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Evan Smith · 12-18-2007, 08:29 AM

Mr. Weak Forse,

I don't mean to be rude, but I seriously reccomend a trip to Borders or Barnes and Noble this holiday season. Your gale force is a weak breeze at best and I am feeling quite a bit of hot air. On your trip, pick up one of the many books on internal combustion and educate yourself, and please get a dictionary for your spelling. You have made but one correct statement so far, more gas will make more power. But it will only do so if you can supply more air and if the engine maintains the proper a/f ratio. Fuel in the internal combustion engine burns (it does not explode, Top Fuel cars explode). Furthermore, the mixture must burn rapidly and at the precise time needed to complete combustion, thus releasing heat energy from the fuel in order to get the necessary rise in cylinder pressure. This is needed to apply maximum pressure on the piston when it is about 7-14 degrees past TDC. Burning the mixture before this time (often results in detonation) or after it (rich condition with elevated EGTs) will have little to no effect on MBT (maximum brake torque). In lay terms it means more fuel doesn't mean more HP for you, EFI or otherwise!

This is one reason larger displacement engines make more power than smaller ones. They flow more air so more fuel can be burned while maintaining the proper a/f ratio. Proper a/f ratio in just about every naturally aspitated engine is about 12.7-13.3:1. You can burn more fuel with a smaller engine if you provide the airflow to match. This requires forced induction, nitrous, or any combination of larger cams, larger induction, more compression, stiffer valvesprings (for the larger cams) and/or increased rpm.

A carburetor dictates its own flow of fuel due to a pressure drop in the venturi, which draws fuel from the fuel bowl, into the boosters, thus causing it to shear of into tiny little particles (read: atomization) where it is then deliverd to the ports. Over jetting will result in a rich mixture and a loss of power, just like with EFI. I'm quite sure you could create a situation where the engine has way too much fuel with EFI in easier fashion than with a carb, but the poor drivability and loss of power would be the same.

You can throw all the fuel you want (which I recommend you try with your Hot Wheels car) at any engine, but it is likely you will see a huge loss in torque and hp, not to mention MPG, which will be a concern to racers as gas prices go up.

Lastly, put down the gasoline.

Evan

12-18-2007, 08:29 AM	#2
Evan Smith Member Join Date: Nov 2001 Location: Tampa Posts: 400 Likes: 7 Liked 115 Times in 5 Posts	Re: Dommination of FI cars. Mr. Weak Forse, I don't mean to be rude, but I seriously reccomend a trip to Borders or Barnes and Noble this holiday season. Your gale force is a weak breeze at best and I am feeling quite a bit of hot air. On your trip, pick up one of the many books on internal combustion and educate yourself, and please get a dictionary for your spelling. You have made but one correct statement so far, more gas will make more power. But it will only do so if you can supply more air and if the engine maintains the proper a/f ratio. Fuel in the internal combustion engine burns (it does not explode, Top Fuel cars explode). Furthermore, the mixture must burn rapidly and at the precise time needed to complete combustion, thus releasing heat energy from the fuel in order to get the necessary rise in cylinder pressure. This is needed to apply maximum pressure on the piston when it is about 7-14 degrees past TDC. Burning the mixture before this time (often results in detonation) or after it (rich condition with elevated EGTs) will have little to no effect on MBT (maximum brake torque). In lay terms it means more fuel doesn't mean more HP for you, EFI or otherwise! This is one reason larger displacement engines make more power than smaller ones. They flow more air so more fuel can be burned while maintaining the proper a/f ratio. Proper a/f ratio in just about every naturally aspitated engine is about 12.7-13.3:1. You can burn more fuel with a smaller engine if you provide the airflow to match. This requires forced induction, nitrous, or any combination of larger cams, larger induction, more compression, stiffer valvesprings (for the larger cams) and/or increased rpm. A carburetor dictates its own flow of fuel due to a pressure drop in the venturi, which draws fuel from the fuel bowl, into the boosters, thus causing it to shear of into tiny little particles (read: atomization) where it is then deliverd to the ports. Over jetting will result in a rich mixture and a loss of power, just like with EFI. I'm quite sure you could create a situation where the engine has way too much fuel with EFI in easier fashion than with a carb, but the poor drivability and loss of power would be the same. You can throw all the fuel you want (which I recommend you try with your Hot Wheels car) at any engine, but it is likely you will see a huge loss in torque and hp, not to mention MPG, which will be a concern to racers as gas prices go up. Lastly, put down the gasoline. Evan __________________ Evan Smith 1798 STK Last edited by Evan Smith; 12-18-2007 at 08:39 AM.