safc help

[magikgsx]

im reasking my questin. what o2 voltage should i be tunning for? i cant seem to get the voltage to the .92v.

if the o2 voltage doesnt want to get past that or close to it, my o2 is bad im asuming right?

[t_jolt]

that or running way to rich or too lean

[thiazole]

I've never seen a bad O2 sensor do that. They usually sit below .1 and don't move when they go bad. If it still cycles during closed loop operations, then it is fine. If it is holding .92 during "closed loop" then it isn't really in closed loop. That would indicated the tune is so far off the ECU is defauting to open loop. I've never used an SAFC, so I don't know anything about tuning them, but I wouldn't try to hard to hit a specific O2 voltage. I've seen some cars that were at 11:1 at .94 volts (looking side by side at a wideband) and others that were at 11:1 at .80 volts.

[magikgsx]

at 1000rpm its max volt is .78 and jumps around from there and 2000 and up the highest it gets to is .85

[thiazole]

Ah, so are you saying you can't hit .92 volts while it is cycling or while at WOT?

[Cloud]

That seems fine to be honest. It's a narrow band and every one I have used cycles slightly different and will read a different value at the upper end when you are at wot. They are not calibrated instruments, they are the shotgun to the long range rifle of the wideband. If you don't have a wb o2 then I would suggest tuning wot with the knock sensor instead of the narrow band.

[magikgsx]

yes sir. i can't hit .92v

[magikgsx]

the pocket logger i have does not read knock. how can i tune against knock then?

[yokotabrat]

The only way with a 2g is with dsmlink or an aftermarket ecu. Without those, the only thing that gets close is to tune based off timing. Look for dips in timing or low timing through a WOT pull. The ecu pulls timing when it hears knock. This isn't a very good method though unless you know what timing should be without knock.

[magikgsx]

this weekend ill be taking the car to chris so he can help me with this. if i reset the lo and hi throttle meaning initialze the safc, would it mess the car up when i drive it? or should i just set things at medium value till then?

[matthewdesigns]

I've always tuned for no knock on my 2g by looking for timing being pulled on my logger. Third gear pulls from ~2.5K-7.5Krpms will show you a good range. I log rpms, timing, and airflow, that's all. You'll be wanting to keep the timing on a nice, smooth curve as it rises. It'll dip when your turbo hits (to maybe around 6*), then it should rise to a peak between 16-18* for a 2g...16* puts you on the highest airflow vs. timing map.

As you read the timing curve, if you see timing being pulled, add a couple percent of fuel for that rpm, and log another pull. Repeat until there's no timing pulled. Then add another point or two for a little insurance across the board. That's how I've always tuned, and it's been pretty safe. Then borrow a wideband to check it all out if you can.

I can email you a pdf of the timing/airflow maps for a 2g, so you'll know what to shoot for. PM me your email if you want them.


Edit: Man I'm typing slow this morning....

[matthewdesigns]

Are your Lo Throttle settings adjusted roughly for your injector size? If so, then set your Hi corrections to match them and leave it. You'll be off (shoot for a little rich), but safe. Just don't get into boost until you get a handle on it this weekend.

If you initialize, and it resets everything, then you'll have to set it back up for # of cylinders, air meter type, and injector compensation to get it to run, anyway.

[magikgsx]

ok. i have the it set i think for the 450s. 18% is where i started 1k for loth.too high or too low?

[matthewdesigns]

For 450's on pump gas, everything needs to be zeroed out on the afc, since those are stock. If you are pulling 18% out, then you'll be too lean. At most, you'll be adjusting only a few % with the afc and stock injectors.

Set your NE points to 30 Lo/80 Hi, and zero out all the corrections for Hi/Lo throttle. Then if you can log some runs, and get a WB, you can safely make small adjustments to the stock injectors. I was only able to get about 15spi out of the stock 450's, so don't expect a lot of power.

[magikgsx]

i did a log so i can tune the high throttle on the safc. i need some opinions on the readouts. i cleaned the o2 and seems to be working better. it reads out to where it should be i believe.

rpm timing o2 o2trim stft ltft
4k 17* .98 0 0 -5
4.5k 12* .98 0 0 -5
5k 14* .98 0 0 0
6k 22* .96 0 0 0
6.5 24* .96 0 0 0

didnt get the 7k reading because traffic was too congested. tried four times.
this is with the boost backed down to 12psi

[matthewdesigns]

Here's a link to the file, if it still has not come through by email...I didn't get a rejection notice, though. Maybe check your junk file.
http://www.mediafire.com/?y4s4m1yxbyx
I've never used a file hosting service, so I can't promise anything...just used the first one that came up on a search. It's only a few pages long, and a good informative read (from the DSMLink manual).

As for the log, you need a LOT more info than that. Like, try to get a sample every 200rpms, not every 500. There should be a way to increase the sample rate in the setup for your logger program. There could be a lot of nasty stuff going on in between. And is the turbo hitting at 4.5K? If not, then that drop of 5* is pretty dramatic...definitely need some fuel there. Increase the sample rate, add fuel until there's little to no drops in timing at the 12psi you're currently set at, and then post back up with another log.

[magikgsx]

second log. 3rd gear pull
rpm timing o2v o2 trim stft ltft airflow
4051 33* .06 4.69 3 0 1.19
4297 20* .96 0 0 0 10.54
4465 19* .94 0 0 0 11.05
4637 19* .96 0 0 0 12.07
4902 21* .96 0 0 0 12.18
5004 20* .96 0 0 0 14.37
5270 20* .96 0 0 0 14.79
5395 21* .96 0 0 0 15.1
5504 21* .96 0 0 0 15.26
5773 23* .96 0 0 0 15.12
5918 24* .96 0 0 0 15.85
6016 24* .96 0 0 0 15.95
6223 25* .96 0 0 0 15.99
6301 26* .96 0 0 0 16.15
6531 28* .96 0 0 0 15.74
6648 28* .96 0 0 0 16.27
6793 29* .96 0 0 0 15.87
6898 30* .96 0 0 0 15.57
6965 31* .94 0 0 0 14.44
7043 37* .8 0 0 0 3.73

[matthewdesigns]

What is your setup?

If it's not stock, and the turbo is actually hitting at 4200, then the log looks pretty good. I'd add a percentage or two at 5K and relog, until that timing drop goes away. Then add a couple psi and do it all over again. Just keep the timing from dropping at any point after the turbo hits full spool (until you let off).

Are you stock turbo, exhaust, etc.? If so, then start your log earlier, around 2.5K, so we can see a wider picture. Are you cruising, then burying your foot at 4K on the stock setup, so it appears to be coming on that late? If it's stock, your foot is in it early, and it's hitting at 4200, then there's a problem somewhere else...pre-turbo exhaust leak, clogged cat? A stock 2g turbo setup should already be spooling up at 3Krpms.

If the car is stock, do this: in 3rd gear, at 2.5Krpms, put your foot to the floor and don't let up until 7K+. I usually do pulls like this on a long onramp (where it's normal looking to be accelerating), just remember that you'll be close to 100mph at the top of 3rd gear, though, when you have to potentially merge into traffic. That will show what's going on from top to bottom, and you'll need to know all of this for a good tune anyway. Also, ditch the trims from the logs for these WOT runs and you'll get even more info, but this one is a lot better/denser than the first one.

[magikgsx]

What is your setup?

If it's not stock, and the turbo is actually hitting at 4200, then the log looks pretty good. I'd add a percentage or two at 5K and relog, until that timing drop goes away. Then add a couple psi and do it all over again. Just keep the timing from dropping at any point after the turbo hits full spool (until you let off).

Are you stock turbo, exhaust, etc.? If so, then start your log earlier, around 2.5K, so we can see a wider picture. Are you cruising, then burying your foot at 4K on the stock setup, so it appears to be coming on that late? If it's stock, your foot is in it early, and it's hitting at 4200, then there's a problem somewhere else...pre-turbo exhaust leak, clogged cat? A stock 2g turbo setup should already be spooling up at 3Krpms.

If the car is stock, do this: in 3rd gear, at 2.5Krpms, put your foot to the floor and don't let up until 7K+. I usually do pulls like this on a long onramp (where it's normal looking to be accelerating), just remember that you'll be close to 100mph at the top of 3rd gear, though, when you have to potentially merge into traffic. That will show what's going on from top to bottom, and you'll need to know all of this for a good tune anyway. Also, ditch the trims from the logs for these WOT runs and you'll get even more info, but this one is a lot better/denser than the first one.

my set is pretty much a stage 1 set up. its a 14b,big fmic, nt tb, 2g ex mani, megan 3" o2 housing with 3" down pipe, high flow cat, 2.5" one piece cat back,450 inj, open element filter,and again 12 psi, a c.o.p, afpr at 42 psi.

i did this run while i was actually on the highway. i started the log around
3k+ or so and barried my foot to the floor. so that where im going wrong in the log? also what do you mean ditch the trims? you mean dont log the all the fuel trims? what all should i log?

[thiazole]

The fuel trims are only useful when you are cruising around/ idling in closed loop (when you O2 sensor is cycling). It is a nice indicator of how much compensation your ECU has to make to get the O2 voltage it is looking for. In open loop you are using the air sensor so the fuel trims become meaningless.

[magikgsx]

The fuel trims are only useful when you are cruising around/ idling in closed loop (when you O2 sensor is cycling). It is a nice indicator of how much compensation your ECU has to make to get the O2 voltage it is looking for. In open loop you are using the air sensor so the fuel trims become meaningless.

ah ok! got it.

[matthewdesigns]

I only log rpm, timing, and airflow for WOT tuning. This is really all you need. The o2 values aren't all that accurate, as previously noted. And just log the trims when you are trying to get the idle/part throttle operation ironed out. If you suspect something else is screwy, add that parameter for log or two, then drop it again after you see what's going on. The fewer the number of parameters you are logging, the higher the number of times the selected parameters will be sampled, so you just get a more detailed picture. Post the full log, from 3K on up, for giggles, or make another one and post it in it's entirety, from ~3K to redline.

I've never had a 14b, so I don't know when it should be spooled up fully, but 4200 seems really high...that's like 20g territory...maybe someone else can chime in here? My E316g is at full tilt by ~3500. The big fmic is certainly causing some lag, but I don't know how much to credit to that. Is there a cat on the car? If so, try to find a test pipe and see if it makes a difference in when the turbo spools. Is the wastegate flapper closed completely? Check that the actuator arm is not sticking partially open. Is your base timing set properly? If that's off, I'd guess that it could affect spool, too, but that's an area I don't know enough about to comment for sure.

[thiazole]

When I first bought my car, the T25 wouldn't hit full boost (being only about 13psi) until about 4300 rpm. It turned out that it had an "el cheapo" exhaust job that was worse that stock. The exhaust zigged and zagged in every direction and used some kind of accordian tubing that had to be terrible for flow.

Another thing to look for is your manifold to turbo bolts. Make sure they haven't loosened up. I've seen that before and it kills your spool up.

[magikgsx]

well after last nights event with t-case issue when it locked up i had to force it in the garage causing the clutch to burn up pretty bad. i took the t-case off and took it for a short drive today and the clutch is slipping BAD in first gear. so i have to get a new clutch.

well before the t-case issue, i had a leak in the ic pipe before the ic so i fixed that and the car started spooling at about 3k and was kicking pretty good.
so with that fact should i start to add fuel at 3k?
oh and the cat was hollowed out because it was bad:p

[matthewdesigns]

So, can you drive the car with the clutch like it is? If the clutch is slipping, you won't get an accurate log, either, because the engine won't be under full load. If it's just first gear that's misbehaving, then do another 3rd gear pull from 2.5-7K, now that the ic piping is tight, and get a new baseline. Then start with the afc adjustments vs. timing drops.

[magikgsx]

So, can you drive the car with the clutch like it is? If the clutch is slipping, you won't get an accurate log, either, because the engine won't be under full load. If it's just first gear that's misbehaving, then do another 3rd gear pull from 2.5-7K, now that the ic piping is tight, and get a new baseline. Then start with the afc adjustments vs. timing drops.

The clutch is only slipping in 1st gear. All other gears feel strong. So i'll do a couple of pulls tonight when my wife gets home.
I don't think it'll be wise if i do one with my son in the car.LOL! :D

[matthewdesigns]

Good luck with everything...hope the clutch holds!

[magikgsx]

Me too! Because if it doesn't hold i'll be stuck on the highway. Thanks for the help with this tuning thing. I think im getting the hang of it.
my partner goes to DADC and were going to put the car on the dyno while i have the transfer case off. Its free and its not too far.
Then i can fine tune it since i'll be able to do about 4 or 5 pulls.

Hey is your car still down?

[matthewdesigns]

Yep, still down. I'm about halfway to having the $$$ saved for the rebuild.

[magikgsx]

What are going to change on the build? I plan on getting a builder block from the junk yard and build a new motor to stand up 4-500 hp. that build will be a while.

[yokotabrat]

my partner goes to DADC and were going to put the car on the dyno while i have the transfer case off. Its free and its not too far.

Be careful with that. If you drive around with the transfer case unhooked you can blow the viscous coupler inside the transmission.

[matthewdesigns]

I had an urge to do it myself, but it's my DD, so I don't want to blow it (again lol). I've never done a complete rebuild on a motor and don't want to experiment with this one :p

So, I'm going to have Jack (JackM on here) build it. He's completely rebuilding the 7-bolt from top to bottom, including forged 1g rods, ARP studs, and an o-ringed head. And I need a new turbo as well...mine's toast. He says the motor will be good for 480hp, which will be plenty strong on my E316g/e85 setup...I think I'll be lucky to hit 400hp. I've been thinking about a mild set of cams on top of this, but that's easier to deal with if I want to go there in the future.

[magikgsx]

I need to read more on how to build these motors, because i plan to build my own. I've built plenty of chevy motors myself so i'll take a stab at with this one. The rebuild on this motor was a all stock set up so it was just a remove replace, no blue printing and all that stuff.

I have to research as to what parts I will go with. The worst thing when I do it is it'll blow.LOL!

Im going to build a 1g awd. Or if i dont build a 4g63, a 700hp 383 stroker will find a place in a 1gawd!:D No im not kidding. That was my plan for this one if the motor would have been damaged in the wreck.

[iamtall77]

The thread got off subject, but O2's are not accurate at all. I'm only reading .70v at WOT and no knock on my 1G (about 20* of timing at 7k). It is not running lean or having any issues. The SAFC is pretty simple once you get used to it. Each car is different, and our mods only make it worse to try and compare apples to apples.

And just because you don't feel your clutch slipping, doesn't mean it's not. The power of a strong pull will make it slip at high RPMs even if you don't feel it. You might just think the motor is strong and revving quickly. I didn't know I had a bad clutch until a simple stoplight put an end to it. I went to the drags the week before and had no issues. Went to a movie the next week. Pulled out. Drove less than a mile. Hit a red light. And then the clutch almost completely quit on me. I could rev it to 3k with the clutch fully engaged and it would just creep off the line. Never saw it coming.