03chi-town0Z

iTrader: (7)

6" would probably be the perfect size to reach the outer edges of the cooling fins, but SPAL doesn't make one in that size, and they are the only brand I would consider putting onto my car. For quality and reliability, there is no other that I know of that can compare.

Once you start getting into the 7" and up range, you may encounter some clearance issues with the different bracketry around that area. You could always remove the factory brackets and make some of your own to increase the clearance, but the increased size of the fan would (as Fuego said) probably not show any added cooing benefits since it would outsize the cooler. Again, this is why I like the size that I chose because (since there isn't any actual "shroud" option available) I was able to use the foam tape to create a good seal with the foam tape around the entire perimeter of the fan to optimize the airflow efficiency across the cooler.

Chaz17

iTrader: (11)

Just saw this. I might have to give it a try.

nunyas

iTrader: (2)

I was inside my bumper this weekend and took it as an opportunity to measure the trans-cooler. It's exactly 7" to the outer plates (non-cooling plates), exactly 6" to the outer most cooling plates. So, it would seem a 6.5" fan might be ideal as it would give you some air flow over the outer most fins. A 7" fan might be too tight of a fit due to the brackets (unless you mod the mounting brackets that is).

03chi-town0Z

iTrader: (7)

Awesome. Give it a try and let us know if you can squeeze the 6.5 in there. I just never bothered to go that big because of the overlap outside the cooling area, but if you can still manage to create a seal around the entire circumference of the fan, that would be great.