broad power range will always give the best speed gain and time, so you have to figure out how much low end you’re willing to give up and how much rev range will be left over for power production for whatever you’re putting in. This is why an appropriate single setup on the S58 should include a properly designed twin scroll manifold and turbo to go with it. .

i still can't believe that the factory turbos are not twin scroll. any reason for that?

[forcefed]

Originally Posted by g21

i still can't believe that the factory turbos are not twin scroll. any reason for that?

Can't have twin scroll with odd number of runners.

[G30M]

Originally Posted by forcefed

Can't have twin scroll with odd number of runners.

i see

[Blue Angel]

BTW, using a REAL filter is the way to go with a turbo (if you can find one), not an oiled cotton media filter… those are just glorified bug screens. I say that somewhat hypocritically as I have one on a car, but it’s not turbocharged.

I would think a housing could be 3D printed if necessary without too much trouble.

Turbos spin so fast that anything in the airstream will chew them up. Previous comment regarding oil contamination is true as well, and turbo bearings (ball or journal) don’t deal well with dirty oil.

[Dasky_spas]

How have the o2 sensors been holding up?

And with the tune and big single, is power delivery linear or does it just crush you into the seat when boost comes on?

[GT3M2]

Originally Posted by Dasky_spas

How have the o2 sensors been holding up?

And with the tune and big single, is power delivery linear or does it just crush you into the seat when boost comes on?

In order to keep the factory rods alive you have to ramp in boost pretty slowly.

The initial hit is way softer than a turbo car, but it pulls harder, higher up in the RPM range.

-GT3M2

[SwankPeRFection]

Originally Posted by g21

i still can't believe that the factory turbos are not twin scroll. any reason for that?

Yes, because the banks are grouped and not divorced. Basically the front three cylinders pulse exhaust at the same time and the back three at the same time, so each single turbo sees pulses that aren’t compounding. This is why that big turbo manifold is a T4 divorced… three cylinders is on one scroll and the other three on the back scroll. If you look at the exhaust housing, you can see that weld ring on the outside which basically shows that it’s definitely twin scroll, so when the pulses from each of the 3 cylinder groups come into it and push the turbine housing kind of like a zipper sort of. There is no turbulence between the pulses, they all just fall in line and work one after the other instead of all coming into a single scroll exhaust housing like a vband setup usually is where they all collide, so you get what you get. If you look at your manifold runners you’ll see how they’re run and grouped into each side of the T4 collector flange.

This is why I like the S58 much. It literally is a modern day 2JZGTE. Only difference is the turbos aren’t sequential, they’re parallel from the factory. Toyota did that original setup like that because they wanted low end torque from the first smaller one and good power up top from the big one. When people go single turbo on those engines (to do it properly for a strong street and circuit high power setup) you do twin scroll like the OP did, so you get somewhat still good usable powerband and response and high top end power that doesn’t run out of steam.

FYI, the RB26 that Nissan did has a setup on the turbos like the S58 does. Good sized medium power ones built for power from mid to upper stock RPM band.

[McBobby Jr]

Originally Posted by BadBoostedBMWM3

I definitely think the 6870 is the sweet spot with the bigger hot side on the 3.0 L, but, talk to me about the 3.5 L? If I were gaining that replacement, then I would go 7275 as well.

What the available options to stroke/bore the s58?

5150 AutoSport currently makes a 3.4L Stroker Kit for the S58. I’m not sure if a 3.5L kit has been made yet, but it could be in the works.

[2Times]

Originally Posted by Dasky_spas

How have the o2 sensors been holding up?

And with the tune and big single, is power delivery linear or does it just crush you into the seat when boost comes on?

First part of the question… BM3 just released an update which allows you to move the O2 sensor so it isn’t under as much stress… requires the ECU to be sent to Femto again though… I’m not doing that but cool that they’ve added it as an option for single turbo applications

[AhsanU]

My single turbo build is finished up, just waiting on a dyno tune



DOC Race single turbo kit running a Next Gen PTE 6870. Precision RaceWorks port injection fuel rail with ID1050x injectors on stock intake manifold for now. Port fueling being controlled by MaxxECU. Currently also running Precision RaceWork's new standalone LPFP for the G8X, the AFS.425 since I'm not chasing big big power (hence why still on stock manifold too). All installed in a timely manner by M PowerHouse over in Mt. Vernon in N.Y.

I drove her on the base map yesterday and she feels and sounds amazing. Currently awaiting Sameh, @SamehYehia, to dyno tune her on 93 fuel then I'll pick her up. I'll be doing street logging for ethanol blends.

You'll also notice the filter on the turbo - it's essential for the longevity of the turbo and car in general. However, it muffles sound so it'll be taken off during specific occasions. On track days and daily puttering about - filter on. When I go to meets and am with friends - a mesh TurboGuard will be on as I refuse to completely raw dog it haha.

Can't wait!

[2Times]

Originally Posted by AhsanU

My single turbo build is finished up, just waiting on a dyno tune
DOC Race single turbo kit running a Next Gen PTE 6870. Precision RaceWorks port injection fuel rail with ID1050x injectors on stock intake manifold for now. Port fueling being controlled by MaxxECU. Currently also running Precision RaceWork's new standalone LPFP for the G8X, the AFS.425 since I'm not chasing big big power (hence why still on stock manifold too). All installed in a timely manner by M PowerHouse over in Mt. Vernon in N.Y.

I drove her on the base map yesterday and she feels and sounds amazing. Currently awaiting Sameh, @SamehYehia, to dyno tune her on 93 fuel then I'll pick her up. I'll be doing street logging for ethanol blends.

You'll also notice the filter on the turbo - it's essential for the longevity of the turbo and car in general. However, it muffles sound so it'll be taken off during specific occasions. On track days and daily puttering about - filter on. When I go to meets and am with friends - a mesh TurboGuard will be on as I refuse to completely raw dog it haha.

Can't wait!

That’s awesome!! So many different manufacturers (tuner) with the same goal.
Fun seeing the options coming out and being supported for the S58

[G MONEY]

Originally Posted by AhsanU

My single turbo build is finished up, just waiting on a dyno tune



DOC Race single turbo kit running a Next Gen PTE 6870. Precision RaceWorks port injection fuel rail with ID1050x injectors on stock intake manifold for now. Port fueling being controlled by MaxxECU. Currently also running Precision RaceWork's new standalone LPFP for the G8X, the AFS.425 since I'm not chasing big big power (hence why still on stock manifold too). All installed in a timely manner by M PowerHouse over in Mt. Vernon in N.Y.

I drove her on the base map yesterday and she feels and sounds amazing. Currently awaiting Sameh, @SamehYehia, to dyno tune her on 93 fuel then I'll pick her up. I'll be doing street logging for ethanol blends.

You'll also notice the filter on the turbo - it's essential for the longevity of the turbo and car in general. However, it muffles sound so it'll be taken off during specific occasions. On track days and daily puttering about - filter on. When I go to meets and am with friends - a mesh TurboGuard will be on as I refuse to completely raw dog it haha.

Can't wait!

Round about pricing?

[LaKuan]

Whats the fastest "downpipe and tune" 1/4 mile u get?

[2Times]

Originally Posted by LaKuan

Whats the fastest "downpipe and tune" 1/4 mile u get?

10.0 at 140mph… it was a no-prep event so traction was a challenge, even with awd

[LaKuan]

Originally Posted by 2Times

10.0 at 140mph… it was a no-prep event so traction was a challenge, even with awd

"No prep", thats really good. Definitely a prep surface, some slicks, port and meth could have easily ran a 9.70 maybe less. G82 have really been growing on me since there are so many G80s.

[Sinister840]

Question what if I wanted to keep my twin turbos and just increase the displacement of the engine? What are the pros and cons of doing that?

[Blue Angel]

Originally Posted by Sinister840

Question what if I wanted to keep my twin turbos and just increase the displacement of the engine? What are the pros and cons of doing that?

Stock turbos and increased displacement?

[Sinister840]

More like upgraded turbos and increased displacement?

[2Times]

Originally Posted by Sinister840

More like upgraded turbos and increased displacement?

Check out the BigBoost upgraded twin kit… they keep the 2 turbo setup… I don’t really see anything good or bad about doing that compared to a big single… with the single I can always go bigger if needed. Twins you’re likely changing the manifold too

[Sinister840]

Is the increase in displacement a striker kit? If so which one?

[2Times]

Originally Posted by Sinister840

Is the increase in displacement a striker kit? If so which one?

I think there will be a few options. I saw the 5150 kit : https://5150autosport.com/products/5...er-kit-bmw-s58

There will be others too

[GT_Juls]

AhsanU

How much power are you planning to push?