R.E.wing_FC3s

today as i was accelerating in 4th wot i think i heard pinging at 5500-6000rpm. it scared me. i wasnt watching afr cause i was merging onto the freeway so i cant confirm.

without a datalogit i cant increase the fuel past 150% of the base map. which is what ive set all of the cells at in the upper p values. and i know im stupid for it but i dont really know what if anything i need to adjust in the ignition menus. Until today i though id manged to do a pretty safe , conservative tune with the wideband and the commander.

what boost level is generally safe with my fuel map and setup? 1989 tII, ap eng power fc, 550 primary 1200 secondary. cosmo fuel pump, stock fpr and ic. hybrid turbo (not sure of the size or a/r) motor built by me with fd rotors and housings, street port housings all around rx8 e shaft and bearings. 3in exhaust no cat.

seandizzie

iTrader: (1)

depending on the size of the sail and street port I wouldn't go past 11 or 12 psi.

R.E.wing_FC3s

would that be the jib or the main?

arghx

iTrader: (3)

Get a Datalogit and a wideband, pronto. it's cheaper than a new engine...

For many applications, the AP Engineering map is junk! the timing is crazy and depending on how you have it set up, there may not be enough fuel. If you get a Datalogit, send me the map that's in there right now and I'll send you one back that will be safer.

R.E.wing_FC3s

for sure. i do have a wideband, which is how ive been road tuning. its tricky since i dont often go wot to redline so i dont have a solid idea what my afrs are in that range since im not there very often and its only for a short time. stupid i know. is the fc edit program included/the same as the datalogit software? will my plx wideband (i belivie it has an output for data logging work with datalogit) i really like the ideal afr overlays i saw for the fc edit program in another thread.
as soon as i get the logit ill send you my map. thx for da help

seandizzie

iTrader: (1)

Snail... missed a key

I have 500/1300's and a streetport. 12psi manifold pressure 11:1 a/f raito and I get around 90% duty cycles. This is in an fd though.

How much boost are you running now?? Do you have the pfc commander.

R.E.wing_FC3s

yes i have the commander, thats how i adjusted the cells to 150% in the upper p range. right now im running around .7-.75 bar. 10psi havent taken to redline under wot very much and its apparent though my tuning may be adequate in the lower ranges i need a datalogit to add more fuel in the upper range. im going to turn the boost down but i still would like to know if anyone has a rough idea how much boost i CAN run on the setup ive mentioned.

90% duty cycle seems high for the boost your running and the size of the injectors. i was hoping to eventually run the 12psi but if your at 90% with injectors 100cc larger then mine it doesn't seem realistic...would i have to step up to 1600CC? maybe i should use a afremarket fpr?

seandizzie

iTrader: (1)

There is a peak hold in the monitor section on the commander. You can monitor inj duty there and see exactly how much fuel you are using. The map watch in trace mode is very telling as to your load and rpm range so you can be sure you are adding/subtracting fuel in the right spots. Remember, Fat is happy!!


If you are unsure about anything just stay out of the throttle until you get the datalogit. Hot timing and lack of fuel warps and breaks seals so be careful. Good luck...

R.E.wing_FC3s

i hope im not using up all the inj duty at what i thought was relatively low boost. i always thought the problem was that i was only able to add +50% fuel and that my injectors had quite a bit in reserve when unlocked with the datalogit. i guess i need to keep an eye on the peak values (obviously). its just that the car runs so well i thought they must be fine, but then again as i kepp saying i don't often push it that hard. any thoughts?

arghx

iTrader: (3)

Without a rewired fuel pump you will not be able to maximize the flow of your injectors and duty cycles will be higher.

Using only the INJ map it is possible on many setups to achieve a safe AFR, but it is difficult to get a smooth AFR curve without a bunch of rich and lean spots.

R.E.wing_FC3s

i thought about doing that. maybe a relay to switch to full power 12v on acceleration and then let the fuel pump resistor work the rest of the time for economy and driveability?

still curious about what boost people would safely run with this setup, or are there just to many variables?

arghx

iTrader: (3)

what do you think the stock fuel pump resistor relay does? I haven't looked at the AP Engineering PFC harness, but it probably does keep the resistor relay working. The problem isn't necessarily the integrated resistor/relay assembly though. It is the power supplied to it through small gauge degraded wire. It is possible to keep the resistor relay while running new wire to it. Somebody actually did a writeup for an S5 T2.

BUT... on a modified car the resistor relay adds more complexity and failure points. That's why I would recommend you get rid of it in the process of rewiring the pump. It's not because there is anything inherently wrong with varying the fuel pump speed/voltage, as long as enough voltage reaches the pump for high load conditions.

The whole point of the two speed system is to reduce the wear on the pump, reduce the amount of excess fuel vapor generated (better for emissions and hot starts), and reduce potential fuel pump noise. From the factory, the two speed system does a good job of accomplishing those goals and there are no major reliability issues with it on a completely stock car. These days, modern cars have switched from 2 fixed fuel pump speeds/voltage levels to fully variable fuel pump speeds through the use of fuel pump control modules.