Turbo Compression Ratio

[Bullet55]

Hey all wanting to turbo a 5k.

 

I'm not to sure tho of you have to run a high 13.0 or low 9.0 compression ratio when your running a turbo?

 

Thanks all sorry about the annoying questions just get great help on this:)

[altezzaclub]

You have a lot of reading to catch up on! :laff:

 

Low compression, as the turbo will boost it way above a stock/modified NA motor. So the motor needs to have sufficient power to be acceptable when its off boost with lower compression, and then the components need to be strog enough to take the pounding when its on boost.

 

Just PM one of the guys who have done it with all your questions, then put up a build thread as you do it...

 

I want to see one mounted vertically with short short manifolds and no lag at all! :laff:

[20vT]

Go EFI tuned for E85 which should allow for up to 2 more points of static compression.

[Evan G]

orite i understand about turbso etc how they work etc etc

 

but the question people at work can't answer is

 

if i got 8.5:1 compression. (160 psi lets say) with 8psi of boost does that mean the compression is gonna be around the 168 (give or take)?

 

hence having a LOW compression 7.5:1 (150psi lets say again) and boost it to 20 pounds and still be a safe compression?

[Trev]

orite i understand about turbso etc how they work etc etc

 

but the question people at work can't answer is

 

if i got 8.5:1 compression. (160 psi lets say) with 8psi of boost does that mean the compression is gonna be around the 168 (give or take)?

 

hence having a LOW compression 7.5:1 (150psi lets say again) and boost it to 20 pounds and still be a safe compression?

 

You do know that the compression rises into the late hundreds to thousands when the engine is actually running.

[20vT]

orite i understand about turbso etc how they work etc etcbut the question people at work can't answer is if i got 8.5:1 compression. (160 psi lets say) with 8psi of boost does that mean the compression is gonna be around the 168 (give or take)?hence having a LOW compression 7.5:1 (150psi lets say again) and boost it to 20 pounds and still be a safe compression?

 

Your general theory is right, the lower the compression the more boost you can run. but the lower the compression ratio the more low end torque you sacrifice it will also effect how quickly your turbo will spool as well. With higher compression and less boost you will get less lag and higher low end torque so really it depends what you looking for in term of power and how that power is delivered