[solstice]

Originally Posted by super51fan

I don't think it is fair to say this car has more lag than the X3 M's S58 until we see dynos to see when and where it makes power since these numbers only tell us peak numbers.

Although the M3 makes 479 @ 2750, there is nothing to say it makes more or less than 443 @ 2600 like the X3 M.

I was thinking the same, the ramp is usually very steep but until we see a graph it’s an open question.

[new2the3]

In comp trim X3/4m is 442 torque at 2600rpm to 5600rpm.

M3/4 comp torque is 479 is 2750 to 5500 rpm.

Anyone know if there are any hardware differences between the two s58 engines or is this simply a software change?

[av.7447]

Originally Posted by new2the3

In comp trim X3/4m is 442 torque at 2600rpm to 5600rpm.

M3/4 comp torque is 479 is 2750 to 5500 rpm.

Anyone know if there are any hardware differences between the two s58 engines or is this simply a software change?

I have a feeling somewhere down below my spine that soon we not gonna care about how many hp or torque those engines produce in their stock form... also not sure you want to have this much torque down low with a rear wheel drive unless you are packing some serious rubber at the back... either way the only real difference between those engines is their software. All I really want to know is how quickly will I be able to get a flash tune on my 6 speed so we can spin that thing all the way to 8000 rpm and get over 600hp while doing it!

[Avaley]

Duplicate thread:

https://g80.bimmerpost.com/forums/sh....php?t=1760190

[vampire81]

test drove an X3MC and i'd take the S58 over S55 anytime.
the midrange power in that heavy X3 was a apparent.
didn't notice more lag than in the S55, M2C.

[stefan]

Originally Posted by SYT_Shadow

Many X3/4M owners have complained there's lots of lag off the line

This is trans related is it not.

[SYT_Shadow]

Originally Posted by stefan

This is trans related is it not.

I couldn't say.

[KoenG]

Originally Posted by xlover

as you know (because you are often in the vanguard on this site ) there is a group of x3m owners who feel the off idle lag in that version of the S58 is unacceptable, of course there are also those who notice and it doesn't bother and those who don't really feel it but the feedback is consistent enough that there is something there. With a clearly different tune I think expectations should be high that it was addressed (and if so x3m owners should write asking for this tune in their LCI next summer)

It's not "lag" actually. There is just not enough torque underneath 2500rpm, and then it hits like a hammer. Lag is another phenomenon and is caused by dynamic inertion to let the turbo spool fst enough to build positive pressure. I didn't read complaints about lag, only about the lack of torque underneath 2500rpm.

[KoenG]

Originally Posted by stefan

This is trans related is it not.

no, nothing to do with the transmission.

[kyrix1st]

Originally Posted by KoenG

It's not "lag" actually. There is just not enough torque underneath 2500rpm, and then it hits like a hammer. Lag is another phenomenon and is caused by dynamic inertion to let the turbo spool fst enough to build positive pressure. I didn't read complaints about lag, only about the lack of torque underneath 2500rpm.

Large throttle input reciprocating to sluggish engine response. That is what people call lag.

[KoenG]

Originally Posted by kyrix1st

Large throttle input reciprocating to sluggish engine response. That is what people call lag.

No, that's entirely wrong and another physical phenomenon.

[kyrix1st]

Originally Posted by KoenG

No, that's entirely wrong and another physical phenomenon.

Yes, you could be technical and say lag equates to turbo lag, but let's dumb it down for ordinary customers who feel the "lag" in the way the car's engine responds. The point here is car isn't fast enough in low rpm in X3Ms.

[xlover]

Originally Posted by kyrix1st

Yes, you could be technical and say lag equates to turbo lag, but let's dumb it down for ordinary customers who feel the "lag" in the way the car's engine responds. The point here is car isn't fast enough in low rpm in X3Ms.

Semantics aside I think most can agree the x3m version of the S58 makes less power off idle than the power band 2500+ suggests it should and many owners want more

The M3 version has both physical changes to components and tuning changes, couple that with some insider hints, it is reasonable to expect they addressed it to some extent...

[KoenG]

Originally Posted by kyrix1st

Yes, you could be technical and say lag equates to turbo lag, but let's dumb it down for ordinary customers who feel the "lag" in the way the car's engine responds. The point here is car isn't fast enough in low rpm in X3Ms.

Fair enough!

[brad850csi]

Boost Threshold is actually what we are all talking about. From low RPM to the threshold where the boost can come up to target.

Lag is when you're above that threshold, say 4000rpm, and floor it - that time is the lag to max boost.

Either way, with the bigger turbos and lower compression while maintaining the same engine capacity you're going to get more delay. But that top end will be strong.

[robopp]

Originally Posted by brad850csi

Boost Threshold is actually what we are all talking about. From low RPM to the threshold where the boost can come up to target.

Lag is when you're above that threshold, say 4000rpm, and floor it - that time is the lag to max boost.

Either way, with the bigger turbos and lower compression while maintaining the same engine capacity you're going to get more delay. But that top end will be strong.

The top end is very strong. It's a shame they paired a ZF with this motor because it has plenty more left at 7200.

[R2i3a]

Ive definitely felt like the X3m/X4m wasn't as fun on the street as even the m40i because of the lag. It's fast but the lag doesn't make it as 'fun'