383 Compression Ratio Question
04-07-2012, 01:27 AM
#25
High compression on an LT1 means big power. I've been told by many extremely knowledgable LTX guys that each full point of compression is worth 10-12 horsepower. On my last build I ran 12.4 to 1 and the car ran great on 93. I've heard of guys running 13 to 1 and DD'ing them. I wouldn't be concerned with anything in the 12's.
04-07-2012, 01:32 AM
#26
13 to 1 on 93 pump gas? Come on now...
There's a limit somewhere ... and when you have to neuter the tune so much to keep it from knocking, what's the point?
I wouldn't go over 12.5 on 91/93 pump, and that's with a good cooling system and good tune as has already been mentioned. Of course that depends on the cam specs as well. Like I said, its all about cylinder pressure.
There's a limit somewhere ... and when you have to neuter the tune so much to keep it from knocking, what's the point?
I wouldn't go over 12.5 on 91/93 pump, and that's with a good cooling system and good tune as has already been mentioned. Of course that depends on the cam specs as well. Like I said, its all about cylinder pressure.
04-09-2012, 07:52 AM
#28
i wouldn't be afraid of 12:1 but if you said you want to DD it that much and take it places far away id run the 11.45:1 ....some places only offer 91 octane vs 93 and it would just be safer for a daily car that may go on roadtrips.......just my two cents...........of course i posted this same question up 4 years ago when i built mine 11.8:1 or 13.9:1?? now im at 14.75:1 lol
