Wargasm

Hello I am new to the powerfc and have some questions....

My car:

T04S/M2 Intercooler/Full Exhaust/PowerFC/1300 cc secondary/street port

1) Is the knock value on the PowerFC worthwhile to look at? I assume not. If so, what should I keep an eye on?

2) On the INJ map, how much is the right amount to bump it up or down to see the effect? Like if I get a little knock reading and want to try some more fuel... what's the correct amount to start as a bump? +1? +5?

3) I assume that if you do not want to blow up your car you're much better off having way too much fuel rather than too little. True? (I know you won't make max power).

4) I am going to tune with a wideband... What numbers are good to see under boost? 11.5 or so?

Thanks!

Brian

airborne

only thing i can comment on is the knock values...yeah they're mostly worthless. but if you are used to seeing a certain level and then you see a number like 100 higher, that is bad and should be addressed.
beyond that...get a j&s

cewrx7r1

iTrader: (2)

1. Knock levels are useful but there is not an exact correlation between a certain value and what it means. This is due to the fact that every engine has it's own range of "normal" noises that can be picked up by the sensor. It is only a reference. I can do a 4th gear boost run and not go over 30, then just drive slowly and shift gears and read in the 100+s. You monitor it to know what
your own normal values are for a particular event like on the dyno. Then if the reading start going
signifiently higher, you know something is happening. Since I have started tuning my timing, my base noise(knock) levels have all gone up. This is expected since making more power puts more strain on all engine parts and drivetrain parts.

2. You would only add more fuel to control knock if your AFR was too lean to begin with. Otherwise, you reduce timing. That is if the intake charge temps are normal.

3. More fuel only helps to prevent knock if the temperature of the intake charge is too hot. It helps to cool it off and reduce it's combustionability. Again if the AFRs are good and you have knock problems, it is best to get a better IC to cool the charge and/or retard timing.
Adding a lot of fuel will work but it is the lame way of fixing the problem. Water injection is better to cool a charge when running high boost levels. They been doing that since WW2.

4. Max AFR that some use is 12.1. It also depends on the use of the car. For sustained high power and high revs like road racing, lower 11s would be better to keep from burning up the tubos. I run in the middle to high 11s because I only run sprints.
You can run higher AFRs in the midrange for better power than then richen it up on the high end to keep the exhaust cooler.

I am not an expert, do some seaches on the single turbo forum where there are some very knowledgeable people.

forcefed1

I'm new to this myself. What I figured about knock, wait till the engine is warmed up and then take a look. Unlike other cars I have tuned, tuning for no knock looks impossible. I plan to tune for no knock greater then 60.

Anyone here who has been tuning for a bit and have things dialed in care to comment. What knock value do you tune for?

Another question. Does this ECU pull timing when it sees knock? It looks like the stock one does NOT and since you all are running a J&S I figure this one doesn't either.
If it does not, what knock do you see on the commander when the J&S kicks in to pull timing? I realize sensitivity can be adjusted, but just give us some thing to work with.

adax

iTrader: (2)

The J&S retard threshold is adjustable. I have mine set to start pulling timing at about 60 on the PFC. The two are relatively consistent but remember that they use different sensors on different housings.

Alan

skotx

Page 13 of the Commander manual states that there is no knock retard system within the Power FC.

Goblin

Adax, could you maybe summarize how to adjust the J&S for pulling out timing? I had a shop install mine while they were doing some other stuff at the same time, and I haven't got a manual or anything for it so I have no idea how to configure it beyond their initial setup.

I know there's the adjustment pot for sensitivity, but are there any other settings that are tweakable?

I start to get retard at high 30's on the PFC, and I'm usually driving around with low 30's peaks, so the second I put my foot down, build boost, and the wastegate opens up, it's all a little too noisy for the J&S.

adax

iTrader: (2)

The best thing to do would be to call J&S and ask for a manual for your particular version. John is very friendly and shouldn't mind but I'd offer to pay him somehting for it if you did not purchase it new. Assuming everything else is set correctly, just adjust the sensitivity dial to the point you want. Where that point is is the issue. The method I used (not necessairly the best) was: Make sure the car is warmed up and you've done a couple of WOT to redline runs. Set boost at something conservative such as 8 PSI, increase sensitivity until you fisrt see some retard, then back off from that a bit. In theory at least, the background noise shouldn't change too much so any increased noise at higer boost could be knock.

My J&S will retard a little the first time I go through the turbo transition and occasionally a little when cold as parts are warming up and making noise.

Alan

Goblin

That's a good idea, I hadn't thought to actually call the manufacturer for a manual (I don't know why not... Oh, well. Hindsight and all.). Thanks.