ah i think we bumped heats on the communication hah sorry about that..

window removed from the equation, the difference is the seal on the cap. the seal being the rubber and a spring assembly that determines the pressure in which to release.

That's what I thought. :tiphat:

So assuming you got a window material that could handle the pressure, it is possible that you could make one that works for both and all 2009-2011 owners would need to do is use a different cap?

I may have a solution to the pressurized system issue. I will design the top threaded bung in a manner that allows for a threaded adapter to be installed where the cap goes that will be able to have a pressure cap fitted. that way 1 part number can be used on all versions and just sell an adapter for those that want it.

I dont have the capabilities to make a pressure cap for a reasonable price but I can make a screw in adapter of some sort.

That's kinda what I was thinking. There's not enough 2012+ Zs out there to really make a separate design cost effective, but altogether there's enough of us to make the price more palatable.

Using the OE cap off the OE pressirized tank?

yes using the oe pressurized cap. the problem lies in the way to use the cap. from a machining standpoint its fairly complex. thus adding more cost. if i can keep that cost out of the normal system it would be best for everyone.

so ill come up with an adapter that will work for everyone!

Here's the set-up on pressure tank on my '13. The first cap on the radiator is just a sealing cap with no pressure relief spring. I presume the coolant in the radiator heats up and expansion moves it under pressure into the pressurized tank where it cools and then returns to the system. Here's a pic of the cap off the radiator.

http://i1234.photobucket.com/albums/...ps2012b47f.jpg

And a close-up of the cap showing it's just a sealing cap with no relief spring.

http://i1234.photobucket.com/albums/...ps348eacfd.jpg

The third pic shows the cap that is on the coolant tank which is a normal radiator cap. I think the idea of the system must be to increase the circulating capacity of the cooling system by 2-3 quarts. It's obviously not just an overflow system. I think this is the same type system on GT-R and the technology may have trickled down from that system.

http://i1234.photobucket.com/albums/...ps846d294b.jpg

Instead of a sight tube or sight glass what if you could manufacture or attach something to the underside of the cap that would allow someone to just pull the cap off when cool to see the fluid level? It could be as simple as a ball chain with two different colored balls :ugh2: along the chain to indicate a high and low, no? Maybe something more like an oil dipstick with a metal rod that has upper and lower markings would be easier to make...I really have no idea and if this suggestion is stupid I would appreciate no flaming.

we can do soething like that.

Maybe I can build that into the cap

Chrome reservoir tank sounds good ;)

:drool:

Are those caps for the radiator tank?

Looks like Oil Filler caps...