Like the title says I need help deciding what filter to get. It is a TO4R so it has a 4" inlet. These are the two I have looked at:

K&N RU-2520 4" inlet, 5 3/8" base, 4 3/8" top, 5" long

K&N RU-2590 4" inlet, 5 3/8" base, 4 3/8" top, 7" long

Which of these two would be a better filter for what I have, or if you recommend something else please tell me.

Thanks
M-P

 

I had a 5" K&N bolted directly onto my turbo, but the turbo was collapsing the filter it was sucking so hard.

I now have a 7" K&N bolted onto 4" tubing that comes from the turbo. It's hard to tell if it's faster or not, but the BOV sounds a lot cooler!

 

If there's room, bigger is generally better (unless it puts part of the filter near a hot part).