Sale ends todayGet 30% off any course (excluding packages)

Ends in --- --- ---

Power FC / Datalogit Logging

General Tuning Discussion

Forum Posts



Tech Articles

Discuss all things tuning in this section. News, products, problems and results. 

= Resolved threads


Hello everyone.

I am trying to tune a 1jz vvti supra on the road. I just have a few Questions .

1. I have hooked up a Innovate LC2 Wide band to the Datalogit Black box on AN1 and AN2. The Map watch window of afr matches the Innovate gauge and also the lm Software virtual gauge but when logging in the 20*20 map grid it seems a bit off. Which one is to be believed when steady state tuning and full throttle runs?

2. Where I live the roads are quite busy, is it possible to get a good tune with the Datalogit by just driving round Keeping an eye on the afr gauge for lean spots and checking the data logs after? I will be using a Plex Knock monitor while doing this.

Thanks James .

1. There is a "hold off" feature that basically filters out samples for a given cell if you were just passing through. Try increasing that value to 1 or 2. Also check the drop box - there is "Avg" and also other options like "max"

2. You can try, but dyno time is better. It certainly helps if you have a road with minimal traffic. Is this the "D Jetro" model (MAF delete) ? That version is pulsewidth based speed density tuning. You have to be careful. Just changing cells here and there will get you a pretty discontinuous and oscillating fuel curve. There's a lot of smoothing required sometimes depending on what your mods are.

Hello Raymond thanks for the reply.

Yes its the D-jetro model . I have the hold off set to 20msec and is on the avg setting. I will have to do a bit more testing and see if i can sort it.

I just have a couple more questions.

1 .With the inj tab all set to zeros the fuel curve graph is flat . Is there anyway to have a graph for the base fueling tab?

2. I am using the apexi 3 bar map sensor so does this mean it has the flexibility to run 2 bar gauge pressure? because the default scaling puts the top column of the map around 1.3 to 1.4 bar.


P.s its just running a stock turbo with a larger compressor ,750cc inj , fmic , walbro fp.

You can rescale the maps to 3 bar absolute.

Remember also that you can load the engine further rynning against the brakes to avoid physically accelerating too fast or having to tune at license loss speeds, obviously this will result in accelerated brake wear and you need to be mindful of how much heat you are putting into the brakes.

My preferred scaling for 3 bar MAP sensors is to have P1-P10 (first 10 rows) be in increments of 1000 pressure units (what they call "PIM," which is sort of like kpa * 100, but more like kg/cm^2). Then P11-P20 are in increments of 2000 pressure units. The reason for this is that the interpolation is very predictable and you can easily manipulate your pulsewidth map (Base map, Base * INJ view selected in drop box) in Excel or in the INJ map.

I am attaching my Excel graphing tool I made a while back. It was created for Rx-7's but the same principles apply.

Attached Files

Thanks guys for the information ,its all starting to make sense now.

Hi James,

Where in the UK are you? a lot of dyno facilities will hire out there dyno so once you've done as much as you can on the road an hour or more on the dyno will help you finish the tune

Hi Chris

I am from the Nottingham area.

We usually reply within 12hrs (often sooner)

Need Help?

Need help choosing a course?

Experiencing website difficulties?

Or need to contact us for any other reason?