How important is the under tray?
 

I was going about 200 km on the highway and then I noticed my stock temp gauge go up to nearly hot. When i brought it to my dad's shop I noticed there was no stock under tray. Is the under tray important and what does it do? Ps Im going to make one from aliunium tomorrow

i've seen nothing good come out of NOT running with the stock one, so def get that back on there. more than once i've read on here about people getting coolant temp probs when they removed it

Yes, it's important! Besides any aerodynamic effects, it seals the bottom of the radiator so air will actually go THROUGH the radiator instead of underneath it!

Why go through all the trouble of fabbing one up when they are only like $130 from Malloy Mazda?

I was planning on getting a peice of aliunium sheet from home depot and cutting it to suit. The car didnt come with one. I thought all FD models came with teh under tray? Mine is base.

Obviously, the previous owner of your car removed it for some reason. I don't think you realize just how complicated the undertray is as far as shape and mounting. It's not just a five-minute job of cutting some sheet metal to suit. Just order an OEM tray, you'll have it in a week or so and it will WORK.

Check out this thread:

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/ive-been-missing-underbelly-pan-years-maybe-thats-why-my-coolant-seals-fail-186812/

With that said, I strongly suggest you check out your car before driving it again. Yes, the stock undertray helps enhance cooling, but it's not the end-all. You won't overheat w/o it. You may run a few degrees hotter consistantly, but not frank overheating.

Oh, and in case you don't know, the stock temp gauge is very heavy..it doesn't move as the temps fluctuate. If it moves, you're in serious trouble...so I'd check out what's causing your temps to rise A LOT (as to actually move that stock gauge) before driving her again. You could very well be damaging your engine...

Lastly, a water temp gauge is strongly recommended your you can relinearize the stock temp gauge (I believe that's the term they use, yes?) Either way, you need something that's a bit more accurate than the stocker, that only reads "Ice," "On," and "Melted" :p:

~Ramy

I also took off the heat shield that covers the cat. Could that have caused the car to run hotter? Reason I took it off was because it was hitting the body of the car and was making an annoying ass sound whenever the car was in neutral and idling.