Coolant expansion tank? Not sure if that is the right thing to call it. Essentially I have my heater core deleted and the hose looped from the block to the head. I'm thinking of building an aluminum container in between those hoses o increase coolant capacity to help with cooling since I'm running a half core. Looking for any opinions on that idea if its a waste of time or do people do this... I just can't find much info on it. I am a total novice in the autox world but its what I've been wanting to do. GSR Turbo'd CRX, runs cool on the streets but I understand beating on it around a track with an average of 2 minute lap times is much different. I have a second bumper already that I opened up greatly to allow some direct airflow to the radiator along with ducting. Contemplating buying a second hood and venting that so whenever these events happen (once a quarter) I can swap the bumper and go about my day.

 

Half core isn't going to cut it. Suggest a dual core full size alum rad with some fans.
I run a mishimoto dual core integra rad in my eg hatch.
I've seen CRX's with the same set up so you have to move the lower rad mounts, and fab some upper ones.
Simple enough with some 1/8 alum strips.
Just make a hole big enough to slide over the top points and put some tight fitting rubber hose to cushion it.
You don't need to increase your capacity with a larger rad and all you need to do it keep your overflo tank.
Done.
Vented hoods also help out too!

 

Unfortunately I can’t run a bigger radiator with the way I just set the car up. It’s a big battle between appearance and street driving versus autox I know. Hard to find the balance. The course appears to be about 1 minute average laps. I just installed a water meth kit and that lowers my IAT’s dramatically so just looking at coolant help. I’ve been running an auto zone thermostat so about to try and OEM one to see if it helps. Still looking for a spare hood to vent and maybe a bumper to cut up a little to allow more airflow mainly for autox days.

 

I'd put the heater core back in, maybe at the front bumper, to be another heat exchanger.

 

Well if you have no room, open up the hood with vents

 

I like this idea... I don't have the original heater core or blower anymore. I wonder if I can find a small tiny one that I can mount in the wheel well or blowing down into the passenger area where my battery used to sit.

that may be where I head but now the heat exchanger idea has me thinking.