PowerFC: Some DIY tuning comments please

[Room42]

Guy just forget about using the afr map with a power fc. Tune by correction and you will have a boner all day long.

You still tuning Chris? Mate I'll have you sorted in a few hours on the road if you are keen. Pm or txt me.

[urtwhistle]

Hi Nathan, yeah I been playing around a little. It's actually pretty good now to tell you the trueth. I will play with it more once I return from India with my new cams. Cheers for the offer tho

[Dose Pipe Sutututu]

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?

I never bother with that A/F chart in FC Edit, just tune the INJ Correction till your WB O2 reads 14.7... I had my car cruising, idling all at 14.7.. returned about 520 km on a tank on the highway to Hunter Valley and back with the A/C on and travelling around the wineries.

[urtwhistle]

the problem that I was having was that I would set the target AF to 9:1 and it still would be too lean and was forced to fix it.

[STATUS]

Guy just forget about using the afr map with a power fc. Tune by correction and you will have a boner all day long.

You still tuning Chris? Mate I'll have you sorted in a few hours on the road if you are keen. Pm or txt me.

its they way most tuners tune like myself (correction mode) but if your learning like these guys then correction usually doesnt mean squat to them... so afr is easy to relate to.

The airflow voltage curve is the important thing to get right, that way all manifold pressures are tuned spot on regardless of throttle position and boost etc (if your fuel base correction is right).

[Dose Pipe Sutututu]

its they way most tuners tune like myself (correction mode) but if your learning like these guys then correction usually doesnt mean squat to them... so afr is easy to relate to.

The airflow voltage curve is the important thing to get right, that way all manifold pressures are tuned spot on regardless of throttle position and boost etc (if your fuel base correction is right).

I still don't know the true usage of the AFM curve, I just set it as the VG30 AFM and off I go. I do however play with the throttle pump, i.e. Accel correction so the car doesn't splutter on throttle jabs.

Hopefully be back on the RB Bandwagon next year again and back to self tuning

[SargeRX8]

Can someone give a map of good cruising target afr's? my car choughs and struggles with tiny throttle, what needs to be corrected to fix that

[Dose Pipe Sutututu]

Can someone give a map of good cruising target afr's? my car choughs and struggles with tiny throttle, what needs to be corrected to fix that

Are you in Sydney? I can give you a hand adjusting the accel adjustments. I found each car is different. I usually start with the stock settings and add till the spluttering goes away. My entire cruise map is all 14.7 when in vacuum and slowly richens up as you increase in revs and approach +ve pressure.

[rob82]

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

Would hate to think what is involved there

Probably wouldn't be that advanced alot of manufactures these days can control the entire ignition system using knock sensor feedback. Some manufactures have really good control some are poor.... 'cough' GM 'cough'.

And testing fuel system flow rates can be done very sucessfully by pressurising the fuel pressure regualtor to the desired boost level with the pump running and then measuring the return fuel flow. IMO its the best way to test fuel system - as you dont need to have the engine at high rpm/load.

[JonnoHR31]

even measuring it and calculating max fuel flow would be different to whats actually happening under full load. the only way to know for sure is to test pressure/return flow under full power

[rob82]

even measuring it and calculating max fuel flow would be different to whats actually happening under full load. the only way to know for sure is to test pressure/return flow under full power

Untrue.

Plus thats not the point - you dont design a fuel system to supply the same amount as the injectors can flow at 100% on. IF you have 6 x 1000cc injectors they can only flow 6l/min of fuel flow so when designing the rest of your fuel system you may want an extra 30% as a safety margin. So when testing this type of fuel system I would be looking for a bare minimum of 7l/min at the desired boost.

[JonnoHR31]

unless you dont need 1000cc worth of fuel. i have 1000cc injectors for future proofing but only run a single 044, which sure as hell doesnt flow 7L/min.

testing it where the problem is occuring is the only way to see exactly what is going on in that situation, unless you have an overkill of a fuel system and simply want to make sure its roughly flowing enough.

[turbomad]

I have been reading through this thread with much interest so i now have a wideband kit on the way and probably go with the fc-hako but what software do you guys recommend to run and where to get it from? Also how do you determine how much timing to add i have tried to open the ign map supplied by Paulr33 on page 14 but it says internal server failure each time, could you email it to me so i can compare what you've done to what my tuner has setup, im not out to play with the wot settings just the stuff inbetween as i doubt they would have spent anytime on it

[discopotato03]

I've just finished this thread as well and I'm going to check my injector settings because I think the trim was at 48 and should be 50 with 740's .

I added 30% when I went to Eflex E70 .

Couple of things I'd like to clear up .

Firstly I noted that Paul33 said his car often didn't get to 80C running water temp and if you look at the water temp enrichment the second last and last parameters are 50 and 80C . I wonder if these PFCs extrapolate between the two and If you run at ~ 76c you would still get a small amount of water temp enrichment .

Secondly both Mafia and Paul33 mention the 02 feedback correction setting in the bottom right hand side of tab 1 . I think the default is 1.047 and I'd like to know what this actually is - possibly Lambda ? If so you'd think 1.047L for petrol would be leaner than 14.7 to 1 .

In post 290 I think Paul mentions he's around 0.94 but how does that equate to 16 to 1 AFR ? He mentions "guys that get poo economy are around 14.7" .

I think I can sort of understand this target AFR and tweak the airflow voltage curve to suit business but thats beyond my capabilities and hopefully Scotty at Insight can do this sort of stuff easily enough .

Thanks all , cheers Adrian .

Edit : I checked my injector settings and they are 62.4 (original setting 48 x 1.3 for E70) and latency 0.15 .

I suppose they really should be 65 (50 x 1.3) and 0.14 latency .

Worth changing ?

Edited October 21, 2012 by discopotato03

[JonnoHR31]

I've just finished this thread as well and I'm going to check my injector settings because I think the trim was at 48 and should be 50 with 740's .

I added 30% when I went to Eflex E70 .

Couple of things I'd like to clear up .

Firstly I noted that Paul33 said his car often didn't get to 80C running water temp and if you look at the water temp enrichment the second last and last parameters are 50 and 80C . I wonder if these PFCs extrapolate between the two and If you run at ~ 76c you would still get a small amount of water temp enrichment .

Secondly both Mafia and Paul33 mention the 02 feedback correction setting in the bottom right hand side of tab 1 . I think the default is 1.047 and I'd like to know what this actually is - possibly Lambda ? If so you'd think 1.047L for petrol would be leaner than 14.7 to 1 .

In post 290 I think Paul mentions he's around 0.94 but how does that equate to 16 to 1 AFR ? He mentions "guys that get poo economy are around 14.7" .

I think I can sort of understand this target AFR and tweak the airflow voltage curve to suit business but thats beyond my capabilities and hopefully Scotty at Insight can do this sort of stuff easily enough .

Thanks all , cheers Adrian .

Edit : I checked my injector settings and they are 62.4 (original setting 48 x 1.3 for E70) and latency 0.15 .

I suppose they really should be 65 (50 x 1.3) and 0.14 latency .

Worth changing ?

Power FC does interpolate between the values for water temp compensation, so at 76 degrees you will get a small amount of enrichment with the standard settings. I had the same problem (never got hotter than 75 on the street) and ended up setting the correction for 50 and 80 degrees to 1.000, so the cold enrichment stops at 50 degrees.

The o2 feedback correction setting determines at what map values the PFC ignores the o2 sensor and stops going into closed loop during cruise. Any cells with a value higher than this setting will use o2 feedback whilst cruising (provided all other o2 requirements are met, such as temperature and constant TPS voltage etc), any cells with a value lower than this setting will ignore the o2 sensor entirely.

If you've already tuned your fuel map don't bother changing the injector correction, it's purpose is to roughly scale the injectors so the main fuel map doesn't need any huge adjustments.

[discopotato03]

Thanks for the 02 correction info , its logical though I wish there was a way to set the feedback target . Maybe the intention is not to let uses set it too lean and burn valve etc in certain light load ranges .

It sounds like Paul cottoned onto something when staying in open loop and aiming for 14.7 at 110 km/h and going a little leaner ie 15-16:1 at 100-80 km/h . I guess he formed his own safe load (speed) based cruise AFR system .

I will try entering zeros into the 50C water correction section and I may try retarding the water temp vs timing section because I think my engine could warm up faster too . From memory the default setings are -1 -3 and -5 and thinking about it my innitial cold running can be a bit snatchy which probaby means its a bit too advanced and rich when cold .

Now to injector latency or "lag time" . Other systems I played with years ago like the SMC allowed you to set the end injection or injector closed timing in the 720 degree 4 stroke cycle . The apexi PFC doesn't give access with Datalogit anyway AFAIK so this must be why having the "right" lag number entered sets the correct/corrected injection timing .

My issue is that I can't seem to get a consistant answer from searching online as to what a S2 R33 GTS25Ts setting should be for direct fit 740cc Nismo side feed injectors . The RB and SR people don't seem to agree that the latency should be 0.14 ms though it seems early SRS and RB25DETs both used the same standard 370cc side feed injector ?

Status (Trent ?) mentioned that is critical to have this right and from my previous mucking around on the autronic SMC that rings true and I think this is because injection timing has an increasing affect at low revs ie from maybe 3000 down to idle .

I suspected that it also affects accell injection and cold start enrichment timing which in turn affects drivability and consumption .

Anyway mine is currently set to 0.15 and changing to 0.14 isn't much but I'll move it anyway .

A .

[discopotato03]

Well I ended up setting the injector trims to 65 and the latency from 0.15 to 0.14 , and the injection vs water temp to zero at 50C .

Overall it seemed to run smoother and have better transients though i had to richen up the very low speed areas to compensate for the water temp enrichment not being there in the 75-80C area .

Many other areas went rich because of the trim number increase from 62.7 to 65 .

There is one thing I've found that puzzles me because I have no answer for it . If I run a log and look at the monitor the ignition timing does not match what the ignition table says . I looked through the various ignition compensations tab and nothing I can see should be altering what the ignition table says .This is at high idle speeds set via the accelerator BTW and the TPS voltage increases when pushing the throttle .

Also somehow the boost kit option was not ticked in my last few saves and I'm not sure why that was .

I think I'm getting better consumption ATM but won't know for sure until the next full tank , and I won't fill it whill fuel prices are as high as they are ATM .

I've never seen Eflex prices as high as they are in Sydney now .

A .

[rob82]

Injection timing and injector latency are two completely different things.

Injection timing if using end angle: is the angle at which the injection will end. Ie at 3000rpm if you end angle is 360deg btdc and the injection on time is 5ms then you will start injection at: (60/rpm)x1000 =20ms (for 1 rotation at 3000rpm) so 5/20x360= 90degrees therefore injection will start at 360+90=450btdc.

Injectior latency: is the mechanical delay of an injector from the time that it's energized to when it is actually delivering fuel. It is more critical at low openings as your injector opening time is quiet small. eg if your idle injection time is 2ms and your actual latency is .8ms but you enter in say .5ms the your error in delivered fuel is (0.3/2.8)x100 = 10% if your injection on time is say 6ms your error is (0.3/6.8)x100=4%. See how it is more important at idle.

[Dose Pipe Sutututu]

............. and the injection vs water temp to zero at 50C .

why would you do that? I always run it rich when the water temperatures are low to keep the motor happy

[discopotato03]

Because 50 is not cold and at that stage the chambers piston crowns and valves will be higher than this anyway .

The issue is that the std thermostats to regulate in the mid upper 70s and the cold temp correction in the 50+ area is set it will add extra fuel tapering off to 80c . So once up to temp if the coolant drops below 80c ie to 77- 78 it will add some extra fuel for no usefull reason . The fix would have been to make the upper set point coolant temp wise more like 70 and even thats a bit high IMO .

A .