## What should the compression ratio be for a boost engine?

Table 1 shows that you obviously can’t try to run 10 pounds of boost on a 9.0:1 compression ratio engine. This gives you an effective compression ratio of 15.1:1, way beyond our 12:1 figure. If you are building your engine from scratch, it is a good idea to try to build it with a relatively low compression ratio, such as 7.5 or 8.0:1.

## How does a 12.1 compression engine work?

It was tuned by pcmforless. It smokes when its cold and spits fuel out the exhaust. The left and right banks are running perfectly in between lean and rich so I am assuming everyting is ok. (I have 2 air/fuel ratio gauges on the pillar) What is the formula? I’d like to figure out my own dynamic pressure.

What should the compression ratio be on a 92 octane engine?

Experience has shown that if you attempt to run more than about a 12:1 effective compression ratio on a street engine with 92 octane pump gas, you will have detonation problems.

### What is the gas compression ratio for 7or?

Compression ratios in the 7or 8:1 range can usually handle 12-20 psi on pump gasoline.

Table 1 shows that you obviously can’t try to run 10 pounds of boost on a 9.0:1 compression ratio engine. This gives you an effective compression ratio of 15.1:1, way beyond our 12:1 figure. If you are building your engine from scratch, it is a good idea to try to build it with a relatively low compression ratio, such as 7.5 or 8.0:1.

### Do you need high octane fuel for 12.5 compression ratio?

In the “old” day, any engine with a 12.5:1 compression ratio definitely needed high octane fuel. Today, who know? Things are much different. A lot of exhaust gas is recirculated. So, it appears there is a proper fuel-to-air ratio mixture added with a lot of inert exhaust gas.

It was tuned by pcmforless. It smokes when its cold and spits fuel out the exhaust. The left and right banks are running perfectly in between lean and rich so I am assuming everyting is ok. (I have 2 air/fuel ratio gauges on the pillar) What is the formula? I’d like to figure out my own dynamic pressure.

When did the LS1 small block engine come out?

The LS1 is the original Gen. 3 small block engine from General Motors used in cars from 1997-2004. The engine specs and information here is for the stock LS1 engine.