Nakoz

iTrader: (2)

I finally got my LC1 and XD16 hooked up and everything is reading, logworks and HPT (A/C pressure sensor). However, i noticed that my HPT is reading high compared to logworks2. I am using the (Voltage/.625) + 10 = AFR equation with a range of 10 to 18 AFR. However, i know that the readings are off in HPT about .30 (ie 14.60 shows 14.90 in HPT). So through more investigation i noticed that if i used .660 instead of .625 the readings would be alot closer, but they are still off and the max AFR output is 17.58, due to the new .660 divisor.

Now I was going through my scans in HPT and logworks2 and noticed that logworks2 captures a reading every .08 seconds and HPT averages a reading every .216 seconds (give or take .02).

Is there anything i can do to get this reading closer? Can i adjust HPT to read quicker and maybe get a more accurate reading from the WB?

Any ideas, not sure if anyone else has this same problem.

Reject

iTrader: (24)

cant you just delete some PID's to the basics? that usually always speeds up the logs

Nakoz

iTrader: (2)

well, even if it speeds up the logs, i still have an accuracy issue with the WB. Not sure what formula comes the closest. I am think somewhere in the .70 - .80 range.

Billf6531

Your problem may be due to the LC-1 reporting too quickly. Use Logworks to set the LC-1 to report at the 1/6th rate.

Nakoz

iTrader: (2)

Yep its set for 1/6th rate. I double checked and reprogrammed it but still same result. Any other suggestions? Im open to anything right now. Even if i have to run 2 interfaces.

WS6 GreeN

Would ground offset come into play using the a/c sensor?

Nakoz

iTrader: (2)

Im not sure, but I would think that since I am using the same ground for the analog output2 and the LC1 itself (minus the heater) that they should not interfere with each other. But hell I dont know its a possibility and I am willing to try switching them. Also, I was sitting here wondering if I should possibly speed up the reading of the LC-1 and use a faster setting than 1/6th, but I am not sure how it will affect the HPT scanner. To me it seems as if the scanner is running slower with the new WB readings in the tables. As if it is trying to keep up.

I have been working on formulas all weekend for the Volts and AFR and I thought I had it narrowed down, but it still looks off. Here is what I have so far:

From MrDude:
(Volts/.625) + 10 = AFR (with an AFR range of 10 to 18)

Ex. using 2.75 Volts from A/C pressure sensor:
(2.75/.625) + 10 = 14.40 AFR

But looking at my AFR from the XD gauge and from HPT side by side, it looks as if HPT is off by .30 - .40, which is alot when trying to tune AFR.

So i tried this equation and it seems a little closer:
(Volts/.57172557) + 10 = AFR

Ex. @ 2.75 Volts
(2.75/.57172557) + 10 = 14.81

Which to me looks alot closer and gives you a range from 10 to 18.75 AFR instead of 10 to 18.

What do you guys think? Am I going in the wrong direction here?

Nakoz

iTrader: (2)

anyone feel like chiming in on this? I am sure I am not the only one see this problem. Although my car has been known to hate me.

KRAZY K 2000 TA

iTrader: (5)

i say a ground offset i know there is a sticky on hp tuners site for it with the math formula for it i cannot remember it,i corrected mine and it was dead on

Billf6531

If you're still fighting with this, here's the method to determine the offset:

http://www.hptuners.com/forum/showthread.php?t=11018

Leave the volts/.625 and adjust the 10 +/- to achieve the correct reading.

Gold Phoenix

iTrader: (1)

If you are getting two different reading, which one would be more accurate?

Billf6531

I'm not sure I understand your question, but you want HPT to read/report what the w/b is giving it. In other words, if you set the w/b to report 14.7, you want HPT to tell you that it's seeing 14.7.

Gold Phoenix

iTrader: (1)

I am getting the same thing, but using a different display. I am more concerned on which would be more accurate, the gauge or HPT.

Billf6531

Both report what the wideband tells it. The source of the data is the wideband. You start with the assumption that the w/b data is correct.

To calibrate things that rely on w/b data, program the w/b to output 14.7 afr. If the gauge reads 14.7, it's accurate. If HPT reads 14.7, it's accurate. If you don't want to do this, and all you want to know is which is more accurate, the answer is Tuesday.

Since you tune via HPT or some other tuning s/w, it's important that it use accurate data to correct the VE and MAF tables. Many users have found it necessary to correct the formula to account for ground off-set, thus the link a few posts above that tells you how to do this.