Jterry- The Hyper Voltage Regulator stabilizes and helps regulate and steady the electrical current flow, example: No dimming, fading, brightening of lights when idling or excellerating, cleaner electric flow throughout the vehicle, I guess... That is how I can best describe what it did for me...
Wdoherty- Thanks for the compliment but I do try to listen to others with more experience then me.. I am not that bold as to defy the experts in most cases. To tell you the truth if I had not already bought this dual flex fan before this thread started I would not have gone for the swap. Since I had the fan already and could not return it I had to give it a try. I just figured Summit Racing and the manufacturing company selling this dual fan specifically made the claim and labeled the fan specifically for a the V8 SC400 Lexus. So taking that into consideration you would have to think they (the company/summit/etc) must have done some testing on the cooling factors for the SC400 V8 motor, etc... That was my thinking and it seemed to work out.. Besides even it it didn't work out, I would have got the large version 16 inch blade electric cooling fans like Lex has on his turbo'd LS400. The dual electric fans work just fine on the Sc400's in all weather conditions....
In regards to the nos I did use a piggy-back ECU to tweak the air/fuel ratio to have the car run just a little rich, also installed a high flow Walbro Electric Fuel pump and cooler running autolite nos spark plugs. I played it real safe with my nos and also set it up for the possibility of a larger nos shot in the future. However, I am just about maxing out the volume capacity on the stock injectors, so larger injectors would be needed most likely on a 200hp nos shot. On a nos shot of 100hp or less I am pretty sure you can get away without tweaking anything other then maybe the spark plugs....
cribby - Cribs with all due respect I am hard living proof that the dual fan works just fine on the SC400 in all weather conditions. It is 85 degrees today in LA California, we don't have winters here really. I was in traffic just today with the car and with the Air Conditioner running for atleast 20 minutes on full blast. Temp needle is steady if not cooler then if it were running the stock hydro fan.. Now Cribs considering what you said just maybe I am cooling better because I have a slightly mod'd brand new radiator, new coolant, and no under engine cover so there is more air flow throughout. That also could be adding to the cooling efforts but I really dought it. In addition to that as you can see I really took the time and effort to do this install correctly. So unless these Supra's run much hotter then my sc400 and require greater cooling efforts, I would have to disagree with you in regards to them failing on the SC400's on the hottest of days... You may be wrong on this one concerning the sc400's.....
My biggest concern on this swap and only concern now is that the hydraulic pulley pump bearing may be overheating, only time will tell. I heard a little squeeling noise for a minute today and quickly opened the hood and it went away. If the hydo pump pulley bearing overheats I figure it will make that kind of noise before failing. So I will keep a close eye on it and know more in a few weeks. If the pump bearing fails I will remove the pump and pulley completely and loop a shorter serp belt and bypass the pump pulley altogether. I will just hope for no serb belt slipage from the crank pulley as the grab will be greatly reduced. The cooling part is not a concern or issue and won't be from this point forward......Man that was a story, sorry......
