AMS Full Downpipes (catted vs catless)

[CaliforniaZ]

Going to pair with HKS High Power Exhaust and Nismo intakes and tune so I decided full DPs are the way to go.

Can't decide between catted and catless. What do ya all recommend?

Cheers

 

[Hernandooo]

Catless

Pros - No Back Pressure, No Restrictions, More Power, bops bangs race car noises, flames, not as expensive
Cons - Very Loud, Rasp in between 3-4k rpm, smoke, stank, really needs a tune

Catted
Pros - Not as stanky, rasp maybe gone, not as loud
Cons - Back Pressure, Restricted (not as bad as stock), slightly less power, less bops bangs race car noises, no flames (unless you want to destoy your cats), expensive

 

[Jah_Happy]

Going to pair with HKS High Power Exhaust and Nismo intakes and tune so I decided full DPs are the way to go.

Can't decide between catted and catless. What do ya all recommend?

Cheers

Unless you plan on making crazy power, you can just go catted and be absolutely fine. You're already going full downpipes and that's enough for plenty of power. I would never want to deal with the noise and smell of catless. Also, if you're worried about restrictions, go for a 3" exhaust rather 2.5" with the HKS. AWE, Boostlogic, and SOHO all make great 3" exhausts.

 

[Mr&Mrs]

I thought the slight power loss of catted DPs was worth the smaller amount of smoke and smell. Even with CATs I cant have the car idle in the garage for more than 30 seconds before the smell is overwhelming, and yes that's with both doors open lol

Once I get my car on the dyno (eventually) we can compare to the big turbo cars without CATs.

 

[CaliforniaZ]

I've decided to go with catted DPs. Now I'm wondering if I should get a 3" exhaust vs 2.5" if I'm getting bolt ons but keeping stock turbo. Would the extra .5" make a significant difference in terms of power?

 

[goeagles11]

Some would say to get the 3” just in case you end up wanting to upgrade the turbos in the future. Otherwise 2.5” might be a little quieter with no power loss.

I’m thinking of copying you with the AMS catted downpipes but going with a valved exhaust to keep the tone down when needed.

 

[Hernandooo]

Keep in mind, if you go with AMS downpipes, they're 3". You'd be creating a bottle neck from the tiny turbos, to 3" back to 2.5" exhaust. It's much better to just go with matching exhaust diameters

 

[CaliforniaZ]

Keep in mind, if you go with AMS downpipes, they're 3". You'd be creating a bottle neck from the tiny turbos, to 3" back to 2.5" exhaust. It's much better to just go with matching exhaust diameters

That's true. I thought about it and I'm leaning towards AAM 2.5" resonated lower DPs. Although it seems like most people don't run catted lowers on here

 

[Hernandooo]

That's true. I thought about it and I'm leaning towards AAM 2.5" resonated lower DPs. Although it seems like most people don't run catted lowers on here

If you're running just lowers, it should be fine for non catted. You'd just be wasting your money if they did came catted

 

[CaliforniaZ]

If you're running just lowers, it should be fine for non catted. You'd just be wasting your money if they did came catted

Makes sense. Do the lowers also cause the car to smell? My CBE is 2.5" so what size lowers should I run? They're mostly 3" but come with adapters too

 

[Jah_Happy]

Makes sense. Do the lowers also cause the car to smell? My CBE is 2.5" so what size lowers should I run? They're mostly 3" but come with adapters too

The lowers do not cause any smell thankfully. Most will come with an adapter to connect your 2.5 exhaust piping. If you have 3" it will fit right up.

 

[Hernandooo]

Makes sense. Do the lowers also cause the car to smell? My CBE is 2.5" so what size lowers should I run? They're mostly 3" but come with adapters too

https://conceptzperformance.com/ppe...-q50-q60-30t-vr30ddtt-b0802-xd210_p_59561.php

and they're resonated, soo less likely to rasp