I am starting a new thread on this subject out of respect for svtseeker, Bruce and anyone reading the thread to gain information of the 2011 GT500 having an alluminum block.
Here is some of the background on what as been discussesed. Starting with post #119 on page 5
http://www.svtperformance.com/forums/shelby-gt500-150/610407-2011-gt500-aluminum-block-5.html
High Compression And Low Compression Dyno Results - Muscle Mustangs & Fast Fords
It began with NathanTSI comment of "I am pretty sure it uses 11:1 compression, so don't hold your breath on acting well with boost."
To my statement as to just because its 11:1 doesn't mean it would make a bad supercharged engine. On the contray in the right circumstances an 11:1 motor will outperform a low compression motor. NOW hold on--Given that both engines are operating under EVERYTHING equal. This means that EVERYTHING except C/R is the same for those that are SLOW. Meaning same timing, boost,Fuel(this is provided that it can support both engines with a resistance compression combustion)
Somehow this transformed into a high boost/low compression vrs low boost/high compression match-up. In which it was not argued as to which was more effeicent.(although a slight disagreement is beginning to rise as to why a adding boost in situations is more effective.)
There are many factors to consider when choosing a C/R for your engine(SC or NA) Fuel-how much pressure can it handle before detenation?(87-116) RPM-A higher operating RPM decreases dwell time at TDC in which lowering the chances of the fuel detonating. Type of power adder-a positive displacement/turbo will require a lower C/R due to its low RPM airflow(again lower RPM more dwell time). A centrifugal blower will benifet from a higher C/R to help increase torque and still be safe as this type of Supercharger requires RPM to make substantial enough flow. (2#@2000rom vrs 12-14#@2000RPM). Cylinder head design& combustion chamber design, and spark plug location. Even the material the head is made of needs to be taken into consideration. And intended use should be your first line. A race car that only makes a blast down the 1/4 on race gas only will be set up different then a Daily Driver. Or even a street/strip car.
:read:
So back to where it is sorta hanging now----
Slow I understand that your drawing is a simple explination. Your numbers are ficticous but I do understand the point you are trying to illistrate. However you are missing the cross over point. You are limited as to how much air and fuel the compressor and fuel injector can flow. At which point to gain HP the only way is to add compression(given the fuel can resist compression combustion) If you take the same amount of A/F and putting it in a smaller space it increases the work output.
My fire cracker in an open hand vrs a closed one was simply to illistrate the importance of the size of the combustion chamber in increasing the effeincy of work being done.
There is fine balancing act as to what is the best combination for you. For instance in Racing governing bodies will limit size and type of power adder, Fuel, piston dish/dome/flat top,Pulley configuration, and minimum cumbustion chamber sizes. Like stated before some of the top modular cars are running compression ratios in the ~11.xx range on twin turbo race car.
Let us not forget also back to one of my points that a high C/R isn't a garauntee, A 4.6 3v with the FRPP blower is rated at 550hp on 10-11# 10"1C/R the 5.4 4v is 540hp at 8.5-9. Part of this is due to a more effeicent blower so lets take that out of the equation. The stock 3v 10:1 but with forged internal made a few more HP then a 4v with 8.5.Both had the same supercharger(2.8H) and the 4v has aruguably better flowing heads. Both on the same fuel.
oke: Admitidly that was just to stir the pot.
Fuel is the biggest limiting factor when it is not the limiting factor other items become the concern-for instance how can you make the most power in a S-trim car running C-10? Everything has its place and equipement and fuel can only go so far.
Here is some of the background on what as been discussesed. Starting with post #119 on page 5
http://www.svtperformance.com/forums/shelby-gt500-150/610407-2011-gt500-aluminum-block-5.html
High Compression And Low Compression Dyno Results - Muscle Mustangs & Fast Fords
It began with NathanTSI comment of "I am pretty sure it uses 11:1 compression, so don't hold your breath on acting well with boost."
To my statement as to just because its 11:1 doesn't mean it would make a bad supercharged engine. On the contray in the right circumstances an 11:1 motor will outperform a low compression motor. NOW hold on--Given that both engines are operating under EVERYTHING equal. This means that EVERYTHING except C/R is the same for those that are SLOW. Meaning same timing, boost,Fuel(this is provided that it can support both engines with a resistance compression combustion)
Somehow this transformed into a high boost/low compression vrs low boost/high compression match-up. In which it was not argued as to which was more effeicent.(although a slight disagreement is beginning to rise as to why a adding boost in situations is more effective.)
There are many factors to consider when choosing a C/R for your engine(SC or NA) Fuel-how much pressure can it handle before detenation?(87-116) RPM-A higher operating RPM decreases dwell time at TDC in which lowering the chances of the fuel detonating. Type of power adder-a positive displacement/turbo will require a lower C/R due to its low RPM airflow(again lower RPM more dwell time). A centrifugal blower will benifet from a higher C/R to help increase torque and still be safe as this type of Supercharger requires RPM to make substantial enough flow. (2#@2000rom vrs 12-14#@2000RPM). Cylinder head design& combustion chamber design, and spark plug location. Even the material the head is made of needs to be taken into consideration. And intended use should be your first line. A race car that only makes a blast down the 1/4 on race gas only will be set up different then a Daily Driver. Or even a street/strip car.
:read:
So back to where it is sorta hanging now----
Slow I understand that your drawing is a simple explination. Your numbers are ficticous but I do understand the point you are trying to illistrate. However you are missing the cross over point. You are limited as to how much air and fuel the compressor and fuel injector can flow. At which point to gain HP the only way is to add compression(given the fuel can resist compression combustion) If you take the same amount of A/F and putting it in a smaller space it increases the work output.
My fire cracker in an open hand vrs a closed one was simply to illistrate the importance of the size of the combustion chamber in increasing the effeincy of work being done.
There is fine balancing act as to what is the best combination for you. For instance in Racing governing bodies will limit size and type of power adder, Fuel, piston dish/dome/flat top,Pulley configuration, and minimum cumbustion chamber sizes. Like stated before some of the top modular cars are running compression ratios in the ~11.xx range on twin turbo race car.
Let us not forget also back to one of my points that a high C/R isn't a garauntee, A 4.6 3v with the FRPP blower is rated at 550hp on 10-11# 10"1C/R the 5.4 4v is 540hp at 8.5-9. Part of this is due to a more effeicent blower so lets take that out of the equation. The stock 3v 10:1 but with forged internal made a few more HP then a 4v with 8.5.Both had the same supercharger(2.8H) and the 4v has aruguably better flowing heads. Both on the same fuel.
oke: Admitidly that was just to stir the pot.Fuel is the biggest limiting factor when it is not the limiting factor other items become the concern-for instance how can you make the most power in a S-trim car running C-10? Everything has its place and equipement and fuel can only go so far.
