boost #'s and drive ratio/% Q's

# Thread: boost #'s and drive ratio/% Q's

1. ## boost #'s and drive ratio/% Q's

I just got back from Cali with my New 14-71 kit It has a 32 tooth upper pulley and a 35 tooth lower pulley.I did some research and this is what I got from Dyers website........

How do I calculate the blower drive ratio?

To calculate the drive ratio, take the difference between the 2 pulleys and divide that number by the lower pulley. For example, if you have a 41 top and a 34 crank, the difference is 7 teeth. 7/34=20.6%. Since the upper pulley is larger than the crank, it is 20.6% underdrive.

here is my setup.....

#1 (Scanario)
32 top and 35 crank, the difference is 3 teeth. 3/35=11.6% Since the upper pulley is SMALLER than the crank, it is 11.6% over drive

Question? What would the boost be?

#2 (Scanario) ....
35 top and 32 crank, difference is 3 teeth. 3/32=10.6% Since the upper pulley is LARGER than the crank, it is 10.6% under drive

Question? What would the boost be?

Does this look right?

2.

3. What would the boost be ?

Mike I don't know jack about blowers but I do know that boost (psi) is just resistance to flow. Therefore your boost on an engine would not only be determined by the over/under drive but heads and cam.

Smaller heads creating more resistance and building more boost, may not make as much power as larger free-flowing heads creating less boost. The larger heads will flow more air under less boost and will not create as much heat so they can and more than likey make more power ( If that makes any since)

Good luck with the project

Sleeper CP

4. Originally Posted by Sleeper CP
What would the boost be ?

Mike I don't know jack about blowers but I do know that boost (psi) is just resistance to flow. Therefore your boost on an engine would not only be determined by the over/under drive but heads and cam.

Smaller heads creating more resistance and building more boost, may not make as much power as larger free-flowing heads creating less boost. The larger heads will flow more air under less boost and will not create as much heat so they can and more than likey make more power ( If that makes any since)

Good luck with the project

Sleeper CP

I found that out on my small blower motor.

This motor will have my AFR 345's on her Im shooting for the 1000hp-1200hp range. It will be full of Straub's goodies(msd,afr's,valves,springs,cam,rollers,etc)

5.

6. Originally Posted by 396_Ways_To_Spit
I just got back from Cali with my New 14-71 kit

7. Ok, Ill post some up in da morning

8. Ring Ring Ring Ring or is it BUZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ tic toc....... we need pics!

9. is this 1/2" drive or 8mm drive????...also...just put a boost gage on it & ck the boost when running to see what u have & chng the pulleys accordingly to get what u want!

FastRat

10. [quote=396_Ways_To_Spit;529576]I just got back from Cali with my New 14-71 kit It has a 32 tooth upper pulley and a 35 tooth lower pulley.I did some research and this is what I got from Dyers website........

here is my setup.....

#1 (Scanario)
32 top and 35 crank, the difference is 3 teeth. 3/35=11.6% Since the upper pulley is SMALLER than the crank, it is 11.6% over drive

check out the website for theblowershop.com and you'll find graphs for pulley/ratios/boost
good luck

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