Hey guys, I'm new here and I just started picking up parts for a LY6 turbo build. My motor has sat at the JY without plugs for a while, so the walls have some minor rust. My plan was to pull it all apart, clean up the rust and lightly ball hone the walls, replace the rings and gap them for boost, check the bearings and replace the rod bolts. I know the stock CR is 9.6:1 (using a .051 head gasket) which isn't ideal for boost on pump gas. Ideally, I'd want something closer to 9:1, which should let me run 10-12psi on 93 octane with a little bit of a safety cushion in regards to the tune. If my math is right, a .075 MLS gasket will get me right around 8.9-9.1:1 depending on if I have to remove some material from the block/heads for a clean surface. What is everyone's thoughts on this? My ultimate final goal using pump/meth is 700-800whp through a 4L80E. It's going into a 52' Chevy Styleline. It's gonna be a weekend "fun" car that's 95% street driven.

you're making 850 to the tire or at the flywheel? You running ARP head studs and Ls9 gaskets? What type of engine management? I was planning on going with a Holley Dominator since I'm building the car from the ground up.

I read up on it being hit or miss going to arp bolts due to the cracked cap design. Maybe I'll just buy new factory bolts for peace of mind.

Thanks. I'm coming from the dark side (4 cylinder imports) and usually we would be between 9-9.5:1 to be able to run about 25-30psi. I know the boost threshold is much less ok these LS engines in terms of actual PSI, but I guess I was comparing apples to watermelons.

what type of power does it make on that setup? What type of turbo?

Absolutely. I plan to install a low level sensor in the meth tank and have it wired to an input on the Dominator as to retard timing when the low level sensor is triggered. I'm not too familiar with the software yet but that's how we used to do it using AEM EMS with the jap cars, so I'm sure it can be setup like that.

how may RPMs are you turning? I haven't decided on a turbo yet. I was leaning toward a cast T6/1.32 S475 or S480. I'd love to do smaller twins but unfortunately I don't have the room. To keep it safe, I'll probably keep my shifts at 6200 and set the limiter at 6600. I don't want to push the stock rod bolts too far.

Bolts aren’t a concern.

when you say flat tops, forged flat tops or stock LQ9 flat tops? Also, how high were you spinning it? I would think that with the small T4 hotside and 83mm turbine wheel it would start to choke out in the higher RPMs.

I've seen that time and time again, I was just curious whether or not there were any adverse results in pushing the turbo that hard.