Aftermarket exhaust and downforce

[wootwoot]

Originally Posted by icemang17

I would say NO......the stock exhaust setup would not benefit a diffuser....diffusers must be engineered correctly to work....typically they start at the centerline of the rear axle and rise UP at around a 15' angle with some vertical slats towards the bumper.....if the angle is much more or less they don't really work....most diffusers you see on cars don't work....they just look cool

Adding an exhaust outleft to the diffuser IS a great way to increase airflow over it....BUT at one drawback, it increases downforce WHILE on throttle, then when off throttle the flow stops and you lose that downforce out the back...which can be compensated for....personally I like a car thats slightly loose on turn in....but it took me years to become comfortable driving this way

Any comment on the borla diffuser design? It looks like it could be functional... but you seem to know more than I do.

[icemang17]

I looked on Borlas website...they show a header and cat back exhaust.....I didn't see a diffuser..... I would guess it just tucks into the factory rear bumper, which has a slight diffuser setup to it.....but its probably more cosmetic than functional....

[boredom.is.me]

What about the Q300 from Invidia?

[wootwoot]

Originally Posted by icemang17

I looked on Borlas website...they show a header and cat back exhaust.....I didn't see a diffuser..... I would guess it just tucks into the factory rear bumper, which has a slight diffuser setup to it.....but its probably more cosmetic than functional....

If you follow the link in my original post you can find a picture of it...

[AlvinT@Borla]

Originally Posted by wootwoot

If you follow the link in my original post you can find a picture of it...

This is Alvin from Borla Performance in CA. I wanted to add some R&D images and share some facts in advance of our product website release (PN-77012).

The Exhaust Diffuser inspiration comes from my years of track day driving, product design experience, and interest in motorsports. Borla does not make any claims regarding downforce performance benefits and we've not performed any formal wind-tunnel testing. Keep in-mind that we've considered thermal expansion of our cat-back exhaust for mechanical fitment and we've designed periphal spacing to allow (exhaust tubing heat) ventilation.

This component is designed to compliment our cat-back (PN-140496) and will NOT fit other exhaust systems due to position of the (rear) exhaust tubing. The diffuser body material is lightweight aluminum finished in a durable silver metallic powdercoat. The kit includes stainless steel brackets that allow easy removal for servicing or touch-up (for those that choose to custom color-match the diffuser). Look to our website release this month with MSRP under $500.

This product is both an aesthetic and functional component. It adds a subtle track-inspired look to your FR-S/BRZ and does not require any drilling or removal of any factory body-panels for installation. This component fills-in the gap of the large (transverse) OE muffler, returning factory-like aero while saving weight. Our cat-back exhaust saves 10-lbs from the OE exhaust and our exhaust diffuser weights 7-lbs (total weight savings ~3lbs).

We believe we have a terrific FR-S/BRZ solution for the track-oriented driver looking for a lightweight exhaust solution, a more agressive exhaust note without annoying cabin-resonance, and a unique look of an exhaust diffuser.

Thanks!

****************
FYI, we offer these vehicle-specific Cat-backs + Exhaust Diffusers:
BMW 1M (PN-77010), Audi TT-RS (PN-77011)

[AlvinT@Borla]

Additionally, adding our UEL Header (PN-17284) to our cat-back(140496) adds mid-range performance + the awesome boxer-engine sound, and has been recently track-tested to comply with (92 dBA) sound limit at Mazda Raceway Laguna Seca..
[ame="http://www.youtube.com/watch?v=i3M_mosJkRs"]FRS passes everyone @ Laguna Seca - YouTube[/ame]

[AlvinT@Borla]

Originally Posted by wootwoot

If you follow the link in my original post you can find a picture of it...

Some pics can be viewed here...
[ame="http://www.youtube.com/watch?v=T53E3xVQR0M"]Borla R&D - Exhaust Diffuser R&D - 2013 Scion FR-S - YouTube[/ame]

[OrbitalEllipses]

Originally Posted by AlvinT@Borla

Some pics can be viewed here...

Many thanks. I've cross-posted this video in our aerodynamics discussion thread in Suspension/Chassis/Brakes.

[JesseE]

Alvin, any dealer discounts and when are these available to order, I ordered through my borla dealer, but still waiting on header to get here, would love to ad these to my order too :-)

[AlvinT@Borla]

Originally Posted by JesseE

Alvin, any dealer discounts and when are these available to order, I ordered through my borla dealer, but still waiting on header to get here, would love to ad these to my order too :-)

Thanks Jesse for your order. Borla production in Johnson City,TN will be building the UEL Header 17284. Sorry for this delay. A limited number of pilot-build headers were made at our Borla CA facility.

Borla CA will be build the Exhaust Diffuser 77012 and these should be available in 2-weeks.

Shop our dealers for your best price. You can locate a Borla dealer on our website, www.Borla.com.

Thanks again for your interest in Borla!

[icemang17]

nice looking product.....I would imagine its effectiveness will only increase with speed....since 60mph and under is difficult to get aero working...

Do you have access to a air pressure tester? Some racing friends have sourced them cheaply and use them to measure pressure differentials on splitters-etc....getting an actual air pressure reading allows you to calculate the actual downforce provided without an wind tunnel....great data....

[AlvinT@Borla]

Originally Posted by icemang17

nice looking product.....I would imagine its effectiveness will only increase with speed....since 60mph and under is difficult to get aero working...

Do you have access to a air pressure tester? Some racing friends have sourced them cheaply and use them to measure pressure differentials on splitters-etc....getting an actual air pressure reading allows you to calculate the actual downforce provided without an wind tunnel....great data....

Air-pressure tester link? Thanks.