Here's an update with the ducts I added to my car. I removed the foglights and brackets to leave open holes. Tried a couple pre-made ducts but none would quite fit even with cutting. The holes in the 87-88 bumper are roughly 5.5x2.75 so 3" hose won't fit and most available ducts have an opening for 3" hose. Other problem as Van mentioned is the IC pipe being in the way on the PS side if you still have a crossover IC piping route. I decided to make a duct from sheet metal and offset the inlet to the outside of the foglight opening so I could squeeze the hose past the IC pipe.
Parts I used; 2.5 Al. flanges (from aircraft shop), 2.5" 500 deg. duct hose (race/aircraft shop), light gauge sheet metal, factory foglight bolts
I bent the sheet metal to create boxes to fit around the foglight openings. Then added the flanges to the middle portion of the box face. Not a true chamfered duct shape that necks down to collect air, more like an HVAC duct shape. I didn't have much time to make these between events, maybe I can improve them to collect better in the future.
Pics:
Showing location of opening in duct on PS, IC pipe can be seen through opening
Duct on DS
Al. flange placed into hole cut in factory dust shield vent location. It's not the ideal spot which would be the center of the spindle to pull air from the center out but this is the best location I found. May be able to use the area near the ABS sensor but I wanted to avoid the sensor and only have one opening so all air is directed through it. I cut the edges and bent them down to better match the dust shield and avoid contact with rotor.
Back side of dust shield with flange sticking through. A 3" flange & hose may be able to squeeze in but the 2.5" I'm using gets slightly pinched by the endlink when front suspension is compressed.
Rear of duct shown with attached 2.5" hose (yes I need a new bumper, sponsors?
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Routing of hose to inlet on dust shield. Added duct tape to hose where slack is hanging from frame to minimize tearing. Need to make sure full movement is accounted for with slack in hose. Secured to flanges with 2.5" screw clamps.
Impressions:
See ya shelby!
I put 15 sessions (25-30 min.) on the front pads but only half were with the ducts and the other half were 95 deg. days. I was much faster the last 2 events being on RA-1s so it's hard to say how much this helped. I did get some odd wear last weekend (45-60 deg.) which cause me to bend the top end of the inside pad backing plate on each side of the car. I'm wondering if it was concentrating too much air to one end of the pad being so cool out. Maybe blocking off the ducts in cool weather is a good idea with this compound, I'll ask the vendor. Overall, no fade on the stock brake system, fluid did not look as dirty after sessions as it did prior to the ducts. I've had instructors ride with me that say I've got great brakes, these guys were driving 240's and FD Rx7's.
Brian
Thanks,
Brian