Sorry I'm so dumb, but I've been trying to tune my car and now everything has me confused. Ok first off I know you souldn't tune by O2 readings, but what is the ideal voltage for the car to be running at during WOT, I've been told .50 volts, but I'm not sure. Next is a fuel question, I'll just tell you my set up and take all the comments on how I need an afpr and smaller injectors, but here it is...I have a 255lbh fuel pump, 650 injectors, stock fpr, safc and stock 14b set at ~16psi. my low throttle settings are about -30 all across, and i've been changing my hi throttle all the time, but at -50 from 2000RPM up and when boost gets up to about 5psi it starts knocking really bad and O2 reads .78-.85. Now I know you all are going to say that I have way too much fuel with the 255 and 650's but with the safc turned all the way down to -50 it shouldn't still be running that rich should it? I'd appreciate any input at all, thanks.

Well in terms of start off settings, do the quick math. 650's are 200 ccs bigger than 450's. 200/650 is 30.7%, so let's call it 31%. Set the SAFC at -31% across the board and you have stock fuel levels just like if you had the 450's in there. Taking 31% off 650 leaves you with the 450's, so you have a "zeroed out" starting point. Now, no "too much fuel" problem to worry about. You were overcompensating WAY too much by making it -50% when ou are in boost in hi throttle. You are now basicaly running 325 cc injectors at 16 psi on a turbo car. Way Lean, much knock, engine explode.

As far as O2's go: With 91 octane, you'd like to see .93 or so, give or take a few hundredths. With higher octane, that number can dip to .91 or so, and with race gas, into the high to mid .80's. When you are getting .75-.85 on pump gas, you are way lean. WAY lean and I can see why you are knocking. The 14b at 16 psi will likely need a few extra % in the small end (1000-4500 rpm) and even more fuel going up to redline. Tune the Hi settings first. It' easiest to set the lo and hi points at 20% and 80% respectively. Then once you have the car tuned for hi setting's just leave the low settings close to stock, or maybe a little richer than stock. At less than 20% throttle, your fuel trims aren't super important. You're cruising at that level so knock isn't much of an issue. Anywhere in between in partial throttle, the SAFC will create the proper trim based on an average of the lo and high settings for that point.

Originally posted by HybriDSM
Well in terms of start off settings, do the quick math. 650's are 200 ccs bigger than 450's. 200/650 is 30.7%, so let's call it 31%. Set the SAFC at -31% across the board and you have stock fuel levels just like if you had the 450's in there. Taking 31% off 650 leaves you with the 450's, so you have a "zeroed out" starting point.

cool. I never actually thought about figuring it out from a mathmatical perspective. I guess I tuned my lo settings pretty well because it's really close. :thumbsup
I'm still super rich while boosting but a boost leak is the culprit. I need to get a reducer for my uicp/tb connection. As hard as I tried, I get get it to seal tight enough. :(

wow, I guess some of my information was a little off, or maybe more than a little. Thanks for telling me before I blew up my car. I got everything set a little better lastnight, and knock calmed down a lot, so now I guess I'll try to fine tune it today. One last question though...Does anybody else have a problem with extremely high oil pressure? I don't mean it goes up and comes back down after a while, I'm saying it is always way up there.

I just wanted to say Matt did an awesome job with his reply. :thumbsup

Originally posted by Jeff_99gs
I just wanted to say Matt did an awesome job with his reply. :thumbsup

He most CERTAINLY did! :cheers Silver star for you. ;)

Agreed. Very well put.

Ok it seems like my 02 sensor doesn't want to go above .89 volts, and I was even killing my car with too much fuel(black smoke/bogging-rich knock). How high are these sensors supposed to go. Also on high throttle with 2000-7000 set at -25 my o2 reads .76...I'm guessing problem. Is the voltage problem a sign that my o2 is shot or what?

Originally posted by sd240
Ok it seems like my 02 sensor doesn't want to go above .89 volts, and I was even killing my car with too much fuel(black smoke/bogging-rich knock). How high are these sensors supposed to go. Also on high throttle with 2000-7000 set at -25 my o2 reads .76...I'm guessing problem. Is the voltage problem a sign that my o2 is shot or what?

That's a sign you're way too lean up top. Definately give it more fuel where those o2 numbers are.

Edit- You got .89 with it killing the engine? Maybe your o2 sensor is bad or the connection is bad. Get a pocketlogger.

What I'm saying is that under WOT my o2 only reads about .76(lean I know)with the hi throttle settings at -25, however it keeps sputtering and has really black smoke(from too rich). My question is what do I do since I'm bogging my car down from too much fuel (rich) while the o2 is saying that it's running too lean. and as soon as it gets past 5lbs of boost the knock sensor goes crazy and shoots all the way up, no matter what the hi throttle settings are(richer or leaner)

Edit: I have a pocket logger with the MMCd, but how can I upload it to my computer? Also I have a chip that converts the factory boost gauge to a knock gauge, so that's what I mean by the knock shoots all the way up.

Originally posted by sd240
My low throttle settings are all at -31, I know what he told me to do, he did a great job explaining. What I'm saying is that under WOT my o2 only reads about .76(lean I know)with the hi throttle settings at -25, however it keeps sputtering and has really black smoke(from too rich). My question is what do I do since I'm bogging my car down from too much fuel (rich) while the o2 is saying that it's running too lean. and as soon as it gets past 5lbs of boost the knock sensor goes crazy and shoots all the way up, no matter what the hi throttle settings are(richer or leaner) Edit: I have a pocket logger with the MMCd, but how can I upload it to my computer?

Well, I don't know then, something is definately wrong with those low o2 readings and too much fuel. Check the o2 sensor is all I got lol.

Yeah I think I'll just buy a new o2 sensor and knock sensor, guess it couldn't hurt anything, well except for my wallet. Thanks for your help, if you think of anything else please let me know.

Buy a new o2 sensor.

This is EXACTLY why you NEVER tune by o2 readings, EVER.

Buy a pocketlogger. It is worth not blowing up your engine.

Originally posted by Jeff_99gs
Buy a new o2 sensor. This is EXACTLY why you NEVER tune by o2 readings, EVER. Buy a pocketlogger. It is worth not blowing up your engine.

He has a pocketlogger. I say, tune from the readings of knock from the pocketlogger, not the factory boost gauge thing. Forget about the o2 readings, at least until you can get an new one, but even then you should be tuning from your pocketlogger knock readings. What do they say anyway?

Originally posted by 420a-Tnthewerks
He has a pocketlogger. I say, tune from the readings of knock from the pocketlogger, not the factory boost gauge thing. Forget about the o2 readings, at least until you can get an new one, but even then you should be tuning from your pocketlogger knock readings. What do they say anyway?

Well then why is he screwing around with the o2's?


Use knock man. Tune till you have no knock. It's not hard. Your o2's could be .000001 repeating, but as long as you have no knock and good timing you are all set.

Originally posted by Jeff_99gs

Originally posted by 420a-Tnthewerks He has a pocketlogger. I say, tune from the readings of knock from the pocketlogger, not the factory boost gauge thing. Forget about the o2 readings, at least until you can get an new one, but even then you should be tuning from your pocketlogger knock readings. What do they say anyway?

Well then why is he screwing around with the o2's? Use knock man. Tune till you have no knock. It's not hard. Your o2's could be .000001 repeating, but as long as you have no knock and good timing you are all set.

Yeah, I don't know, he just said he had a pocketlogger a few posts back. Maybe he doesn't know it reads knock :shrug.

Yes I know the pocketlogger reads knock, but it says that it's knocking too. They both say it is knocking. Today I had the SAFC set at -30(HI) and it is knocking horribly, also you can see black smoke coming from the exhaust when I get on it(that means too rich correct?) And won't the computer alter the fuel maps if it senses that it it running too lean? I'm so confused because I didn't know if I had rich knock or lean knock, and I was just using the O2 reading to figure out if it was too lean or too rich, but it doesn't seem to be working properly, so now I'm stuck. Oh and does anybody know how I can get the logs from my pocketlogger to my computer? Again I have the MMCd software.

TIMA O2-R TPS RPM KNCK INJP ---
38° 0.00V 16.5% 2688 0 1.79ms 5
38° 0.00V 27.5% 2719 0 4.35ms 12
34° 0.00V 83.1% 2750 0 6.14ms 18
31° 0.49V 99.6% 2750 0 6.91ms 20
30° 0.76V 99.6% 2875 0 7.42ms 22
29° 0.76V 99.6% 2969 0 7.94ms 25
28° 0.76V 99.6% 3031 0 7.68ms 24
27° 0.76V 99.6% 3125 0 8.70ms 29
26° 0.74V 99.6% 3219 7 9.98ms 34
21° 0.74V 99.6% 3375 18 13.06ms 47
14° 0.74V 99.6% 3563 24 14.34ms 54
12° 0.76V 99.6% 3625 24 14.08ms 54
12° 0.74V 99.6% 3688 27 14.34ms 56
11° 0.76V 99.6% 3938 32 14.85ms 62
9° 0.74V 99.6% 3969 31 15.36ms 65
9° 0.74V 99.6% 4281 31 15.36ms 70
11° 0.76V 99.6% 4375 31 15.62ms 72
10° 0.74V 99.6% 4313 30 16.13ms 74
10° 0.74V 99.6% 4531 30 16.13ms 78
9° 0.74V 99.6% 4656 29 16.13ms 80
9° 0.74V 99.6% 4875 29 13.57ms 70
11° 0.74V 99.6% 5031 28 15.62ms 83
12° 0.74V 99.6% 5000 28 15.62ms 83
14° 0.74V 99.6% 5219 28 15.10ms 84
14° 0.74V 99.6% 5438 27 15.36ms 89
15° 0.74V 99.6% 5438 32 15.10ms 87
12° 0.74V 99.6% 5625 31 14.85ms 89
16° 0.74V 99.6% 5813 41 15.10ms 93
14° 0.74V 99.6% 5750 43 14.59ms 89
14° 0.74V 99.6% 5844 43 14.34ms 89
15° 0.74V 99.6% 6031 43 14.08ms 90
15° 0.74V 99.6% 6000 42 12.80ms 82
15° 0.72V 99.6% 6188 43 13.31ms 88
14° 0.74V 99.6% 6281 43 13.57ms 91
15° 0.74V 99.6% 6375 42 13.82ms 94
13° 0.74V 99.6% 6625 43 9.22ms 65
13° 0.74V 99.6% 6625 43 12.80ms 90
13° 0.72V 99.6% 6750 43 13.06ms 94
13° 0.74V 99.6% 6719 43 12.80ms 91
12° 0.74V 99.6% 6781 43 11.78ms 85
14° 0.74V 99.6% 6844 43 10.75ms 78
13° 0.74V 99.6% 6813 43 12.80ms 93
11° 0.74V 99.6% 6938 43 11.78ms 87
12° 0.74V 81.2% 7094 42 0.00ms 0

There is my log at -20 on the Hi side(note: it was sputtering and jerking almost the whole time from too much fuel)

43 counts of knock? Wow, I bet you have faulty knock sensor.

THANK YOU that is what I needed to hear. I kind of thought it might have been bad, but I've had no expirence with anything like it before, so I didn't know.

43 counts of knock is certainly possible on a functioning knock sensor on a very poorly tuned car. Replace the knock sensor, but I bet it has more to do with the tuning.

Originally posted by Jeff_99gs
43 counts of knock is certainly possible on a functioning knock sensor on a very poorly tuned car. Replace the knock sensor, but I bet it has more to do with the tuning.

Yeah, but something's not adding up at all. O2 readings say lean, knock sensor has 43 counts, but he's getting signs of too much fuel.

I'd replace both sensors just to make sure.

my car bucks and is gay when i set the cruise to anything above 70. i see black smoke shooting out too. i just dont set the cruise at that speed or higher :) also do you have the 'tick' from your lifters? sometimes your knock sensor will pick that up. hopefully that helps. peace

I do have a LITTLE lifter tick, but I really don't think it would be enough to give me 43 counts of knock.

i completely understand :) i didnt know if maybe that could be an issue for sure or not. anyways, good luck with everything be sure to tell us what you find out.

ok, try this. Go here:
http://www.roadraceengineering.com/newafcsetting.htm
Find a setup similar to yours and use that as a baseline.
It won't be the "best" tune right off the bat but it will give you something safe to start with. Get some logs and start making minor adjustments as needed.

Well I replaced my knock sensor and o2 sensor and that was a huge waste of money. Knock is just as bad, and o2 reads the same as before. Also something that might be note-worthy, the old o2 was really black and you could tell it had been running rich. I checked the ground just in case, and there wasn't a significant loss in voltage anywhere on the engine. Just in case it matters my idle is pretty crappy, but I just figured that to be because of the bigger injectors. I'm leaning towards the computer now, but that is a lot of money I don't have. I'm thinking of taking out the stage 2 chip from dsmchips.com, and putting the stock one back in...What do you all think, could this possibly be the problem? Thanks again for all the good advice so far

Originally posted by sd240
Well I replaced my knock sensor and o2 sensor and that was a huge waste of money. Knock is just as bad, and o2 reads the same as before.

Might as well check your caps, but I guarantee you the car just needs to be tuned.

Originally posted by Jeff_99gs

Originally posted by sd240 Well I replaced my knock sensor and o2 sensor and that was a huge waste of money. Knock is just as bad, and o2 reads the same as before.

Might as well check your caps, but I guarantee you the car just needs to be tuned.

I wasn't expecting it to run better with the new sensors, but to see if it gave you better numbers to tune by.

Are they still giving you the same numbers? Give us a log again.

Wait do you have a stage 2 chip adjusted for the larger injectors already AND the AFC compensated at ~-30% too? Dude, if that's the case, of course you are knocking like a motherfucker. The stage 2 chip is already making the compensation that you are trying to manually make with the AFC. Now it's like you are pulling out ~65% fuel.

If we had known about the new chip previously, all of these problems would have been gone a long time ago. You are essentially running 200cc injectors.

With the stage 2 chip in, set te AFC to 0 and tune from there. With stock chip, set it to -31% and tune from there.

Originally posted by HybriDSM
If we had known about the new chip previously, all of these problems would have been gone a long time ago. You are essentially running 200cc injectors.

OMG, you are so VERY lucky you haven't damged anything yet. I just went back up and looked at the log you posted and when I saw you brought it up to 6500 rpms while starving for fuel, it made me cringe. :-o

Have you done a boost leak test? Blowing out black smoke and knocking simultaneously is a good sign of a good boost leak. Say you've got the boost set at 16psi, but you have a good leak at anything above 9psi, the turbo will spool to all hell to maintain 16psi with the leak, when in actuality it could be spitting out more like 24psi. The constant loss of boost will indeed cause the black smoke, and the overworked turbo shoving superheated air into the engine will cause knock at the same time. Thats how I cracked my #2 ring lands. Anything over 10psi and I could audibly hear detonation, but I had tons of fuel. Turns out when I tested it, I couldnt get the system to hold more than 8psi with a 30 gallon compressor working its ass off. So, I'd check for leaks.

OK take it easy I've been busy/gone all weekend, don't worry the stage 2 chip is set for stock 450 injectors. I'm not completely dumb, just partly. I bought the 650 injectors a while after the stage 2 chip. I haven't done a boost leak test yet, so I guess I should try that. Oh and another observation it sounds like something is kind of rattling under the hood aroud the time the knock count really kicks up. Also I took the old knock sensor and hooked it up and just left it hanging there in the engine bay, and it still said it was knocking just as bad, maybe a little less, but not hardly noticeable. I don't really know if that helps any or not, but I thought it might be worth a try.

1. Ask JEff O' to burn you a new chip...only cost $15. I have no idea why you have a stage anything chip with stock injectors.

2. Where did you get the 650s from? If not from a shop, are you sure they are 650s?

3. Your log indicates you have a nice boost leak...your timing doesn't dip till 3500rpms.....it should dip around when boost starts.

That rattling is your ring lands hating you. Thats detonation for sure. I experienced the exact same thing with my boost leak, and it ended up cracking the #2 ring lands. Pressure test her as soon as possible. Boost leaks are a good 90% of most DSM driveability issues, they cause all kinds of odd problems that people pull their hair out trying to find.

your bad idle is caused from overrunning your fpr you need a afpr with the 255

thats also why i think your running into your knocking problem try and get a fp gauge and see what your pressure is

this wont really affect you when your in wide loop mode though

not a dumb questions. i had the same problem