383 Compression Ratio Question

Reply Subscribe

Thread Tools

Search this Thread

Apr 5, 2012 | 01:54 PM

#21

Z28Camaro30Ann

Thread Starter

12 Second Club

iTrader: (15)

Joined: Mar 2007

Posts: 1,928

Likes: 0

From: Cheyenne, Wy

Lmao, Im calm brah! What time is the track day Saturday?

Apr 5, 2012 | 04:27 PM

#22

gregrob

TECH Senior Member

iTrader: (8)

Joined: Sep 2008

Posts: 5,130

Likes: 4

From: 6,000+ feet

They're supposed to start tech at 08:30

Apr 5, 2012 | 05:29 PM

#23

Z28Camaro30Ann

Thread Starter

12 Second Club

iTrader: (15)

Joined: Mar 2007

Posts: 1,928

Likes: 0

From: Cheyenne, Wy

I might stop by

Apr 6, 2012 | 02:42 AM

#24

gregrob

TECH Senior Member

iTrader: (8)

Joined: Sep 2008

Posts: 5,130

Likes: 4

From: 6,000+ feet

Ok cool. See you then

Apr 7, 2012 | 01:27 AM

#25

za355tx

TECH Resident

iTrader: (109)

Joined: Dec 2007

Posts: 994

Likes: 2

From: Dfw

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.

Apr 7, 2012 | 01:32 AM

#26

gregrob

TECH Senior Member

iTrader: (8)

Joined: Sep 2008

Posts: 5,130

Likes: 4

From: 6,000+ feet

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.

Apr 8, 2012 | 12:02 AM

#27

nitrous2fast

TECH Fanatic

iTrader: (2)

Joined: Dec 2010

Posts: 1,084

Likes: 0

From: Oklahoma

Head chamber design also has a big impact on how high cr you can go...

Apr 9, 2012 | 07:52 AM

#28

quik95lt1

9 Second Club

iTrader: (7)

Joined: Dec 2008

Posts: 4,464

Likes: 12

From: Rhode Island

Quote:

Originally Posted by nitrous2fast

Head chamber design also has a big impact on how high cr you can go...

^ what he said...........

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