Supercharger Installation Cost
08-22-2009, 02:58 PM
#16
Drifting
What good would a SuperCharger be absent lowering the static compression ratio(***) to take optimum advantage of the BOOST pressure, intercooled BOOST pressure presumiably. Same with TurboCharging but much more important.
I can't imagine that doing it correctly would cost anything less than 6-8,000 dollars.
*** double head gaskets or thicker ones.
I can't imagine that doing it correctly would cost anything less than 6-8,000 dollars.
*** double head gaskets or thicker ones.
08-22-2009, 03:27 PM
#17
Race Car
What good would a SuperCharger be absent lowering the static compression ratio(***) to take optimum advantage of the BOOST pressure, intercooled BOOST pressure presumiably. Same with TurboCharging but much more important.
I can't imagine that doing it correctly would cost anything less than 6-8,000 dollars.
*** double head gaskets or thicker ones.
I can't imagine that doing it correctly would cost anything less than 6-8,000 dollars.
*** double head gaskets or thicker ones.
I guess you have never experienced driving a high compreesion engine that is boosted. Night and Day compared to a low compression setup. High compression engine is much more powerful at low rpm than is the same setup on a lower compression engine.
08-23-2009, 12:43 PM
#19
Drifting
My point is/was that if the engine CR is already close to optimum, and what Porsche engine isn't, there isn't much "room" for an increased dynamic CR using Boost even with an intercooler.
08-23-2009, 01:11 PM
#20
Race Car
Maintaining high CR in an engine maximizes performance in off boost driving.
08-23-2009, 05:09 PM
#22
Burning Brakes
A higher CR engine with boost will make more down low power, at the compromise of the capability to run higher boost...
The ability to drop CR slightly (1 point) with the usage of our head gasket shims is a possibility. I like to keep moderate CR with boost for the best mix of reliability/performance/longevity/safety.
A new intercooled supercharger kit is being tested now, its nothing like anything presently on the market.. The biggest handicap of a supercharged set up is elevated intake temps that reduce output and increase the chances of detonation.
I am finishing a boost specific engine combination now... Slightly less CR (through custom pistons), head work, enhanced valve train and a set of boost specific cams, etc.. But I prefer a Turbo. :-)
The ability to drop CR slightly (1 point) with the usage of our head gasket shims is a possibility. I like to keep moderate CR with boost for the best mix of reliability/performance/longevity/safety.
A new intercooled supercharger kit is being tested now, its nothing like anything presently on the market.. The biggest handicap of a supercharged set up is elevated intake temps that reduce output and increase the chances of detonation.
I am finishing a boost specific engine combination now... Slightly less CR (through custom pistons), head work, enhanced valve train and a set of boost specific cams, etc.. But I prefer a Turbo. :-)
08-23-2009, 05:26 PM
#23
Race Car
Everything else being equal, it make no difference whether you have low compression high boost or high compression low boost. If boosted compression ratio is the same, the risks and rewards at maximum boost are the same. However, the engine with the higher CR will overall, out perform the one with lower CR.
Boosting a 9.6:1 engine with 13.5 lbs of boost is no safer than boosting a 11.3:1 engine with 9 lbs of boost.
Boosting a 9.6:1 engine with 13.5 lbs of boost is no safer than boosting a 11.3:1 engine with 9 lbs of boost.
08-23-2009, 06:45 PM
#24
Race Car
08-23-2009, 07:10 PM
#25
Race Car
Yes, we do know. The maximum power will be virtually EQUAL with a slight edge to the car with the lower boost due to less heat generation. Furthermore, the car with the lower maximum boost will have more power off boost and at low boost, so overall performance goes to the car with the higher static CR and lower boost.
08-24-2009, 12:44 AM
#26
Poseur
Rennlist Member
Rennlist Member
Phil had a problem with the output hose (about 2-1/2 in diameter) sucking down upon itself and some fuel starvation issues. One shop was trying to sort out whether the s/c was a factor or not. The owner is now seriously reconsidering his choice to s/c the 9974S in the first place as it has loads of torque of hp to start with (355 PS). I suggested that he learn to drive what he has now before he worries about adding another 100 hp. He's new to the 911 concept.
08-24-2009, 10:44 AM
#27
Phil had a problem with the output hose (about 2-1/2 in diameter) sucking down upon itself and some fuel starvation issues. One shop was trying to sort out whether the s/c was a factor or not. The owner is now seriously reconsidering his choice to s/c the 9974S in the first place as it has loads of torque of hp to start with (355 PS). I suggested that he learn to drive what he has now before he worries about adding another 100 hp. He's new to the 911 concept.
08-24-2009, 10:59 AM
#28
Race Car
Yes, we do know. The maximum power will be virtually EQUAL with a slight edge to the car with the lower boost due to less heat generation. Furthermore, the car with the lower maximum boost will have more power off boost and at low boost, so overall performance goes to the car with the higher static CR and lower boost.
Unless you have far exceeded the impellers efficiency and are trying to achieve more boost once out of its range, then I agree.
The other point, If you mean that the overall torque/hp curve is flatter with the higher compression/lower boost, I buy that but I like big hp #'s.
Phil had a problem with the output hose (about 2-1/2 in diameter) sucking down upon itself and some fuel starvation issues. One shop was trying to sort out whether the s/c was a factor or not. The owner is now seriously reconsidering his choice to s/c the 9974S in the first place as it has loads of torque of hp to start with (355 PS). I suggested that he learn to drive what he has now before he worries about adding another 100 hp. He's new to the 911 concept.
The inlet hose can collapse but not the outlet. Fuel starvation is not the kits fault either.
Starving a forced inducted motor is very detrimental. I've lost many from it.
The only way I predict he was starving for fuel and knowing this was the car was cutting out. Running lean will just start melting things like the head gaskets or pistons.
08-24-2009, 11:28 AM
#30
Race Car
I disagree on this point. Putting more air into a motor will make more power than squeezing the air more.
Unless you have far exceeded the impellers efficiency and are trying to achieve more boost once out of its range, then I agree.
The other point, If you mean that the overall torque/hp curve is flatter with the higher compression/lower boost, I buy that but I like big hp #'s.
Unless you have far exceeded the impellers efficiency and are trying to achieve more boost once out of its range, then I agree.
The other point, If you mean that the overall torque/hp curve is flatter with the higher compression/lower boost, I buy that but I like big hp #'s.
What I stated is absolutely true on paper and in practice. There is no "unless" since we agreed on "all things being equal".