Anyone Switched AA Catted Downpipe to Catless?

[SooopraSD]

I had switched from AA catted to catless with HKS. slightly louder but was not as drastic as I thought. Here’s a small clip.

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[DarkZupra]

I went Catless -> GESI Catted.

WAY too much rasp. Increased volume was causing rattles in the car. No thanks.

 

[EddieNel]

Catless and cool!

 

[ColonelAdama]

I thought that was maybe about a guy over boosting on a catless downpipe. At least back in my STI days that was a symptom of driving it in cold weather due to increased air density, but idk how the supra's operate catless in the winter.

@tub54500 @Batmo

Yes, catless does cause overboosting. And also yes, it does affect MT cars worse.

I really wouldn't recommend it unless you are tuning for it, which JB4 can do as well.

i actually have a "stock boost" map on my JB4 just so I can tune out the overboost with wastegate control and run smoothly at stock power level without crazy throttle activity.


At stock power levels, the throttle can mostly control the overboosting from being catless, but could be noticeable in some circumstance. Running a piggyback without wastegate tuning will 100% cause issues.

 

[Batmo]

@tub54500 @Batmo

Yes, catless does cause overboosting. And also yes, it does affect MT cars worse.

I really wouldn't recommend it unless you are tuning for it, which JB4 can do as well.

i actually have a "stock boost" map on my JB4 just so I can tune out the overboost with wastegate control and run smoothly at stock power level without crazy throttle activity.


At stock power levels, the throttle can mostly control the overboosting from being catless, but could be noticeable in some circumstance. Running a piggyback without wastegate tuning will 100% cause issues.

Back then I just swapped out the up-pipe for a grimmspeed one with an external wastegate to deal with the boost creep and had that tuned for, but I imagine it isn't that simple on the B58? I'd want catless only because I like when the whistles go whoo whooooooo.

 

[ColonelAdama]

Back then I just swapped out the up-pipe for a grimmspeed one with an external wastegate to deal with the boost creep and had that tuned for, but I imagine it isn't that simple on the B58? I'd want catless only because I like when the whistles go whoo whooooooo.

It is because electronic wastegate on the B58.

Only way is proper tune or JB4 with EWG connector.

 

[CafeRacerQueen]

isnt there a thread that recommends not going catless for manual ?

For untuned

 

[Danimal]

Stock exhaust for me with catless downpipe and the sound is sublime. Quiet with flap closed, amazing when it’s open and sport mode pops and burbles. It smells bad, but worth it.

 

[ColonelAdama]

Stock exhaust for me with catless downpipe and the sound is sublime. Quiet with flap closed, amazing when it’s open and sport mode pops and burbles. It smells bad, but worth it.

Agreed. I'll probably never buy a catback.

 

[Danimal]

Stock exhaust for me with catless downpipe and the sound is sublime. Quiet with flap closed, amazing when it’s open and sport mode pops and burbles. It smells bad, but worth it.

Oh, and turbine noise

 

[Extreme Power House]

Stock exhaust for me with catless downpipe and the sound is sublime. Quiet with flap closed, amazing when it’s open and sport mode pops and burbles. It smells bad, but worth it.

If you want the max sound without upgrading the exhaust, catless is the way to go but of course you have to deal with the fuel smell and CEL.

I like catted better, the midrange has more volume and the high rpm sound is clean. the raspy catless sound is not for me.

 

[OldHead-MKV-Owner]

Interesting..... so more or less getting rid of your cat got rid of the drone. Did that drone you had with the HKS set up also cause the plastic in your door panels and stuff to rattle?

I'm one of the lucky ones. I literally have zero rattles... never had any in the car. The closest thing I have to a rattle are, the sub grilles on certain songs and there used to be a clicking noise coming from the rear springs when I lowered the car. Fixed that with a coil sleeve.

 

[SgtAlers]

I recently switched but I have a stock exhaust. It’s a little bit louder now. Sounds a lot better too.

You looking to sell the catted one? I'm shopping for a used one.

 

[ewwphil]

I just sold it last night

 

[CafeRacerQueen]

I'm over here with a AA catted downpipe AND AA catback, and every time I drive it, I wish it had some more volume and scream when you're on the throttle. I know that as soon as I decide to tune it, it's going catless. I know everyone is different, but catless turbo cars are just nowhere as loud as n/a cars were. Maybe eight years with a cammed, catless FBO LS2 GTO broke my sense of what's loud and what's LOUD.

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