Plastic quarter window

[Gregf]

In looking over a customers ITS car for a race weekend the question came up regarding a replacement rear quarter window that was used to install a Naca duct for driver cooling. One of our newer racers said it is not allowed in the rules but I clearly remember it being in Fastrack that one window could be replaced for the purpose of driver cooling. Where did this go? Greg F

[Gregg]

In Spec Miata you may replace the vent window for this purpose, but to my knowledge there is no such allowance for what you describe in IT.

That said, with both front door windows either down or removed, it should be pretty easy to draw cool air for the driver.

[Greg Amy]

I concur with Gregg. What you read was for Spec Miata; not allowed to replace the quarter in IT.

[Andy Bettencourt]

'Rear' quarter window? What kind of car? Are we sure this is a Miata?

And IIRC, the rules for this type of replacement DO exist for IT (front quarter).

[Greg Amy]

'Rear' quarter window? What kind of car? Are we sure this is a Miata?

He didn't say it was a Miata, he said it was an ITS car.

And IIRC, the rules for this type of replacement DO exist for IT.

"Quarter window", Andy? As in the rear window on a 2-door car? Ain't sayin' it's not there, but you'll need to cite that in the regs...

[tac911t]

Section 9.i, mentions driver/passenger window area can have ducting added. No mention of replacing glass with plastic. I have seen NACA ducts positioned in line with the plane of the open drivers or passenger window to capture air into a hose that is routed to the driver.

[Andy Bettencourt]

"Ducting may be added to provide fresh air to the driver/
passenger compartment. This ducting shall be located in the
driver and/or passenger window area, with no modifications
to the bodywork. Only the cooling duct is permitted in the
window area. It is not permitted to otherwise fill in the window
area. The complete duct assembly in the plane of the window
shall be no larger than 100 square inches."

So I would submit that a window in the drivers compartment can be replaced with a plastic NACA duct set-up provided it does not exceed 100sq inches.

[Knestis]

Section 9.i, mentions driver/passenger window area can have ducting added. No mention of replacing glass with plastic. I have seen NACA ducts positioned in line with the plane of the open drivers or passenger window to capture air into a hose that is routed to the driver.

...but it allows that duct assembly an area in the plane of the window of up to 100 sq in.

K