VE table tuning in speed density

[Firebird94]

Hello,
I've recently started learning how to tune and was able to start adjusting my Primary VE table yesterday after getting my AEM 4110 wideband installed on my 1994 firebird with a gen 2 LT1 and a torqhead 24x kit. I just wanted to make this post and hopefully have someone check and see if I'm going in the right direction with my tuning since I'm new to this. I'll attach my base tune that is setup for speed density according to Goat Rope garages video on gen 3 speed density tuning as well as the first data log with the wideband and then my first corrections and the following log. The reason I wanted to get someone to double check is because the car was seeming to get better as I was tuning yesterday but I couldn't seem to fix a "WOT" bog/stumble due to a lean condition. Again I really appreciate the help and please let me know if there's any info I'm missing that would be helpful.

[bk2life]

HGoat Rope garages video on gen 3 l.

i like his videos, but i dont like how he uses the WB for everything.
I like WB for WOT only.
Everything else i like the vehicles NB o2s to do the fueling, becuase what are you tuning to the wideband, or are you going to remove that and use the fcatory narrow band 02s for fueling?

Also, your stft+ltfrt is only showing 2 numbers all across the board, thats not right.

Here is a fuel trim log using narrow band O2s. You can see i went up to 3600rpms, and nearly everywhere it was very rich, pulling 20% of fuel in some spots.

432654172_753987516926166_2177257979672889718_n.jpg

[04silverado6.0]

See if this gets you any closer. That timing seems excessive for the time being. Get your ve dialed in and track tune the spark advance.

[bk2life]

Also i just looked at your VE table. It is spikey, and has some wierd sudden drops.

Your High octane spark table isnt copied to your low octane table either.
And the spark table looks pretty crazy too.

This is also going off of gen 3 info, not real sure how itd look on your LT1, but, there should never be any sharp sparks or valleys anywhere.
Id, suggest using your stock O2 sensors to dial in your MAF/VE and timing up to the 4k rpms.
Then reisntall your WB and get the WOT tuned.

[Firebird94]

So the STFT and LTFTs are actually disabled in these logs so that?s why they?re reading 0 and -2 across the board. My understanding of the wideband is that I?m using it solely to adjust the VE table and get it close enough to the point that the fuel trims hardly have to do any work once I turn them back on. At the moment I?m to the point where my AFM Err chart is looking pretty good but the car will not accelerate in the high load situations or under heavy throttle.

[Firebird94]

Do you have any recommendations of videos or tutorials on how to adjust spark tables safely?

[Firebird94]

04silverado6.0
So I tried your recommended timing table adjustments the other night and found that the car seemed to start running a lot worse however I saw what you meant about the timing table being very weirdly shaped and spikey. I'll attach the logs of with and without your timing tables applied to the vehicle. Any recommendations would really help. Thanks!

[Alvin]

See if this gets you any closer. That timing seems excessive for the time being. Get your ve dialed in and track tune the spark advance.

Timing for a GEN 2 LT1 should be between 32-42 degrees at wide open. They aren't like LS's at all.

[Alvin]

Hello,
I've recently started learning how to tune and was able to start adjusting my Primary VE table yesterday after getting my AEM 4110 wideband installed on my 1994 firebird with a gen 2 LT1 and a torqhead 24x kit. I just wanted to make this post and hopefully have someone check and see if I'm going in the right direction with my tuning since I'm new to this. I'll attach my base tune that is setup for speed density according to Goat Rope garages video on gen 3 speed density tuning as well as the first data log with the wideband and then my first corrections and the following log. The reason I wanted to get someone to double check is because the car was seeming to get better as I was tuning yesterday but I couldn't seem to fix a "WOT" bog/stumble due to a lean condition. Again I really appreciate the help and please let me know if there's any info I'm missing that would be helpful.

I started my career tuning these things.. with the OEM computers that is.

Is the car cammed? What is the setup?

Cammed LT1's suffer from a "split BLM" problem. If bad enough you might end up needing to be in open loop all the time. One side will just max out rich while the other goes lean. Very common issue to watch out for.

The tolerance of what they will put up with with stock o2s/fuel trims is a bit less than LS's stuff.

The timing table looks like a reasonable start. The VE table is a decent start. Some rough spots that can be smoothed/extrapolated better. They will look different than a LS. More like plateau.

I didn't see any WOT in your log, you should log a bit more btw. But under heavy throttle I did see it go lean. I'd put a fuel pressure gauge on it ASAP. 30 year old car could very possibly have weak fuel pressure.

[Firebird94]

I started my career tuning these things.. with the OEM computers that is.

Is the car cammed? What is the setup?

Here is the current setup on the car that I sent to torqhead.
Engine Size (L):5.7L

Transmission Type and Model:T56 6-speed

Transmission Spec (Stock or Built):Stock

Rear End Gear Ratio: 4.11:1

Current Tire Size:245/50 R16 front and rear

Desired Shift Firmness (Slight, Moderate, or Very Firm): N/A

Torque Converter (Make/Stall): N/A

Injectors (Make/Model/Size): OEM injectors

Fuel Octane: any pump gas 87-93 would be preferred for this tune

Thermostat (Stock/160/180/195): Stock

MAF (Stock LT1/3.5? LT1/Other): Stock LT1

Ported MAF (Yes/No): No

De-screened MAF (Yes/No): No

MAP Sensor (stock, 2 bar, 3 bar): stock

Throttle Body Size: Stock

Cold Air Intake (Yes/No): Yes ( this car is a formula car however the previous owner installed an aftermarket ram-air hood and a modified 93-97 TA air box

Intake Manifold (Stock LT1/Ported LT1): Stock LT1

Exhaust Manifold (Stock/Other ?): Pace setter mid length headers (will attach photo to this email) Side note: the headers have the ports on them for an air pump and EGR however the air pump has been deleted off the car and plugs have been installed into the ports on the headers The vehicle does have the EGR connected at the moment but I was considering blocking it off while installing the cam as I'm pretty sure the EGR valve has failed because it sets an EGR flow code whenever I am crusing down the highway.

Catalytic Converters: None

Cat Back Exhaust: 3in exhaust with a hooker muffler

Nitrous (Yes/No): No

Camshaft (Make/Model/Specs): GM performance LT1/LT4 Hot Part Number:24502586
Cam Specs:
Hydraulic roller
Duration @ .050" Lift( Deg): Intake: 218 / Exhaust: 228
Maximum Lift (in) W/ 1.5 Rocker: Intake: .492 / Exhaust: .492
Maximum Lift (in) W/ 1.6 Rocker: Intake: .525 / Exhaust: .525
Lobe Centerline ( deg): 112
Cylinder Head Specs: Stock LT1 cylinder heads

Rocker Ratio: Stock Rocker ratio

Compression Ratio: Stock compression ratio

[edcmat-l1]

You need to plot your AFR error and apply it to your table. All you're doing so far is digging an idle hole in the table.

[Firebird94]

I started my career tuning these things.. with the OEM computers that is.
I didn't see any WOT in your log, you should log a bit more btw. But under heavy throttle I did see it go lean. I'd put a fuel pressure gauge on it ASAP. 30 year old car could very possibly have weak fuel pressure.

I have done some more logging since and tried going under WOT but every time I do the problem areas all seem to be going lean when I try to so I'm trying not to stay in it to long. I'll attach the most recent logs that I have of a couple ~30min drives so hopefully those will show you more.

Note: These logs were recorded after making some more adjustments to my VE table and doing some smoothing of the table as some people have recommended.

[Firebird94]

You need to plot your AFR error and apply it to your table. All you're doing so far is digging an idle hole in the table.

That's exactly what I thought I was doing... the logs I have attached to this post should have an AFR error chart displayed and I have just been logging, copying my error table, using paste special "multiply by half %" and pasting them into my VE table, smoothing the graph and then re flashing the car and repeating that process.

[edcmat-l1]

I haven't seen an updated file so I'm just going off the first one and first data log.

[04silverado6.0]

Timing for a GEN 2 LT1 should be between 32-42 degrees at wide open. They aren't like LS's at all.

That doesnt mean you need all the timing before the ve is dialed. Good way to break some rings.

[bk2life]

when you post your log, and have have changed your tune, post the tune also.

For verification, how is your MVPIx set up right now? How or what are you tuning, and or trying to accomplish with these logs?

There is more data on 'longer drive to work' and it looks like its using the vehicle O2 sensors?
Then there is the 'long drive to work' and are you using a wideband for that log?

Me, i use the vehicle O2 sensors and try to get the 3500prm and below VE set so its not rich nor is it lean. This is step 1 for me.
Then step 2 is doing the same for the MAF.
I don't do any WOT until those are pretty close to where they should be.

Currently you have some pretty good lean spots that need fuel added, and the circle showss an entire area that we dont know whats happening there.

So, to recap, you stated in your 1st post youre still new to tuning, thats why i wanted to verify so were all on the same page.

[Alvin]

That doesnt mean you need all the timing before the ve is dialed. Good way to break some rings.

This isn't a LS. It will cause problems to run WOT timing that low.

[Alvin]

I have done some more logging since and tried going under WOT but every time I do the problem areas all seem to be going lean when I try to so I'm trying not to stay in it to long. I'll attach the most recent logs that I have of a couple ~30min drives so hopefully those will show you more.

Note: These logs were recorded after making some more adjustments to my VE table and doing some smoothing of the table as some people have recommended.

Did you check fuel pressure yet?

[04silverado6.0]

This isn't a LS. It will cause problems to run WOT timing that low.

OK.

[Firebird94]

Did you check fuel pressure yet?

I have not been able to check fuel pressure under WOT yet however with the vehicle idling the fuel pressure at the rail is around 40psi and stays at about 40-45psi when I disconnect the vacuum line to the pressure regulator.