fyi, wiseco does not make a 9.0:1 piston
 

Many retailers advertise 9.0:1, but this is not what they sale. So now, I just sold my old 8.6:1 pistons because I wanted a higher compression, and I'm getting 8.5:1 pistons.

I guess I have to buy the FM 9.0:1 Wiseco pistons, since its a custom piston.

no... JE Pistons bro, I just ordered some a couple days ago. They come in 83.5, 84, and 84.5 mm for about $500 w/rings.
http://www.jepistons.com/cat/je/sport/mazda/bp.shtml

I still think you're retarded for selling the supertechs.

Why would you go through the trouble of selling your 8.6:1 ratio pistons and only upgrade to 9:1??? If your so worried about low compression ratio's as to sell your 8.6:1, you might as well go to 10:1. If you don't you'll probably be selling your 9:1's before long. JE makes 12:1 I believe, buy those. Buy something and install them and be happy.

I drove an 8.5:1 supercharged car, and it fucking sucked ass. I don't want to deal with the lower compression, on a motor that has too big of a turbo.

My vw was a fucking turd out of boost at 8.5:1.

yeah, spend $2000, and enjoy living with your fucked up mistake, shitty slow car which never spools.

More timing off of boost (used to run up to 60* off boost on a 3sgte with a 66mm turbo and C16, off boost was peppy). Or mill your head...

See I would have kept the 8.6:1 and had the head and/or block machined to get a more compression.

Do you seriously expect to be out of boost much driving the car on the track?

the slight bump in compression will get the car moving out of boost, and spool earlier. I want the turbo to spool before 4000.


I'm about to take the 8.6 supertechs to UPS anyway, I already accepted the paypal monies.

my jetta had 1500rpm of power with the big turbo, and I don't want to live with that in the miata.

You are so over thinking this.

its easy to say when its not your money, and your car driving like shit. I'd like to have more than 1500rpm of power.

It's easy to say because it is true. The silver lining is that y8s get's a good deal on some pistons.

So exactly how much earlier will your turbo spool because of the additional compression from the 9.0:1 over the 8.6:1? How much more power are you going to make?

I guess for piece of mind and the placebo it might be worth it for you.

So what are the pistons in my car. They're .020 over, all the documentation i've read says 9:1.

:rofl:
To each his own. You know what has 9.0:1 pistons? The stock motor. Just do it and be fucking done already.

#K533m835 is 8.5.

I just went and checked their catalog. Looks like 8.5-8.8:1 is what they say the .020 over pistons were.

My car is not slow out of boost and it spools my little turbo just fine. I'll let you know how the larger T3 setup spools when i swap it over.

what turbo and exhuast? Its going to take a lot more air to spool my gt2860rs with the low comp slugs. I want to see 12 psi by 4000rpm. I'd rather change pistons now, than try to sell this turbo and waste more money on a gt28r which I probably should have purchased in the first place.

Bore has nothing to do with compression. Look at "dish" and deck-height.


I'm so tired of the anxiety over this. I lose sleep over this crap.

Little Garrett T25 .80/.48 with a super shitty downpipe that has a crushbend in the bottom that necks it down to more like 1.8", the rest of the exhaust is 2.5" with some shitty generic baffled muffler.
Our engines aren't slow revving slugs, they rev fast and climb in RPMs fast. When you want to go fast you're going to be getting into the pedal deep anyway. THe GT2860rs is not a slow spooling turbo. Isn't that the whole reason people buy it, fast spool and big power.
Quit losing sleep about the pistons man they don't suck.

Hurm, my stock 1.6 spooled that size turbo to 10psi just a little past 4k. With no tuning done... and a damaged turbine wheel.

well, everyone aside from the guy who sold me the turbo thinks its too big or too small for 250whp. I think the 9.0:1 pistons can only help since I'm only going to put down 250whp, and I'd like to have 12psi at 4000rpm so I don't have to constantly slam gears on the track like I do at 94whp.

Hopefully I didn't fuck up by selling these pistons.