Will this CR be safe on boost?
Will this CR be safe on boost? I'd like to use an L33 (5.3) with my current TSP 5.3 stage 2.5 heads. With that combo, I am at about a 10.5:1 CR. If I ran a .060 gasket, it would drop me down to about a 10.37:1 CR.
I am planning on running either a S475 or a PT7675 and running about 15#'s of boost regularly, and turning it up to 20-25#'s every once in a while.
This would be done on pump gas (93 octane where I am at) and an FMIC, with the help of meth injection.
Originally I was thinking I'd need around a 10.1:1 CR, or maybe even lower to keep me safe with that setup. But it seems lately more and more have gotten away with running higher CR and boost safely.
If I have to, I could sell my TSP heads, and just run the stock 5.3 heads from the L33 (which should be around a 9.9:1 CR). But if I could, I'd rather run the heads I have since they have already been worked over and flow very good.
What are your thoughts?
I am planning on running either a S475 or a PT7675 and running about 15#'s of boost regularly, and turning it up to 20-25#'s every once in a while.
This would be done on pump gas (93 octane where I am at) and an FMIC, with the help of meth injection.
Originally I was thinking I'd need around a 10.1:1 CR, or maybe even lower to keep me safe with that setup. But it seems lately more and more have gotten away with running higher CR and boost safely.
If I have to, I could sell my TSP heads, and just run the stock 5.3 heads from the L33 (which should be around a 9.9:1 CR). But if I could, I'd rather run the heads I have since they have already been worked over and flow very good.
What are your thoughts?
well if it means anything to you im doing a very similar build. stock 5.3 heads and l33 bottom end. not running a 7675 but a 6673 borg turbo.
i did have a normal lm7 bottom end with 243 heads around 700+ rwhp with a pt7675. that was around 9:1 compression and meth injection. though the computer picked up knock at times on that setup the pistons were absolutely perfect when i took em out and i always suspected it was false knock. anyways with a good tune i believe you will be ok but big power on this compression will be far less forgiving in the tune
i did have a normal lm7 bottom end with 243 heads around 700+ rwhp with a pt7675. that was around 9:1 compression and meth injection. though the computer picked up knock at times on that setup the pistons were absolutely perfect when i took em out and i always suspected it was false knock. anyways with a good tune i believe you will be ok but big power on this compression will be far less forgiving in the tune
