OBD-II and Tuning

Fakhelek

Member
I had a question but it lead to a larger issue, so I started this thread. We know that detonation is our biggest problem in raising boost. We have a knock sensor in our engines. My question is, Is it possible to tell if the knock sensor has been triggered through the use of software or equipment that interfaces with OBD-II. I was thinking that if so, then we can use that while tuning to find our highest safe boost without knock. Better than listening for detonation.

The bigger issue is, How useful is OBD-II for tuning. If I understand it right, we can get A/F ratio and all kinds of other data that way. It seems to me that a laptop loaded with diagnostic software would be much better than installing 5 or 6 gauges that you will only use while tuning.

Anybody out there using diagnostic software? Let's hear your experiences.
 
there was a thread on this a few days ago. there are softwares, not really diagnostic software, but tools to help with tuning that run on either a palm or laptop. http://pocketlogger.com/ is one. for basic knock monitoring, http://maritime.dsm.org/tech/vfaq/knockled/ tells how to do it for a 2g dsm, and i assume it is somewhat similar at least. all it does is wire an led light to the knock sensor, so when it sees knock it will blink, and the more knock the more it will blink.
 
Thanks for the info! I've seen some of the software/hardware for this (like AutoTap, etc). I didn't know that you could put a light on the knock sensor. That's great.

I still have questions though. Is the palm or laptop software as reliable as gauges for monitoring things like A/F ratio? I hear people talking about how they did their tuning and it seems like everybody is using gauges.

I am new to tuning and don't want to buy 3 or 4 different $200 units until I find one that does what I want (not that I even know what I want).

Anybody else know of techniques/hardware/software that makes use of OBD for tuning?

P.S. I will try to find that thread you mentioned jred, but I don't have a lot of luck finding things with the search here.
 
I had that LED in my 1g DSM. It doesnt' actually "detect knock" it just detects when the ECU has ordered the BCS (boost control solenoid) to close. In the closed position, you can only get about 8-9 PSI, when open, you get the full 14 (or whatever your max boost is).

This knock was kinda helpful, but after a while, you could "feel" when it was open anyway, since the car would run like crap :). Also, it would pull timing, and this is a lot what feels like hapening in my MSP too ...

Has anyone tried pocketlogger on an MSP? I believe our ECUs are made by ford, and if it uses the ford protocol, it won't work with pocketlogger ...
 
http://mazdamp3.com/vbb230/showthread.php?s=&threadid=26399
is the thread i was talking about, just so you don't have to search :) not super useful info, just offers some alternatives. all this does is tap into wires that get data from the ecu, just like any other a/f gauge where it would just tap into wires going to the ecu. i took the idea from the dsm, but i would guess that you could tap into one of the wires on a knock sensor itself and wire an led to the actual knock sensor this way to see when it is detecting knock, if it didn't work like the dsm led. either way, it isn't very accurate and dataloggers can either tell knock or you can see timing getting pulled, which most likely means there is knock. the led is more of a before getting a datalogger tool so you don't blow stuff up.
 
Yeah, I just read the page on the LED and I don't think that will work on our cars. (Anybody know if we have a BCS? I don't think so.)

As for protocols, the way I understand it, Ford, GM, and Chrysler have extensions to the protocol. Imports use the OBD protocol, but do not add anything to it. I believe that Mazda has stayed independent of Ford enough that their ECUs are not influenced by Ford.

I think it would be really cool to put my laptop on the passenger seat and be able to monitor stuff that would take $500 or more in gauges to track. Graphing things like A/F would be great too.

I just don't want to put my money into toys. If it helps to tune, great. If not, then it is a waste.
 
all loggers do is read inputs going to the ecu, as a dealership would if you brought your car into them. electric gauges, like a/f, do the same thing, so they are going to be just as accurate. many people swear by dataloggers, and i have only downloaded the trial versions but they are very cool and useful. the big thing to monitor is knock, timing, o2 voltage (i.e. a/f ratio), and fuel trims, all of which are done accurately through data loggers. it would be more than a toy, it's a cool tuning device :)
 
jred321 said:
all loggers do is read inputs going to the ecu, as a dealership would if you brought your car into them. electric gauges, like a/f, do the same thing, so they are going to be just as accurate. many people swear by dataloggers, and i have only downloaded the trial versions but they are very cool and useful. the big thing to monitor is knock, timing, o2 voltage (i.e. a/f ratio), and fuel trims, all of which are done accurately through data loggers. it would be more than a toy, it's a cool tuning device :)
I see someone has used the intel knockoff in their avatar. NICE!

Sorry, resume thread. Jacking is complete.
 
blynzoo said:
I see someone has used the intel knockoff in their avatar. NICE!

Sorry, resume thread. Jacking is complete.
(wiggle) (thumb) (hump) (yippy) (yes) (rockon) (headbang)
(mspblack)
 
Oh, actually I do have a bit to add. You can actually move down to a PDA from a laptop. There is palm software out that can do everything a laptop can as far as logging and real-time display.

The laptop is better for on-the-fly readings, unless you get a dash mount for the PDA.
 
I am actually more interested in the Laptop software since I don't have a PDA but will be getting a laptop from my employer soon.
 
many companies make dataloggers for laptops as well, you just have to look around. in the other thread i posted i think people said what they were using on their laptop.
edit: i got a palm for $50 a few months ago that will work just fine, the requirements for palms aren't very high so you can get an m100 or something older even
 
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Ive used OBDTool on my car, and I didnt see anything related to a knock sensor. Basically I could see Air Intake rate, Air Intake Temps, O2 sensor voltages, RPMs, Speed, and Fuel Trims.

-Six
 
i'm not sure if obdII let's you monitor knock directly (i know it doesn't on dsm's, but i'm not sure if that is just a dsm thing), but you can see timing, and when the timing starts to get pulled that most likely means that you are getting knock. so if you can see what your timing is doing as you log, you can determine when knock is happening even if you can't see knock counts directly.
 
I work for Snap-on and I have a Graphing scanner in my car all the time. I can do about 1/2 hour of data logging at a time.

Pretty good tool for Generic OBD II.

But you can get similiar software off the internet for 100 time less money than this Scanner. It's more of a privilege than anything to have this Scanner. I couldn't afford it any other way.
 
MSPDAVE125 said:
I work for Snap-on and I have a Graphing scanner in my car all the time. I can do about 1/2 hour of data logging at a time.

Pretty good tool for Generic OBD II.

But you can get similiar software off the internet for 100 time less money than this Scanner. It's more of a privilege than anything to have this Scanner. I couldn't afford it any other way.

You lucky bastage! :p

Hopefully I'll find something good out there. Can't believe how much the stuff costs though. The software can't be all that hard to write and the cables are worth like $5. Too bad people are willing to pay hundreds of $$.
 
A knock light LED would be a nice thing to have for those of us at entery level tuning. If anyone has done this let us know how it is done! Hell, there maybe a way to tap into the alarms LED sense it is only used for the alarm when the car is off anyways.
 
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