I am currently working towards a blower car setup and my question is how well will a forged bottom end, stock block ls1 hold 12-15 psi from a procharger. Keep in mind appropriate cam will be applied, stage 3 ls6 heads, stepped 1 7/8 headers, and at a 8.5 to 1 CR. A similar setup I saw in person, went for a ride, and saw the dyno put down 671 rwhp through stock exhaust and cats. It was a z06, so less drivetrain loss than a f-body. None the less, there is worry of how long the block will hold that kind of power. Just wanted to know what yall thought.

 

at 8.5 to 1 cr 15 psi is a lot of boost. what blower you using? as far as durability goes, you should be ok. if you're worried about it, i know where there is a ls1 stud girdle in houston you could pick up.

 

Think that maybe I should drop it to 8 to 1? What does the stud girdle do? Forgot to mention that it is a procharger. I just thought of doing a 383 with 10-12. Just curious as to whether and aluminum block can hold it.

 

I would run 14lbs and have compression at 9-1.The biggest problem you will have is keeping the belt on.

 

8:1 is too low...it will be a dog when it's not in a nice boost range...ideal is prolly 8.5-9:1...aluminum blocks are plenty strong...just check out harlans car...stock ls6 block, stock crank, forged rods and pistons...well over 1000hp and runs low 8's

 

i meant that it takes alot of boost to have 15 psi with that low of a cr. i would probably run a set of 6.0 heads unmilled to lower the compression, and put stock cr forged pistons back in. thats what we did on inspector12's car, and it's doing fine.

 

I was thinking of doing the LQ9's. I guess 9:1 would do just fine. If I leave the stock crank in, I should still make good power. No point in paying the extra for the 4" crank.