I’m running a Pro alloy triple pass, on my Honda’d S2. Done a few trackdays and got stuck in some traffic, no problems and seems to keep temps down ok.
2.5 years actually
Well … I decided on a proalloy triple pass in the end.
Looking forward to fitting it …not !
Cheers for all the input folks.
not that hard to do, you will need a 10mm ratchet spanner for a couple of bolts on the front clam behind the doors, it is not really hard, there are just a lot of bolts, don’t forget to use copper slip or similar on the bolts during reassembly even if you do use stainless to replace the crap lotus use 
Anyone running a triple pass ever looked at the pressure drop across the core compared to the single? Or ever compared back to back single vs triple on an otherwise similar core? I think you might be surprised if you were once sold on triple concept and did some testing on the single. IME, money is better spent on the single for these short little radiators…
-PV
My actual rad was converted by Proalloy from single pass to triple, there was a noticeable difference in running temperature on track, I was struggling running in the high 90’s on a cool day once I added the gearbox cooler (shows how much temperature it takes out of the gearbox) . So I took the rad out and proalloy converted it for me. This has resulted in my car now running in the low 90’s or even high 80’s on comparable days and tracks. To me this means it is a worthwhile upgrade 
Good data point, Ade. I’m not sure I’m sold. I’ve done similar back to back tests and found large improvements converting the triple to single. Much lower pressure drop, more volume, less coolant temps, etc. Are you doing anything to bleed the system or just running the stock header tank and routing? I ask because I’ve seen several cars where the customer is CERTAIN the system was air free to later find out it wasn’t…
Interesting but I too am not sold. My OEM plastic end rad never overheats with over 300 ponies, ,but accept I’m pushing my luck and it is a next winter job. So watching this thread with interest. I harp back to Randys experience with the rads in the Europa. The higher resistance of the triple pass meant you couldn’t get the same flow rate through it, even if the cooling of the fluid was greater in raw temperatures, there was less volume cooled.
More stats please
I see it like this …
Proalloy = very respected in motorsport…
Triple pass = no reported issues …
Yes , debate is good but scaremongering aint
John
Any rad that doesn’t leak is better than one that does
The end 
Scaremongering is a poor choice of word, it suggests malice and stimulating sensible debate is not underhand.
Agreed