Air/fuel ratio datalog

[[Twitch]]

So I finally got my wideband AFR working and I did some test run to see where I am at.

Here one of my runs. I have done many runs, but when measuring AFR, you have to try to be consistent. I have to keep the TPS at 100%, as you can see, I let off a little at the end.

Here a table of RPM vs TPS and the AFR

Here's another run, this time much better, TPS consistent 100% which will give a better AFR measurement.

3-axis graph of my run

At exactly 4000RPM, the AFR will hit 13:1. This happens on every run I've done. From the graph, it looks pretty good, but I have to recheck from 2000 to 4000rpm again because some runs, it shows around 15~14:1 in that range. Time to do more runs.

So what do you guys think?

My mods:
- K&N FIPK2 intake
- GMS Intake elbow
- Steeda Underdrive pulleys
- Mac ProChamber O/R
- Diablosport Predator

 

[sgarlic]

Thanks for posting that. I'm curious why you're using a wideband with the mods you listed?

 

[[Twitch]]

Thanks for posting that. I'm curious why you're using a wideband with the mods you listed?

Wideband is pretty much the onyl sure way to tell you what's happening with your car. Many people say the Diablo tune makes it run rich or intake mods make the car run lean. So I had to find out myself, test and tune. Now I can play around with the fuel. Without wideband, you are pretty much tuning with a blindfold.

Also, I've been to a dyno and it showed me I was running really rich, so that night at the track, I leaned out the mixture but had worse times at the track. So maybe the dyno shop wideband(tailpipe sniffer) was inaccurate.

With your own wideband, you can check it yourself, retune and test again. This is good for future mods like cams or forced induction. Also, my wideband datalog kit is transferable to another car if I ever get a new car.

 

[sgarlic]

Wideband is pretty much the onyl sure way to tell you what's happening with your car. Many people say the Diablo tune makes it run rich or intake mods make the car run lean. So I had to find out myself, test and tune. Now I can play around with the fuel. Without wideband, you are pretty much tuning with a blindfold.

Also, I've been to a dyno and it showed me I was running really rich, so that night at the track, I leaned out the mixture but had worse times at the track. So maybe the dyno shop wideband(tailpipe sniffer) was inaccurate.

With your own wideband, you can check it yourself, retune and test again. This is good for future mods like cams or forced induction. Also, my wideband datalog kit is transferable to another car if I ever get a new car.

I know what a wideband is for, but thanks for the lesson anyway.

I was just wondering why you'd spend the cash on a wideband, when you could spend it on an upgrade or something..

 

[[Twitch]]

I know what a wideband is for, but thanks for the lesson anyway.

I was just wondering why you'd spend the cash on a wideband, when you could spend it on an upgrade or something..

Like I said before, it to know what's happening on your car after mods. Also, ít only costed me 280$ for this.

As for spending in other mods, the only other bolt on mod missing is a 75mm throttle body, after that, I have to get internal mods(cams or SC) so why not get a tool that you can keep forever that is useful for these kind of mods.

Also, its not only for AFR, it also a great datalogger adaptable to any car, so you can calculate a RPM acceleration curve, how fast you shift, ECT cooling methods, and many other things than you can do with datalogging. (Diablo datalog is not based on seconds). Hell, next week I get to play around with my friends Cobra to test and tune.

Many people want to test and tune themselve, I guess I'm one of them...

 

[urban96]

do you have the RPM converter for the LM1 or just the basic kit?

 

[[Twitch]]

do you have the RPM converter for the LM1 or just the basic kit?

I have the LM-1 and the RPM converter.

 

[jstreet0204]

Are you datalogging with the lm1 or the predator? If the predator has an anolog input you'd be better off logging with the predator, so that you can see how the fuel trims compare to your actual afr, although you are limited in the amount you can tune.

 

[[Twitch]]

Are you datalogging with the lm1 or the predator? If the predator has an anolog input you'd be better off logging with the predator, so that you can see how the fuel trims compare to your actual afr, although you are limited in the amount you can tune.

Predator has no analog inputs for datalogging, that's the reason why I have the LM-1. If I had a Xcal2, which comes with analog input, I would need the LM-1, but instead just the LC-1 with the gauge display.