5.3 turbo build questions?

[o2camaross]

I hear ya. Almost all builds are budget builds lol. Mine was too but there's some things you want to do right the first time. The 706 can work but there was a bad batch of them and you may have a pair from the bad batch. 317 will lower cr too much and I would advice against milling them if you want to push it

[EmmerichLSx]

I hear ya. Almost all builds are budget builds lol. Mine was too but there's some things you want to do right the first time. The 706 can work but there was a bad batch of them and you may have a pair from the bad batch. 317 will lower cr too much and I would advice against milling them if you want to push it

Good points. I was going to say if you take a 706 head and have it ported you've pretty much got a 317 with a smaller combustion chamber and a little bit smaller intake valve. I run 706 heads with nothing done to them and make over 500 to the ground.

[cjcalhoun]

Good points I pluged everything in to my compression ratio calculator and with flattops if my math is correct would be about 9.18.1? Maybe a little more.

[cjcalhoun]

Ok so with flat tops and ls9 cam 706 heads say 550hp at 10 psi. Flat tops with ls9 cam 317 heads 500hp at say 15 psi. Numbers are just thrown in there for comparison. This what Yall telling me I'm new to forced induction this will be my first build so I'm completely stupid at this point lol

[kerrige]

This is an easy way to consider it. Take the power your motor makes NA. Then @7.35lbs assume you will add 50% more power. If you add 14.7lbs you will double your HP. This is a rough rule of thumb with a lot of variables. This is why a motor that makes 300hp can jump to 600hp with 15lbs. This is also why a more powerful motor NA will make much more power with the same boost.
Hence if you have a more powerful higher compression motor it will take less boost to make the same power. This can be applied to many changes that may be made.

[cjcalhoun]

Ok I got u. I just don't know of any good head porters around here. And I wonder what the cost would be.

[kerrige]

A decent P&P job on a stock casting head shouldn't cost more than $600.

[darnie1987]

mine was about that with P&P milled and new ls6 springs, locks and retainers, and valve seals..... also got a ported matched intake manifoild, helped a grip! still 706 heads but they opened up alot

[o2camaross]

Honestly you dont need to touch the heads. Im running stock 862's, stock intake and throttle body and it makes at least 650 rwhp @ 15 psi, probably more really

[EmmerichLSx]

Honestly you dont need to touch the heads. Im running stock 862's, stock intake and throttle body and it makes at least 650 rwhp @ 15 psi, probably more really

I agree.