Intake Air Temperature what's the standard temp and what's too hot?
Typically 20-30 deg. F above ambient. This is the air temp after the intercooler, just before the throttle body.
Engine Coolant Temperature what's the standard temp and what's too hot?
Once the engine is warmed up, about 190-200 deg.
Injector Pulse Width in msec. what's the number suppose to be +/-
At idle, around 1.4. At WOT, anywhere from 16-23+ depending on mods and boost levels. This value can be used to determine whether or not the injectors are reaching capacity.
Long Term Fuel Trim what's the number suppose to be +/-
I believe, and someone correct me if I’m wrong, that on the SRT-4 this will range from -20 to +20. This is the range for Fords anyway. This value represents the correction to base fueling in closed loop operation and is calculated over a long period of time to eliminate changes in ambient conditions. This can be particularly useful when tuning after making significant engine mods such as a cam or head work. The closer to “0”, the better the base tune. Once this value hits +/- 20, the PCM can no longer compensate and you’ll need to have the car re-tuned. This is it in a nutshell, to fully understand it you may have to do some more research.
Short Term Fuel Trim what's the number suppose to be +/-
Similar to above but this term is calculated based on short term conditions such as changes in weather. The long term correction is based off of trends of the short term.
O2 Sensor Voltage what's the number suppose to be +/-
At idle it will oscillate between 0-1000 mv, above and below 440mv (stoichiometric which = 14.7:1 A/F ratio). At WOT it will read around 900mv, indicating a A/F ratio closer to 12:1, which is appropriately rich.Manifold Pressure (vacuum/boost) Easy to read
Ignition Advance what's the number suppose to be +/-
Will vary between 0-50, depending on rpm and engine load. This is most useful to look at under WOT, which for a stock car is around 30-35 deg. if I remember correctly (mine’s not stock anymore). Monitoring this will tell you if timing is being pulled, and allow you to compare values between tunes when they become available for these cars.
Knock Retard what's the number suppose to be +/-
Should be close to zero. When the PCM detects detonation or knock, it will pull timing to eliminate it. This value represents how much timing is being pulled. Getting more the 3-4 degrees would tell me to back of the boost, add octane, of reduce the WOT timing advance (if possible).
Throttle Position Percentage what's the number suppose to be +/-
In theory it would read 0-100%, but the SRT-4, like most cars, seems to have a narrower range. I think I see like 7-90%.
Engine Load what's the number suppose to be +/-
Calculated by the PCM to represent how much of the engine’s power is being used. It’s actually a little more complicated than that, but that’ll give you a start in understanding it.
I’d recommend researching all these terms a little more if you want a complete understanding of them. Some are pretty simple, some are complicated calculations that a tuner or someone wanting to fully understand the operation of the car would want to know. Once tuning software becomes available, you’ll be glad to have access to some of these values.
What Values would be the most important to monitor on the SRT-4 all the time , I know all of them are important.
So far I have found two since I have only one gauge.
Ignition Advance what's the number suppose to be +/-
Will vary between 0-50, depending on rpm and engine load. This is most useful to look at under WOT, which for a stock car is around 30-35 deg. if I remember correctly (mine’s not stock anymore). Monitoring this will tell you if timing is being pulled, and allow you to compare values between tunes when they become available for these cars.
Knock Retard what's the number suppose to be +/-
Should be close to zero. When the PCM detects detonation or knock, it will pull timing to eliminate it. This value represents how much timing is being pulled. Getting more the 3-4 degrees would tell me to back of the boost, add octane, of reduce the WOT timing advance (if possible).
Most stock cars running premium will probably not ever see knock, but my stage 1 running 18 psi does so I monitor that religiously. I also look at inj. PW when I play with boost, although I've confirmed that I am ok so I don't monitor it as much. I have intake air temp up a lot, as I've messed with diifferent intake kits and like to see how efficient they are.
When I went stage 1 I watched the ignition advance, to see how much more/less timing I was getting. A also wanted to see if the new cal. effected the long term fuel trim.
Once I get a A/F kit I'll look at that full time, and may also add an EGT. The analog inputs will be used a lot I think for those with significant mods who need to monitor things not found on a stock car. Oil pressure, or perhaps a 3 bar MAP as well. You can log these things alongside the standard parameters. On my other car I frequently will log A/F ratio with RPM, to get a complete picture of my fueling throughout the rpm range. Once you get your A/F connected I'll bet you'll do the same.
I hooked up my AEM UEGO to the SRT-4 Interceptor gauge today.
This was very easy, the output from the wideband is the white 0.5 V wire and the Interceptor has a green and a white one, the white one is Input 1 so this is the one I used (could use either one ), then this is what Todd told me to do.
Turn the gauge on and scroll through the menu and select the appropriate analog input which I used Input 1 . You'll go to a new screen which will allow you to enter the conversion (slope = 002.0, intercept = 010.0) for this AEM unit (voltage * 2 +10 = A/F ratio) and it worked perfectly. I can't wait to record my A/F Ratios, I'll let u know how everything worked out later on .
what 4 are the best ones to display all the time. i was thinking
knock retard
short term fuel trim
o2 sensor reading
air intake temperature.
whats your guys oppinions of the 4 best to view all the time??
Well since i have a single setup in my vehicle i like to toggle between the
-manifold pressure (boost)
-air intake temp
-knock retard
-coolant temp
I guess it's just preference though.
what 4 are the best ones to display all the time. i was thinking
knock retard
short term fuel trim
o2 sensor reading
air intake temperature.
whats your guys oppinions of the 4 best to view all the time??
On gauge 1, I have A/F ratio from my wide band on analog 1, the output from a 3 bar MAP in analog 2. Gauge 2 has knock retard and intake temp or ignition advance.
Monitor your Ignition Advance for timing!!!!!!!!!!!!
Quote: Originally Posted by forcefedjunkie
Ignition Advance what's the number suppose to be +/-
Will vary between 0-50, depending on rpm and engine load. This is most useful to look at under WOT, which for a stock car is around 30-35 deg. if I remember correctly (mine’s not stock anymore). Monitoring this will tell you if timing is being pulled, and allow you to compare values between tunes when they become available for these cars.
Knock Retard what's the number suppose to be +/-
Monitor your Ignition Advance for timing!!!!!!!!!!!!
Quote: Originally Posted by forcefedjunkie
Ignition Advance what's the number suppose to be +/-
Will vary between 0-50, depending on rpm and engine load. This is most useful to look at under WOT, which for a stock car is around 30-35 deg. if I remember correctly (mine’s not stock anymore). Monitoring this will tell you if timing is being pulled, and allow you to compare values between tunes when they become available for these cars.
Knock Retard what's the number suppose to be +/-
so is ignition advance the same for a stage 1 car?? Do i always want to maintain between 30-35 and if i go lower or higher i have to change boost?
I've found that ignition advance on stage 1 is lower at WOT than stage 0. Aaron at Realtune pointed this out to me and I verified it by re-installing my stock PCM. I was getting 22-23 degrees with stage 1, and now am seeing 27 or so with the stock PCM back in.
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