Forum » Off Topic Discussion » You should really do a webinar on Charge temp approximation table tuning.

You should really do a webinar on Charge temp approximation table tuning.

Off Topic Discussion

If it's not really about tuning or wiring. Then it belongs in here.

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I know how it works. What i am strugeling with is to come up with a good procedure to tune it. And im not the only one i noticed.

Thats all

That's a great idea. I've explained what it does/how it works in a previous webinar but you're right, a technique for tuning it is a little less obvious. To be honest, tuning this table perfectly is difficult since we don't really get the opportunity to see how the combination of load/rpm and IAT?ECT influences the actual IAT at the valve.

This is something I planned to do some testing on with our 86 since I can actually temporarily install an IAT sensor (well actually a thermocouple) very close to the intake valve through the port injector location. By running the engine on DI alone, I can get a pretty good picture of how actual IAT changes during a range of driving conditions.

I'll give some thought to what we can bring you guys. Thanks for the suggestion.

Bringing this up for air again.

Im starting to think that the new "modeled" fuel ecuation in link/vipec should be left alone (really talking for myself here) since it depends on the charge temp approximation table to be utilized, and is basicaly useless without it. Since there doesnt seem to be a good and "easy" way to do this without an actual temp probe just over the valves it seems better to just stick to the old "traditional" equation. Never really had any problems with it (the old one).

This thread is a few years old but showes a bit of the struggle to get it right.

I've had really good results using the new modelled fuel mode in the G4+ range. I agree that an accurate and simple process for tuning the charge temp table is problematic and I'm working on it. I've found though that even the suggested table in the help file is a good place to start and should have you running pretty well.

Of course you could always use this table to focus completely on IAT and ignore the ECT and then the ECU will respond much like the traditional fuel model anyway. In this case it will however take the IAT value directly into account in the ideal gas law, however you can still override this if you want using the IAT Fuel trim table so you can get a similar effect to the traditional mode if you prefer this.