[Z06] Highest compression for pump gas?
10-30-2011, 07:34 PM
#1
Drifting
Thread Starter
Highest compression for pump gas?
Light the title says, what is the highest compression you can run in an LS7 running pump gas 93 octane (E10). I just got thru reading a thread about piston selection and I got curious. I'm not sure if there is a trade off between compression and timing or what.
Thanks.
Thanks.
10-30-2011, 08:24 PM
#2
Melting Slicks
All depends on the cam you run, or in the end what is called dynamic compression
10-30-2011, 08:37 PM
#3
Team Owner
Member Since: Apr 2001
Location: Elmhurst, IL (West Suburb of Chicago) & Home of MEGA Horsepower
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St. Jude Donor '06
And with the right cam and quench usually on these engines 11:8 to 1 (static) compression is a no brainer and can also get away with 12 to 1 on 93 octane, but the cam and quench need to be able to support this. 
10-30-2011, 09:04 PM
#5
Le Mans Master
10-31-2011, 03:47 AM
#11
Instructor
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Great question. Im having my heads built over the winter to already compliment my beautiful bump-stick from Ragin Racin. We use 94 octane out here which is 10% Ethanol and i would like to know how much to mill them for maximum HP gains.
Using a STRIKER II cam... 240/260 661./661. 109lsa 31* overlap. Not trying to hi-jack...
Using a STRIKER II cam... 240/260 661./661. 109lsa 31* overlap. Not trying to hi-jack...
10-31-2011, 04:47 AM
#12
Instructor
Great question. Im having my heads built over the winter to already compliment my beautiful bump-stick from Ragin Racin. We use 94 octane out here which is 10% Ethanol and i would like to know how much to mill them for maximum HP gains.
Using a STRIKER II cam... 240/260 661./661. 109lsa 31* overlap. Not trying to hi-jack...
Using a STRIKER II cam... 240/260 661./661. 109lsa 31* overlap. Not trying to hi-jack...
10-31-2011, 01:26 PM
#13
Safety Car
Feel free to do whatever you like, ill never build a pump gas engine with more then a 11.5 compression ratio.
10-31-2011, 01:41 PM
#14
Safety Car
My buddy's 441 LS7 runs 13.8:1 static compression, and with his cam... it comes out to 9.4:1 dynamic compression. It runs great on just 93. However, recently he added a meth kit which made it run even better.
On the nitrous... it's just stupid.
Moral of the story... with proper tuning, you can run massive compression and get away with it.
On the nitrous... it's just stupid.
Moral of the story... with proper tuning, you can run massive compression and get away with it.
10-31-2011, 01:48 PM
#16
Race Director
With the heads that are available today? Yeah, 11.5:1 is enough. Now, when *GM let's us have heads that are DI*, then 11.5:1 will be extremely LOW comp heads. Good for blowers pumping 1 bar, I guess.
Or, n/a heads with 13.25:1 (on pump 91!)
Oh boy, I can't wait!
* GM was ordered to "remove the DI heads" from their GT-1 cars. SCCA says it's "an unfair advantage..."
I like "unfair advantage." It builds better competition by forcing competitors to improve their own products....
Or, n/a heads with 13.25:1 (on pump 91!)
Oh boy, I can't wait!
* GM was ordered to "remove the DI heads" from their GT-1 cars. SCCA says it's "an unfair advantage..."
I like "unfair advantage." It builds better competition by forcing competitors to improve their own products....
10-31-2011, 02:02 PM
#17
Melting Slicks
My buddy's 441 LS7 runs 13.8:1 static compression, and with his cam... it comes out to 9.4:1 dynamic compression. It runs great on just 93. However, recently he added a meth kit which made it run even better.
On the nitrous... it's just stupid.
Moral of the story... with proper tuning, you can run massive compression and get away with it.
On the nitrous... it's just stupid.
Moral of the story... with proper tuning, you can run massive compression and get away with it.
I bet he's running a very very safe tune he's not even taking advantge of his setup if he put some C16 or E85 and retune he will gain a lot more..
I think 12.1 compression is the limit if you want to be on the safe side.
BTW DSteck Any new vids of your car?
10-31-2011, 04:16 PM
#19
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10-31-2011, 04:35 PM
#20
Burning Brakes
My buddy's 441 LS7 runs 13.8:1 static compression, and with his cam... it comes out to 9.4:1 dynamic compression. It runs great on just 93. However, recently he added a meth kit which made it run even better.
On the nitrous... it's just stupid.
Moral of the story... with proper tuning, you can run massive compression and get away with it.
On the nitrous... it's just stupid.
Moral of the story... with proper tuning, you can run massive compression and get away with it.
What's his power or mph #s on 93 octane?