Looking for someone to look at datamaster file & give advice

[steveo]

try this more conservative timing table and check for driveability (i think you can just copy paste it)

it's my failsafe 'fbody with a cam' timing table if you're having surge problems, but should work fairly well in your 'vette (might just want to add a bit more WOT timing later on since you have a lighter car)


28.0 28.0 28.0 28.0 28.0 28.0 28.0 26.5 23.0 20.0 18.0 15.5 15.0 15.0 15.0 15.0
28.0 28.0 28.0 28.0 28.0 28.0 28.0 27.0 24.0 21.0 18.0 16.0 15.0 15.0 15.0 15.0
28.0 28.0 28.0 28.0 28.0 28.0 28.0 27.5 25.0 23.0 20.0 17.0 16.0 15.0 15.0 15.0
30.0 30.0 30.0 30.0 29.0 29.0 28.5 28.0 27.0 24.5 23.0 20.5 18.0 16.5 15.0 15.0
34.0 34.0 34.0 33.0 31.5 30.5 29.0 28.5 28.0 26.0 24.0 22.0 21.0 19.0 17.0 15.0
35.0 35.0 35.0 34.0 33.0 32.0 31.0 30.0 29.0 28.5 27.5 26.0 24.0 22.0 20.0 18.0
35.5 36.0 36.0 36.0 35.0 33.5 33.0 32.0 32.0 31.5 31.0 29.5 27.0 24.0 22.0 21.0
36.5 37.0 37.0 37.5 36.5 36.0 35.5 35.0 34.5 34.0 33.0 32.0 30.0 27.0 26.0 24.0
37.5 38.5 39.0 39.5 38.0 37.5 37.0 37.0 36.5 35.5 35.0 34.0 33.0 31.0 28.5 28.0
39.0 40.0 41.0 41.0 40.0 39.5 39.0 38.5 38.0 37.5 36.5 35.0 34.0 32.5 31.0 30.0
39.0 40.0 43.0 43.0 42.0 41.0 40.0 39.5 39.0 38.0 37.0 36.0 35.0 34.0 32.0 31.0
39.0 40.0 43.0 43.0 42.0 41.0 40.0 39.5 39.0 38.5 37.5 37.0 36.0 35.0 33.0 32.0
38.5 40.0 43.0 43.0 42.0 41.0 40.5 40.0 40.0 39.0 38.0 37.0 36.5 35.5 33.0 33.0
38.5 40.0 43.0 44.0 43.0 42.0 41.0 41.0 40.0 39.0 38.0 37.0 36.5 35.5 33.0 33.0
38.5 41.0 43.0 44.0 43.0 42.0 41.0 41.0 40.0 40.0 39.0 38.0 37.0 35.5 33.0 33.0

[steveo]

... you also need to smooth your VE table, or your off-idle will be sketchy

[johnny_b]

I will try to point out the areas it runs rough as well as get a specific data capture of this area as much as possible.

The Beta tool you mentioned I would be interested once I get a better feel/understanding for tuning. This is my first time really tuning an EFI.

As far as driving goes......Yes I'm not able to drive the car to far from home as my tag is expired. I plan to renew it tomorrow and I will try to drive as long and as diverse as possible while gathering data.

What can I do to fix the "entire tune being too lean"?

The MAF will go back on as soon as the VE tables are good. Unless there is a reason I should switch back now?

How do I go about smoothing my VE table? is there a certain process I should use or just by eye? Not sure what you mean by the "off-idle" will be sketchy.

[johnny_b]

I went back and looked at my most recent datamaster log and I see what you mean about it being lean everywhere. I went back to an older log to see and it was way worse, So it is slowly getting better.

[steveo]

really, for your first tune, aiming for around 120-126 in your trims across the board would be good enough. just fyi a '120' trim is like 5-6% rich. that's 'bout 14:1.

a bit richer is very safe, runs well, and let the O2 sensors take up the slack.

once you get the rest of fuel and timing dialed in you can take it the rest of the way and fine tune it very gradually.

How do I go about smoothing my VE table? is there a certain process I should use or just by eye? Not sure what you mean by the "off-idle" will be sketchy.

view your VE table in a 3d graph. you'll notice you've basically carved an area out of the table and made it leaner in an attempt to fix idle. now view a stock VE table. notice how all the transitions in the graph are gradual.

in general if you're tuning and you find a gigantic spike or drop somewhere that doesn't look natural or fit the rest of the table, it's due to an error in data or an incomplete data set, and that's when you get to 'fill in the blanks' for data you dont have, or smooth it out.

if you want me to try to baseline a VE table for you, i can do that, but i'll need a good long log of actual driving in a variety of ranges, not just feathering the throttle.

[Fast355]

try this more conservative timing table and check for driveability (i think you can just copy paste it)

it's my failsafe 'fbody with a cam' timing table if you're having surge problems, but should work fairly well in your 'vette (might just want to add a bit more WOT timing later on since you have a lighter car)


28.0 28.0 28.0 28.0 28.0 28.0 28.0 26.5 23.0 20.0 18.0 15.5 15.0 15.0 15.0 15.0
28.0 28.0 28.0 28.0 28.0 28.0 28.0 27.0 24.0 21.0 18.0 16.0 15.0 15.0 15.0 15.0
28.0 28.0 28.0 28.0 28.0 28.0 28.0 27.5 25.0 23.0 20.0 17.0 16.0 15.0 15.0 15.0
30.0 30.0 30.0 30.0 29.0 29.0 28.5 28.0 27.0 24.5 23.0 20.5 18.0 16.5 15.0 15.0
34.0 34.0 34.0 33.0 31.5 30.5 29.0 28.5 28.0 26.0 24.0 22.0 21.0 19.0 17.0 15.0
35.0 35.0 35.0 34.0 33.0 32.0 31.0 30.0 29.0 28.5 27.5 26.0 24.0 22.0 20.0 18.0
35.5 36.0 36.0 36.0 35.0 33.5 33.0 32.0 32.0 31.5 31.0 29.5 27.0 24.0 22.0 21.0
36.5 37.0 37.0 37.5 36.5 36.0 35.5 35.0 34.5 34.0 33.0 32.0 30.0 27.0 26.0 24.0
37.5 38.5 39.0 39.5 38.0 37.5 37.0 37.0 36.5 35.5 35.0 34.0 33.0 31.0 28.5 28.0
39.0 40.0 41.0 41.0 40.0 39.5 39.0 38.5 38.0 37.5 36.5 35.0 34.0 32.5 31.0 30.0
39.0 40.0 43.0 43.0 42.0 41.0 40.0 39.5 39.0 38.0 37.0 36.0 35.0 34.0 32.0 31.0
39.0 40.0 43.0 43.0 42.0 41.0 40.0 39.5 39.0 38.5 37.5 37.0 36.0 35.0 33.0 32.0
38.5 40.0 43.0 43.0 42.0 41.0 40.5 40.0 40.0 39.0 38.0 37.0 36.5 35.5 33.0 33.0
38.5 40.0 43.0 44.0 43.0 42.0 41.0 41.0 40.0 39.0 38.0 37.0 36.5 35.5 33.0 33.0
38.5 41.0 43.0 44.0 43.0 42.0 41.0 41.0 40.0 40.0 39.0 38.0 37.0 35.5 33.0 33.0

The timing around idle seems really relaxed in this table. The LT4 Hotcam is not going to want to idle smoothly with that little timing. It is going to want more in the neighborhood of 30-36* at 800 rpm at idle. It will also want an instant advance increase above idle with as much as 40-42* by 2,400 rpm @ 40-50 kpa.

[steveo]

yeah, it is relaxed. like i said it's my failsafe table, just a good starting point, not a final timing table. if transitional problems occur, i usually try this first to see if it smooths out.

the lt4 hotcam is not a giant cam; i'd never tune in more than 28-30 degree of closed tps advance, but i've actually never tuned one with an automatic so maybe that changes things a bit.

the off-idle transition with these mid-sized cams seems to be way nicer if you dont jack too much timing up outside of operating range before it's necessary. especially with the increased compression and low end torque of a 383, it just shouldn't need it.

but to each his own, i guess. experimentation will yield the best drivability.

for example my car with a 210/220 114LSA wussy cam went from a lurchy shitty off-idle transition under light throttle to buttery smooth when i ran 27 degrees flat all the way up to 1500rpm.

a friends car with a bigass lloyd elloit cam did the same if i made it a pancake right up to 2000rpm. it still snaps your neck if you give it any sort of heavy throttle of course, and since it's a sports car and you never drive it there except when you first hit the gas, there's no downside to fuel economy or anything.

[Fast355]

yeah, it is relaxed. like i said it's my failsafe table, just a good starting point, not a final timing table. if transitional problems occur, i usually try this first to see if it smooths out.

the lt4 hotcam is not a giant cam; i'd never tune in more than 28-30 degree of closed tps advance, but i've actually never tuned one with an automatic so maybe that changes things a bit.

the off-idle transition with these mid-sized cams seems to be way nicer if you dont jack too much timing up outside of operating range before it's necessary. especially with the increased compression and low end torque of a 383, it just shouldn't need it.

but to each his own, i guess. experimentation will yield the best drivability.

for example my car with a 210/220 114LSA wussy cam went from a lurchy shitty off-idle transition under light throttle to buttery smooth when i ran 27 degrees flat all the way up to 1500rpm.

a friends car with a bigass lloyd elloit cam did the same if i made it a pancake right up to 2000rpm. it still snaps your neck if you give it any sort of heavy throttle of course, and since it's a sports car and you never drive it there except when you first hit the gas, there's no downside to fuel economy or anything.

It may also be the difference between tuning an automatic truck or van vs a sports car.

This is my go to timing map for a L31 Vortec with a LT1 or LT4 cam. I run alot of closed throttle spark advance as it increases idle vacuum and off-idle torque which a stock stall, stock gear truck can't make enough of.



I can make a LT4 Hotcam drive practically like a stock cam.

With a carb setup the LT4 Hotcam is a touch more tricky but I bring the advance in quick and run a good amount of manifold vacuum advance to achieve 30-34* at idle. Idle is good at 700 in gear with a Vette/S10 converter.

[johnny_b]

try this more conservative timing table and check for driveability.

Steveo I flashed to the spark table you provided and my motor did not like it. The low rpm roughness got noticeably worse.

I went back to my spark table and it subsided back to how it was before. With my table it seems to run rough right around 1200-1800rpm 30-55kpa. the spark advance when this happens is around 37-39*. My assumption for this (and please correct me if I'm wrong) is that with the increased compression my motor has 11:1, the stock spark timing is just to aggressive in these regions?

Trying to reduce spark advance in these regions has kind of thrown my spark table all out of whack:

16.0 16.0 25.0 25.0 25.0 25.0 24.0 24.0 20.0 20.0 18.0 14.0 12.0 12.0 6.0 6.0
24.0 24.0 25.0 25.0 25.0 25.0 25.0 25.0 24.0 21.0 18.0 16.0 15.0 12.0 10.0 8.0
27.0 31.0 31.0 31.0 31.0 31.0 29.0 27.0 25.0 23.0 20.0 17.0 16.0 14.5 13.0 10.0
32.0 33.0 33.0 31.0 30.0 29.0 29.0 27.0 28.0 26.0 23.0 21.0 18.0 15.0 14.0 12.0
34.0 35.0 35.0 33.0 33.0 31.0 31.0 28.0 28.0 26.0 24.0 22.0 21.0 19.0 17.0 15.0
35.0 35.0 35.0 33.0 32.0 33.0 34.0 33.0 34.0 32.0 30.0 28.0 25.0 22.0 20.0 18.0
35.0 36.0 36.0 34.0 34.0 35.0 36.0 35.0 35.0 34.0 32.0 30.0 27.0 24.0 22.0 21.0
35.0 36.0 37.0 35.0 35.0 36.0 37.0 37.0 38.0 37.0 35.0 33.0 30.0 27.0 25.0 24.0
35.0 36.0 39.0 37.0 35.0 36.0 37.0 37.0 38.0 38.0 36.0 34.0 33.0 32.0 30.0 28.0
35.0 40.0 43.0 41.0 40.0 38.0 38.0 37.0 39.0 38.0 36.0 35.0 34.0 34.0 32.0 30.0
35.0 40.0 43.0 43.0 42.0 41.0 40.0 40.0 39.0 39.0 37.0 35.0 35.0 35.0 33.0 31.0
35.0 40.0 43.0 43.0 42.0 41.0 40.0 39.0 39.0 38.0 38.0 36.0 36.0 35.0 34.0 32.0
35.0 40.0 43.0 43.0 42.0 41.0 41.0 40.0 39.0 39.0 39.0 37.0 37.0 35.0 35.0 33.0
35.0 40.0 43.0 44.0 43.0 42.0 41.0 41.0 40.0 39.0 38.0 37.0 37.0 35.0 35.0 33.0
35.0 41.0 43.0 44.0 43.0 42.0 41.0 41.0 40.0 40.0 39.0 38.0 37.0 35.0 35.0 33.0

I'm sure I have some issues with the closed tps spark advance blending with this table as well.

[steveo]

well if my table didn't help, that means less spark probably isn't what it needs. the roughness might not even be related to ignition timing. you'll just have to play with it until it works, but you can't solve everything with timing.

[Mean LT1]

well if my table didn't help, that means less spark probably isn't what it needs. the roughness might not even be related to ignition timing. you'll just have to play with it until it works, but you can't solve everything with timing.

What about taking out less fuel in the problem areas? I've heard of this helping as well.

[johnny_b]

Ok I know its been awhile since I've posted here but i figured id give an update.

since my last post, I have since bricked a PCM, bought a spare, revived the one I bricked, and several other car related repairs. I have just recently got it back to where it is reliable to drive.

for the closed tps timing I conducted an experiment that seemed to show it likes the 33*-34*. I will post the document which contains several graphs related to the advance, i used csv data from datamaster to create it, the graphs show avg, meadian, and modes for each spark advance data set just as a sort of "sanity check". I know many people are usually only concerned with avg.

Setting at 33-34 brought my idle BLM's much closer together.

I used $EEHack to log data for the first time today. AWESOME AWESOME software. I haven't used it to flash/read bins yet but I plan to soon.

I will be purchasing a wideband O2 sensor soon to further aid in tuning.

As far as my timing table goes I have flashed back to the factory spark table for my car -2*. My car responded really well to this and I did not encounter any knock. so I plan to leave it there for now until I get my wideband.

[steveo]

hey, you're back

the game has changed since i wrote eehack

it will help you nail timing way more quickly. use the autospark feature going a few degrees up or down in an entire region to see what it likes and fine-tune from there. it's a coarse adjustment but it helps you tune by 'feel' instead of just with data.

same with idle, just turn the thing up and down a bit while you manipulate idle speed until it seems happy and makes max vacuum.

if you do a bunch of logs, just press 'analyze' it'll build you a new ve table pretty quickly too...

[Fast355]

Ok I know its been awhile since I've posted here but i figured id give an update.

since my last post, I have since bricked a PCM, bought a spare, revived the one I bricked, and several other car related repairs. I have just recently got it back to where it is reliable to drive.

for the closed tps timing I conducted an experiment that seemed to show it likes the 33*-34*. I will post the document which contains several graphs related to the advance, i used csv data from datamaster to create it, the graphs show avg, meadian, and modes for each spark advance data set just as a sort of "sanity check". I know many people are usually only concerned with avg.

Setting at 33-34 brought my idle BLM's much closer together.

I used $EEHack to log data for the first time today. AWESOME AWESOME software. I haven't used it to flash/read bins yet but I plan to soon.

I will be purchasing a wideband O2 sensor soon to further aid in tuning.

As far as my timing table goes I have flashed back to the factory spark table for my car -2*. My car responded really well to this and I did not encounter any knock. so I plan to leave it there for now until I get my wideband.

Gotta love that it was right in the middle of the 30-36° at idle I said it would enjoy. Nothing new about a Hotcam to me.

[johnny_b]

Gotta love that it was right in the middle of the 30-36° at idle I said it would enjoy. Nothing new about a Hotcam to me.

yep fast355 you were right. I may flash to that timing table you posted for the lt4 hotcam and see how it likes it.