budget turbo 5.3
Not to steal your thread but I am running 317 heads(71CC) on a stock 4.8L.
If I am calculating correctly, the compression is at about 8.3:1
The car runs and drives fine under boost....no nut at all when not boosting
When the car is just cruising with no boost, it sucks
Putting the car in 6th gear under 50 mph makes the engine struggle
Also, the boost takes a while...with a TC 76..15 PSI does not hit until 4K rpm
I would suggest putting on the set of LS heads
I am in the process of looking for a set of 853's or 241's for $100
That way, the 66 cc chambers will bump me up to about 8.8:1.
So, from my experience (subject to criticism of course
) is run the LS1 heads My car is not a daily driver nor will it ever be so I am fine with the lower compression. Make sure you throw on some MLS head gaskets, and ARP head studs probably arent a bad idea either if you plan on boosting 10 or more PSI.
Trending Topics
The Best V8 Stories One Small Block at Time
As far as the tune, I would ussually not trust a mail order tune on a turbo setup. There are so many factors having to do with the outside weather and air intake temp, etc that you'll never get the true potential with a mail tune. There are so many shops that tune LSx motors these days that you have to be able to find one within a close distance to you.
My buddy's wife mini van can spank me up to 30 but then it is all over after that of course. Also, when you are cruising, the car has not nut.
I know that I will be changing heads to increase the compression.
Running at 9.5:1 with 93 octane should not be a problem if you are keeping the car under 700 hp. There are a lot of guys doing it and not having any issues.
And like Nightmare said, Studs and MLS gaskets will keep you from pushing water.
9.5-9.6:1 or whatever they are stock is fine.. My 6.0 was stock and I ran 15psi and 25 degrees of timing on E85... 18 degrees on 93 octane... never had any KR.
Last edited by pwrtrip75; Aug 26, 2011 at 12:32 PM.




