I was wondering what kind of tips you have for tuning the Power FC. I'm not planning on doing anything too extensive, but I would like to get better ratios. The dyno will have a wideband to use up there. The ECU was done by Ray at SR so they should be running rich. I've done some small changes in the fuel map (upper left 100s to 106). Give me some idea of what numbers I wanna see on the wideband and what areas of the maps I should pay most attention to. I wish there was a way to change those cells faster seeing as it's downtime while my car's hooked trying to change maps around... Thanks a lot.

Richard

 

You'll need another bung hole cut into the downpipe for them to install the wideband sensor to get a reading, which they can then close off after you get done dynoing. As far as cells, first run with the wideband hooked up, be in the trace map mode, which will show what cells you are in at WOT. After the run, if you wideband shows you to be in the low 11.s or 10's your too rich and can take a small percentage of fuel out (2%) in those cells and dyno again. What tends to be the norm is a 11.XX number that starts to rise as boost builds...11.80 by redline. If thats the case, then take out 4% early on and then drop to 2% of fuel taken out by 6k to redline. Keep playing with those cells at WOT and to some extent those cells right above it since like Chuck said, the PFC will extrapolate from the closest 2 cells if it falls inbetween cells. On mine, I'm in pressure cells 17, so I change fuel in pressure cell 17 , rpm 7 through 20 and also pressure cell 16, but not as much across the same rpm range. Try to hit 11.4 11.5 early on with it rising to 11.8 area. On most cars that safe and also gives good power.

Tim Benton

 

Rising A/F to redline? That's okay as long as you NEVER plan on doing a top speed run on your local highway. It depends on what kind of driving you do, but I guarantee you 11.8 is definite engine/turbo damage at reline in 4th or 5th gear. To control EGTs, you'll need to run richer than that or don't pull your car alot in 4th or 5th. Damage won't occur everytime, but consistent of constant pulls in 4th or 5th is definite damage. Just a tip.

 

Actually you don't need to weld anohter bung on your downpipe. Most wideband lambda sensor is attached to your tail pipe. If they really have to attach to your downpipe, go to your ETC menu and disable the oxygen sensor feed back function. As for A/F ratio, everyone has different preference and there is not an exact number. I would set mine at 11.0 A/F or even 10.5 if the engine can run smoothly. Just add fuel to make it to the rich side with the engine still running smoothly. Work it toward the 10.5 goal. Some engine runs smoothly with 10.5 a/f and some don't. BTW, run rich first and slowly lean it out. Do not richen it from lean. Your engine is going to blow. Some so called tuners try to richen the fuel mixture from lean and ended up blowing many motors on the dyno.

Chuck Huang

 

If you check the single turbo forum old posts, 10.5AFR to 11.0AFR are too rich. You would only run something like that if you have a small IC, your fuel and ignition systems are not upgraded to properly handle higher power, or you are very conservative thinking. We are talking about modified engines. For a stock engine with restrictive exhaust, yes you would want richer mixtures to help keep the engine cooler due to the high thermal load cause by the restriction and high back pressures.

The M&W Ignitions UEGO manual lists normal petrol turbo AFR range for tuning as 11.0 to 12.5. Many of the single turbo guys run the low 12s or high 11s.

From my first O2 test with Ray's maps, I was 11.8 to 12.2 across the board. I plan to run 11.5 to 11.8. If it does not rain this weekend, I plan round two of my street testing.

If you are conservative, run as close to 11.0 but not lower.

Just my personal view.

 

Is cooling going to be a problem? I don't want to have a hot IC or coolant, so would it be worthwhile to bring a cooler of ice bags for the manifold and I/C?
General consensus on the AFR would be about 11.5 at redline, so I'm going to aim for that.
Is there anything to worry about on the ignition maps? I have heard that there are some overlapping numbers on trailing and leading. Should I correct this before I go or will it be okay?
Finally, what kind of numbers do you think I should turn with 93 Octane and 12lbs?

I appreciate all the input!!!!

Richard

 

Richard,

The only place overlapping timing(negative split) is dangerous, is when under non-boost heavy load or on boost.

With a SMIC, cooling does become a minor problem with repeated runs as it's temperature will increase. Most shops do not have fans that even come close to the cooling affect of driving. A FMIC is a little better here but also has water cooling problems. If you have a fan mod switch, have it on during the whole time the car is on the dyno, or at lease hook a wire to the control box to ground. This especially favors FMICs as it cools both the IC and radiator.

If using an O2 sensor during the test and the air pump is still operational,
unplug the air pump connector. This will help give more accurate lower rpm AFRs.

 

Can you explain this, what is richen from lean?

Thanks guys.

BTW I think cewRX7r1 needs the PFC award of the year or something for all his contributions to this section.

 

What he means is dont try to tune the engine from an already lean state. Make sure you are running rich, then slowly take fuel out and add timing until you reach the AFRs you want. If you try the oposite you could blow your engine easier before you get to where you want to be.


Oh, and I second the motion for cewrx7r1 (Chuck) to get the PFC award of the year!

 

Just as a comment on PFC's from SR. I got mine and had it installed with DP, hiflo cat, catback. out of the box i pulled a whopping 220rwhp. Thats fine if you're stock but come on. Tuner had to raise the boost and adjust the timing to max out my f'd up clutch around 270rwhp...its still rich too. So yeah, your map from SR may be extremely conservative so uh, be prepared for that, or something...yeah.

 

I only changed the fuel numbers in row 17, highlighted. The first number is the number Ray put in and the second number is what I ended up with before my last run.

Richard

PS If my scanner weren't broken I would scan in the dyno chart, I'll see if I can find a scanner soon.