What is the IAT Sensors job in SD Tune
01-31-2015, 09:15 AM
#21
Moderator
Since hot air is less dense, it will "dump" less fuel and you will be a bit lean.
01-31-2015, 12:33 PM
#22
If I move my sensor will my tune need to be tweak?
Now with it located at the TB, it's reading the air temp at the TB. If I move it to the front of the car somewhere, where it's getting a cooler air reading, that's not the same cooler air by the time it reaches the TB. With the heat off the engine mixed in.
In my opinion that would be telling the PCM that cooler air is entering the TB.
How much ET are we talking about here.
That's all I'm worried about.
Now with it located at the TB, it's reading the air temp at the TB. If I move it to the front of the car somewhere, where it's getting a cooler air reading, that's not the same cooler air by the time it reaches the TB. With the heat off the engine mixed in.
In my opinion that would be telling the PCM that cooler air is entering the TB.
How much ET are we talking about here.
That's all I'm worried about.
01-31-2015, 04:57 PM
#23
Moderator
That depends upon upon details of your tune. If it was tuned while the IAT was at ambient temp, then your tune is fine because the PCM is properly adjusting according to the IAT.
Since my air intake is completely thru my raised hood, there is no engine temp mixed in, at least not at high throttle.
I tune on the street and at the track and therefore need accurate IAT.
How much ET is hard to tell. Depending upon your WOT A/F ratio, e.g. 12.6, your engine might produce a bit more power leaned out to around 13.0. However you might start picking up some knock retard due to the leaner A/F.
No easy answer here; clearly manufacturers put a lot of effort into keeping the IAT as accurate as possible. If your IAT changes by 30F+ during a run there is no way you are going to have optimal performance.
Since my air intake is completely thru my raised hood, there is no engine temp mixed in, at least not at high throttle.
I tune on the street and at the track and therefore need accurate IAT.
How much ET is hard to tell. Depending upon your WOT A/F ratio, e.g. 12.6, your engine might produce a bit more power leaned out to around 13.0. However you might start picking up some knock retard due to the leaner A/F.
No easy answer here; clearly manufacturers put a lot of effort into keeping the IAT as accurate as possible. If your IAT changes by 30F+ during a run there is no way you are going to have optimal performance.
02-02-2015, 10:50 AM
#27
The TPS is varying between 92% and 95%. You will probably gain more getting that to read 100% than worrying about the IAT. Could be just the way it displays on the 4150 TB if it actually opening 100%. If it is you should adjust the TPS to show 100%. And with no wide band data there is no way to know what the fueling is.
02-02-2015, 11:15 AM
#28
Yeah, the TPS is showing 92 and 95%, but it's open all the way. I'll adjust it to say 100%.
The only way I can read the AFR is in the table file, I think that's what's it called. Can 't read the AFR on the chart graph or gauge chart.
Did you see where the timing stayed at 25* through out the run?
Thanks for taking a look at it.
The only way I can read the AFR is in the table file, I think that's what's it called. Can 't read the AFR on the chart graph or gauge chart.
Did you see where the timing stayed at 25* through out the run?
Thanks for taking a look at it.
02-02-2015, 03:54 PM
#32
Moderator
Post your tune and I promise to look at it tonight.
As mentioned, without a wideband O2 sensor connected to your log file, we know nothing about the A/F tuning. The A/F tables only tell us what the tuners wants, not what really is happening. For example, if you have non-stock injectors, the actual A/F could be way off.
May I humbly suggest that you learn more about tuning before you worry about ETs.
Greg Banish has several books on it and a $250 Video.
As mentioned, without a wideband O2 sensor connected to your log file, we know nothing about the A/F tuning. The A/F tables only tell us what the tuners wants, not what really is happening. For example, if you have non-stock injectors, the actual A/F could be way off.
May I humbly suggest that you learn more about tuning before you worry about ETs.
Greg Banish has several books on it and a $250 Video.
02-02-2015, 07:54 PM
#33
Moderator
I looked at your log files, but they are not very interesting.
As mentioned there is no A/F wideband logging.
I know you are running a TH400 and therefore the PCM is not shifting, but IMHO sloppy to see the MPH off by a factor of 3.
In the second log file you hit the rev limiter.
What is your question?
We cannot help you with anything related to A/F or IAT because there is no wideband data.
As mentioned there is no A/F wideband logging.
I know you are running a TH400 and therefore the PCM is not shifting, but IMHO sloppy to see the MPH off by a factor of 3.
In the second log file you hit the rev limiter.
What is your question?
We cannot help you with anything related to A/F or IAT because there is no wideband data.
02-03-2015, 08:47 AM
#35
Moderator
What brand WB are you using?
Does it have a data output line?
If yes, that should be connected to the aux-in on the HPT device.
Then you have to add a new entry to your scanner cfg file.
And finally add that entry to the logging.
It shouldn't be hard to find all the details; google "hp tuners connect wideband".
Your log shows a top speed of only 42mph. I don't think anything in the engine tuning uses mph, but accurate data is still useful.
Does it have a data output line?
If yes, that should be connected to the aux-in on the HPT device.
Then you have to add a new entry to your scanner cfg file.
And finally add that entry to the logging.
It shouldn't be hard to find all the details; google "hp tuners connect wideband".
Your log shows a top speed of only 42mph. I don't think anything in the engine tuning uses mph, but accurate data is still useful.
02-03-2015, 09:53 AM
#36
AEM Wideband, standard HPT, got the WB wired into the EGR Valve wire. No EGR.
It's set up in HPT like it said. Don't know why it's not reading.
MPH is wired into front left ABS Sensor, maybe don't have the right valuables in.
Not worried about reading MPH, time slip does that.
This car is a 100% race car, WOT 100%.
It's set up in HPT like it said. Don't know why it's not reading.
MPH is wired into front left ABS Sensor, maybe don't have the right valuables in.
Not worried about reading MPH, time slip does that.
This car is a 100% race car, WOT 100%.
Last edited by RENE'S RAGE; 02-03-2015 at 11:22 AM.
02-03-2015, 10:31 AM
#37
If hooked through the EGR then your going to have to compare your actual A/F what logged in HPT and keep adjusting the values until actual A/F matches logged A/F to make up for the ground offsets. There is a very good chance whatever A/F you logged isnt correct unless you corrected the ground offset already. Its not just plug n play when going through the EGR.
02-03-2015, 10:39 PM
#40
Moderator
I took a quick look. Nothing that really stands out. Just a few things:
* While you have #48 injectors, the "Offset vs Volts vs VAC" table is for the stock injectors. Doesn't really matter for a 100% WOT race car.
* The VE primary table has values up to 125 which indicates something else might be a bit off.
* The VE secondary table has a few values different from the primary table.
* It appears you have no MAF in which case the DTC for the MAF should be set to "0 Mil on First error" and not "2 No MIL light". Your setting might be confusing the PCM.
Again, what is your question or concern?
* While you have #48 injectors, the "Offset vs Volts vs VAC" table is for the stock injectors. Doesn't really matter for a 100% WOT race car.
* The VE primary table has values up to 125 which indicates something else might be a bit off.
* The VE secondary table has a few values different from the primary table.
* It appears you have no MAF in which case the DTC for the MAF should be set to "0 Mil on First error" and not "2 No MIL light". Your setting might be confusing the PCM.
Again, what is your question or concern?