high knock levels

[420_240]

Took the s14 to Knowledge Performance in Kennesaw, GA for some tuning (they're listed on the apexi website as certified excel tuner/dealer)

All of my mods are listed below in my sig. minus the powerFC boost controller... i'm using a xs power boost controller nowAnyways...Made 371 hub HP and 297ftlbs of torque @ 13.7psiTorque on the left.......HP on the rightBoostTorque on the left..... A/F on the rightNotice the A/F ratio is a little high in the higher rpm range

Got the car back home now and When i get on it i start to see knock levels of 135 in the high rpm revs around 12-15psi...

I posted this on the skylinesaustralia forums and they're suggesting my walbro 255lph is taking a crap and can't support enough fuel...So I first wanted to see if it was just a voltage issue... I hardwired the fuel pump to the battery and now it's seeing a full 13+ volts

Only other way i could test this is put it on a dyno and unhook the fuel return line... put a bucket down... if the flow reduces to a trickle or even stops then it's the fuel pump taking a crap.... or take the hood off and rig the fuel press. gauge so the passenger can moniter the psi while i give it hell... if it drops then it should be the fuel pump....

Next possiblity...

I'm still using the rb25 MAF... is the MAF being out flowed by the motor and no longer reading the extra air... causing the powerFC to not supply enough fuel?

Any ideas are welcome... just keep the negativity to a low

[eh?]

WTH- 371whp on a stock RB25 maf? You got balls....The maf voltage must be pegged at 5.1v from 5k rpm on..

Upgrade to the Z32 maf please

[klh6686]

i would say to get that maf replaced.

Side note: would you happen to have your stock RB25 exhaust cam? email me at klh6686 at gmail dot com

[420_240]

Yeah i figured that was the culprit but still not sure.... Who's got one for sale???

Klh6686: I doubt i still have it... I got rid of a lot of old parts... not sure if i tossed it or what

[Imissmyturbo]

Even thought you MAF is maxed out the pfc can caculate fuel and timing off of RPM and TPS. What is ign timing at while you are under full boost?

[gawdzilla]

if you're all the way down on your y-axis in the map tracer, you've maxed the maf. or check your sensor/sw for maf and see if it pegs at 5v under high load.

135 is pretty high... you're either way lean or running too aggressive timing. running out of resolution on your maf will keep your timing the same and you'll only move across the x-axis in the inj/ign maps

[420_240]

Timing on the pfc reads 43* whenever i start to see high knocks...

I can bounce it off of the rev limiter in 1st gear and see a knock level of about 18

2nd gear is just as good... but third gear and up when the pedal is to the floor, that's when it begins to knock and i see my engine light flashing...

I've got a z32 maf on the way

Any thoughts why it's running fine in 1st and 2nd gear then going to **** 3-5?

[Carl H]

holy **** 43* of timing at full boost, you need to back that sucker down.proly got that much advance because of the maxed maf...fix that asap.reason why it knocks more in 3-5 is because in higher gears the car is loaded more for a longer period of time, gives it time for the egts to rise and for bad things to happen.

[gawdzilla]

how are you seeing this 43*? that doesn't sound right at all... way high for full load. the reason you're detonating in higher gears is because thers more load

[eh?]

looking at those graphs, fact you have high knock levels, and the fact they didn't know the maf is maxed tells me that tuner really sucks... cmon now ~12.2:1 AFR at peak TQ??

Are you still using the datalogit I sold to you? You could do a better tune yourself.

[420_240]

I took the car to knowledge performance... they tune with apexi software... but yeah i'm gonna have to agree wtf were they thinking about the a/f ratio... and yeah i'm seeing 43*... I'll snap a picture of the peak #'s on my hand controller sometime today and post that up.I've still got the datalogit software i bought from you... I'm waiting to hear back from a buddy about tuning it locally...

[eh?]

Get a log file or screen shot from the datalogit, much better. But please get a Z32 or Q45 maf before you do any runs.

What I did is have my g/f start the log as soon as I got on the throttle and stopped it as soon as I got off. That way I have a nice clean graph and is 100x easier to tune. Have your friend do that for you. (providing you have a nice empty and wide straight road)

[gawdzilla]

I took the car to knowledge performance... they tune with apexi software... but yeah i'm gonna have to agree wtf were they thinking about the a/f ratio... and yeah i'm seeing 43*... I'll snap a picture of the peak #'s on my hand controller sometime today and post that up.I've still got the datalogit software i bought from you... I'm waiting to hear back from a buddy about tuning it locally...

if you're reading 43 degrees as your max value off the pfc, thats probably some number you see before you reach full boost or after you've already let off. peak torque and beyond should be in the 20s, MAYBE low 30s... maybe even upper 10s to start out.. you're not going to be able to see your wot timing with the hand crontroller unless you have a buddy looking at the screen while you're in the middle of WOT, full boost. best way is to datalog it.

your A/F looks really jumpy and lean. i'd definitely get that fixed first or even consider resetting your pfc back to factory settings.

[Imissmyturbo]

Just FYI. My car us running 15 degrees timing from 4200 up (right were my I see full boost). The stock map is all over the place. It runs fine and never see's any knock. I know I could make more power if I were to increase the timing slightly in the higher rpms but I haven't spent time to street tune it.

[420_240]

Well today i hooked up my datalogit gear and went for a drive... I was trying to log a spirited drive...

The logging would work perfectly if i was just driving casually or fairly aggressive... but as soon as i would stomp the pedal it would stop logging and say, "interface not responding"

checked all the connections between the ecu and the laptop and everything was tight... i don't understand why it was giving me this message... so i could only log up to a certain point...

How can i host a .txt file format if anyone would care to take a look
Modified by 420_240 at 7:07 PM 8/29/2006