I asked the moderators to lock this thread: https://www.clublexus.com/forums/sho...5&pagenumber=1

While it contains some good info, I found a mistake that's a little difficult to recover from. My calculations are correct, but my claim that TT pistons contribute 4cc's to the clearance volume is just plain wrong. Read Lance's write-up about Motorola Cup specs concerning the head volume, squish, and piston dish, and you'll notice it's actually 13.8cc's.

There's still hope, however. If you can find a 4cc dished piston, then 8.6:1 is what it comes out to. Arias pistons makes a well-respected piston in the 9:1 range which means the dish volume is < 14cc's. (They advertise it at 9.6:1, but that was incorrect because they used an improper dome volume when computing the C/R).

In the end... one TT hg goes a long way at making the NA motor turbo friendly. I just wish TT pistons were the right volume to close the deal.

Sorry guys... my bad.

-scott

 

Arias pistons have a -10cc dish... you can get custom pistons made to any size you want... we have some Ross pistons with a custom dish that came out quite nice