Cadillac

I'm not feeling good about this one. I advanced the timing on my LO3 8* this weekend and it's running just fine. I'm worried about what this is doing to my engine however. I'm burning 91 octane and there is this "non-stock" chip onboard. I've heard that this can be good for fuel economy as well as performance. Driving at multiple speeds I can hear no knock whatesoever.

What's the story here? SHould I put it back to 0*?

92rsbowtie

4* is perfect, one time i put it at 8* and it seemed to run fine...but every once in a while at idle it would sputter and id get engine clatter, but other than idle it ran great....

BronYrAur

iTrader: (1)

I'm sure the extent of your "stage 1 chip" is additional timing and fuel. You adding 8* to the base timing adds 8* everywhere in the table. The chip may have thrown in extra fuel to disguise too much timing, which could explain no knock, or its knocking and the knock sensor is kicking your timing back anyways.

In any event, I would want to know what's in that chip, and until then I wouldn't run anything over 4* at the distributor.

ShiftyCapone

iTrader: (7)

I agree. See if you can at least hook up your data logger and view your knock counts.

f_body_4_life

hey 92rsbowtie how many octane you runin with 4* timing? oh and Shifty howmany knock counts is normal?

Ramair21

iTrader: (3)

Hey Cadillac i just put mine back at 4* and my car runs so much better. No more knocking

92rsbowtie

i always run 93 octane

Cadillac

I think when you get into ALDL, I'll want ot jump on board with that too. I have the laptop and want to start messing with this next. At this point it's been a little intimidating to me but it really shouldn't be.

Maybe we can hook up again and set mine to 4*? Like I said, it's running fine now but without all the data setting it down from 8* might be wise.

Lastly, should this be better for my fuel economy or is it hard to tell with without the information on the chip? Would it be better with the stock chip?

Ramair21

iTrader: (3)

what i always do to check my Gas Mileage is fill complety up and drive my car for about a week and fill up again and divide my miles that i traveled by the gallons i put in... FOr example: 225miles/7 gallons= 32.14 miles per gallon.

About that ALDL stuff.. Im down for that for sure. I have the laptop too and all i need to get is the program and hardware for the readings of the engine. Let me know Mike.

92rsbowtie

i hope that 225/7 is just a figure your using for your example, i would kill for that good of gas mileage

Ramair21

iTrader: (3)

no 92rsbowtie, I really did get that when i went to LA. no joke at all. I know this is hard to bite but you got to beilve me This is with the corvette servo, 2055 hooker headers, 3" cat back, flowmasters, timming at 6* advanced, and Open element, new spark plugs (AC delco rapid fires) Taylor spark plug wires. Thats about it and some good gas for good luck.

Cadillac

I think Joey told me he got that kind of mileage on a tank once. Am I right?

Anyway, I sent email to the guy I got my chip from and he is echoing what is being said in this thread. Basically I should drop it down to 4* and compare.

The cool thing soon is that the West Coast region guys have a dyno day set up with a local performance shop. 3 pulls and a simulated quarter mile for 55 bucks. I can't think of a better opportunity to see the difference in the thre timing settings: 0*, 4*, and 8*. Joey... you should try and make it. Sounds like a really fun day. I wonder if we can hook up with a data port in-between now and then.



I'll post up the results of the dyno you can rest assured.

BMmonteSS

http://winaldl.joby.se/

Here's the link to winALDL, it's probably one of the best loggers for TBI. Tuner pro 4.0 also works well, it's a bit more graphical but no neat table unless you spit your datalog into excell. Also TBI uses the slow 160 baud interface, so the neat headsup display in tunerpro is a bit chopy.

http://winaldl.joby.se/aldlcable.htm

You want to use the second schematic in that link, it's pretty easy to make, or you can pick up a premade unit off ebay (too expensive) or get a max232 cable from AKM cables, that way you can scan the faster TPI ecm's too. Our tbi cars don't need the fancy cable, but I have one just in case any of my TPI friends need help. AKM might make the simple cable too.

Keep an eye out for knock counts (theres a table in winaldl). Any more than a few scatered counts is not good, use your best judgment if you only get 1 or 2 counts when first smack the throttle, don't worry about it, but if you see your counts slowly or quickly climbing in the upper RPM range, then your ecm is seeing knock and is retarding your timing. You really shouldn't ever hear knock on these cars, the knock sensor should head off any knock way before it gets to the audible level. I think it was grumpy that said that on a scale of 1 to 10 audible knock was an 8 or 9. Your knock sensor can hear in the 1 to 2 range.

Ramair21

iTrader: (3)

Yeah Mike your right about the gas mileage. The dyno Thing sound great, let me know when that day come, We should meet up before then to get things dialed in. I want to see what my car can do with all its mods it has.

Thats web site seems really helpfull BMmonteSS, all i need is just the hardware right? to hook up to the ALDL

BMmonteSS

yep, the cable is all you need, the software is FREE!!!! Gotta love DIY community. I was talking to a DSM tuner guy about tuning on my buddies eclipse, he couldn't believe the software we were using was free. He paid mucho bucks to be able to do DSM's. Think 4 digits

Cadillac

Well, I feel like this is a movement from one side of the force to another. I'm guessing that the movement to DIY is not the dark side.



Please forgive the nerdy comment. I'm around this kind of stuff all day.

Joey, the dyno day is tentatively shceduled for 7/16. I'm almost positive it is in Concord. Bring your timing equipment.

Ramair21

iTrader: (3)

Where can i get this Cable at? I was going to buy the Tuner software too. That was alot of money.

Mike I really want to go. Ill tell my dad and see what he says, Oh fo SHO i will bring my timming tools. Dont worry about that Star Wars comment, I was wondering if that was the dark side. I dont want to do a Anathin to my car (Kill my Car)

BMmonteSS

http://www.akmcables.com/ic.htm

you need number 5 or 6, this cable will do all obd1 GM vehicles, you don't need this cable, but like I said all your TPI friends will be owing you. You can build the simple cable in the above link with parts from radio shack or check ebay for the simple cable.

Ohh and may the force be with you

kdrolt

I can't comment (sensibly) on the ignition advance added by the chip, beyond what's already been said. I can say however that the TBI engines got less ignition advance because those engines used swirl port heads --- and in GM's own words (in the GM Performance Parts book) those heads need less ignition advance because the swirl speeds combustion. This comment doesn't apply to TPI engines because they didn't get the swirl port heads so IIRC they got 6 deg advance that the TBI engines didn't get. IOW they are ignition-timed differently because the heads are different and the octane rating used on each engine might also have been different.

BOTH TBI and TPI engines can gain some power from added advance but remember that the GM engineers intentionally dialed back the ignition timing to account for all possible combinations of poor gas, intended fuel octane rating, carbon buildup in the combustion chambers, altitude and weather. When you change the base timing, you are eating into the safety margin built-in by GM.... so that means you might have to run higher octane fuel than what the factory specified. And more ignition advance doesn't always mean more power. The idea is to start burning the mixture when the piston is still rising in the cylinder so that more pressure exists in the cylinder on the downstroke than it does on the upstroke... as well as to ensure that all the fuel burns. If you add too much timing advance, then the engine might not ping but it also might not make optimum power.

You really have to test with an accelerometer or on a track to see if you really are making more power after altering the ignition timing. HTH, FWIW.

Cadillac

Or with a dyno?

Thanks for the excellent summary kdrolt. Slowly but surely the mechanics of my engine are sinking in.

kdrolt

Oops..... forgot that one. Yes.... with a dyno.

Cadillac

The dyno day is over a month away but I will post the results. When I arrived at this forum I stated that all I was aiming for was 200 HP with my LO3. The dyno will tell me where I should spend my money next. Possible options:

• Intake maniifold: Edlebrock Performer TBI maybe?
• Ignition: MSD, Mallory, or something like that;
• Headers?
• larger injectors?

Since 200HP is the goal, and I have been reading about exhaust and that with 200HP, I may not need a 3inch pipe. Headers maybe?

I look forwad to the plan we will make.

ShiftyCapone

iTrader: (7)

I think you will find that headers will land in your on-line parts basket soon. You won't make much power with the other parts until you have headers. After that should be chip tuning.

Cadillac

Ah yes. How could I forget?



Seriosuly though... with the mods I have now and then maybe headers, can I get to 200+HP with the chip?

ShiftyCapone

iTrader: (7)

That would be a 10-4 good buddy. In non-dork lingo that means yes. Most full exhaust LO3 cars with chip work make between 185 and 200 at the wheels.

Cadillac

I don't want to beat a dead horse but with only 200 HP is the full 3 inch exhaust really needed?

My reference: Check the post by 1989GTATransAm

ShiftyCapone

iTrader: (7)

Yes it is needed. If you have any plans to add further mods to your car it becomes even more crutial.

As for the link. Don't let to much of that get to your head. There are thousands of F-bods that run a single 3" exhaust making anywhere from 170 to 400hp. There was one post where a guy made more peak power with a 4" on his 300 hp motor but I have yet to see the entire power curve. An LO3 makes about half the power he has and won't respond in the same manor. There have been many people in the exahust forum that have jumped on the "bigger is better" band wagon. They make all kinds of false excuses that a certain amount of power doesn't require a certian amount of air flow. I stopped posting in those threads.

weberflorida

iTrader: (2)

Does bumping the timing to *4 really make that big of a difference? I mean is it noticable?

Bill

Ramair21

iTrader: (3)

I have a 3" exhaust and i love it, Flows better specialy with the Hooker 2055 headers. Cadillac you shoud def. get Headers on your Bird, I wouldnt get the MSD cause our Ignition system is really strong already. I think im pushing around 190 with my mods, and i know that i need chip work too.


Weberflorida, I noticed a quicker throttle response when i did mine. My tires always break loose at a stop. Just try not to go to far now

Rocket-Doc

iTrader: (11)

4* degrees? Ok I'm confused by book shows that I'm supposed to be at 6* advanced so why run 2* retarded?

Dewey316

the LB9 and L98 (TPI engines) run at 6* initial timing, the LO3 runs at 0* initial timing. Check the emissions sticker under you hood, it will show base timing at 0*

Rocket-Doc

iTrader: (11)

yeah well that sticker was missing... thanks for straightning that out......

gatoRS92

I run at advanced 6* timing with 93 octane, noticed better power and better mileage.

Fast355

iTrader: (2)

I started at 6* initial too before tuning, but I also have 081s though. At 0* there is a very noticeable lack of response on the bottem end.

MikeDirntRulez

Ummmmmm....

Is 93 really necessary at only 4* advanced?

I would figure 91 would be fine, maybe 89 but probably not.

Benm109

All just depends on the car. I've seen cars need 93 to run pretty much anything past the stock timing (not 3rd gens though). I'm currently running 4* advanced with 87 octane and haven't had any problems (no pinging, no high knock counts, etc.).

ezrs

I just put mine at 6* today -- my timing was actually slightly retarted. I didnt notice any problems, but I decided to put 89 octane in also. The car feels a little more responsive, but nothing really drastic.

92rsbowtie

how does it idle with 6*. that might be a little over kill, with 89 octane you still might run into predetonation. at 6* in my lo3 i noticed a little bit of knock at idle, but it ran great other than that.

ezrs

I didnt notice any problems, but I have not had a chance to drive all that much yet either so I can only say that in the couple of days of driving it around it idled fine.

BMmonteSS

92rsbowtie, actually that couldn't have been knock at idle. Most of the time you can run tons of timing at idle and not get audible knock. The motor may start running funny around 40 degrees but it shouldn't knock. Also your knock sensor will pick up any knock way before you get to audible detonation. Thats why it's very important to play with timing while you data log that way you can watch for knock counts and make sure your not relying on the knock sensor to keep your engine alive. If the knock sensor ever goes south your gonna hurt somthing quick.

92rsbowtie

alright, i know what audible knock is... trust me. and where have you heard you can run tons of timing at idle? idle is where predetonation is most acute at.

Fast355

iTrader: (2)

You CAN run alot of advance at idle without hurting a thing. When I was carbed I ran 32* advance at idle with room for more, if I had limited centrifical advance to about 18* instead of 22. That was 12* initial and 20* vacuum. Idle was actually better as well as off idle response if I ran 16* initial. Your ECM only has about 26* advance at idle. That means that 6* advance shouldn't be a problem.

I once read Smokey's recomendation for timing on a street driven small block. It went along the lines of 20* initial advance, 18* centrifical all in by 2,000, and 10* of vacuum advance.

92rsbowtie

well not all motors are the same, some can handle it, some can't. mine tends to idle pretty rough at 6*, but smooths out throughout the rpms.

BMmonteSS

I've done it, not read it. When I say 40 degrees I mean total not your initial timing at the dissy. Yes most motors run ruff with too much timing, but most of the time ticking noises at idle are more of an exhuast issue. My headers for instance ping prettly loudly at idle, I can hear it change pitch with different timing settings. It's not a leak, just thin header sounds. Your not going to be running much more than 25 or 30 degrees total with the initial timing set at 8*.

JPrevost

I don't get it, how is it you guys are talking about advancing the timing 6 degrees base and not touching the chip... then saying it's fine at idle! Who cares about idle, what about when you snap open the throttle hard. You might have too much timing at low RPM and high MAP.
Without touching the chip you guys are just going to confuse yourselves into a circle of 50/50 good/bad experiences.
Let's, for just a second, look at the freeware here for everybody to ponder through. TunerPro and the xdf file I have shared (pick it up from Craig Moates fileshare).
Under the constants there is "Knock - .... threshold". Open up any $61 (8746 ecm) factory bin and take a look at these thresholds. The AXKT bin needs 10mph and 1000rpm before it'll start retarding timing based on the knock counts. So at idle, you could be pre-igniting the mix and leading to detonation EASILY. It'll feel fine for a few seconds, then it'll stumble, stall saver, high idle (above 1000rpm), it's fine for a while, then the cycle repeats. This isn't healthy for your engine, so why lie to the computer that controls the ever important spark advance? Set the base timing to 6, tell the ecm it's set at 6. If you don't, the Max SA won't be correct in the chip (stock it's 40.8) instead it'll be 6 degrees more. So when the ecm thinks it's commanding 32 degrees at WOT, the engine will be seeing 38 degrees.
For the $110 it costs for a G2 adaptor and the burn1 with a flash chip I can't for the life of me understand why so many of you don't just get it. It's nearly impossible to break anything.

Fast355

iTrader: (2)

I thought when you told the ECM you had the base at 6* it still used the same timing table just adjusted when the injectors fired. So in other words I am only getting 30* advance at WOT and 3,600 instead of the 36* that I thought I was.

You should see the timing curve I am running in my chip along with the 6* at the ECM.

RPM Load kPa
30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
3600 40.08 40.08 40.08 40.08 40.08 40.08 40.08 40.08 37.62 35.16 32.70 29.88 29.88 29.88 29.88
3200 40.08 40.08 40.08 40.08 40.08 40.08 40.08 40.08 37.62 35.16 32.70 29.88 29.88 29.88 29.88
2800 40.08 40.08 40.08 40.08 40.08 40.08 40.08 40.08 37.62 35.16 32.70 29.88 29.88 29.88 29.88
2400 40.08 40.08 40.08 40.08 40.08 40.08 40.08 40.08 37.62 35.16 32.70 29.88 29.88 29.88 29.88
2200 37.27 37.27 37.27 37.27 37.27 37.27 37.27 37.27 34.80 32.34 29.88 27.42 27.42 27.42 27.42
2000 34.45 34.45 34.45 34.45 34.45 34.45 34.45 34.45 31.99 29.53 27.07 24.61 24.61 24.61 24.61
1800 31.99 31.99 31.99 31.99 31.99 31.99 31.99 31.99 29.18 26.72 24.26 21.80 21.80 21.80 21.80
1600 29.18 29.18 29.18 29.18 29.18 29.18 29.18 29.18 26.72 24.26 21.80 18.98 18.98 18.98 18.98
1400 26.37 26.37 26.37 26.37 26.37 26.37 26.37 26.37 23.91 21.45 18.98 16.17 16.17 16.17 16.17
1200 23.55 23.55 23.55 23.55 23.55 23.55 23.55 23.55 21.09 18.63 16.17 13.71 13.71 13.71 13.71
1000 20.74 20.74 20.74 20.74 20.74 20.74 20.74 20.74 18.28 15.82 13.36 10.90 10.90 10.90 10.90
800 17.93 17.93 17.93 17.93 17.93 17.93 17.93 17.93 15.47 13.01 10.55 8.09 8.09 8.09 8.09
600 17.93 17.93 17.93 17.93 17.93 17.93 17.93 17.93 15.47 13.01 10.55 8.09 8.09 8.09 8.09
400 17.93 17.93 17.93 17.93 17.93 17.93 17.93 17.93 15.47 13.01 10.55 8.09 8.09 8.09 8.09

Didn't turn out the best but you get the idea. It is basically the same curve I used with my carburetor.

ezrs

my total timing at idle was 20* with it advanced 6 degrees.

people dont buy the chips because burning chips is a pain in the butt and you (like you said, hit or miss though) may be able to bump up your timing and save $110 and get most of the effect if you can get your hands on a timing gun.

The data logging is certainly a good idea, I will probably do that myself and once I learn what everything looks like may be more tempted to start messing around with the chip burning.

JPrevost

I don't understand your question.
If the main calculated SA is say for example, 30 degrees when the calibration has 0 set in the initial SA, and the ACTUAL initial timing (base timing) is 6, the ecm will think the engine is seeing 30 degrees when in reality it's actually seeing 36 degrees. So long as the initial in the chip matchs the initial on the engine you can't get caught with your pants down. One quick way to adjust your idle timing is to just move the initial timing when using an emulator. It's smarter to just move the Main SA bias. Either is smarter than adding to the WHOLE main SA table .
Most SBC's like idle between 20-36* depending largely on the cam. With SD you need to record what MAP you're at so you can adjust the "idle" SA in the main table AT your actual idle area. For the most part, the lower the vacuum (higher MAP in kpa) the more spark it wants/needs to keep the plugs clean. This is largely due to the dynamic compression ration being so low (intake valve is open when the piston is coming up from BDC). Poor cylinder filling is what it's called in the tuning circle. I hope people understand that when their engine is stumbling at idle, it could very well be from too much base timing.

JPrevost

I haven't touched my base timing in 3 years. Nore have I messed with the fuel pressure. All that can be done with a wrench can now be replaced with a few key strokes from within the comfort of your home or driver seat. Tell me that alone isn't enough incentive to drop down the cash and get into the computer. It's the evolutionary process, either you're still dragging your knuckles thinking to yourself that you aren't smart enough to tune your own chips or you're doing it! Anybody that can find this website and type on a keyboard can program their own chips. I find the "oh I'm scared" to be a cop out on doing things the right way because it might appear to be the hard way (when in the long run it's the complete opposite).

ezrs

I see your point, just understand mine also. If I stick with a TBI setup then ill be forced into the chip burning. Its not that people are scared, its just that it takes a lot of patience, trial and error, and understanding to do it correctly. Im not a real patient guy and I dont want to spend tons of time getting up to speed unless I know I am going to be committed to this path long term.