I'm swapping an LS1 into a 93 RX7 and had a quick question for the HPTuner gurus. I have a standard serial interface and will have some spare pins on the PCM since I won't be running EGR or the rear O2 sensors. Is it possible to reuse these pins (preferrably rear O2) to log with a wideband? I would think that I would just need to assign a custom PID, but I haven't played with the software on a running car yet, so I'm not as familiar with it as I'd like to be. Thanks in advance.

 

I don't think the unused pins in the PCM would work for you. You'd be better off finding a way to get an EIO. If you were clever, you'd get with a dude, give him a little cash, and swap your regular interface for their EIO since you get the same trade-in value for either...granted, the other dude would have to be ponying up the cash to upgrade to USB.

 

I had thought about that, but I can't transfer my credits (99 V8 F-bodies and 04 V8 trucks) to a different serial interface to get a serial EIO. The eventual plan is to build a carputer for the car that will be used for logging/tuning as well as the normal MP3 and navigation stuff. Because of that blackbox logging, the main reason to upgrade to a USB EIO for me, won't be needed.

 

i used the data out on my dynojet wideband thru the egr wire to log my wideband with hptuners...just like you said...custom pid

 

AC pressure input works too.

 

if you do the rear o2s you have to be able to change the output voltage from 0-5v to 0-1v. LC1 will do this. I dont know how fast the computer samples rear o2s though.

 

does anyone have a cfg with a custom pid to use the egr and one for the a/c?? im sure it would be something to put up in the stickies.

 

Thanks for the good info guys. I'll probably just use the EGR input since it has been done before and is already a 0-5v source. I would assume that you can adjust the sample rate on the rear O2s when you create a custom PID, but I could be wrong since I'm not real familiar with it. The AC pressure input is also not a possibility for me since I'm in Texas and AC is a necessity most of the year.

 

Good idea to use the EGR input. I was going to buy the EIO interface for HP Tuners. I wont need to now. I'll give this a go over the weekend. I got rid of my EGR valve a few months back.

 

Guys, post up how the EGR input works out.....I'd really like to be able to tune w/wideband without upgrading to EIO.

 

I have got rid of my EGR, I have cut the connector of and taped the ends, to make it look a little nicer under te spiral wrap. I beleive its the brown (not sure) wire, by putting between 0V and 5V on this the PCM can read it. Will have to check the wire to make sure it is the right one. Remember to delete all EGR stuff in your PCM. You will need to create a custom PID in your tuning software. The output from your wideband controller should be 0-5V, run this wire to the EGR input (I will do this at the point of where I cut the connector off) You will need to create a little formula on your custom PID this will depend on what wideband controller you are using. This formula will contain a little offset and a multiplication. Eg, for 0-5V you want it to read 10:1 to 17:1, not these exact numbers just pulled them out of the air. Get the wiring done and you can play ith the forumla at a later date, the voltage output vs AFR will be documented in your Wide band controller information.

 

Once someon does this and confirms it works fine... if you could do a small write up w/some example log files I can add it to the stickies

 

I'l be aiming to do it this weekend, was hopoing to do it last wekeend but time just slipped by. I'll let you all know how I get on.

 

Well got some good news. Got my wideband wired up to the laptop and viewed in HP Tuners with no EIO Using a wire which used to go the the EGR valve.

Parts used:-
AEM Wideband guage was this wire with bosch sensor (http://www.thunderracing.com/catalog...&vid=3&pcid=62)
Length of wire
2 x crimps

Time to install about 15mins.

The output from thre AEM guage is 0-5V. This is the white wire.
The EGR valve had been removed some time back. The connector has been cut off to tidy up the wiring loom. The wire you want is the brown wire, this reports back 0-5V to the PCM. I tested it was this wire by using a resistor to 5V and verified this on this using HP Tuners.

The wire from the AEM guage was extented to reach the EGR Brown wire using a bit of wire and two crimps. Now the output from the AEM guage will be routed to the PCM, if you monitor the EGR reading in the PCM you will see it changed with AFR.

Now you need to create a custom PID.
In HP Tuners
For the AEM guage the formula would be
=(EGR_Volts/0.5)+10
Other guages may need a different formula, this should be documented in your wide band guage leaflet of what voltage euqals what AFR.


Turned on ignition and the AEM guage read 14.7:1, but HP Tuners read 15.1:1, now this isn't a problem, we can just adjust the formula. Probably just down to reference voltages and volt drops down wires.

As the EGR valve was removed some months back all EGR references in the PCM have been disabled. Once you have done this Wideband/EGR mod you will need to go to Engine/General/EGR Enabled = Enabled, if this is disabled then the EGR voltage wont be read into the PCM, this needs to be enabled.
Check that Spark Control/Spark Advance/EGR Spark Advance is all zeroed out.

 

nice! glad you got it working. so then i guess for the lc-1 the analog out wire (dont remember what color) could just be spliced into the brown egr wire and bam! create your pid, adjust your formula to make sure the a/f is correct and your good to go?

 

Yep as simple as that. dont know if this has ever been done before, but its realy not that difficult I'm surprised its not so well known. My main reason for doing it is to save money on the EIO interface, living in an other country I would have to send of my tuning pod, loose it for a month or so.

 

Nice work and documentation, I'm sure that will help out a lot of people.

It has been done before, but nobody took a lot of time to document the "how-to" like that. Harlan actually did this a couple years ago with I believe another scanner. As he mentioned above, he used his A/C pressure input, but it was the same principle. I didn't know enough about tuning at the time to really put it to use.

 

Does everyone seem to have this problem?

 

I noticed something similar when I was tuning on a buddy's car on the dyno the other day. I just gave it about 60 seconds or so and things came back inline. I have no clue what was causing that.

I know previously I had a problem where it was consistently reading off, which was due to the LM1 not being set up with the right voltages.

 

I slightly adjusted the formula for translating the Wideband output voltage into the ratio in HP Tuners

([PID.2811]/0.53)+9.8

My original formula should have been ([PID.2811]/0.5)+10, this was slightly off, but all sorted now, I'll just keep checking my guage reads the same as the logging software.

PID being the EGR voltage.

Now the numbers that show up on the guage tally up with the ones shown in HP Tuners.