Diy Tuning

[rollex]

Yeah I'm going to spend the weekend reading all of the guides to get an understanding then start doing some datalogging to confirm what my car is doing with the current tune. I still need to purchase a wideband so be a few weeks away before I start playing.

[camo86T]

For me, reading these tuning threads is sort of like being tied up and thrown into a tank full of 18yo single malt

#wayovermyheadanddrowningbutreallyenjoying it

[gaz097]

Camo read a few of the common threads once a week. Sinks in pretty quick. I'm yet to take the plunge but I'm confident I can tune my car pretty quick, and it will be tuned towards 450rwkw on e85 which will add a few extra layers.

[Peppy_t92]

The HP forum is good for info on using the software, but you should also understand the how's, whys, what's, of tuning and combustion engines, there's plenty of books that give you a guide

This was a great read

once you start logging your own car and matching maps to logged data you learn pretty quickly what does what and by how much

Edited 20/08/15 08:23 PM by Peppy_t92

[Ralph Wiggum]

All of Greg's books are excellent. Unfortunatly nothing has been specifically written for Aus Ford but as Pep started if you understand the basics you can build on that.

It's not Rocket Surgery, It's all about inputs and outputs from the PCM.

[rollex]

I posted this on HPT but wondering if anyone has different answers here:

Ok so I've been reading the lasota racing manual and msot of it is stuff I already understand but it is definitely a good read. The following questions are mainly about speed density as that is the thing that is doing my head in.

To try and understand things better I've assumed two things in this scenario, wide open throttle (TPS of 50%) and no variable cam timing, eg it is locked and no other correction maps in play, eg ignoring temp etc.

This means the simplified equation is:

fuel_injected = commanded lambda (fuel base vs rpm vs tps) * MAP at x cam degrees at y rpm * actual air pressure in inlet

This means the PCM will figure out the fuel to inject based on the air pressure * volumetric efficiency in the MAP per airmass high res table * commanded AFR

Now this brings a few questions up. What if I want to run 11:1 AFR at WOT with 18psi but I want to run 12:1 AFR at WOT with 12 psi? The main fuel base map is rpm vs TPS? Why is it not rpm vs load eg like the spark maps?

Now I'm sure I could get the result I'm after by tweaking the injector slopes or a bunch of other methods but that means making a hack tune which isn't what I want to do.

The next question is what about the cam position, how is this commanded? I'm guessing the reason the cam angle vs rpm table exists is because the different cam angles change volumetric efficiency? eg the amount of fuel required to obtain a given AFR at a given psi changes

Also can anyone answer this question about map resolution?

http://www.hptuners.com/forum/showthread.php?53120-help-rolls-transition-from-a-tuna-to-a-tuner&p=395279&viewfull=1#post395279

Edited 24/08/15 10:35 AM by rollex

[eff xr6t]

Why do you want to make it richer with more boost?

[rollex]

Well if I'm running low boost then I can probably get away with 12 or 12.5 AFR without detonating, eg half throttle on a straight line or 1/4 throttle up a hill.

If I'm WOT then I will need closer to 11-11.5:1 with 16+ psi.

The issue is load isn't proportional to your foot position, you can get close to full load with half throttle going up a hill. Going down a hill at a lower speed you won't get f*ck all load with half throttle.

The reason I asked is I normally tune load vs rpm. Eg very easy to simply add more fuel at peak torque at full load, doesn't matter if I'm 25% or 100% throttle, if there is that much airflow it will be that rich. There is a good reason why the ignition tables are load vs rpm, because going up a hill vs going down a hill at the same boost and throttle position will accept differing amounts of spark before detonating, I just don't get why AFR is programmed differently in these cars.

[rollex]

Another question is how good is the knock detection in these cars, can I simply log knock and it will let me know if there is mild detonation? Or do I require knock ears?

[rollex]

Anyone ?