[fastgoat]

This is a bit of an odd situation with either the car or myself. Recently, the car just doesn’t feel like it has the pep on demand with consistency. For a short time it would give me a bit of a jerk or rough feel on deceleration, but no codes. It also just doesn’t seem to consistently pull hard.

Needless to say, last week I swapped the plugs but did not change the ignition coils as I was wandering in the dark. Engine seems to run smooth, but for some reason I’m just not feeling the same speed as before. But again, no engine trouble codes. Could there be anything else or is this a me issue?

Good example, I was leaving a stoplight today and saw two Kia Stingers in front of me. Light goes green and they go and thought I’d have a bit of fun…but they slowly pulled me. I supposed they could be modified, but figured a stage one m550 with 30k on the clock would be closer than that.

[silverydragon72]

Were you in sport+ mode with traction control off or running ina different mode? Even with a 2018 m550 you shouldn't lose to a kia stinger as to be honest they just aren't that quick. Have you tried an app to actually see what your performance figures look like such as 0-60? Lastly, I'm assuming your tires are in good shape and you aren't losing traction? I know on mine when I was getting close to the end of my rear tires life it wasn't giving me the same acceleration off the line.

[fastgoat]

Originally Posted by silverydragon72

Were you in sport+ mode with traction control off or running ina different mode? Even with a 2018 m550 you shouldn't lose to a kia stinger as to be honest they just aren't that quick. Have you tried an app to actually see what your performance figures look like such as 0-60? Lastly, I'm assuming your tires are in good shape and you aren't losing traction? I know on mine when I was getting close to the end of my rear tires life it wasn't giving me the same acceleration off the line.

Car was in sport+ mode and transmission in the sport position. Traction was on, but didn’t have any slip or bogging issues. And tires are in really good shape with aftermarket BBS wheels and 295s in the rear. Car has a Dinan exhaust and tune. I haven’t tracked the 0-60 in it.

[silverydragon72]

Sounds like something is off then if you have it tuned as well. Maybe it's the tune if it's not consistent or something is off, but your results don't sound correct. Mine is completely stock and is very consistent. Id probably recommend you record some runs of it and see if its matching what its supposed to based on your tune.

[Joe-BMW33]

I've got both the Dinan tune and exhaust. How hot is it in your area? There is definitely a hit on a super hot day. That said, it sounds like you are just sluggish for some reason.

Something to try just for the hell of it - pop the jumper in the piggyback to bypass it just to see what it feels like. It's purple I think and should be in the box.

[fastgoat]

Originally Posted by Joe-BMW33

I've got both the Dinan tune and exhaust. How hot is it in your area? There is definitely a hit on a super hot day. That said, it sounds like you are just sluggish for some reason.

Something to try just for the hell of it - pop the jumper in the piggyback to bypass it just to see what it feels like. It's purple I think and should be in the box.

I'm in the Chicago area so a typical midwestern summer. I may disconnect and reconnect the Dinan tune to see if that does anything. Will also run it with the bypass plug. Worst case scenario...update to the new M2

[Joe-BMW33]

Originally Posted by fastgoat

I'm in the Chicago area so a typical midwestern summer. I may disconnect and reconnect the Dinan tune to see if that does anything. Will also run it with the bypass plug. Worst case scenario...update to the new M2

I’m pretty sure the jumper will accomplish the same thing as disconnecting it.

Definitely a weird one here with no codes or misfires. Nah, you can do better than an M2! Too small coming from an M550. It will be fun for 5 minutes.

[Boosted_8]

Get some data then the internet might be able to help. E.g. 60-130 times to compare against other Dinan cars.

[fastgoat]

I wasn't able to get 0-60 times, but did take the time to replace the coils after the spark plug swap. The car feels quite a bit stronger and consistent. Not sure if one of the coils was on the way out or not, but a worthwhile endeavor.