I want to replace my stock plastic looking intercooler piping to something like a greddy 2 or 3 pices unit. My question is can i still use my stock intercooler? let say i want to upgrade to a bigger IC later on in the future will the greddy unit be ok? or i have to switch to a different piping again?

 

Depends on the IC you upgrade to... If it's a stock mount IC, then the stock mount pipes will work.

 

 

something like a M2 stock mount? how much bigger are the stock mount vs a stock from the factory? do i need a 2 or 3 pices piping for the future upgrad?

 

Take a look at the M2 site:

http://www.m2performance.com/pinterc.htm

(*Replacement of the stock air-box is required. Requires the use of Greddy Intake Elbow. Modifications are required if used in conjunction with an Efini Y-Pipe. Parts included are: (1) IC core, (1) IC duct, (2) polished aluminum IC pipes, (4) silicone couplers, (8) constant torque hose clamps.)

As for the size, take a read through the following link. They have size comparisons of the various IC's:

http://www.scuderiaciriani.com/rx7/intercoolers.html

 

The Greddy piping kits will only work with the stock, Greddy stock mount intercooler and ARC stock mount. It wont work with any others as far as I know.

Jason
www.rx7store.net

 

If you are planning on getting the m2 then don't get the greddy pipes for the stock intercooler because you will just have to sell them.