After being away from track stuff for some 15 years, I’m trying get get back into Driver’s schools this year. I have two miatas. A clean 96 that is a nice street car and a dinged up but solid 93. The plan is to use the 93 for autocross and HPDE. No competition stuff just for fun. I’m somewhat concerned with being frustrated driving the Miata because of all the high hp cars out now. Years ago I tracked my 914 and the last few years I didn’t enjoy myself as the other cars got more powerful.
I already have FM coil overs to install and I’ll need a rollbar. But now I realize that the car still has the original radiator. The 96 still has the original as well and I’m guessing they could crack at anytime. The price to get this car on track keeps going up. So do I really need a 450 FM radiator for a stock 1.6? I thought about buying a stock radiator and going to a couple events and if it’s not enough, put that rad. in the 96 and then buy an upgrade for the 93.
The price to get myself back into the sport keeps going up. Help me spend my money wisely. Thanks!
You can get a good solid radiator for $256 for that car. https://supermiata.com/CSF-radiator-miata.aspx
No reason for the FM one. It'll be much better than stock and give you all the cooling you'll ever need.
In reply to bmw88rider :
Does that require any modifications to fit?
Not that I know of. I am 95% sure it's supposed to be a drop in factory replacement. I'd ping them and ask real quick.
Looks like Good-Win has them on sale for $225 https://www.good-win-racing.com/Mazda-Performance-Part/61-1516.html
I've never had a problem with the 1.6 on track, even in a chump event with the stock radiator. I'll bet if you were in spec where you're constantly in the draft and on R-comps, you'd have an issue. We were running hotter than we wanted with the 1.8, but the next race after the engine swap we got a cast off spec miata aluminum radiator, so I don't have hard data and we didn't have a failure related to either engine when running the stock radiator.
Are the end tanks discolored? The failure mode on those is a bit of general cracking around the clamp, so it's not normally a catastrophic failure model. If it's not too discolored, I'd say run it for an HPDE. Keep an eye on your temps and coolant level throughout the day, if they're climbing then you have a leak so back off a bit :)
I will say if you're running forced induction, those FM radiators can't be beat. I have two friends who had chronic overheating issues with any radiators they tried before those FM ones came out.
Subscribing to this because I too, am broke
Rodan
HalfDork
2/18/19 7:56 p.m.
I have an NB2 1.8 in my NA, and have been running for two years with a stock replacement radiator. I had planned to eventually put in an aftermarket radiator, but it just hasn't been necessary, even running in 90* temps. I'm running a coolant re-route, but you should be fine if everything else in the cooling system is in good shape. Keep the undertray, and seal the upper area in front of the crossmember to force airflow through the radiator. A cheap piece of ABS plastic can be used for this.
A good temp gauge is a worthwhile investment, as the stock one is 'imprecise' at best... 
