Actual Readings +/- ???? - SRT Forums

MoparbeastSRT4 · 04-29-2006, 02:24 AM

Does anybody know what the standard reading should be with tolerances.
I love the gauge but i would like to know what's good and what's bad.
Sorry for ingnorance but that's why I bought this gauge.

An example,, Where I live right now the temp is around 60 and 65 and I was monitoring my Intake Air Temp and the gauge was reading around 80 to 85 degrees, so I drove to a city where it's around 75 to 85-90 degrees and the gauge was reading 95 to 100 +.

RPM Easy to read

MPH Easy to read

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 200 deg. +20-10 degrees

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.

Hope that helps a little bit.

Todd

__________________
'04 Silver SRT-4

Aeroforce Technology

uncommon© · 04-29-2006, 02:35 AM

Quote: Originally Posted by MoparbeastSRT4

Does anybody know what the standard reading should be with tolerances.
I love the gauge but i would like to know what's good and what's bad.
Sorry for ingnorance but that's why I bought this gauge.

An example,, Where I live right now the temp is around 60 and 65 and I was monitoring my Intake Air Temp and the gauge was reading around 80 to 85 degrees, so I drove to a city where it's around 75 to 85-90 degrees and the gauge was reading 95 to 100 +.

RPM Easy to read

MPH Easy to read

Intake Air Temperature what's the standard temp and what's to hot?

Engine Coolant Temperature what's the standard temp and what's to hot?

Injector Pulse Width in msec. what's the number suppose to be +/-

Long Term Fuel Trim what's the number suppose to be +/-

Short Term Fuel Trim what's the number suppose to be +/-

O2 Sensor Voltage what's the number suppose to be +/-

Manifold Pressure (vacuum/boost) Easy to read

Ignition Advance what's the number suppose to be +/-

Knock Retard what's the number suppose to be +/-

Throttle Position Percentage what's the number suppose to be +/-

Engine Load what's the number suppose to be +/-

we should get these answered and make it a sticky. that way people will know how to even monitor these readings correctly.

MoparbeastSRT4 · 04-29-2006, 03:12 AM

Yeah!!!!!!!!!!! Exactly!!!!!! Thanks Uncommon

heckel26 · 04-29-2006, 05:25 PM

Great question.Put together perfectly.I would like to know the same answers.

a707 · 04-29-2006, 06:08 PM

I was thinking the same

MoparbeastSRT4 · 04-29-2006, 10:31 PM

Quote: Originally Posted by heckel26

Great question.Put together perfectly.I would like to know the same answers.

Thanks, well now we need help from our vendor or the manufacturer or anybody that knows these things better.

MoparbeastSRT4 · 04-30-2006, 07:26 PM

Nobody?

Bump

heckel26 · 04-30-2006, 07:32 PM

Quote: Originally Posted by MoparbeastSRT4

Nobody?

Bump

Its the weekend,I'm sure the guys will chime in after they get a bit of rest.

Hell knows I'm about all lazy on the weekends.

a707 · 04-30-2006, 08:03 PM

I was seeing knock retard today on my car. Don't exactly know what that means, but I'd say that's one you'd want to always read 0.

xtconcepts · 05-01-2006, 08:43 AM

Ok guys i'll get forcefedjunkie to chime in here he's a very busy man,but he'll be here to answer all of your technical questions ok...

FranknBeans · 05-01-2006, 05:07 PM

Quote: Originally Posted by MoparbeastSRT4

Does anybody know what the standard reading should be with tolerances.
I love the gauge but i would like to know what's good and what's bad.
Sorry for ingnorance but that's why I bought this gauge.

An example,, Where I live right now the temp is around 60 and 65 and I was monitoring my Intake Air Temp and the gauge was reading around 80 to 85 degrees, so I drove to a city where it's around 75 to 85-90 degrees and the gauge was reading 95 to 100 +.

RPM Easy to read

MPH Easy to read

Intake Air Temperature what's the standard temp and what's too hot? This would depend on the tempature of the air outside. Not sure if there can be a set answer for this. example: Temp in FL is 110* outside. Temp in PA is 70* outside. The IC cools the air down depending on how cool the air is outside.

Engine Coolant Temperature what's the standard temp and what's too hot? Stock thermostat gauges are 190* So i give or take 5-10* tepending on driving conditions.

Injector Pulse Width in msec. what's the number suppose to be +/-

Long Term Fuel Trim what's the number suppose to be +/-

Short Term Fuel Trim what's the number suppose to be +/-

O2 Sensor Voltage what's the number suppose to be +/-

Manifold Pressure (vacuum/boost) Easy to read

Ignition Advance what's the number suppose to be +/-

Knock Retard what's the number suppose to be +/-

Throttle Position Percentage what's the number suppose to be +/- TPP just read how far you have the gas pedal depressed.

Engine Load what's the number suppose to be +/-

Engine load would be how hard the engine is working to move your car. If you rev up the car in netrual the load will be 0%. Now stick it in gear and start going down the road. YOu will see the load increasing depending on how hard you are running the motor.

Not sure about the other ones.

thetable · 05-01-2006, 05:41 PM

Knock retard should be 0 unless the engine is seeing knock in which case you will see some value for knock retard.

a707 · 05-01-2006, 05:43 PM

So, the intake air temp is AFTER the intercooler?

FranknBeans · 05-01-2006, 05:44 PM

Yeah it is.

N0sferatU · 05-02-2006, 10:17 AM

also at idle engine load will more than likely be below 5%. I used a scan tool on my 4th gen Camaro and it would read 2% engine load at idle and 4% at idle if I kicked the A/C on. Driving it'll vary...though I don't think it ever fully hit 100% load.