how bad are these afr's?

[hek1620]

once warm it'll idle 13-14's. in gear decel(of the gas) blinks lean/air. on wot 14-15. while cruising in 5th, 13-14. no tuning has been done yet. max boost is set at 6.5psi. so is this why im overheating on the highway? remember these are not exact numbers.

[BillKlineVT]

seems good except for WOT at 14-15... thats UBER lean. In boost, you should be around 11.5:1 and no leaner than 12.0:1

[Jookmasta]

u say these arent exact numbers, so im curious as to which wideband ur using to measure ur a/f's. also +1 for what billklinevt said.

[virus77]

I like to be 14-15 at idle or cruising for fuel economy and alot richer on boost. 11-12 is acceptable

[MarkEmark]

once warm it'll idle 13-14's. in gear decel(of the gas) blinks lean/air. on wot 14-15. while cruising in 5th, 13-14. no tuning has been done yet. max boost is set at 6.5psi. so is this why im overheating on the highway? remember these are not exact numbers.

Optimal A/F ratios also depend on what you're running for timing WOT, and what octane gasoline you're using, if you're using an efficient intercooler, etc.

12.5:1 may be too lean for someone running 91 octane @ 15 psi with a nice intercooler, but not for someone running 93 octane @ 15 psi with an intercooler and methanol injection.

But yeah, those A/Fs don't make sense to me...the engine is running richer during idle than it is WOT? How is that possible? Even if you were just using the stock ECU designed for a NA KA, it'd richen up the mixture under full load compared to idle.

[Structure240sx]

would have nothing to do with overheating on the highway

[crzycav86]

what's your setup?

[fiznat]

Dont ever run WOT with that AFR reading. You're going to destroy something. Get your stuff worked out right before you drive that car again...

[hek1620]

as for not exact, i have to drive and look at the plx r300. plus the numbers don't stay still. as for setup, stock rebuild, .48/.42 t3, 38mm wg, open dump, 2.5in. d. pipe, 3in. exh., sci coil, 8.5mm wires, ngk 6re's, fat intercooler, 2.5in. piping, z32 fuel filter, stock fpr disconnected, ssq bov, stock timing, stock ecu. i think that's it. as for overheating? i've changed the water pump, taken out the thermo, flushed the system, bled it, and i run altima fans. everything seems to be o.k.. so i was under the impression that i could be overheating due to running lean. so what now?

[racin-type]

OMG disconnected FPR why in the world would make you do that? do you have an aftermarket one connected?

[hek1620]

no. i read that with it disconnected u get something like 43psi. while it's connected it's something like 34psi. flamers please control urselves.

[Florida240sx]

Lol as you increase pressur(build boost) your FPR senses more pressure so increases your fuel. You need to have the damn thing hooked up. I don't know how you are driving without it. My car hit a brick wall as soon as I hit boost when mine slipped off. That would explain you fuel #'s though. You need to be under 12.5 at wot in boost. Anything over is asking to blow your engine. I tune my car for a 12.0 across the board @ WOT. 14-15 while idle and cruising.11.5-12 is what would be best for your AFR under boost Gives you power and is safe. Without any other additives.

[crzycav86]

no. i read that with it disconnected u get something like 43psi. while it's connected it's something like 34psi. flamers please control urselves.

I'm having trouble controlling myself.

Anyway, put the vacuum line back on the fpr. It will solve some lean issues under boost, as well as your slightly rich condition under vacuum.

This thread has given my laugh of the day. Good luck with any other quirks you might come across.

[SeVa-S13]

no. i read that with it disconnected u get something like 43psi. while it's connected it's something like 34psi. flamers please control urselves.

That's quality comedy right there.

[MarkEmark]

as for not exact, i have to drive and look at the plx r300. plus the numbers don't stay still. as for setup, stock rebuild, .48/.42 t3, 38mm wg, open dump, 2.5in. d. pipe, 3in. exh., sci coil, 8.5mm wires, ngk 6re's, fat intercooler, 2.5in. piping, z32 fuel filter, stock fpr disconnected, ssq bov, stock timing, stock ecu. i think that's it. as for overheating? i've changed the water pump, taken out the thermo, flushed the system, bled it, and i run altima fans. everything seems to be o.k.. so i was under the impression that i could be overheating due to running lean. so what now?

the plx reads narrowband 02 voltage (0-1 volt), so it's pretty much useless.

and where in the HELL did you read soemthing saying that it's a good idea to disconnect your FPR when boosting?!?!

[nb07bcar]

I thought plx 300 reaD BOTH NARROW AND WIDE. iT DESPLAYES THE WIDE BAND FOR YOUR gauge AND IT GIVE THE STOCK ECU THE NARROW BAND SIGNAL? tHAT WHAT i THOUGHT.

[crzycav86]

I thought plx 300 reaD BOTH NARROW AND WIDE. iT DESPLAYES THE WIDE BAND FOR YOUR gauge AND IT GIVE THE STOCK ECU THE NARROW BAND SIGNAL? tHAT WHAT i THOUGHT.

You are correct. it has 0-5V wideband output, but also has 0-1V narrowband "simulator" output so that it can replace the stock o2 sensor if wanted.

[Jookmasta]

i think markemark was thinking of something else. anyways, hook up back the vac line and then run the car to see what a/f's u get around town. u didnt mention what injectors ur using and if ur using an safc or emanage or something else to control em. please elaborate on that so we can help ya out a bit further.

[hek1620]

it's all stock. no bigger injectors, no piggy back.

[virus77]

So no FMU or anything. Just slapped on the turbo and starting mashin it huh.

[2FourTee]

it's all stock. no bigger injectors, no piggy back.

and it still runs...??

[Jookmasta]

this is y ur running lean. u MUST have larger injectors than stock size. u WILL NEVER achieve a good a/f in boost unless u have an adjustable fpr, fmu, or larger injectors. realize that ur risking blowing your engine.................in other words u have a 95% chance of blowing your engine the next time you go into boost. please go and get larger injectors and an safc or emanage or get ur ecu tuned. this is equivalent to sky diving without a parachute.

[S14tat]

this is y ur running lean. u MUST have larger injectors than stock size. u WILL NEVER achieve a good a/f in boost unless u have an adjustable fpr, fmu, or larger injectors. realize that ur risking blowing your engine.................in other words u have a 95% chance of blowing your engine the next time you go into boost. please go and get larger injectors and an safc or emanage or get ur ecu tuned. this is equivalent to sky diving without a parachute.

haha its more like sky diving with a rocket pack strapped on but its aimed to push you to the ground faster.

[hek1620]

i know guys. actually she's been running like this for about 4 months since i took my car to a shop that claimed to be the bomb and was well recomended, but they sucked. they never finished my car after having it for a month and a half. all they did was install the hardware. so now i'm on the mission to tune. i have an emanage at home, but i'm thinking of just tuning/chipping the ecu. but i know nothing about tuning. if i could get a tuned chip from someone i would just try to trade my blue for an safc2 and fine tune with that and call it a day. what i really want is to get a willems and burn my own chips but i wouldn't know where to begin. i've been reading alot on hybridka but it's all jiberish to me. and i don't really have 500-600 bux to throw at jwt. so i'm stuck.

[Jookmasta]

no ur not stuck, take out those stock injectors, trade em in to deatchwerks and get 550s or 480s from them. they will take off some money off of the cost of the injectors for ur stock injectors. then install those and install ur emanage. then tune away.

[MarkEmark]

i think markemark was thinking of something else. anyways, hook up back the vac line and then run the car to see what a/f's u get around town. u didnt mention what injectors ur using and if ur using an safc or emanage or something else to control em. please elaborate on that so we can help ya out a bit further.

yah my bad, I was thinking about an MDM techtom for some reason...and then when he said it just blinks lean (instead of giving a precise reading, like my zeitronix, which, btw, is 21.0:1 under complete vacuum and decelerating), I figured it was just a narrowband input.

But knowing your A/Fs doesn't do you much good unless you have someway to alter them anyhow.

[racin-type]

i'm sorry buy why do people even try to go turbo when they don't know a damn thing about their car, even the basic things?

when i hear sh1t like this, i'm so let down on the knowledge of people that try to make their cars faster. People are so lazy, whatever i give up.

[hek1620]

i have rx7 550's at home but u know i can't put them in until i have something to run them with. if i knew how to tune i would have put those and the emanage in already.

[Jookmasta]

well if the rx7's are high impedance and side feed, drop em in and install that emanage. just because u dont know how to do something, doesnt mean you can't learn how to. if you install these things, im sure anyone with an emanage on this board would be more than willing to help you learn how to use it. gotta get it in first and then we can go from there.

[turbo98_240sx]

IF you pay for my plane ticket to FL I will help you install the 550's and the e-manage, then help you tune it as I have the cable and the software to do so I just lack a laptop and hey a second set of eyes to watch the a/f's are allways good, on a serious note though the e-manage install was stright forward as long as you know how to read a ECU pinout and can use a soldering iron, the Injectors should be easy if they are side feed and High impedance once again assuming you know how to solder(sp)..... yahoo has a e-magage group that has the software for free and tons of info as well as everyone here that knows alot about the e-manage