Downpipes & Best Practices

[el mágico]

Running spool 3” race lowers w/ awe touring exhaust - no pop, no drone & no rasp. This setup is quieter than my M/T stock exhaust with the A/T muffler delete mod. It is a tick louder at WOT with a nice tone.

Also, with the A/T muffler delete mod i picked up a bunch of resonant frequency buzzing noises during light acceleration. All disappeared with the spool / awe combo.

Nice. Driving enjoyment in this car has a lot to do with exhaust note. Dial it in and you'll never wanna put her away!

 

[thesilverbullet]

Do you happened to know who still offers a 2.5"? I've checked Spool, B6a, and AMS but it seems as though most people are only making the 3" version now.

I was thinking B6a.. didn’t realize they dropped the 2.5” version - maybe call them to see if they will make a set….

Otherwise you can mount 3” lowers with a 3” - 2.5” adapters..

 

[thesilverbullet]

AMS does offer a 2.5" adapter on their offerings. They are also the most expensive option.

It’s a standard 2 bolt flange - so any 3-2.5” adapter will work - maybe can use a good quality 3-2.5” gasket.

 

[thesilverbullet]

Nice. Driving enjoyment in this car has a lot to do with exhaust note. Dial it in and you'll never wanna put her away!

I’m pleasantly surprised with the spool / awe combo. Nice tone, no drone all with good flow & hp.

 

[thesilverbullet]

Do you happened to know who still offers a 2.5"? I've checked Spool, B6a, and AMS but it seems as though most people are only making the 3" version now.

Looks like Mo-Powa still offers 2.5..

https://mo-powaperformance.com/collections/nissan-z-rz34-2023

 

[KrackaC8]

Looks like Mo-Powa still offers 2.5..

https://mo-powaperformance.com/collections/nissan-z-rz34-2023

I was just about to link these, you beat me to it! These are what B6A used to sell as their 2.5" LDPs.

They're on eBay for cheaper:
https://www.ebay.com/itm/1869572966...sImageDedupe_BP&tu=01KVEKB3JCQ75EZ6KP4R95HTR9

 

[trajiiic]

yooooo, thanks guys! added to cart.

 

[kevinbonds]

Hey everyone, I've read about 2/3 of this thread from the start and haven't come across an answer to my specific question. I want to ask if there's anything I need to keep in mind when using any LDP with and aftermarket Y-pipe (ISR/Z1/PLM) where it's 2.5" to 3" collector. I currently have the ISR single axle back

No, don't need to do anything special. I have 3 inch Boosted 6 LDP to a Megan Racing 2.5 y-pipe, the supplied gaskets work fine, don't overthink it.

 

[trajiiic]

No, don't need to do anything special. I have 3 inch Boosted 6 LDP to a Megan Racing 2.5 y-pipe, the supplied gaskets work fine, don't overthink it.

Thanks man, I appreciate the wisdom!

 

[trajiiic]

I found one more non-res 2.5" LDP option. Someone mentions Circuit Werks earlier and I finally figured out how to use their search.


Circuit Werks 2.5" Non-Res LDPs:
https://circuitwerksusa.com/product...wer-downpipes-vr30ddtt?variant=42891369480389

Mo-Powa 2.5" Non-Res LDPs:
https://mo-powaperformance.com/products/mo-powa-infiniti-nissan-z-lower-downpipes

Mo-Powa 2.5" Res LDPs:
https://mo-powaperformance.com/products/mo-powa-nissan-z-23-resonated-lower-downpipes-2-6


I will likely go for the Mo-Powa since it's resonated.

 

[kevinbonds]

I found one more non-res 2.5" LDP option. Someone mentions Circuit Werks earlier and I finally figured out how to use their search.


Circuit Werks 2.5" Non-Res LDPs:
https://circuitwerksusa.com/product...wer-downpipes-vr30ddtt?variant=42891369480389

Mo-Powa 2.5" Non-Res LDPs:
https://mo-powaperformance.com/products/mo-powa-infiniti-nissan-z-lower-downpipes

Mo-Powa 2.5" Res LDPs:
https://mo-powaperformance.com/products/mo-powa-nissan-z-23-resonated-lower-downpipes-2-6


I will likely go for the Mo-Powa since it's resonated.

I will likely go for the Mo-Powa since it's resonated.

Why would you go 2.5 when better options exist in 3.0? The best ones on the market right now are the boosted 6 resonated 3 inch pipes, it will match up with any exhaust you have.

 

[KrackaC8]

Why would you go 2.5 when better options exist in 3.0? The best ones on the market right now are the boosted 6 resonated 3 inch pipes, it will match up with any exhaust you have.

3.0" into a 2.5" isn't as efficient for exhaust flow without a smooth transition. Hitting a steel wall (flange) creates turbulence.

 

[wisner99]

3.0" into a 2.5" isn't as efficient for exhaust flow without a smooth transition. Hitting a steel wall (flange) creates turbulence.

Smooth flow is a good consideration! Exactly why I have the Mo-Powa 2.5" resonated LDP's flowing to my Z1 resonated Y pipe. I also have the Z1 competition titanium exhaust. 2.5" -> 3" -> dual 3" exits. Sounds great to me and gets quiet enough still depending on my right foot.