South African BRZ performance exhaust - Fitted @ Centurion Toyota

[FT_86_SM_GP]

Originally Posted by Ayrton

Just did some measuring with my vernier whilst in the midst of 'load shedding'.

The BRZ pipe is approx. 63 mm, OEM 54 mm. The mighty horns coming out of the BRZ rear muffler = 74 mm each. OEM = 54 mm again.
The OEM pipe is a mass of bends and crimps. The BRZ is just so much straighter!

Love the torquey rumble of the BRZ Xhorst.

Out of interest, is the BRZ pipe diameter 63mm measured NOT taking into account the pipe/flange thickness (Picture A) (Ie. Inner Diameter) or
taking into account pipe/flange Thickness (Picture B) (Ie. outer Diameter) ?

Im assuming the pipe thickness is approx. +- 1.5mm

[sav]

Why would he measure the flange?

[Freedom]

Originally Posted by sav

Why would he measure the flange?

Well no one likes a loose flange

[sav]

Haha true story!!

[Dammod]

Originally Posted by FT_86_SM_GP

Out of interest, is the BRZ pipe diameter 63mm measured NOT taking into account the pipe/flange thickness (Picture A) (Ie. Inner Diameter) or
taking into account pipe/flange Thickness (Picture B) (Ie. outer Diameter) ?

Im assuming the pipe thickness is approx. +- 1.5mm

Picture A

[FT_86_SM_GP]

Originally Posted by Dammod

Picture A

Thanks

Reason for asking is that I am researching headers and overpipes combo's and noticed the different sizes with various brands

Eg.

Borla UEL Header:
Collector "Outer" Diameter - 2.25inches (Approx 58mm)

Primary Tube Outer Daimeter 1.625inches (Approx 41mm)

(Not sure how to interpret this data from the Borla website)

Tomei UEL Header and Kamak Dynamic UEL Header:
60.5mm Diameter (Not sure if its inner or outer pipe Diameter?)

It seems like the Tomei or Kamak UEL Headers are the way to go if you want better airflow / performance and a refined rumble.

I recently got myself a Borla Version 2 UEL header purely for the love of a louder rumble and the resulting exhaust tone.
(Did not (realize) think about performance when purchasing it )

I was advised by Borla that there is no need to change the stock overpipe as it will not make much difference...
(Stock overpipe has a Diameter of approx 54mm)

I do trust their judgement and advice from their reputation and R&D...

But I am still trying to understand how the stock overpipe (being 54mm in diameter) will not make a difference if changed to an aftermarket 63mm overpipe ?

Maybe the Borla UEL Header is 54mm "Inner" Diameter as well?
(Scary how restrictive it is - Same to stock)

- I do know that trying to keep all components a consistent size
(From Header to Muffler Ie. "Header Back system?") will optimize airflow and enhance performance..

To stick with stock overpipe... or not

Here is a rough picture of what I am trying to explain / need advice on...

[FT_86_SM_GP]

I managed to get some time tonight to measure the inner Diameter of the Borla UEL:

Borla UEL Header has a similar Inner Diameter to the Stock header.
(Excuse the poor camera angles and R2 Ruler)

1st juncture port exit = +-45mm (Stock is 45mm)

2nd juncture joint pipe = +- 54mm (Stock is 54mm)

[Ds3ire]

Maybe if you compare these to the Toyota 86 exhaust you will see a difference.
From what ive read (on this forum) the Toyota exhaust is the one that is so much more restrictive than the Subaru. Maybe you will see the differences in sizes there?

Just a thought...

[Dammod]

Originally Posted by FT_86_SM_GP

Thanks

Reason for asking is that I am researching headers and overpipes combo's and noticed the different sizes with various brands

Eg.

Borla UEL Header:
Collector "Outer" Diameter - 2.25inches (Approx 58mm)

Primary Tube Outer Daimeter 1.625inches (Approx 41mm)

(Not sure how to interpret this data from the Borla website)

Tomei UEL Header and Kamak Dynamic UEL Header:
60.5mm Diameter (Not sure if its inner or outer pipe Diameter?)

It seems like the Tomei or Kamak UEL Headers are the way to go if you want better airflow / performance and a refined rumble.

I recently got myself a Borla Version 2 UEL header purely for the love of a louder rumble and the resulting exhaust tone.
(Did not (realize) think about performance when purchasing it )

I was advised by Borla that there is no need to change the stock overpipe as it will not make much difference...
(Stock overpipe has a Diameter of approx 54mm)

I do trust their judgement and advice from their reputation and R&D...

But I am still trying to understand how the stock overpipe (being 54mm in diameter) will not make a difference if changed to an aftermarket 63mm overpipe ?

Maybe the Borla UEL Header is 54mm "Inner" Diameter as well?
(Scary how restrictive it is - Same to stock)

- I do know that trying to keep all components a consistent size
(From Header to Muffler Ie. "Header Back system?") will optimize airflow and enhance performance..

To stick with stock overpipe... or not

Here is a rough picture of what I am trying to explain / need advice on...

In my opinion: Since you want optimum exhaust gass velocity for peak performance, having equal size piping from the header back would be first prize, including a matching overpipe.

Although Borla claim to see no difference with adding an appropriately sized overpipe, other vendors have found the opposite to be true. Granted, in both cases this could be down to marketing.

Don't get me wrong, I don't think you would see massive gains in power (NA) but when you have a few components that all make a "negligible" difference, those "negligible" differences can add up to being a good 7kw (for example) and we all know that when staying NA every kw counts...budget dependent.

I don't think swapping your Borla header out for a Kamak/Tomei will result in enough of a gain to actually FEEL the difference, but when combined with an overpipe, DIF and free'er flowing 63mm exhaust, it might actually add up to something.

It might be worth mentioning: We haven't managed to get hold of a set of Borla headers for back to be testing personally, but a well respected member from Durban who has no affiliation to any specific company has confirmed that the Kamak headers seem to flow better then the Borla's they tested.

Originally Posted by Ds3ire

Maybe if you compare these to the Toyota 86 exhaust you will see a difference.
From what ive read (on this forum) the Toyota exhaust is the one that is so much more restrictive than the Subaru. Maybe you will see the differences in sizes there?

Just a thought...

Are your referring to the headers which are being measured above? If so, the BRZ and GT86 have the same stock headers.

[Freedom]

Most of it has already been done here:

http://www.ft86club.com/forums/showthread.php?t=42555

[sav]

Why are we splitting hairs over a horsepower or two?

[ShaunWRX]

Originally Posted by Dammod

In my opinion: Since you want optimum exhaust gass velocity for peak performance, having equal size piping from the header back would be first prize, including a matching overpipe.

Although Borla claim to see no difference with adding an appropriately sized overpipe, other vendors have found the opposite to be true. Granted, in both cases this could be down to marketing.

Don't get me wrong, I don't think you would see massive gains in power (NA) but when you have a few components that all make a "negligible" difference, those "negligible" differences can add up to being a good 7kw (for example) and we all know that when staying NA every kw counts...budget dependent.

I don't think swapping your Borla header out for a Kamak/Tomei will result in enough of a gain to actually FEEL the difference, but when combined with an overpipe, DIF and free'er flowing 63mm exhaust, it might actually add up to something.
.

Agree! Having an overpipe to match the rest of the exhaust system will most certainly make a positive difference, it will however be very small as the overpipe is very short. Not worth the money IMO unless it come part of a packaged deal

[FT_86_SM_GP]

Originally Posted by Freedom

Most of it has already been done here:

http://www.ft86club.com/forums/showthread.php?t=42555

This was Anthony's reply to the overpipe (Aftermarket Vs Stock) question:

"I highly doubt it would be noticeable at all. The over pipe is only a few inches long, and since it's not smaller than your headers, I don't think it would do anything. Now if it were smaller than your headers, it would be creating a pinch point, but if all your numbers are correct, that's not the case."

The sound of his exhaust setup is insane

[ame="https://www.youtube.com/watch?v=ocO6y-R3GHk"]Borla UEL headers, PLM over pipe, Tomei front pipe, Tomei 60R, OFT 1.58 stage 2 tune, FR-S BRZ GT86 - YouTube[/ame]

[FT_86_SM_GP]

I contacted TMSS in JHB and got a quote of R1,150 excl VAT for a custom 2.5inch/63mm Outer diameter overpipe.

Beats aftermarket overpipes which are +$200 to $300.

I had a look at their work on Facebook (Search: "TMSS Motorsport") and I must say its exhaust porn for me.....
But those Mandrel Bends

Will look into the cost of getting a custom exhaust from these guys.

Heres some exhaust porn: