The Motor Build up is about to begin...just a quick question
 

Guys, as some of you know I have purchased a 1.8 motor for a while now. I am getting ready to build it and I have decided to abort the 2.0 Route. I want to keep it as a 1.8 however I want it to be fully built. Anyways, i was looking at some pistons to order and came upon the wiseco pistons. I see that there are 3. Which one should I go with? Their Compression ratios are 8.5-8.8 for their turbo pistons.

http://www.wiseco.com/PDFs/Catalogs/...aMiniMitsu.pdf

um how about just getting the largest overbore size. On that list it is 1mm over, will add a little bit of displacement. Another option to look into is getting the rod journals offset ground .75mm to stroke it out slightly and at the same time lowering compression slightly. With the combination of these two things, i bet you could get an extra .1L making it around 1.9.

yay..don't back out like some of the users here.

any guides or thoughts on compression ratios and what boost levels benefit the lower compression?

lower compression just allows for more error in tuning and running higher boost pressures more reliably ... after all boost is just an increase in compression.

I'd say a 8.5-9.0 compression piston is a good compromise. Too low a compression and you sacrifice spoolup.

interesting points made guys, and no im not backing out of this I just want to make sure I get the right parts. Its also a motor from a 95 miata. My list soo far is

-99 head
-Rods
-Pistons
-Titanium valve springs and retainers
-1mm oversize stainless steel intake and exhaust valves
-Metal head gasket
-arp head and main cap studs
-1.8 Conversion kit from flyin miata

After all thats bought I want it to go to a machine shop and get all machined. Port and polish and what not. Hopefully that will be taken care of as i like and I will be able to slap a 30R on there for shits and giggles on the highway.

wiseco pistons come in .5, 1, and 1.5mm overbore, get 1.5 over for biggest bore, that's what I got. But you will not have any more room to rebuild if something goes wrong, but used blocks are cheap.