There's no doubt that the standard radiator in an SE is a superior unit and in all likelihood would be all that I require for my purposes as I'm not going for huge power gains or planning to track this car. That being said I work on the basis that as components wear out I will always consider if there is a better product available rather than simply replacing with OEM. This improvement can be in the form of performance, reliability or some other factor such as astheics.
In the case of the radiator it appears that you have to start spending some serious $$$ before you get any real performance gains in this department, and if you go for an eBay cheapie you potentially even have poorer performance compared to the SE radiator sepecifically.
tomli123001 wrote:- However, the fins are less dense than on the SE.
- SE Radiator had this foam thing around to direct air. The aftermarket ones don't. Even with a cover plate in place, there is gaps in NB cars.
- I have installed an oil temp sensor in the oil filter relocation kit. The oil temperature did NOT drop in hard driving compared to before.
Thanks for the direct comparison tomli, a couple of thoughts on your observations;
- The lower fin density could lead to higher air flow rates through the 'cooling stack' (intercooler, AC condensor & Radiator) potentially resulting in improved performance at speed (just speculating here)?
- Foam?, I'm aware of this and it's the same case for all non-OEM radiators, I was planning to add foam to suit to seal this gap with whatever I end up getting.
- I suppose the lower fin density + 10mm thicker core balance out to have similar performance, I wonder if it would do better with foam added to seal the gap and force more air through the core?
I've come to the conclusion, for my purposes, that it's a decision of two options really, (others with different goals would obviously consider other options);
1) get a factory OEM replacement which would be good for another 10 years and be quite adequate for my uses (ironically this is also manufactured by Koyo).
2) get the aftermarket Koyo (pretty settled on this brand/model) which might perform slightly better under certain circumstances with foam installed.
OEM is cheaper and a known performer.... Aftermarket has possible benefits in terms of performance (maybe), reliabilty (no plastic tanks) and asthetics (shiny!) but comes with a weight penalty (extra coolant). The only tangible benefit in real terms of the aftermarket is asthetics really.....
So the choice is 'Bling' or 'Budget'!
Oh dear, I think I know which way I'll end up going.......
Then off with it to Dann for a turbo kit 
