Which csl airbox to buy?

[SQ13]

At what RPM do you go WOT? With an exhaust, it used to be that you would wait till 4k RPM and slowly go WOT. With the airbox, it is very loud WOT at 2.5k RPM all the way to redline.

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.

[SQ13]

Maybe my expectations are unrealistic and/or I have defective ears. It sounds great from the outside and inside with the windows down, but it’s kinda underwhelming with windows up. I was watching the Harry’s Garage manual CSL vid recently, and it seemed like that car sounded a bit different than my car. My intake is the only one I’ve experienced in person so far, so I could totally be wrong. I mean, the dB reader a few yards from the dyno read 116 dB..def loud. I don’t think it makes much of a difference, but I have the Karb/ITG foam filter.

The Haimus sounds pretty fucking loud at WOT at high rpms. You can definitely tell from where in the engine bay the sound is emanating. Do you have the race version or csl style karb?

Probably something you'd need someone like NZ_M3 to confirm. Since he owns a CSL and has owned a car with a karb intake, pretty sure at the same time. I would hazard to guess they are pretty similar and videos just don't quite show that.

NZ_M3 Hi, pls help

[Slideways]

I feel like my Karb intake sounds a bit too quiet, even with stock exhaust. I don’t understand why the intake sounds much louder in real CSLs (in vids of course). Does the lack of sound deadening contribute to that?

At what RPM do you go WOT? With an exhaust, it used to be that you would wait till 4k RPM and slowly go WOT. With the airbox, it is very loud WOT at 2.5k RPM all the way to redline.

[zzyzx85]

I feel like my Karb intake sounds a bit too quiet, even with stock exhaust. I don’t understand why the intake sounds much louder in real CSLs (in vids of course). Does the lack of sound deadening contribute to that?

When you compare them back to back, the Karb/CSL intake is noticeably louder. I noticed it immediately after I swapped my boxes.

I suppose you do get used to it after a while and it doesn't seem as loud anymore.

[Slideways]

If anything, most of the CSL videos don't do a great job translating how loud it is. Karb, CSL, Turner, they all (basically) sound the same.

[heinzboehmer]

Probably something you'd need someone like NZ_M3 to confirm. Since he owns a CSL and has owned a car with a karb intake, pretty sure at the same time. I would hazard to guess they are pretty similar and videos just don't quite show that.

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

Hmm... you should go compare in person!

[Thoglan]

I feel like my Karb intake sounds a bit too quiet, even with stock exhaust. I don’t understand why the intake sounds much louder in real CSLs (in vids of course). Does the lack of sound deadening contribute to that?

Probably something you'd need someone like NZ_M3 to confirm. Since he owns a CSL and has owned a car with a karb intake, pretty sure at the same time. I would hazard to guess they are pretty similar and videos just don't quite show that.

[Gearhead55]

I feel like my Karb intake sounds a bit too quiet, even with stock exhaust. I don’t understand why the intake sounds much louder in real CSLs (in vids of course). Does the lack of sound deadening contribute to that?

The Haimus sounds pretty fucking loud at WOT at high rpms. You can definitely tell from where in the engine bay the sound is emanating. Do you have the race version or csl style karb?

[Gearhead55]

So what 2.5" sec. 3's currently exist besides SCZA and the Supersprint made to order 2.5" ?

Somewhat surprised to hear negative remarks about the RE mufflers as from what I understood that muffler had pretty good airflow due to the flow through design.

The engine must simply want a bigger diameter pipe all the way down the line with these types of modifications..

Yea I think the RE type mufflers are sufficient (even optimal maybe) until you start uncorking these things with headers and intake. They just really respond to breathing better.

[EthanolTurbo]

Just word to the wise, do not think that you will hear the airbox over loud exhausts.

This is a folly.

Should be fine as long as I cut a hole through the dash to allow airbox noise to come through into the cabin. Poor man's GT4 RS.

[heinzboehmer]

I feel like my Karb intake sounds a bit too quiet, even with stock exhaust. I don’t understand why the intake sounds much louder in real CSLs (in vids of course). Does the lack of sound deadening contribute to that?

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.

[SQ13]

I feel like my Karb intake sounds a bit too quiet, even with stock exhaust. I don’t understand why the intake sounds much louder in real CSLs (in vids of course). Does the lack of sound deadening contribute to that?

[Gearhead55]

It'll be so loud you won't hear the air box induction noise anymore lol

Lol that’s what I’m worried about

[Epoustouflant]

Strength of the dollar vs. euro right now is making Karbonius / Haimus options look like a pretty good deal.

100%! The CSL trunk GB participants are getting free candy with this lol - some silver lining to the EU situation I guess.

[Sharocks]

Just word to the wise, do not think that you will hear the airbox over loud exhausts.

This is a folly.