PowerFC: Some DIY tuning comments please

[STATUS]

Does any 1 want to share there Inj map so that I can have a quick gander at what they used as a target AFR's across the board?

Would I be correct in saying that every car would need a slightly different airflow curve?But for the most part the target afr or inj map would stay pretty much the same. For example my car is a neo RB3025 with a GT3576 and z32 AFM. it would have a different airflow requirements to a RB25 with a GT3576 and z32 AFM due to the extra capacity. But the fuel map would be quite similar.

I obviously did it the other way by using the standard airflow curve and tuning the inj map to compensate. So once I get the idea through my head of how it works, I might start slightly tweaking it via the airflow curve.

regards

Chris

Chris im pretty sure ive posted up a few in tuning threads before, the target afr map or target injection ms table is tweaked between different engines and turbos and obviuosly fuels, but yes in broader terms it is very similar.

[STATUS]

If I send you my tune can you have a look at it and if possible make any suitable adjustments? I am happy to $ for your work if you believe you can make a difference. It seems sloppy in the lower range. If you are able to, PM me.

Sorry ive turned off pm's as i rarely get screen time nowadays. feel free to email it to me [email protected] with mods and car type. I wil look at it for you for free, as for changing it i will see how it looks first, and maybe make sugestions, do you have WB logging?

An easy way to see if your tune is pretty poor is the color grading in the map, if it doesnt smothly blend colours it needs work.

here are two examples the top one is a real map, see the large steps and troughs.... this is all bad for driveability etc. Compare the second map to the original to get an idea of what im getting at. (please understand the touched up one is dramtised a bit to make it more obvious).

The top map was tweaked to remove the steps and troughs only and this was the reply from that UK customer "Car Feels really good mate, never felt the car as powerful as that before and was only getting between 22-30 knock"

Smoothness is paramount for driveability

EDIT: found the thread, save these files as .DAT and you can compare the before and after to get the jist of my ramblings. (ignore the fuel map though as it was to dangerous to rewrite a UK based car with no WB, its cleaned up not rewritten to target afrs from memory)

http://www.skylinesaustralia.com/forums/topic/295349-can-somone-with-datalogit-check-my-map-please/page__p__4924793__hl__map+smooth__fromsearch__1#entry4924793

[SargeRX8]

Sorry ive turned off pm's as i rarely get screen time nowadays. feel free to email it to me [email protected] with mods and car type. I wil look at it for you for free, as for changing it i will see how it looks first, and maybe make sugestions, do you have WB logging?

An easy way to see if your tune is pretty poor is the color grading in the map, if it doesnt smothly blend colours it needs work.

here are two examples the top one is a real map, see the large steps and troughs.... this is all bad for driveability etc. Compare the second map to the original to get an idea of what im getting at. (please understand the touched up one is dramtised a bit to make it more obvious).

The top map was tweaked to remove the steps and troughs only and this was the reply from that UK customer "Car Feels really good mate, never felt the car as powerful as that before and was only getting between 22-30 knock"

Smoothness is paramount for driveability

EDIT: found the thread, save these files as .DAT and you can compare the before and after to get the jist of my ramblings. (ignore the fuel map though as it was to dangerous to rewrite a UK based car with no WB, its cleaned up not rewritten to target afrs from memory)

http://www.skylinesa..._1#entry4924793

I downloaded the tune and had a quick squiz at it and it does look very uniform and tidy. I can see alot of work went into the AF table too. You have email!

[Dose Pipe Sutututu]

Curious why everyone likes a totally ruler flat A/F...

I tend to richen up my tunes at maximum break torque when the cylinder temps are at their greatest

Also I don't see many people dial in a few more degrees once the torque decays

[STATUS]

Curious why everyone likes a totally ruler flat A/F...

I tend to richen up my tunes at maximum break torque when the cylinder temps are at their greatest

Also I don't see many people dial in a few more degrees once the torque decays

Put simply you never give gold away for free.... and as such a mail order free touch up is no where near an in house dyno derived tune... as one needs to compensate for a myriad of things.

thats why i said (please understand the touched up one is dramatised a bit to make it more obvious) and (ignore the fuel map though as it was to dangerous to rewrite a UK based car with no WB, its cleaned up not rewritten to target afrs from memory)

but your post above is correct, most of our tunes dont have flat af curves and definately have a non linear timing line. Most go up, some go up down up... all the benefits of live tuning.

[Dose Pipe Sutututu]

It seems these days the general consensus is ruler flat af on boost is a good tune.

I've seen many times people give only credit to af ratios that are ruler flat.

I must admit before I knew anything about tuning I thought the same.

We need a tuning sub forum!

[rob82]

It seems these days the general consensus is ruler flat af on boost is a good tune.

I've seen many times people give only credit to af ratios that are ruler flat.

I must admit before I knew anything about tuning I thought the same.

We need a tuning sub forum!

Hmmmm wait till you start tuning engines that can continuously move inlet cams or even both inlet and exhaust. Then add variable runner length and direct injection into the equation. You'll start to realize that you know very little about tuning.

I thought I knew tuning quiet well until I talked to a former gm calibration/ experimental combustion engineer.

[zebra]

Hmmmm wait till you start tuning engines that can continuously move inlet cams or even both inlet and exhaust. Then add variable runner length and direct injection into the equation. You'll start to realize that you know very little about tuning.

I thought I knew tuning quiet well until I talked to a former gm calibration/ experimental combustion engineer.

I would love to talk to the guy who tuned the Saab variable compression turbo engine.

Would hate to think what is involved there

[Birds]

A lot of trial and error? Hahaha

[urtwhistle]

Hey Trent, cheers for pointing me in the direction of that tune. It was very handy to compare how others have set it out.

I copied the fuel map to experiement with but I think I may have found another issue that I was over looking. When it's making full boost it doesn't seem to be richening up as much as it should be so I think the craptacular walbro fuel pump is running out of flow. But I'll confirm that soon but I hope not cos I really really don't wanna have to strip my stereo out to get access to it.

[Duncan]

easiest way to check that is a fuel pressure gauge, any decent dyno will have a mechanical one handy.

if not, you can remove the fuel rail return at the tank return and run it into a bucket. If you get no fuel at max torque/boost, the pump is not up to scratch

[JonnoHR31]

peak power uses the most fuel, so see what the pressure/flow is doing there

[urtwhistle]

Yeah true, thats exactly how I was gonna test it. like you said with a bucket and apply 20psi to the pressure reg with my air compressor. if nothing or only a little comes out I know theres some thing wrong.

[SargeRX8]

STATUS: Did you get my email containing my current tune?

[zebra]

Yeah true, thats exactly how I was gonna test it. like you said with a bucket and apply 20psi to the pressure reg with my air compressor. if nothing or only a little comes out I know theres some thing wrong.

That won't work bud.

Injectors need to be running etc

[JonnoHR31]

yep will be very different with the motor running. you need a dyno or a remote fuel pressure gauge to test it

[urtwhistle]

I do realize that there would a portion of fuel that would no be getting consumed by the motor. But what it would tell me is if the fuel pump is almost stalling at those pressures at the very least. unfortunatly I don't have a dyno in my shed, but good point on the remote fuel pressure gauge. That is something that I do have. sounds like a job for when I return from work in India with my nice new 260 poncams.

[urtwhistle]

So I did a simple test by just setting the bottom 6x6 of the map to 9:1 from around 11.5 and it dropped the AFR's from 12.4 to about 11. So the fuel pump might just be ok. but will do a proper test later on.

I think I just needed to be more agressive with airflow curve above 3.5v

[SargeRX8]

I got my wideband today. Just fiddling with it, my idle was around 11.3. I went to lean it out a little and in the FC Edit, I had to set my cell for that idle cell close to 17, almost 18 just to get the engine close to stoich... Why are they so far out?

What is a good idle afr? Does anyone have a target AFR for the whole board? I am thinking of retuning my whole injector map by resetting my tune, adjusting injector settings for my nismos, setting the afm to z32 and then copying my whole ignition map across and dropping ignition by a couple degrees then richening up the ignition table and start adjusting. Good or bad start?

[urtwhistle]

its probly the same reason my target afr's were odd. set the cells on your injection map where the car idle's to 14.7. Then open the monitor screen and check the Airflow meter voltage at idle. Now once you know what the AFM voltage is go to tab 3 where you will see the airflow curve's. IF z32 is third AFM selection down then look down at curve 3 which is below it. now scroll across to the corresponding voltage that matchs to what your car does at idle. NOTE* My car idles with a AFM voltage between 1.18 and 1.2volts. now increase the value by a few points and update your pfc while logging with your wide band and keep doing this untill your target AFR is the same or very close to your actuale AFR.

IS that clear as mud?