[Zuzu]

Originally Posted by Soylent

For how long though?

How long is a piece of string !!!

[corbs09]

Originally Posted by perryreid90

ah yeah torque limits on 6MTs are a different ball game. i think pushing past 6mt torque limits is fine to a degree, but with the expectation that more frequent clutch replacement will be necessary. if you want to risk it and tune, maybe stock up on replacement clutches until the aftermarket comes up with a nice billet alternative, which im sure they are probably already developing as i write this

I think the OEM clutch will live for a little while with a stage 1 tune if we are able to keep torque low. I am just going to wait for an aftermarket replacement. Buy once cry once.

[Circa77]

Originally Posted by corbs09

I think the OEM clutch will live for a little while with a stage 1 tune if we are able to keep torque low. I am just going to wait for an aftermarket replacement. Buy once cry once.

Is the primary concern with the 6MT's torque limits all in the clutch or is it the gearbox in general?

Cause if it's just the clutch, that seems like a really simple problem to get in front of.

[corbs09]

Originally Posted by Circa77

Is the primary concern with the 6MT's torque limits all in the clutch or is it the gearbox in general?

Cause if it's just the clutch, that seems like a really simple problem to get in front of.

Not sure, I think the trans would handle 650-700 ft/lbs before it got dicey. I know there are F80s making this and supposedly its the same trans.

[Limegrntaln]

If its just a clutch issue, someone could come out with a nice twin disk to take care of the problem.

[hernanipalma]

Originally Posted by Soylent

For how long though?

My x3m went boom with only 3k miles after stg2

[Soylent]

Originally Posted by hernanipalma

My x3m went boom with only 3k miles after stg2

Oh boy. What broke? Is that the same S58 as in the G8x? Or without forged parts?

[kyleb350]

Originally Posted by Soylent

Oh boy. What broke? Is that the same S58 as in the G8x? Or without forged parts?

Yes, only w/o the forged crank. LCI's have them though.

[F85MTuNED]

Originally Posted by kyleb350

Yes, only w/o the forged crank. LCI's have them though.

Originally Posted by hernanipalma

My x3m went boom with only 3k miles after stg2

Originally Posted by Soylent

Oh boy. What broke? Is that the same S58 as in the G8x? Or without forged parts?

Not having a forged crank is a major difference IMO.

[SatinblkF90]

Originally Posted by kyleb350

Yes, only w/o the forged crank. LCI's have them though.

With the forged crank I really doubt stg2 would of went boom, that sucks man.

[hernanipalma]

Originally Posted by kyleb350

Yes, only w/o the forged crank. LCI's have them though.

I think x3mc also came with forged right ? Had issues w/ rod bearing

[heavyD^2]

Originally Posted by hernanipalma

I think x3mc also came with forged right ? Had issues w/ rod bearing

First I have heard that any S58 engines were made without a forged crankshaft.

[perryreid90]

Originally Posted by Circa77

Is the primary concern with the 6MT's torque limits all in the clutch or is it the gearbox in general?

Cause if it's just the clutch, that seems like a really simple problem to get in front of.

a little bit of both. with a manual trans, you have a direct mechanical connection between your engine and the pavement, there is zero cushion or slip (why you stall if you arent in neutral) so, the clutch takes the brunt of that hit as its splined/unsplined constantly. with a torque converter auto trans like the ZF8, its a hydraulic coupling, which means there is a little bit of cushion between engine and pavement. this helps preserve the service life of the trans dramatically, and they can also handle more power as a result

[hellcat2m4]

Originally Posted by heavyD^2

First I have heard that any S58 engines were made without a forged crankshaft.

All x3m/x4m have forged crank the LCI one is just updated, and a tad bit lighter.

Tons of X3M/X4M guys have been running stage 2 tunes including myself for many miles and no issues so far. Sure you get an outlier, or someone that gets bad gas, or miscalculates their ethanol mix and we all know what that leads to...

[Avaley]

gives me hope for the ICE inline 6. I hope they make improvements to it over time.

[forcefed]

Did anyone notice how much torque this motor is making? Basically double the amount of torque as the stock s58 yet at the same rpm, those were some magical turbo's

Not sure what they were doing to the head but it seems they lowered the compression even further by taking out material.

[Gotta_Go_Fast]

@forcefed it looks like a port and polish. The screenshot you have is performing the "port" part of that by increasing the size to align better with the gasket and block it's getting bolted to

[m4ml]

Originally Posted by Gotta_Go_Fast

@forcefed it looks like a port and polish. The screenshot you have is performing the "port" part of that by increasing the size to align better with the gasket and block it's getting bolted to

This actually looks like they are CNC machining the combustion chambers (which is consistent with lowering the compression ratio).

Porting and polishing is done inside the intake/exhaust runners. Some clean up is often done from the combustion chamber side, but this picture shows fresh metal in the first combustion chamber compared to the second which leads me to believe that they are CNC machining the combustion chamber. Plus the tool doesn't look like a tool that would normally be used for port/polish.

It's been a long time since I've done head machining though, so take what I say with a grain of salt.

[Big_tugg]

Originally Posted by m4ml

This actually looks like they are CNC machining the combustion chambers (which is consistent with lowering the compression ratio).

Porting and polishing is done inside the intake/exhaust runners. Some clean up is often done from the combustion chamber side, but this picture shows fresh metal in the first combustion chamber compared to the second which leads me to believe that they are CNC machining the combustion chamber. Plus the tool doesn't look like a tool that would normally be used for port/polish.

It's been a long time since I've done head machining though, so take what I say with a grain of salt.

I agree.

I'm new to the BMW world... is getting ported/polished heads or service not typical?

[Soylent]

Looks like cc'ing. Reducing the amount of fuel charge blowing out the exhaust ports if running larger turbos?