Which csl airbox to buy?

[Tbonem3]

In my experience, the slower (less powerful engine and/or less power mechanically sent to the wheels) car with CSL airbox makes a better sound. I can't say louder, but to me, better. I think it's due to being a slower sound.

Try this experiment. Go WOT uphill, then go WOT downhill and see which sounds better. When I did 4.10s, my CSL airbox sounded worse to me. So, in my experience, the more load you put on the engine, and the slower you move through the powerband, the better sounding the CSL induction.

I think the best CSL induction you could ever make would be to take a healthy vert and only do the airbox conversion and headers. And then just rip through the canyon walls.

[Sharocks]

Pretty sure the only difference in sound deadening in front of the driver is the piece on the underside of the hood. The rest of the sound deadening that was removed is all behind/next to/above the driver (under rear bench, door cards, roof, etc.). So I'm not sure why there would be a difference in volume between CSLs and regular M3s. My airbox is pretty loud, but I've also never been in a CSL.

I've been in two different CSL's at speed.

They're much louder in the car.

It's 100% to do with sound deadening.

Both CSL's had aftermarket exhaust systems too.

[jet_dogg]

Ah I didn't read all of the posts so didn't know he was referencing the rpm specific resonance, my apologies.

[Thoglan]

While that is true when looking at extreme differences in power. More power does just mean more air in and more air out, subsequently more noise. However, you rarely (never) see people saying how much louder their induction noise is after having their car tuned. Sounds like SQ13 is hunting for a particular resonance that you get from the airbox based off the harrys garage clip he linked. I don't think that is tied to its peak hp on the dyno shown, just with the way he's driving since from my experience I get that exact noise from the low end pickup with high load.

[jet_dogg]

Big oof! I am on the stock exhaust setup. I do plan to do more power mods after I’m done with the silver car, specifically full catted exhaust (Supersprint V1 hopefully). Idk about Turner pulleys or anything else for the blue car.

Why would more power make it louder, better flow and efficiency?

Think about it, if the car made 1000whp everything would be loud. If the car made 100whp it would be silent. Those guys are louder because their engines have more mods, better exhaust and engines are healthier. Or you're just trippin and it's all in your head 🤠

I read jet's comment as ironic at first. That sounds like bullshit lmao. Your car making an additional 20hp will not magically start resonating the airbox differently. Chances are it's just the way you're driving it. Reset throttle adaptations and do some wide open throttle from lower in the rpm range.

You really never know when I'm being serious.

Forty to fifty wheel horsepower and say 20lb-ft is not an insignificant increase (people spend thousands for that) and as a result it stands to reason that at wot everything will be incrementally louder as the engine makes more power. This really isn't a radical concept and at that increase there is a noticeable difference in acceleration and seat of the pants feel.

Maybe there's something wrong with his car, I don't know what mods he actually has but his power level is near stock.

[SQ13]

I’ve been punked 😭

I have a foxwell diagnostic tool on the way, so I’ll try to reset adaptations. Honestly think my intake is fine and that I’m just being an idiot.

[Thoglan]

I read jet's comment as ironic at first. That sounds like bullshit lmao. Your car making an additional 20hp will not magically start resonating the airbox differently. Chances are it's just the way you're driving it. Reset throttle adaptations and do some wide open throttle from lower in the rpm range.

[SQ13]

Big oof! I am on the stock exhaust setup. I do plan to do more power mods after I’m done with the silver car, specifically full catted exhaust (Supersprint V1 hopefully). Idk about Turner pulleys or anything else for the blue car.

Why would more power make it louder, better flow and efficiency?

[jet_dogg]

Yours isn't as loud probably because you're making less power than everyone else.

If your car was making 320-350 with more torque it would be louder but you're putting down 13 more than a bone stock m3.

[SQ13]

Is that your car in the Video you posted of the interlagos on the dyno? Because that sounds pretty spot on. What does your dyno graph look like?

Yeah that’s my car. I may very well be an idiot lol.

[Thoglan]

Thoglan
Senior Member
Join Date: Aug 2020
Posts: 359
Location: NZ

Hmm... you should go compare in person!

I have yet to convince him to take me for a thrash in the CSL, but he's definitely a handy guy to live 15 minutes from when you own an M3.

[Gearhead55]

Software/tune issue preventing 100% throttle?

Is that your car in the Video you posted of the interlagos on the dyno? Because that sounds pretty spot on. What does your dyno graph look like?

[heinzboehmer]

Yeah, all carbon airboxes make that noise - 3K RPM and WOT.

+1, my car makes that noise too

[SQ13]

Yeah, all carbon airboxes make that noise - 3K RPM and WOT.

Software/tune issue preventing 100% throttle?

[Slideways]

Usually around 3.5k. It honestly doesn’t seem very loud at lower RPMs even at WOT. At 13:14 in the vid below, that noise you hear is lacking in my car. I guess what I need to do it go on an extended/spirited drive or take it to COTA to appreciate it more.

Yeah, all carbon airboxes make that noise - 3K RPM and WOT.