HKS Exhaust Choices - Which one do I go with?

[Clipdat]

Why do you think they chose to not go with full 2.5" piping?

Originally Posted by weederr33

Let me rephrase that. I meant could the exhaust support the flow from a supercharger. I ask since it's only 60mm vs 63.5mm. Though I am very tempted to get it considering the ACE header is super expensive.

[weederr33]

Originally Posted by Clipdat

Why do you think they chose to not go with full 2.5" piping?

Japanese noise requirements? Iono...

[swarb]

Originally Posted by Clipdat

Why do you think they chose to not go with full 2.5" piping?

My guess is because metric.
Usually piping sold in 5mm increments, but marketed/manufactured in 10mm increments, 60/65/70/75/80, In merica' we use .25" increments- 2.25"2.5", 2.75", 3" Off by a mm or three, but close enough.

Usually 2mm(1/16") wall thickness.

[Ashikabi]

Originally Posted by swarb

My guess is because metric.
Usually piping sold in 5mm increments, but marketed/manufactured in 10mm increments, 60/65/70/75/80, In merica' we use .25" increments- 2.25"2.5", 2.75", 3" Off by a mm or three, but close enough.

Usually 2mm(1/16") wall thickness.

Beat me to it. It's a metric pipe. Also, 3.5mm is pretty close to an 1/8 inch. Not something I would spend money to upgrade to. If you need more diameter then you'll likely need a larger jump in diameter than that.

If HKS thinks it's good enough for their super charger I don't see why it wouldn't be good enough for a similar output turbo. Ace headers are supposed to be some of the best you can get though

[SuperTom]

Well my setup is 60mm(2.35") all the way front to back to keep the velocity speed constant. I think this is best if you are staying NA

If you are going forced induction I would jump up to 63mm(2.5") as you want to push out more volume, velocity is less of a concern.


Most exhausts coming from Japan (HKS ect.) are going to be 60mm, American exhaust companies will be 2.5"

[weederr33]

Thanks for the info. I agree for more power I might as well go for a 2.5" exhaust. But that sound haha! I'll give it more thought. I found a local coater to get the header ceramic coated too (to give that mad velocity). Here's a clip of the exhaust if anyone is interested:
[ame="https://www.youtube.com/watch?v=FqiM2cz9v1g"]TOYOTA 86/SUBARU BRZ HKS SUPER EXHAUST SYSTEM LMS - YouTube[/ame]

[djezlee]

I am a noob... just picked up my '17 BRZ last monday. I am thinking about picking up a HKS exhaust (Hi Power Spec L Cat Back Exhaust), but after doing a little research it looks like the pipes are 2-2.5 inches. Can I continue to use this cat back if I buy a turbo in the future? Is this wide enough to support hp gains?

-Lee

[SuperTom]

Originally Posted by djezlee

I am a noob... just picked up my '17 BRZ last monday. I am thinking about picking up a HKS exhaust (Hi Power Spec L Cat Back Exhaust), but after doing a little research it looks like the pipes are 2-2.5 inches. Can I continue to use this cat back if I buy a turbo in the future? Is this wide enough to support hp gains?

-Lee

They are 60mm which comes to 2.35". Im sure it will be fine with a turbo although a true 2.5" will be better. Read my post right above again.


I didn't go with the Hi Power Spec L even though it was light because you have to add some kind of diffuser or tray to take the place of the hole changing the stock muffler will leave behind. Its the case with any type of F1 or cannon style exhaust not covering the hole will be a big parachute area behind the bumper catching air. That's if you care about the aerodynamics built into the car.

[weederr33]

Originally Posted by djezlee

I am a noob... just picked up my '17 BRZ last monday. I am thinking about picking up a HKS exhaust (Hi Power Spec L Cat Back Exhaust), but after doing a little research it looks like the pipes are 2-2.5 inches. Can I continue to use this cat back if I buy a turbo in the future? Is this wide enough to support hp gains?

-Lee

It depends on your goals and such. Obviously everyone will suggest 3" but it still should be OK.

[Ashikabi]

Originally Posted by djezlee

I am a noob... just picked up my '17 BRZ last monday. I am thinking about picking up a HKS exhaust (Hi Power Spec L Cat Back Exhaust), but after doing a little research it looks like the pipes are 2-2.5 inches. Can I continue to use this cat back if I buy a turbo in the future? Is this wide enough to support hp gains?

-Lee

Since HKS offers a supercharger I wouldn't be concerned if you plan on a small turbo kit. If you are planning on making 400hp, then you'll want to go bigger

[djezlee]

thanks great info!

[djezlee]

Originally Posted by SuperTom

They are 60mm which comes to 2.35". Im sure it will be fine with a turbo although a true 2.5" will be better. Read my post right above again.


I didn't go with the Hi Power Spec L even though it was light because you have to add some kind of diffuser or tray to take the place of the hole changing the stock muffler will leave behind. Its the case with any type of F1 or cannon style exhaust not covering the hole will be a big parachute area behind the bumper catching air. That's if you care about the aerodynamics built into the car.

Perfect! you rock!

[Spawn_Of_Creation]

Does the Legamax Sports Cat-Back (Dual Tip) fit with the TRD rear bumper that is already set up for quad exhaust tips?

[weederr33]

Originally Posted by Spawn_Of_Creation

Does the Legamax Sports Cat-Back (Dual Tip) fit with the TRD rear bumper that is already set up for quad exhaust tips?

It most likely will