Home

    dragparts.com

 

Toll Free! 800/576-7661

 

  

  
 

Search
                 Hit Enter Key

  
Home • Search • Index • Performance Products • Pre-Owned Parts • Technical • Race Team • Contact Us

Compression Ratio

[ Up ] [ Common Questions ] [ Engine Recommendation ] [ Compression Ratio ] [ Blower Stages ] [ Blower Parts Breakdown ] [ Engine Belt Chart ] [ Ratio Charts ] [ Carb Service ]

FINAL COMPRESSION RATIO CHART

This chart shows the final compression ratio by combining the static compression ratio of an engine and the maximum blower boost from the blower system. It is to be used as a guideline in determining the proper maximum boost level for a specific application. Final compression ratios in excess of 12.4:1 are not recommended for use with "pump gas". The higher the final compression ratio, the higher the octane rating of the fuel must be in order to help prevent detonation and serious engine damage.

The formula for calculating your exact Final Compression Ratio is as follows:

Final Compression Ratio (FCR) = [(Boost/ 14.7) +1] x CR

COMP RATIO

2

4

6

8

10

12

14

16

18

20

22

24

6.5

7.4

8.3

9.2

10

10.9

11.8

12.7

13.6

14.5

15.3

16.2

17

7

8

8.9

9.9

10.8

11.8

12.7

13.6

14.5

15.3

16.2

17

17.9

7.5

8.5

9.5

10.6

11.6

12.6

13.6

14.6

15.7

16.7

17.8

18.6

19.5

8

9.1

10.2

11.3

12.4

13.4

14.5

15.6

16.7

17.8

18.9

19.8

20.9

8.5

9.7

10.8

12

13.1

14.3

15.4

16.6

17.8

18.9

19.8

20.9

21.9

9

10.2

11.4

12.7

13.9

15.1

16.3

17.6

18.8

20

21.2

22.4

23.6

9.5

10.8

12.1

13.4

14.7

16

17.3

18.6

19.8

21.1

22.4

23.6

24.8

10

11.4

12.7

14.1

15.4

16.8

18.2

19.6

20.9

22.2

23.6

24.8

26

10.5

11.9

13.4

14.8

16.2

17.6

19.1

20.6

21.9

23.4

24.8

26.2

27.6

11

12.5

14

15.5

17

18.5

20

21.6

22.9

24.5

26

27.5

28.9

 

Boost = Maximum blower boost

14.7 = PSI at sea level       CR = Engine Compression Ratio

Altitude plays an important role in determining compression ratios. If the altitude in the area where you normally drive is significantly higher than sea level, then your compression ratios will also vary. To determine the effects of the altitude on a calculated compression ratio, use the following formula:

Corrected Compression Ratio = FRC – [(altitude/1000)x 0.2]

 

 

Toll Free: 800/576-7661

"Our Ultimate Goal is Your Success"

Back Home

• Home • Search • Index • Performance Products • Pre-Owned Parts • Technical • Race Team • Contact Us •

   This site has been created and is maintained by Good Vibrations. All text material from Good Vibrations is © Copyright 1998-2008, Good Vibrations. All logos and images are reserved.