Jaycar Boost and Fuel Control

[skidkid]

Got more boost!!! Yeehar!. Changed act. lines around. Went for a drive and started adjusting. Smoothed the boost climb up to 10lbs, just need to trim to keep at 10-11lbs and keep spick to a min. When my 'Multi ckecker' turns up I will get in and have a go at tuning the SAFC I have hooked up.

[Sydneykid]

Firstly I should remind the auto owners that I tune them with 2nd gear selected and the “snow” setting on the ATTESA, they stay in 2nd all the time then, no kick down. If you try and tune in 3rd gear you will find that the gearbox will kick down to 2nd when you put load on the dyno. This makes the car jump around on the rollers something fierce, sometimes they can even jump sideways, very nasty.

Moving on to the main subject................

Recently a few guys have been asking me about how to get around the DFA (SAFC) compromise of leaner A/F ratios at high boost and higher rpm and richer A/F ratios during (and sometimes just after) boost build. The problem is if you increase the AFM voltage at higher rpm (to get richer A/F ratios) the standard ECU sees this as increased airflow, which may push it into R&R mapping. Which results in power dips and a lack of response. Sometimes this doesn't show up on the dyno but raises it ugly head when you drive in variable conditions on the road or track.

To fix this “R&R versus too lean at higher boost” problem you have to increase the fuel pressure (via an adjustable fuel pressure regulator). The trick is to increase the fuel pressure just enough to get the A/F ratios to the target (say 12 to 1) in the rpm range that it is currently running too lean (usually above 4,500 rpm).

For adjustable FPR I use the Nismo bolt on style, ~$150 from Nengun.

Once you get the higher rpm A/F ratios in the range that you want them, you use the DFA (SAFC) to lean it out in the other rpm ranges where it will then be too rich. This (reduced AFM voltage) also helps with preventing the ECU going to R&R, as it uses lower airflow map load points. So you get 2 benefits.

In order to lean out the A/F ratios, the DFA settings are used to reduce the AFM voltage (that the ECU sees) which usually advances the ignition timing. So the SITC is used to retard the ignition timing. This retarding is mostly required at revs over 4,500 rpm. Most times under 4,000 rpm you can sneak in a bit more advance, which improves the response considerably.

If you are using a suitable turbo (eg; GCG ball bearing high flow) the adj FPR, DFA and SITC you should be able to get the boost up to 1 bar, maybe 1.1 bar. That will give you another 30 to 40 kw over the 12 psi that you may well be restricted to if you don’t use the adj FPR to cure the high rpm leanness first. It does require some fiddling around, but no more than trying to achieve the same results with a Power FC on a manual. It’s just a matter of tuning the right bit first.

Hope that was of some help to fellow auto owners.

cheers

[GorGasm]

Excellent post.

[NewKleer]

Once you get the higher rpm A/F ratios in the range that you want them, you use the DFA (SAFC) to lean it out in the other rpm ranges where it will then be too rich. This (reduced AFM voltage) also helps with preventing the ECU going to R&R, as it uses lower airflow map load points. So you get 2 benefits.

wont the reduced voltage increase the timing and hence make it more likely to go into R&R (due to pinging) and hence the need for the SITC as per ur next paragraph?

In order to lean out the A/F ratios, the DFA settings are used to reduce the AFM voltage (that the ECU sees) which usually advances the ignition timing. So the SITC is used to retard the ignition timing. This retarding is mostly required at revs over 4,500 rpm. Most times under 4,000 rpm you can sneak in a bit more advance, which improves the response considerably.

probably worth a mention to give the run a runabout in high gear/low revs (not so easy in auto, moreso for those in manual) as thats often one place where pinging will rear its head, especially if reduced AFM (and hence advancing timing at a given rpm).

not sure if ive got all that right/remembered everything correctly there.

[Sydneykid]

wont the reduced voltage increase the timing and hence make it more likely to go into R&R (due to pinging) and hence the need for the SITC as per ur next paragraph?

probably worth a mention to give the run a runabout in high gear/low revs (not so easy in auto, moreso for those in manual) as thats often one place where pinging will rear its head, especially if reduced AFM (and hence advancing timing at a given rpm).

not sure if ive got all that right/remembered everything correctly there.

You are pretty much spot on, the standard ECU will see excessive knock and retard the ignition timing, it also does a bit of richening. That's why you need the SITC. You can simulate most things on the dyno, such as lots of load at low rpm, but you can't simulate everything that the car experiences in a normal week's driving.

cheers

[Tangles]

apparently you can pull the big brown fuse that is between the battery and the headlight, and that keeps the car stuck in 3rd gear. I havent tried it as yet but was told this by dangerman4 (who has auto R33 with 300rwkw with powerfc)

btw: this is exactly what will be happening to my Stagea on tuesday... using a z32, fpr, safc, sitc and highflow turbo Im expecting to be able to get a decent tune at 1bar. I'll mention the 2nd gear/snow mode point to them, and try the brown fuse trick myself.

[benro2]

Recently a few guys have been asking me about how to get around the DFA (SAFC) compromise of leaner A/F ratios at high boost and higher rpm and richer A/F ratios during (and sometimes just after) boost build. The problem is if you increase the AFM voltage at higher rpm (to get richer A/F ratios) the standard ECU sees this as increased airflow, which may push it into R&R mapping. Which results in power dips and a lack of response. Sometimes this doesn't show up on the dyno but raises it ugly head when you drive in variable conditions on the road or track.

To fix this “R&R versus too lean at higher boost” problem you have to increase the fuel pressure (via an adjustable fuel pressure regulator). The trick is to increase the fuel pressure just enough to get the A/F ratios to the target (say 12 to 1) in the rpm range that it is currently running too lean (usually above 4,500 rpm).

For adjustable FPR I use the Nismo bolt on style, ~$150 from Nengun.

Would I need to do this for a stock (other than Apexi pod air filter) GTS-T auto @ 10 psi? Or will the standard DFA suffice?

Also, would it be likely that I would need a new fuel pump for the sort of power I can expect?

Just out of interest, what sort of rwkW can I expect out of my setup, after the DFA has been tuned on the dyno? I was hoping for 160 rwkW, assuming the stockies put out ~120 rwkW, or an increase of ~40 rwkW. Does that mean my flywheel kW will be around 225?

[Sydneykid]

1. Would I need to do this for a stock (other than Apexi pod air filter) GTS-T auto @ 10 psi? Or will the standard DFA suffice?

2. Also, would it be likely that I would need a new fuel pump for the sort of power I can expect?

Just out of interest

3 what sort of rwkW can I expect out of my setup, after the DFA has been tuned on the dyno?

4. I was hoping for 160 rwkW, assuming the stockies put out ~120 rwkW, or an increase of ~40 rwkW.

5. Does that mean my flywheel kW will be around 225?

Suggestions follow;

1. Depends on you power target, around 190 rwkw seems to be the compromise limit

2. Depends on your power target, the standard fuel pump is OK for ~200 4wkw

3. Using the standard exhaust and compliance cat, around 160 rwkw

4. R33 GTST autos put out ~120 rwkw standard, a tuned DFA and 10 psi will get you to around 150 4wkw

5. The tranmission losses are pretty much constant, so what ever kw increase you see at the wheels will translate to kw at the engine.

cheers

[benro2]

Thanks for the info Sydneykid.

I've just thought of another couple of questions: does the torque converter lockup affect rwkW measurements? When I put the gearlever in 2nd (ie: "normal" mode) and give it full throttle, the torque converter locks up at about 4,000 rpm. I presume this will appear on the dyno readout as a slight increase in power. But does this affect the tune?

Also, does anyone know if the torque converter will lockup at some point when the brown fuse is removed (as Tangles mentioned above), or does it stay unlocked? Would it be better to avoid lockup or not, and what sort of rwkW loss is involved without lockup?

[AlexCim]

I think I was the inspiration for SK's large post above.

2 weeks ago I got the car tuned at 180awkw using a DFA/SITC/EBC combo.

I could not go over that power limit as I was hitting fuel cut over 12psi. I could go over 12psi, up to about 1 bar, but that was causing a "leaning spike" around 4,500rpm.

I will buy a FPR and retune the car and let everyone know my results.

[yokotas13]

hrm...this is interesting. i need to find this SITC thing

Edited February 25, 2007 by yokotas13

[adamR33]

hey just to ask i just finish puting my feul adjuster and hand controler and now with the fuel adj,,, i connect the positive and negertive to where they suppose to go and now the LED just comes on for a sec and then its off and the hand control doesnt diplays anything ....? anything u know????/

[xRHETTx]

Di you have the handcontroller plugged in before you connect the power/turn the car on?

You have to have the controller plugged in before you turn the car on... or else it doesnt display anything. at least thats how it works with mine.

[adamR33]

ok ill do that soon and lastg thing is that if u just plug the positive and negative in the fuel adjuster and not have anything in the (in)and(out) thing will it still display anything just to see if it works?

[adamR33]

hi i went through my ecu diagram and on r33 gtst S1 it says pin 26 is my AFM Ground and pin 27 is my AFM Sense which one do i use ????

Edited March 4, 2007 by adamR33

[ashlogan]

I was really hoping not to have to do this but here i go...

When i power up the IEBC i get all three LEDs lit up and i cannot get the hand controller to display anything at all.

I have tested all resistors, put the link in to the 4mhz (*edit* and 20mhz) "crystals", plugged the controller in before I power up the IEBC, the link under the db25 socket is in, I have played with the Hand Controller trimpot, I have been over the notes and I have the correct cable. All my soldering looks ok to me, although, obviously i am far from an expert.

At this stage I am struggling to maintain my sanity. If anyone can help I would be extremely appreciative.

Here are some pictures...

IEBC top.

IEBC bottom.

Hand Controller Top.

Hand Controller Bottom.

*Post revised. Now i think it makes a little more sense.

Edited March 6, 2007 by ashlogan

[adamR33]

hey as above i am going through the same things as u by the way what u have there is not a DFA its a DPA u wont be happy if u did all that for the wrong thing ... well i am going to jaycar tomorrow to ask what they can do about this .... cheers..

[ProphetR33]

Hey guys I've got an IEBC and hand controller and assembled them.

I have one problem though.

When I connect the IEBC to the hand controller it only displays blocks on the screen. I've read through this thread and I'm not much of an electronics guru so I'm useless at testing.

However I have done all the things that have been listed previously

Made sure the hidden link is connected in the hand controller.

Swapped the dot and line processors (I know I have it the right way around as with one of them on 2 of the LED's light up instead of the 3.

I know all the chips are in correct orientation because I burnt out a resistor testing it in the opposite direction.

I have bought the cable from Jaycar and my local computer shop with no luck.

Toyed around with the trimpot on the IEBC. Made sure all the jumpers were correct.

Went over every joint a again on both devices to make sure they weren't dry.

So if all 3 lights are working on the IEBC does that suggest that my problem is with my hand controller? I'm seriously stuck and about to throw the thing.

Can anyone think of anything else that may not be causing it to work?

[Oosh]

Are you powering it up in the right order?

You must connect the Hand Controller and IEBC first, then apply power to the IEBC, not the other way around (which results in blocks like what you're describing).

[ProphetR33]

Are you powering it up in the right order?

You must connect the Hand Controller and IEBC first, then apply power to the IEBC, not the other way around (which results in blocks like what you're describing).

Yep everything is connected before I give it power.

Its got me stumped, I can't find anywhere of someone having a similar problem.