Bill Hincher wrote:The intake manifold is just a funnel for air, it has to allow and orginize 9000 gallons of air to burn one gallon of gas at 12.5 air fuel ratio
The number one priority to understand Horsepower is ratio between lbs per hour of fuel that the engine is capable of burning efficiently. With that number you must provide enough air to burn the fuel, then you must provide the enigne with the management tools to achieve a smooth power flow
it has to do with the velocity of the air in the intake tract, you have to maintain a mach speed value to aviod 'turbo lag' effects
It is exactly the same as a 2 barrel carburator vs. 4 barrel carburator , to a dual quad set up, its all about control, distribution and having fuel available
There are many, many advantages to a twin injector set up
larger injectors add more fuel,... and its not like two injectors per rail increases the total airflow.
My injectors can add 1000cc's of fuel with a base fuel pressure of 43 psi, which is still more than two 450cc injectors. So the amount of power my single injector per cylinder set up is capable of is higher than twin 450cc injectors. You can't really compare EFI to carburated set ups, as everything is DRASTICALLY different. With EFI set ups, you don't really need multiple injectors unless you run into drivability issues, or no one makes injectors big enough for your fuel demands. I know a lot of guys on the dsmlink forums are running 1600cc injectors on their daily drivers. I was considering it, but since I'm only running a burned chip, I thought it would be easier for me to tune via hex for the 1000cc injectors, and I don't see myself outrunning 1000's. The only issue that really came up was that the idle rpm needed to be increased because your ability to add small quantities of fuel decreases as you increase injector sizing. The ecu sends the injector a "pulse width" signal which basically tells the injector a duration to stay open. The pulse width is quantized, so the ecu is only able to send certain signals. If I remember correctly, the math on my injectors came out to about .7% changes (aka .7%, 1.4%, 2.1%,...)
I can see if you want twin injectors for like 780cc and like 1600cc back ups or something, but in the case of twin 450cc injectors, its rather pointless since 900cc injectors are very drivable.