Anyone have suggestions on brake duct routing. Prior to becoming a scholar of cooling from this thread, I had mangled my stock under tray to allow the ducts to come from the fog light holes and path along essentially where the 'side' of the under tray is. There doesn't appear to be enough space to force all of it to the inside of the tray and there definitly doesn't appear to be enough space on the outsid eof the undertray without the tires taking large chunks out of the ducting. I must be missing something. Almost every picture I've seen of brake ducts, there is no undertray installed, so I'm floundering.

 

Assuming you are talking about an NA/NB, big 3" ducts need to be inside the frame rail generally. That means either hacking up the OEM tray or just building something. The side sections of the OEM tray are obviated when you put a full coverage undertray in. Important details is to have as few bends as possible in hose. Every bends chokes airflow. 2.5" duct with 3-4 bends has virtually no useful airflow. If you plan on 2.5" ducts, you would be better off with big printed or fabbed deflectors mounted to the FLCA and no backing plates.

 

I have the 3" from singular. Any suggestions on what you mean by a full coverage undertray or are you talking about something fully custom? Prior to be un-******* the under tray, essentially it bent very gently going from the fog light. I had it tied off to the sway bar and then a 90ish degree turn from the sway bar to the ducting plates. I'll look again, but it jsut feels like squeezing 10lb of **** in a 5lb bag.

 

I ran them with turbo intercooler plumbing, a modified OEM undertray, and power steering (but AC removed). Basically they run from the fog light holes back to just behind the radiator, duck inside the frame rails through holes that I cut in the undertray, back for another 8-10 inches to allow the tire to come in, then back out through another set of holes in the undertray and along the tie rods to the wheel.

From underneath:


Passenger side:


I don't have a photo from the driver side wheel well without the undertray, but it runs between the sway bar and the (black) intercooler plumbing here:


Lots of bends in the ducts so I'm sure it doesn't flow as well as might be ideal, but it did work. Also, as you can see this isn't perfect and the wheels do still tend to chew up the ducting over time. I think that's pretty much inevitable with any brake ducting.

--Ian

 

Started a new thread just for brake ducts, since we didn't have one.
https://www.miataturbo.net/race-prep...8/#post1673189

Way too bendy. Buy a cheap anemometer from amazon and see for yourself.

 

Has anyone had experience with the Chikara oil cooler kit? I have not added ducting yet. I'm not sure where to put that oil cooler. Wondering if others have played around with it here. Was also looking at their 78 C thermostat. I still have the stock one on my coolant reroute.

 

Cooler thermostats don't improve cooling issues. Once it is open, it's open. Either the car stays cool or it doesn't.

 

I would think it would just delay the heat soak. The sooner it is flowing at full capacity. If you are doing 20 minute sessions this could give you the 20 minutes you need to do 1 full hard session before you need to do a cool down lap.

 

I'd aim for more like 100-105C. 78C is too cold for engine oil. We're happy with 240F oil temps which is 115C

 

In theory maybe. In practice, the oil temps will skyrocket if the cooler isn't working well enough. 78C is too cold for engine oil. OK for diff and trans. But the Chikara kit looks good, he shouldn't have a problem with normal 105-115C oil temps.

 

Extreme wear occurs at cooler operating temperatures. A chart was shared here years ago. It might even be in this thread. Below 180-185 is no bueno under a load. 172.4*F may bite you.

 

Just a quick note about the Chikara oil cooler - the model you linked does not have a thermostat. For the same reasons you want the right thermostat in your cooling system, you want one in your oil system. Especially as (IIRC) this is a dual-duty car.

 

Oil specifically, yah. Needs to be hotter to work. Above 210 anyway. Coolant temps on most modern engines need to be around 200 or a bit lower for best power and efficiency.
Low coolant temps can be bad on a stock ECU.

 

Makes sense,

They said they do have one with the thermostat. Good call out