compression ?
09-06-2007, 05:04 PM
#1
compression ? the APS system is designed to work with stock compression ~10:1 depending on engine wear etc, if i'm building a turbo motor and plan on using this system, it is nessecary to lower my compression??
I'm planning on a 427 @ about 10:1 (i'm going to use a lunati stroker kit that yeilds a 10.6:1 SCR using 69cc heads, with 72cc heads and i'll try and get it as close to 10:1 as possilbe by playing around with the gasket thickness).
now if my logic is working correctly, i should be able to pull it off if i don't use any more boost than the system is setup to run with normally, ~8psi. if i can, i'm also going to try and screw around with the tune and meth to get a high boost level of ~12 to 15psi for racing (road racing) only.
if any of this seems absolutly impossible, please let me know. OR if any of it seems entirely feasible, once again, please tell me. any help is greatly appreciated.
I'm planning on a 427 @ about 10:1 (i'm going to use a lunati stroker kit that yeilds a 10.6:1 SCR using 69cc heads, with 72cc heads and i'll try and get it as close to 10:1 as possilbe by playing around with the gasket thickness).
now if my logic is working correctly, i should be able to pull it off if i don't use any more boost than the system is setup to run with normally, ~8psi. if i can, i'm also going to try and screw around with the tune and meth to get a high boost level of ~12 to 15psi for racing (road racing) only.
if any of this seems absolutly impossible, please let me know. OR if any of it seems entirely feasible, once again, please tell me. any help is greatly appreciated.
09-06-2007, 09:34 PM
#3
the car is going to split its time evenly between street and track and i want to make as much power on motor as i can to not only improve street manners and drivability, but also to reduce the accellerated premature wear that is commonly associated with running higher boost levels.
if the motor is running higher compression, it should, in theory (because sometimes things just don't work out), make more power on the lower end of the powerband - torque - than a similar motor of less compression. this extra low end power would be highly beneficial to a street car. add to that, higher compression engines tend to be a little more efficient than low compression engines, especially in the lower power band (that is, at or below 2000rpm) when the turbos wouldn't yet be making enough boost to compensate for the loss in power due to lower compression, and it's just a better idea.
i know some is going to point out that the difference in effceincy is only marginal, but at nearly 3$ a gallon for 93 octane, i'll take all the margin i can get.
if the motor is running higher compression, it should, in theory (because sometimes things just don't work out), make more power on the lower end of the powerband - torque - than a similar motor of less compression. this extra low end power would be highly beneficial to a street car. add to that, higher compression engines tend to be a little more efficient than low compression engines, especially in the lower power band (that is, at or below 2000rpm) when the turbos wouldn't yet be making enough boost to compensate for the loss in power due to lower compression, and it's just a better idea.
i know some is going to point out that the difference in effceincy is only marginal, but at nearly 3$ a gallon for 93 octane, i'll take all the margin i can get.
