hi all,

this thread was originally started by me to fix a fuel problem i had, which later turned out to be a dead clutch.
this thread has since been going on for some time with mainly DIY self tuning comments and pointers.
theres quiet a lot of useful stuff in here, you should read it from start to finish if you are interested.
i have a posted a few various maps in the threads, feel free to use the data if you wish.
be wary of just blanket loading my maps as it your car may go bang or lean out too much etc.

thanks

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If you've fitted a new pump and now getting a flat spot it will be due to it running too rich.

Drop the ign. timing back to where it was and pull some fuel out of that area.
Be carefull though.

Unfortunately you will never know exactly how much fuel to pull, looks like its dyno time again.
Be carefull, those rb25det ring lands are fragile.

hey thanks for reply
well i tried +4 deg and 1.101 inj correction this monrning and it ran great more zest everywhere and a tiny bit of knock but still that ood spot at 2800ish. i now get clutch burnt smell almost all the time and it seems more and more likely my clutch is slipping. last night after 15mintues of hard work it slipped from 4500 to about 6500 in 4th under full load. today it was fine but that very minor slip or flat/wierd spot at 2800. is it likely to be clutch and just a concidence at that same time i did the fuel pump ? also my fuel economy is out the window. off the charts. 200 to 3/4 of tank. ill be lucky to get 250 to a full tank. previously before the pump 330 easily most of the time

The only way changing fuel pumps makes a difference to A/F raios is when the previous pump was not holding pressure. The tuning was done to allow for this drop in pressure, now there is no drop in pressure, so the tuning is rich. If the igntion timing (maps) were right on the old pump, they will be right on the new pump, just the A/F ratios need to be retuned.

Clutch slip during boost build (rpm) is very common, time for a new clutch, drive gently until then othwise it WILL let you down.

thanks for the help guys. im not sure on the a/f or how it was tuned previously other than the dyno graph ive got. any ideas why my fuel economy is off the scale now? is it because its mega rich now. i know the previous pump was maxing out or pretty close too as they said it was leaning out when they did a test tune at 0.90bar (dont run that normally).
should i try a drive with 0deg ing and -0.900 inj correction to lean it out a bit and see if it doesnt knock around too much. if this -0.900 inj is OK and not knocking too much then its most likely they tuned around the pump but not since a new pump is in i need to lean it out a bit? will have a think about the clutch and what my costs are, may just back the boost off a bit for a while

will do some hunting around on some clutches and see what i can find. definetly getting clutch burn smell. turned boost controller of so im at 0.45 bar and its fine no slipping so its driveable and not the end of the world but still an issue. is there a relatively easy/cheap way of getting my fuel economy back? maybe ive screwed up the level float for the fuel tank somehow and its not really 1/4 left but more like half or something? who knows. thanks for help guys

hey guys

back to the self tuning point, the point of this post anyway. im going to get my clutch issues sorted out. but in regards to my comments:

"should i try a drive with 0deg ing correction and -0.900 inj correction to lean it out a bit and see if it doesnt knock around too much. if this -0.900 inj is OK and not knocking..".

I am trying to make the tuning of my car easier for when i take it to get done so that the tuner doesnt just go dyno run yep its ok doesnt knock sweet all done. $200 thanks.
I tried +4 deg correction and it was knocking. adding more inj correction and knocking dropped to normal levels. The tuner would obviously benefit from knowing this as they can immediately crank all ign maps up 4 for each value. now would it be wise for me to do this at home and change each value before the dyno run and just run on a little inj correction to keep it from knocking until tuner sorts out the rest. this is so i dont get charged for the tuner to go through every single ign value in the ign map. i also suspect the tuners im going to arent actually doing hardly any map changes and only making minor changes to ones the map tracers hits on a 4th gear run

what are other people experiecnes with pfc tunes? have you actaully watched your tuner go through and edit every value? is it really needed?

not trying to be a smart ass or anything just trying to get the best use out of the powerfc, learn a bit, maybe do up some documentation and get some more power / have some fun. it would be great to goto my tuner and go my car runs sweet on +xyz deg ign and +xyz inj correction make it so and make sure it doesnt go bang or do whatever to make sure its safe

once ive got it all sorted ill get a mod to remove all the crap regarding my clutch and fuel pump as they are irrelevant to the initial topic. thanks again

I tuned my car myself on a mates dyno. It certainly a slow process. We tuned it at light throttle, zero boost then at full boost at all rpm levels monitoring this by the map trace. Increments of 400rpm made this a slow process. During this we altered A/F ratio levels. I noticed we didnt really alter the timing levels just making sure there where no funny movements on the ignition map. As load increases , timing is pulled out which should be in factory tune. A/F ratios where very rich so we picked up alot there. Overall its a great experience and now i fully understand the functions of the power fc in my car.

Experiment with it, but you really need a dyno to see what A/F ratios are. It took us at least 3 hours.

Tuning with a PFC pretty easy, the base maps are not too far from the right shape. All up the R32GTST took about 40 minutes to tune. My method for A/F ratio tuning;

1. Do a power run with zero correction, took about 8 seconds.

2. Closely look at the A/F ratios from that power run. Took about 3 minutes

3. Pick a range where the A/F ratios were fairly constant but very crappy, which in my case was 4,000 to 4,500 rpm where they were just under 10 to 1.

4. Do another run and used the dyno load to hold it in that rpm range and apply correction until the A/F ratios were between 11.8 and 12.0 to 1. Make sure there is no pre-ignition with those corrections. Took about 15 seconds.

5. Make careful note of that correction, about 5 points made 1.5 A/F ratio diff. Then make guesses for the other load points following the A/F ratios from the first power run. Took about 10 minutes.

6. Do a power run, and tidy up the A/F ratios as required. Took about 40 seconds.

7. Finished.

The real trick is #5, noting how much correction does what to the A/F ratios and where the various load points are on the map. That reduces the time under load on the dyno and it is very fast loading up corrections off line. Doing it in during a power run is tricky and much slower, plus it heats up the engine rather quickly and is not good for the transmission (no 160 kph airflow to cool it down).

Ignition timing is even easier, stick the ears on and advance it up until you hear it ping then back it off. Do that at around 5 or 6 load points, then (off line) extrapolate that over the map. It's always a bit tricky at boost building time, so we have to spend a few minutes in that area getting the timing just right.

One power run to log everything and then maybe a little tidy up here or there. That's the real advantage of a PFC, the base stuff is already there, so you don't have to approach it like EVERYTHING needs changing.

Most of the tuning on the race team cars is done by our dyno guy, he has a "feel" for it. What takes me 10 minutes to get 99% right, he does in 2 and gets it 100% right. :fart:

Hope that helps

cheers guys, owe you all many thanks for feedback. will get my dump fitted and clutch sorted and see where im at and hopefully get this tune cranked up. is it normal to be able to throw in 4+ deg and some fuel and the car run fairly well. i noticed more power and zest but had to add some fuel cos it was knocking. will update next week some time

Paul roughly what ign. timing are you running at wot through the load points?

um i recall seeing around 15 odd at full stick, when i threw in +4 it was around 19deg and i had a nice power increase. does this make sense? i can do a test tomorrow at say 5k in 4th and check what ign deg it is

What boost? 19degree's sounds a little high for the 9:1 RB25DET.

The stock base map pretty much always makes the rb25det ping, generally timing is pulled out.

I'm running 16degree's any more and it will start to ping. Bl4ck32 has a highflowed turbo that free's up the exhaust and is able to run a maximum of 18degree's up top with around 17degree's everywhere else from memory.

Its too hard. Get it on the dyno for a cheap power run to see whats going on.

0.80bar. will check what the values are tomorrow.

Make yourselves some Excel charts with all your settings. Takes about 30 mins.
It gives you a full picture to examine when you're doing road tuning, not that little screen.
Do a before and after set from your dyno tune and list your mods so you can e-mail to others.
Regards.