First off I would like to say you guys have a pretty cool site.
I have been visiting this site for a couple of months now to get some ideas for a 89lx 2.3 mustang I'm building for an entry level circle track racecar. With that said, I know alot about the 2.3/2.5 ford lima motor. I currently have a Pro4 car that has a 325hp carbed motor in it.
But I dont have a clue about what can be done in a FI/computer controled application. What I guess I need to know is how big can I go on cam size before it affects the computer. I have a gutted upper intake and knife edged lower intake for the car. I also have a header, and mildly ported closed chamber head with over sized valves. I just don't know what to do about injection and computer. Any help would be great. Also the class doesnt allow turbos or carbs, Fuel injection only. Thanks D
Speed Density. It uses the vacuum of the engine to tell the computer what load the engine is under. MAF tells the computer how much air the engine is taking in.
To swap over to MAF you need the whole wiring harness and convert over to use coil packs. So either buy a MAF car or run a carbed car
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The sad thing is, with 15 PSI, straight back exhaust, and a bobs log, it still feels slow...
Maybe 20PSI, new computer, new 3" VAM, and some porting will make it faster
What the guys are trying to say is that the Speed Density system calculates the amount of air being sucked into an engine based on Manifold Absolute Pressure (MAP) aka manifold vacuum and takes that value and applies it to a table in the computer's program and measures out the corresponding amount of fuel. If you change the amount of air entering the engine at a given vacuum amount, you throw the systems equilibrium off so to speak. Without changing the values in computer, you're severely limited as to how much work you can do to the engine without running into tuning issues. This is why the "Superchip" became so popular in the mid-late 80's when factory EFI systems were becoming the norm. It corrected the program.
Mass Air Flow (MAF) systems actually measure the incoming mass of air and correlate it to a set of values in the computer. It's much more receptive to changes than it's counterpart as it actually sees the change in air mass and can relate it to a table in the computer. The sky isn't quite the limit here. The limit is the flow capabilities of the MAF sensor, and once again, the computer's table of MAF info vs. everything else. If you add a larger MAF sensor, the table in the ECU is no longer valid and needs to be corrected with the proper flow information. Think of it this way. You were bailing water with a 3 gallon bucket and you're counting how many buckets of water you've bailed. Now someone hands you a 5 gallon bucket and you continue bailing and counting buckets the same way. You've moved just as many bucket fulls, but you ended up moving more water. The engine's computer only sees "buckets" So if you use a larger MAF meter the volume of air across the board is higher, but the computer doesn't see it. Basically the same problem as speed density. Once again, Superchips stays in business.
This is a simplified explanation of course. There are more factors that affect engine operation, but they are monitored the same way whether it's Speed Density or Mass Air.
Mega Squirt is an aftermarket DIY Speed Density engine management package that is very flexible and relatively easy to tune. It's all done via laptop and you can tune to your heart's content or get help from a very knowledgeable support base on their forums.
With that said, I know alot about the 2.3/2.5 ford lima motor. I currently have a Pro4 car that has a 325hp carbed motor in it.
Hello: I d like to know if someone could please give me information about this cars customization. I need to reach at least 300 hp with mi 2.850cc. all information will be appreciated ( I only reached 238hp).
The motor that is in my pro4(cirletrack) car is a 2850cc bottom end with a reworked esslinger ARCA head (junk unless you blend the runners) I had a intake custom made to help the transition from the carb throat to the head. The piston comes 36 thousandths out of the block. The chamber on the head is aprox 31.8cc. The motor makes almost 15 to 1 compression. I run 118 octane race fuel and 32-36 degrees advance ignition timing (this wont work on a street car)the engine rarely runs under 5800rpm. I run dual 44mm mikuni sidedraft carbs.The engine made 325.7 hp and 316ft lb torque at 7600rpm at the wheels. We dynoed the car with a Keith Dorton 500cfm 2bbl and it made 301hp and 291ft lbs torque at the wheels.
The motor that is in my pro4(cirletrack) car is a 2850cc bottom end with a reworked esslinger ARCA head (junk unless you blend the runners) I had a intake custom made to help the transition from the carb throat to the head. The piston comes 36 thousandths out of the block. The chamber on the head is aprox 31.8cc. The motor makes almost 15 to 1 compression. I run 118 octane race fuel and 32-36 degrees advance ignition timing (this wont work on a street car)the engine rarely runs under 5800rpm. I run dual 44mm mikuni sidedraft carbs.The engine made 325.7 hp and 316ft lb torque at 7600rpm at the wheels. We dynoed the car with a Keith Dorton 500cfm 2bbl and it made 301hp and 291ft lbs torque at the wheels.
Incredible! thats good info! thanks!
what is ¨to blend the runners¨
2.3 build questions 
