ST4 Rear quarter window brake ducts and undertray question

[kjbrew01]

Hi,

 

I see in section 6.3.9

9) NACA ducts, air ducts, or air hoses placed in a side window frame solely for the purpose of driver cooling.

In my rear quarter windows I have naca ducts to feed my rear brakes.  I see allowances for fenders and bumper modifications to feed brake ducts but nothing about the quarter side windows.  do I have to move my brake duct intakes somewhere else like under the car?  

 

in section 6.3.1

1) Flat undertray/belly pan forward of the centerline of the front axle, extending no lower than the bottom of the front fascia.

 

I assume in a strict reading of this that the undertray must be perfectly flat.  I am looking at the pan listed below.  as you can see this pan raises as it goes rearward to stay tight to the existing car subframe, making it not flat.  would this pan not follow the intent of the rule?  because if not I will have to space the pan down significantly from the structure of the car because the bumper lip is so much lower than the subframe.  

 

https://www.hammereng.com/product-page/mk3-supra-under-tray

[Greg G.]

On 10/11/2022 at 5:45 AM, kjbrew01 said:

Hi,

 

I see in section 6.3.9

9) NACA ducts, air ducts, or air hoses placed in a side window frame solely for the purpose of driver cooling.

In my rear quarter windows I have naca ducts to feed my rear brakes.  I see allowances for fenders and bumper modifications to feed brake ducts but nothing about the quarter side windows.  do I have to move my brake duct intakes somewhere else like under the car?  

 

in section 6.3.1

1) Flat undertray/belly pan forward of the centerline of the front axle, extending no lower than the bottom of the front fascia.

 

I assume in a strict reading of this that the undertray must be perfectly flat.  I am looking at the pan listed below.  as you can see this pan raises as it goes rearward to stay tight to the existing car subframe, making it not flat.  would this pan not follow the intent of the rule?  because if not I will have to space the pan down significantly from the structure of the car because the bumper lip is so much lower than the subframe.  

 

https://www.hammereng.com/product-page/mk3-supra-under-tray

Yes, you would have to use another source for brake duct air.  Note that you can go through the inner fender, but not the outer/visible fender.

The part you show seems to show the pan "lowering" (going closer to the ground) as it goes rearward.  It almost looks like the opposite of what you are describing where in the photo, the bottom of the front lip appears higher (farther from the ground) than the subframe.  Either way, flat means flat.  If it is not possible because the front lip is too high compared to the subframe, then...warts.  If the front lip is lower, then yes, still flat, and hanging below the subframe.  Note that these side pieces would not be compliant.