After some lengthly conversations with my tuner. I might be interested in doing a engine build. I'm just writing this up. So, that I know where to find all my info and if other experienced members wish to comment and help.
So, here goes. After lenghty talks and possible upgrade routes discussed. I think i'm going to get my tuner to build me a engine. What I've found out so far is that they use Ron formally of axis power to do their engines. Which is nice to know. They also recommended Mahle pistons if I wanted a quieter engine. Mahle pistons are in a majority of german engines and are in porsche engines. So, this seems like a no brainer right? Wrong...their lead tech said with a warning. Don't get the weak mahle pistons. Which I had to research to find out wtf he was talking about.
Ok, so theirs two different kinds of forged piston alloys. 4032 alloy and 2618 alloy. The Mahle pistons that are known to break are of 4032 alloy. Why? Well after reading unabombers piston faq. (
Piston FAQ: Read if you are thinking about buying them! - NASIOC )
Its because 4032 alloy is made for use in N/A engines. 2618 alloy is made for blown, marine, and nitrous applications. Do they make a mahle 2618 alloy piston? Yes...they do.
The reason my tuner recommends Mahles over CPs is because they don't have the piston slap, oil burning, and blow by on cold starts. That and the over all noisey aspect that CPs tend to have. They run smooth and quiet...near stock noise levels. Now, normally why CPs are agreed to be better. Is because CPs are from what I understand only made as 2618 alloy. But, the CPs wrist pins aren't at the stock location like the Mahles. Which is where the piston slap comes from. That and the piston has to warm up and expand into the cylinder.
EJ_Rex: I was really considering the hypereutic silcia alloy pistons until I read this in unabombers piston faq.
Quote (A. Graham Bell, in his book "Forced Induction Performance Tuning" (published in 2002 by Haynes), says hypereutectic pistons are a poor choice for turbocharged engines. Hypereutectic cast pistons have twice as much silicon in the aluminum alloy as regular cast pistons (15-20% instead of only 7-8%). According to Bell, the added silicon leaves them "quite brittle and, as such, prone to breaking when subjected to detonation.")
Oh, my tuner also said eagle rods were crap. I have to talk some more on what rods to get. If I get them upgraded as well. I don't know. I want around 350 whp and piece of mind. After reading this:
Public Service Announcement. "I want 400whp!" Are you sure? - NASIOC . That midniteblack posted a while back really makes me want to do a engine build before I go turbo upgrade. I don't want a piston to shit the bed while driving it hard every once in a great while.
Like the thread topic....feel free to comment. I'm just mulling over my options. Oh and I'm going to live by the K.I.S.S. (Keep it simple stupid) motto on my build. Like I said before at most: pistons, rods, and apr studs. I'm not chasing shoaf numbers, lol
EDIT: Thanks to Josh.
Compression ratios:
WRX 8.4:1
STI 8.2:1
Mahle 2618 pistons are rated 8.5:1 (which, I'm thinking will have to be accounted for in the build)
