Downpipes & Best Practices

[Hernandooo]

Aaaaa I went Catless LDP too. Only reason to up grade to FDP is if you are upgrading turbos and going for big big power. Other than that LDP upgrade is adequate with oem turbos up to 480HP to wheels.

Maybe 480hp at the crank, not the wheels. With the same setup as the AMS alpha package, I can see that happening

 

[Bumflik]

Maybe 480hp at the crank, not the wheels. With the same setup as the AMS alpha package, I can see that happening

Ahhh gotcha

 

[thesilverbullet]

5" diameter? That's a bit overkill for fdp

I would just match it all the way through?

I agree - but not seeing an exhaust that is straight thru. They all have x / h pipe section that is less than straight thru. I’m looking at installing 3” lowers merging into what size x / h pipe? 4 or 5”?

So far it looks like the AWE is the best option. Their X/H pipe looks like a slight bottleneck. But since it’s 3” pipe, i’m guessing a little neck-down in that area is not going to hurt. Should still be ~5.5”dia.

i like remark‘s clean lines but wish they made a 3“ version. not sure about 2.5” inlets merged into a 3” single then split back into 2.5” pipes?

invidia’s x pipe looks good. I guessing it will flow like a ~5” pipe…

https://invidia-usa.com/products/invidia-22-up-nissan-new-z-dual-n1-s-s-tip-cat-back-exhaust

 

[Hernandooo]

There are plenty cat-back exhausts out there with 3" piping

For best sound and performance, I'd recommend

https://www.boostlogic.com/product/boost-logic-formula-series-titanium-exhaust-for-400z/

I've got this paired with AMS Catted FDPs

If your looking at +4", you're looking at getting a custom exhaust job from your local welder

 

[thesilverbullet]

Boost logic look bad to the bone and their x pipe merge looks like it keeps a full 6” cross section area - like a true dual. my goal is the keep the catback cost to <2K.

With that said I’m not looking for 4” pipe. i think 2.5-3” pipe dia. is good to go.

my concern is the merge collector on some of the these exhuast designs.

Looking at the remark setup, two 2.5“ pipes (5” total) necked down into a single 3” merge collector. what is the 3” merge collector hp limit @ 17+ psi boost? The only reason I’m looking at the remark setup - i love how smooth / straight their lines are - the fewest bends of the bunch. but I’m not sure what hp the 3” collector is good for.

Stillen list their X pipe’s cross sectional area (4”). So that 5” feeding into 4” - better than 3”. AWE is feeding 6” into what looks like 5.5”+

 

[kevinbonds]

Boost logic look bad to the bone and their x pipe merge looks like it keeps a full 6” cross section area - like a true dual. my goal is the keep the catback cost to <2K.

With that said I’m not looking for 4” pipe. i think 2.5-3” pipe dia. is good to go.

my concern is the merge collector on some of the these exhuast designs.

Looking at the remark setup, two 2.5“ pipes (5” total) necked down into a single 3” merge collector. what is the 3” merge collector hp limit @ 17+ psi boost? The only reason I’m looking at the remark setup - i love how smooth / straight their lines are - the fewest bends of the bunch. but I’m not sure what hp the 3” collector is good for.

Stillen list their X pipe’s cross sectional area (4”). So that 5” feeding into 4” - better than 3”. AWE is feeding 6” into what looks like 5.5”+

The AWE touring flows more then you will ever need, the piping is pretty straight, and the collector is large enough diameter to meet any HP number you could dream of.

 

[thesilverbullet]

The AWE touring flows more then you will ever need, the piping is pretty straight, and the collector is large enough diameter to meet any HP number you could dream of.

no concerns with the AWE. My concern is wih the remark 2.5 piping into a 3” collector. any idea what the HP limit for a single 3” merge collector?

 

[kevinbonds]

no concerns with the AWE. My concern is wih the remark 2.5 piping into a 3” collector. any idea what the HP limit for a single 3” merge collector?

You won’t make enough power with this platform to worry about that. Unless you are building the motor and going big turbo, you won’t have any issues. My GT500 was stock 2.5 exhaust and cats, I was making 700hp to the wheels and had no issues.

 

[thesilverbullet]

AI to the rescue. Looks a 2-1 (2.5”-3”) merge collector is good for ~500-600hp. I‘m sticking with 93 pump & stock fuel system, so remark should be good to go…

 

[thesilverbullet]

You won’t make enough power with this platform to worry about that. Unless you are building the motor and going big turbo, you won’t have any issues. My GT500 was stock 2.5 exhaust and cats, I was making 700hp to the wheels and had no issues.

Thanks for the intel. I’m only doing intake, lowers & catback w/ ecutek. I was looking at going with a remark catback exhaust and was concerned with having a 3” merge collector as the bottle neck. But looks like that will not be an issue.

 

[KrackaC8]

A single 3" will be just fine for ~500whp. A single 4.0" will outflow dual-2.5", for example.

On previous builds, I found single 3.0" into dual-2.25" worked out really well and made great power. Going into dual-2.5" just made more noise/drone for zero gains.

It's not about the diameter, but the total area and surface tension.

 

[el mágico]

I've got the Boost Logic '3. I am pairing it with the '3 Spool Performance full resonated dp. I'll post a clip WHEN the install is complete (for those interested).

Without the dps now I still get a bit of turbo spool with the Boost logic. Let's see how it changes...

 

[Bumflik]

I've got the Boost Logic '3. I am pairing it with the '3 Spool Performance full resonated dp. I'll post a clip WHEN the install is complete (for those interested).

Without the dps now I still get a bit of turbo spool with the Boost logic. Let's see how it changes...

Yesssss!!!!!

 

[thesilverbullet]

A single 3" will be just fine for ~500whp. A single 4.0" will outflow dual-2.5", for example.

On previous builds, I found single 3.0" into dual-2.25" worked out really well and made great power. Going into dual-2.5" just made more noise/drone for zero gains.

It's not about the diameter, but the total area and surface tension.

thanks for the info

 

[thesilverbullet]

Looking at lowers - I see AMS is using studs like oem for installation. Also AMS does not have a logo plate tack welded to the pipe - a plus for coating.

for the brands using standard bolts for installation, would you install all the nuts on the bottom side or keep same direction as stock?

for the logo plates, do you remove or just coat over them?