94 F-body LT1 solving problems/tune

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Originally Posted by yoheer

What about better intake and headers in vette?
Will modifying theese tables take effect in fbody?
And only 1 knock sensor. Detonation?

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Changing the exhaust and intake will cause changes in how air flows into and out of the engine. Engines are at their core just air pumps, after all. Much of these changes can be accounted for by the closed loop O2 sensor feedback system. You would have to make much more extreme changes to fall out of the range of what the PCM can account for, which changes to intake and exhaust won't do. If you disabled closed-loop feedback or you just want to adjust the tables yourself, then get a wideband O2 sensor and get to doing your own tuning. There's no magic bullet. But if the question is just "will I blow up my engine if I use the Corvette tables," the answer is no.

No, reducing the knock sensors from 2 to 1 won't cause detonation. On the 94-95 $EE PCMs, whether you have one sensor or two there's only actually one channel being used on the PCM end (the 96-97 PCM used two channels). What's important with regards to the knock feedback system is not the number of sensors, but is rather the calibration stored on the knock module inserted into the PCM. This module is what takes the output from the knock sensor(s) and filters it to tell the PCM when knock is occuring. Making changes to the acoustic profile for your engine will cause this knock feedback system to malfunction, but it's not the fault of the sensor. It's the knock module.

Unfortunately, short of designing your own knock module, you're not going to be able to get around this. Once you start doing custom work in your engine bay, it's best to just disable the knock feedback system entirely and rely on proper tuning, or run an external knock feedback system if you're paranoid.

Thank you for such detailed answer.
Do you mean that if I have any loud perfomance muffler even with stock headers then i'd better disable knock sensors? Because of false knock.

GM used a different knock module when they upgraded the valvetrain on the '96 & '97 LT4.
The Impala SS Forum's collective experience has shown that using roller rockers and/or headers could cause 'false knock'.
The LT4 Knock Module has been out of production for many years now.

You should be fine with your loud mufflers, though.

I've made mods to my bin. Lots of vette tables and parameters applied
Here is short log with PE mode and 100% TPS.
Seems to be very lean. Knocks detected. Can anyboby take a look and say what should I move to?

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Originally Posted by yoheer

Thank you for such detailed answer.
Do you mean that if I have any loud perfomance muffler even with stock headers then i'd better disable knock sensors? Because of false knock.

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Not necessarily. I can't tell you what's going to change the acoustic parameters of your engine, but generally a muffler on the other side of the car isn't going to be what does it. It'll be changes related to the engine bay, or what's immediately nearby the engine bay. Things directly attached to the engine. What you can do is lower the timing on your engine to a point where it won't knock and then test. If you can make the knock reliably appear and disappear by messing with the timing, then it's probably real. If on the other hand you get knock with unusually low timing and/or in parts of the map that have no real load or RPM, it's probably false knock.

And as said, there's no way to fix this in the tune. It's not handled by the tune--it's handled by a physical component, the knock module. So if you find out you have false knock, you either have to make your own knock module tuned to your specific setup's acoustic parameters, or just disable the knock feedback system.

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Originally Posted by yoheer

I've made mods to my bin. Lots of vette tables and parameters applied
Here is short log with PE mode and 100% TPS.
Seems to be very lean. Knocks detected. Can anyboby take a look and say what should I move to?

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I had a look at your log. The "knock" at 1500 RPM and 40 MAP is probably not real. That's very low load and RPM. There are specks around 4000 RPM, but those could be false too, depending. The fueling at PE looks fine. The closed-loop fueling looks like it wants more fuel, sure, but your log is also pretty darn short, and you don't really cover the whole range without going into PE, so this 'lean' normal operation appears to be well within normal values. The O2 feedback system can handle deviations this small without any issue.

I have my older logs, before vette tables. There is no knock at about 4000. I'll try to make more cruising logs.
Also I dont like maf readings. 6-7 at idle. I'll try to clean, but I'm afraid he is dying.
No vac leaks. Checked
O2s readings vary to much (left/right)
Rarely I get right or left (dont remember)bank lean condition dtc.

Btw maybe someone has a good tuned file for stock or like-stock car?
I'd like to compare with stock. Is it noticeable chages in car behavior? I mean can I feel em myself

Here.

Thank you. Can you write some description about the car, mods and what is made about tuning?

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Originally Posted by yoheer

Thank you. Can you write some description about the car, mods and what is made about tuning?

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Absolutely OE, no mods, no tuning.
You asked to compare with stock. It's stock.

Nope ) I do have lots of stock files. I asked tuned file for stock car.

here is my combined bin
I will be grateful for the analysis and corrections.
To those who have f-body. It would be cool if you try this tune and say what corrections are required.

Guyz.
I compare corvette and f body trans tables. Can't understand one thing.
95' vette 2.59 gear vs 95' f-body 2.77 gears
Vette pressure table values are higher in all range.
But. Vette modifiers are much lower and even have negative values. F-body modifiers are higher and positive values.
What is it for?
Does it mean, that vette has softer shiftings and f-body has rougher shifting?
Why vette pressure is higher but it is gets lower with modifiers. What is the sense of all this?
Vette=high pressure+low modifiers
F-body=low pressure+high modifiers
And as a result pressure is somewhere at about same values. But the way cars gets this values differs. Why?

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Originally Posted by yoheer

Guyz. I compare corvette and f body trans tables. Can't understand one thing.
95' vette 2.59 gear vs 95' f-body 2.73 gears
Vette pressure table values are higher in all range. But. Vette modifiers are much lower and even have negative values.
F-body modifiers are higher and positive values. What is it for?
Does it mean, that vette has softer shiftings and f-body has rougher shifting?
Why vette pressure is higher but it is gets lower with modifiers. What is the sense of all this?
Vette=high pressure+low modifiers
F-body=low pressure+high modifiers
And as a result pressure is somewhere at about same values. But the way cars gets this values differs. Why?

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Good question, I can only guess at an answer, and my guess success rate is not good enough for me.

I.E.: the 4L60E line pressures for LT1 Caprices RoadMasters & Fleetwoods do not protect those 4L60Es from enthusiastic driving, at least not for very long.
Only notable exceptions are 9C1-LT1 Caprices and V4P 7000lb tow package Fleetwoods.

Since your car is probably heavier than a 'vette, I'd use the higher base line pressures & carefully study where & when the negative modifiers are applied.
My GUESS is that you can probably safely raise the negative modifiers to zero preemptively with no danger.

And what if i will apply higher vette pressure tables keepeng f-body positive modifiers?

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Originally Posted by NomakeWan

Log analysis

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Here is highway logs.
Dunno if i'm right but it seems to me lean. Blm ~135
If it is so then what are the next steps?

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Originally Posted by yoheer

And what if i will apply higher vette pressure tables keeping f-body positive modifiers?

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Start slow, make small incremental changes, save your previous version, see what happens.

Were I you, I'd use the 'vette base pressures AND raise all the negative modifiers to zero, based on my experience with several Caprices and a few Fleetwoods …
… but remember that I'm not there testing your car in real time with you.

Your shifts will probably get a bit firmer.

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Originally Posted by yoheer

Here is highway logs.
Dunno if i'm right but it seems to me lean. Blm ~135
If it is so then what are the next steps?

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Either use the "Analyze" function in EEHack to give suggestions on changes, or export a CSV by clicking the "Main" tab and then clicking "Export CSV" so that you can feed that data into Trimalyzer. Note that in Trimalyzer you must change the default "Trim Input Type" in the upper-right corner to "+/- Percentage" in order to correctly read CSVs from EEHack in Trimalyzer.

Also note that if you have the MAF enabled, you cannot adjust the VE tables. EEHack/Trimalyzer will not give you accurate data for the VE Tables with MAF enabled--they will only be able to give you MAF adjustment data. If you want to tune the VE Tables--and you should if you haven't--then disable MAF mode and start there first. Once your VE tables look good, then switch back to MAF tuning. Or just tune the MAF and see where that gets you, I ain't yer daddy.

Thank you for the info. This is the only place where I can ask for help. Im trying to do all my best

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Dunno if i'm right but it seems to me lean. Blm ~135

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remember, a blm of 135 doesn't mean you're really running lean, it just means it was lean for just a moment and the ECM had to add about 5% more fuel to fix it. it's nothing to worry about. that's what closed loop is for. you could add 5% of fuel to that area so next time it doesn't have to adjust.

To the OP, thanks for posting you factory bin. I snagged it for storage. I had not saved a factory bin from my Z28 PCM before I sent it off to a tuner. I've since been tuning my own stuff but it's nice to have a stock F body bin to look at if I need to. Especially a TA bin because I might be adding the performance mode for transmission stuff.

http://fbodytech.com/tutorials/bin-files/

there are a lot of factory bins here, if you're interested in checking them out for comparison

I can't figure out with detonation in PE mode.
Main spark table is modified, but it seems to be almost okay.
Extended spark table is stock. Retard @4200 is up to 10 degrees. Commanded afr is really rich in PE. ~12.0 . It should be at least.
Im running 93+ octane. MAF car. No vacuum leaks.
Short eehack log below. (remove ".txt")
any ideas?