Upgrading cooling system
 

Hey guys im looking to upgrade the cooling system in my FD and i want to mainly upgrade to a front mount and a bigger radiator but i dont want to have to trouble anything with the ac lines. Whats a good aftermarket radiator and front mount intercooler to get that i wouldnt have to trouble anything. Btw my fd is stock.

If you want to improve cooling, the last thing to do is put on a front mount intercooler. For one, you're putting a huge heat-sink in front of the radiator. There's also more fab work, plumbing and usually cutting or compromising the front bumper at least to an extent. And not sure if there's any chance of keeping the A/C condenser with a FMIC.
KOYO N-FLO or FLUIDYNE are popular aftermarket radiators. KOYO is about 100% larger, Fluidyne about 50% larger. The larger tends to have a little more fitment issues.
A nice cooling mod that is completely plug n play is a Series 5 (89-91) RX7 fan thermoswitch. That lowers low-speed fan threshold temperature from 108 C. to 96 C.
Run as much distilled water to coolant as you can get away with in your area, but not less than 20% coolant.
Use upholstery foam to plug gaps around the radiator/intercooler duct. Just look thru the bumper nose and you'll see what I mean.
Do a cheap bastard mod to the stock intake box. This sources ambient air from the nose instead of the stock intercooler duct. Search in the 3rd Gen. FAQ stickys at the top of this page under cheap bastard for more info.

If it's stock you shouldn't have issues overheating. I would get a little larger rad, if you can find a beter intercooler for stock mounting. I would get dual oil coolers if you don't have them., put some Evans coolant.
If you are stock don't want mess too much with it. Leave it alone.

Good point on a second oil cooler if the OP doesn't already have one. But I don't think you can just put in "some Evans". IIRC no water or traditional coolant can be in the system. I think they even have some sort of flush procedure. It's a nice idea, zero pressure and better heat transfer. But it does come with some baggage. It's about $45 U.S. a gallon and you really should keep some extra around, just in case.

The Big Fat FD3S Cooling Thread

https://www.rx7club.com/3rd-generati...thread-571088/