Dumb Question Thread - No Flaming Allowed

[cobra]

Here's a random question.

How many S54's have had real actual damage (crank damage, spun rod bearings)? There are thousands of people who have shown rod bearing wear, so we know that the S54 gradually wears the rod bearings. But I have only seen a couple that actually ended catastrophically and they were either severely neglected with high miles, or being run at redline on the track for long periods of time.

Anyone got data on that?

[E46_M3_ZCP]

A work colleague of mine who is the original owner and what we fellow forum members would consider a non-enthusiast owner of an E46 M3 spun his rod bearings on his 2005 car at like ~130K miles. Speaking to this guy, you instantly figure out he's not a true enthusiast as he does zero preventative maintenance and has not resolved a single lock down item on the car from RACP to Vanos to rod bearings. He claims he was not driving the car aggressively or doing anything out of the norm when he spun a rod bearing. Like I said, he's not an enthusiast as he seems to treat his M3 like a civic so I'm not surprised the engine blew.

[Tbonem3]

A work colleague of mine who is the original owner and what we fellow forum members would consider a non-enthusiast owner of an E46 M3 spun his rod bearings on his 2005 car at like ~130K miles. Speaking to this guy, you instantly figure out he's not a true enthusiast as he does zero preventative maintenance and has not resolved a single lock down item on the car from RACP to Vanos to rod bearings. He claims he was not driving the car aggressively or doing anything out of the norm when he spun a rod bearing. Like I said, he's not an enthusiast as he seems to treat his M3 like a civic so I'm not surprised the engine blew.

That was due to:

infrequent oil changes
possibly incorrect oil spec, or poor additive pack
too many cold starts, and engine shut offs before reaching temp
lugging (low rpm load)

S54s driven/maintained properly are going 200k

S54s maintained properly, but beat on properly, will do 100k-150k.

[skristedja]

Anyone know what could cause a low pitch creaking sound when going over low speed bumps in turns? I have an angled driveway I go over everyday at work and I hear this creaking sound coming from my car (sounds like the front but it could be the rear). I took my car in for an alignment and they checked all the bushings and joints in the suspension and they said no issues so idk. RACP is reinforced with redish plates and vincebar so I'd like to rule that out lol.

[cobra]

Anyone know what could cause a low pitch creaking sound when going over low speed bumps in turns? I have an angled driveway I go over everyday at work and I hear this creaking sound coming from my car (sounds like the front but it could be the rear). I took my car in for an alignment and they checked all the bushings and joints in the suspension and they said no issues so idk. RACP is reinforced with redish plates and vincebar so I'd like to rule that out lol.

It's a random thought but my rear seats squeak and clunk as the car goes over angled surfaces. Try putting your rear seats down and see if it goes away.

Other than that it could be SO many things...

[bimmer]

Anyone know what could cause a low pitch creaking sound when going over low speed bumps in turns? I have an angled driveway I go over everyday at work and I hear this creaking sound coming from my car (sounds like the front but it could be the rear). I took my car in for an alignment and they checked all the bushings and joints in the suspension and they said no issues so idk. RACP is reinforced with redish plates and vincebar so I'd like to rule that out lol.

When I had this it was due to a just slightly loose sway bar end link. Really had to yank on it to realize it wasn't tight enough. But it could be many things.

[ridebikes]

When it comes to square vs. staggered wheels....

...would it be a bad idea to run a staggered 19" set up on the street when the car is set up for a square 18" on the track? Including alignment, camber, etc.

Would the handling be compromised by running bigger and staggered wheels?

🙏

[IamFODI]

When it comes to square vs. staggered wheels....

...would it be a bad idea to run a staggered 19" set up on the street when the car is set up for a square 18" on the track? Including alignment, camber, etc.

Would the handling be compromised by running bigger and staggered wheels?

🙏

Expect the stagger to cause more understeer / less oversteer. It depends on the exact sizes and tires in question, but that's the general trend.

Wheel size affects handling as well, but it'd have roughly the same effect regardless of setup/alignment.

[skristedja]

When I had this it was due to a just slightly loose sway bar end link. Really had to yank on it to realize it wasn't tight enough. But it could be many things.

I'll check that out. Pretty much exactly where the sound is coming from. Thanks

[Tbonem3]

Ya alignment has nothing to do with it unless one set of wheels, likely the fronts of the square set, requires more camber to fit, which would cause more toe out.

Theoretically, you could set the 19" setup to have zero or a little toe in with minimal camber like -2 to -1.5, then slide camber plates in to a pre-marked point that corresponds to -3 or so. Then you'd end up with toe out, but you'd have to practice on an alignment machine or DIY to figure out how much is right, and even then, getting repeatedly perfect amounts over time would be difficult. It just never seems to be perfect when you play around. You'd also have to want toe out, which some do (I like it).

[ridebikes]

Expect the stagger to cause more understeer / less oversteer. It depends on the exact sizes and tires in question, but that's the general trend.

Wheel size affects handling as well, but it'd have roughly the same effect regardless of setup/alignment.

Cool, good to know. In this case, the sizes would be:

Track Setup (Square):

• APEX ARC8 18x9.5" ET35
• 265/35/18 Tires

Street Setup (Staggered)

• OE ZCP 19" - 19x8 ET47 / 19x9.5 ET27
• 245/35/19 + 265/35/19 Tires

[Tbonem3]

ZCPs are 9.5" rears and you should use a 275/30 tire with 245/35 or a 235/35 with 265/30. 265/35 is not an appropriate size for the car/DSC/gearing

[Fresh1179]

Does BMW suggest performing a compression test with the engine hot, "warm", or cold. Under the correct conditions, what PSI is considered within the healthy range. I've seen Redish Motorsport do it cold looking for 170, but I would like to do it the correct way prior to a leakdown test.

[HanSooloo]

I am thinking about a CSL conversion in the near future where I intend to bring down the weight of the car. My main objectives are to continue having a comfortable daily driver that looks better than before, sounds better than before and drives faster than before.

Question is, whether it would make sense to change the shocks/springs because of the reduction in weight? The reduction will come in the following areas:

1. Carbon roof (have a moonroof right now)
2. ZCP wheel set (from the OE 18”)
3. Lightweight CSL trunk
4. Lightweight air filter housing and cover (believe it or not, apparently saves several kilos / pounds)
5. (maybe) CSL front bumper … although I just can’t get over the asymmetric single breather hole.

[Tbonem3]

What suspension? You don't get to make incremental spring rate changes unless you have coils with linear springs. Not sure how much weight loss you're going for, but the roof alone isn't THAT much and it's spread over the car (unlike dropping 30lbs of muffler weight off rear).

Dropping weight INCREASES spring rate, which imo, is usually a good thing, though the ride can get bouncy if you can't slow the rebound of the dampers (adjustable).

Where are you getting a lighter hvac filter housing?