Max Effective Compression 93+H2O/Meth
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Joined: Sep 2014
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Max Effective Compression 93+H2O/Meth Using the Boost ECR Formula: Effective Compression Ratio
square root{[boost+14.7]/14.7}*static compression ratio
I came up with a 14.21 ECR at 15psi and 10:1 static compression. 93 octane pump gas alone is good up to 12-12.5 ECR. Can I run 93 with water/meth injection and be able to run this set up safely assuming a good tuner tunes this set up.
TVS 2300 cogged, 10% OVERDRIVEN, 2.8 pulley
forged ls3
Brian Tooley stg 3 cam (according to specs this cam has no overlap)
PRC 247cc heads
square root{[boost+14.7]/14.7}*static compression ratio
I came up with a 14.21 ECR at 15psi and 10:1 static compression. 93 octane pump gas alone is good up to 12-12.5 ECR. Can I run 93 with water/meth injection and be able to run this set up safely assuming a good tuner tunes this set up.
TVS 2300 cogged, 10% OVERDRIVEN, 2.8 pulley
forged ls3
Brian Tooley stg 3 cam (according to specs this cam has no overlap)
PRC 247cc heads
Thread Starter
On The Tree
Joined: Sep 2014
Posts: 144
Likes: 2
Using the Boost ECR Formula: Effective Compression Ratio
square root{[boost+14.7]/14.7}*static compression ratio
I came up with a 14.21 ECR at 15psi and 10:1 static compression. 93 octane pump gas alone is good up to 12-12.5 ECR. Can I run 93 with water/meth injection and be able to run this set up safely assuming a good tuner tunes this set up.
TVS 2300 cogged, 10% OVERDRIVEN, 2.8 pulley
forged ls3
Brian Tooley stg 3 cam (according to specs this cam has no overlap)
PRC 247cc heads
square root{[boost+14.7]/14.7}*static compression ratio
I came up with a 14.21 ECR at 15psi and 10:1 static compression. 93 octane pump gas alone is good up to 12-12.5 ECR. Can I run 93 with water/meth injection and be able to run this set up safely assuming a good tuner tunes this set up.
TVS 2300 cogged, 10% OVERDRIVEN, 2.8 pulley
forged ls3
Brian Tooley stg 3 cam (according to specs this cam has no overlap)
PRC 247cc heads
So far the old school mentality and industry standards believe that you shouldnt go over a static comp of 9.5 for boosted applications. Thomas Hendrix of Hendrix Engineering and the The Tuning school say that that is no longer the case. They say its just a matter of being conservative with the timing at WOT. Their justification is the examples of ls2 ls3 cars with stock internals running up to 12psi of boost with stock compression no issues.
Just looking for a general forum consensus
Staging Lane
Joined: Feb 2005
Posts: 97
Likes: 2
From: Lynbrook, NY
I've never seen that formula before.
More conservative:
(((boost+ATM)/ATM)^.74074)*static compression ratio
The .74074 exponent is the reciprocal of the approximate ratio of variable heats (1.35).
More conservative:
(((boost+ATM)/ATM)^.74074)*static compression ratio
The .74074 exponent is the reciprocal of the approximate ratio of variable heats (1.35).
