HowTo klze cooling mod!
Geplaatst: 26 apr 2012, 22:06
Explaination of how it works:
The coolant sensor mod works by placing the ecu into open loop at a
lowerthrottle angle. ( There is no way of doing this by manipulating the tps)The ecm thinks that the coolant temp is between 145-155 degrees in ferinheit at that temp the ecm is keeped in open loop at throttle angles of
25-100% anything under 25% is reverts back into closed loop.
How does it make more power:
When the ecm is in open loop it adds more fuel to the engine by changing the p.w. " Pulse width". When in open loop the ecm does not rely on the o2 sensors to change a:f ratios. By keeping it in open loop it puts the a:f ratios closer to 11-13 parts of air to 1 part of fuel range. You will create your most power generally at 12.5-13.0 parts of air to 1 part of fuel. The a:f will increase or decease depending on your mods and where your timing is set, but for the most part all otto cycle engines will make the most power at 12.5-13.0 a:f. Another good thing is that even though it is in open loop it will still fine tune the a:f per the Iat sensor since this sensor is still used during open loop. ( In laymens terms) The coolder the air that the Iat sensor reads the more fuel it will add and visa versa the hotter the air it reads the more it backs off on fuel but still keeps a closer ratio to 11-13 a:f ( Remember the Iat sensor only fine tunes fuel) The Vaf sensor is only good for Low air amounts and is very sensative to them, but at higher throttle angles it basically is ignored. Keeping a a:f ratio of 14.7.1 is really good for cruising and fuel ecconamy, but not for max performance.
The down fall:
Ok, so you know the wonderfull benifits of this, but there is a few down falls that some of u may not want to deal with. First thing is that when the engine sits for awhile it cools off right! Well here is the problem, Our cars have what is called a cold start enrichment program that adds fuel when the engine is cold, it uses the Ect sensor and the Iat sensor. Well we are going to trick the ecm into thinking that the coolant temp is at 145-155 degrees all the time no matter what the engine block temp is. So since the ecm does'nt know that the engine is cool when it sits over night it won't go into its cold start enrichment program. It needs that extra burst of fuel to start right up (like first crank). Why? Because the air in the block is cool and the cylinder temp is no where near 200 degress which is the ideal temp for complete combustion. (basically it is going to take longer to start and may run slightly ****ty until it goes into closed loop, but don't frett it only takes a good heated o2 sensor about 30-60 seconds to make the ecm go into closed loop) at that time the o2 sensor will compensate for the leaner condition that it reads and add more fuel. I have been trying to find a way to fix this by finding a thermosistor to read higher resitance at lower temps and lower resistance at higher temp but i havent found one that falls within the right range of 25k ohms down to 560 ohms.
This down fall im about to tell u about is not so much a problem but a pain in the ars. U must wire the coolant fan or fans on to the key or a seperate switch. Which ever is your preference! You have to do this since the same cts that where are going to manipulate is the same one that turns the fans on. The ecm will supply a ground to the fan relay when it see a highter temp than the one that the emc is going to see (145-155 degrees) it is probably around 200-225 degrees. Some Technical skills will be required obvously!
Parts and instructions for coolant mod:
You need to get a 560 ohms resistor, you can get these from Radio Shack or any electronics store like Radio Shack for your area. It doesn't matter what wattage it is either. I think the one i have is a 1/2 watt 560 ohm resistor. Ok, We need to unplug the coolant sensor harness from the sensor, but only when you have the resistor in hand and ready to do the job of course . Sorry i had a stupid moment! Anyway with the resistor in hand crimp the ends of it over to a loop like how a staple does it when it is put through paper. This is just my perfered method so it won't come out when your driving. Place the resisor in the coolant temp sensor harness. You will know when it is in there and working because if it is not in there right and the engine is running then both coolant fans will come on high speed and the rpms will rise slightly, not to mention there will be a cel. This is all do to the computer not seeing a coolant temp reading. If the resistor is not in there right it will also dump fuel.Lastly Make sure to wire you fan on. I have mine wired to the key. THATS IT ALL DONE!!!!!!!
The coolant sensor mod works by placing the ecu into open loop at a
lowerthrottle angle. ( There is no way of doing this by manipulating the tps)The ecm thinks that the coolant temp is between 145-155 degrees in ferinheit at that temp the ecm is keeped in open loop at throttle angles of
25-100% anything under 25% is reverts back into closed loop.
How does it make more power:
When the ecm is in open loop it adds more fuel to the engine by changing the p.w. " Pulse width". When in open loop the ecm does not rely on the o2 sensors to change a:f ratios. By keeping it in open loop it puts the a:f ratios closer to 11-13 parts of air to 1 part of fuel range. You will create your most power generally at 12.5-13.0 parts of air to 1 part of fuel. The a:f will increase or decease depending on your mods and where your timing is set, but for the most part all otto cycle engines will make the most power at 12.5-13.0 a:f. Another good thing is that even though it is in open loop it will still fine tune the a:f per the Iat sensor since this sensor is still used during open loop. ( In laymens terms) The coolder the air that the Iat sensor reads the more fuel it will add and visa versa the hotter the air it reads the more it backs off on fuel but still keeps a closer ratio to 11-13 a:f ( Remember the Iat sensor only fine tunes fuel) The Vaf sensor is only good for Low air amounts and is very sensative to them, but at higher throttle angles it basically is ignored. Keeping a a:f ratio of 14.7.1 is really good for cruising and fuel ecconamy, but not for max performance.
The down fall:
Ok, so you know the wonderfull benifits of this, but there is a few down falls that some of u may not want to deal with. First thing is that when the engine sits for awhile it cools off right! Well here is the problem, Our cars have what is called a cold start enrichment program that adds fuel when the engine is cold, it uses the Ect sensor and the Iat sensor. Well we are going to trick the ecm into thinking that the coolant temp is at 145-155 degrees all the time no matter what the engine block temp is. So since the ecm does'nt know that the engine is cool when it sits over night it won't go into its cold start enrichment program. It needs that extra burst of fuel to start right up (like first crank). Why? Because the air in the block is cool and the cylinder temp is no where near 200 degress which is the ideal temp for complete combustion. (basically it is going to take longer to start and may run slightly ****ty until it goes into closed loop, but don't frett it only takes a good heated o2 sensor about 30-60 seconds to make the ecm go into closed loop) at that time the o2 sensor will compensate for the leaner condition that it reads and add more fuel. I have been trying to find a way to fix this by finding a thermosistor to read higher resitance at lower temps and lower resistance at higher temp but i havent found one that falls within the right range of 25k ohms down to 560 ohms.
This down fall im about to tell u about is not so much a problem but a pain in the ars. U must wire the coolant fan or fans on to the key or a seperate switch. Which ever is your preference! You have to do this since the same cts that where are going to manipulate is the same one that turns the fans on. The ecm will supply a ground to the fan relay when it see a highter temp than the one that the emc is going to see (145-155 degrees) it is probably around 200-225 degrees. Some Technical skills will be required obvously!
Parts and instructions for coolant mod:
You need to get a 560 ohms resistor, you can get these from Radio Shack or any electronics store like Radio Shack for your area. It doesn't matter what wattage it is either. I think the one i have is a 1/2 watt 560 ohm resistor. Ok, We need to unplug the coolant sensor harness from the sensor, but only when you have the resistor in hand and ready to do the job of course . Sorry i had a stupid moment! Anyway with the resistor in hand crimp the ends of it over to a loop like how a staple does it when it is put through paper. This is just my perfered method so it won't come out when your driving. Place the resisor in the coolant temp sensor harness. You will know when it is in there and working because if it is not in there right and the engine is running then both coolant fans will come on high speed and the rpms will rise slightly, not to mention there will be a cel. This is all do to the computer not seeing a coolant temp reading. If the resistor is not in there right it will also dump fuel.Lastly Make sure to wire you fan on. I have mine wired to the key. THATS IT ALL DONE!!!!!!!
