2K Corvette C5 / SuperCharged tune check

[06Chev5.3]

Guys,

I am looking for a second set of eyes on my tune file. I know the file is fat on fueling and I think I will keep it that way until I get my WBO2 installed. So some things I am looking for a double check on are the transmission setup and the PE enter TPS %/RPM.

2000 Corvette C5/LS1/Auto
Car has A@A Vortech kit (9PSI), 60lb injectors, cat back and 160 stat, otherwise stock auto.


Any feedback is appreciated.

[mowton]

Did you tune the VE and MAF separately? The VE seems a bit choppy. Maybe try a bit of smoothing. Assume you tuned to 4000 rpm in VE, then the MAF across the board and then went to the closed loop "blended" startegy.

Secondary VE table should equal the corresponding row of the primary. Copy and Paste.

Disable COT Over Temp protection when tuning; will add enrichment at times and throw off your fueling logs. You changed the enrichment rate there, not sure why?

Finally, did you have to "tune" the PE to get the AFR right in WOT? What AFR were you going for? Did you run out of MAF? Normal practice is to straight line the PE (1.28/11.5 AFR for FI) and tune the fueling to attain the commanded AFR. If you run out of MAF, then you increase the PE at those RPM points to make up the difference, or tune in Speed Density.

Hope this helps

Ed M

[06Chev5.3]

Thanks for the reply!

[06Chev5.3]

Thanks for the reply!

I have not had a chance to log it with this tune yet. I just noticed I left COT enabled, fixed now. THis is my first attempt at a full tune so to speak. In the past I have payed for a base mail order and then "fine Tuned" it. So, this one will probably take me some time to get dialed in. I like your idea on the PE table, so I am going wiith that.

What do you think about the trans settings, and when it enters PE?

[smithers]

Hard to tell, but I hope when you had tuned the VE and MAF in Open Loop, you had your EQ ratio table 1.00 everywhere. - oh nope I re-read, you dont even have a wideband yet...ok, well.

Things I noticed:
a) You need to figure out what TPS vs rpm when boost is hit to create your own TPS PE Enable curve. (I cant see that current one working properly)

b) Your PE table is crazy! lol, commanding 10.17:1 AFR ? why are you progressing the Air Fuel as RPM goes up? - trying to follow the PSI created by the procharger?
10.1:1 is very rich for approx 9psi.

c) are you sure your not going to max out the MAF? - its probably going to happen, then you will have to go SD or get a larger SLot MAF and re-tune (either way). - well, I would DEFINATELY watch how close you get with the Hz and g/sec


d) your IAT spark Advance correction Im sure is being triggered (especially if you are not intercooled)... you may want to log and adjust.

e)VE - 3600/80kpa doesn't make sense.

f) Your adaptive idle is never being triggered with a low 160° stat.
You want to lower from 176 on your Min ECT

g) no wideband yet? sigh...like why bother?

[smithers]

If you run out of MAF, then you increase the PE at those RPM points to make up the difference, or tune in Speed Density.

Ed M

I dont recommend this method. (its a hack solution in my opinion)

I agree with everything else.
Flatline the PE table.

[Jabbott]

Wouldn't it be better to replace the MAF if you hit the ceiling? I don't know that I would call the PE mod a hack, because there are allot worse things out there being done and that is the way it was done back then. I think going to the bigger MAF, and new 3 bar MAP and then scaling the program will make it operate correctly. I don't like going just SD, I am in a small group but I like the MAF sensor.

[mowton]

I dont recommend this method. (its a hack solution in my opinion)

I agree with everything else.
Flatline the PE table.

Tuning all you can and then using the PE to fill in the top end when you just run out of MAF is not a HACK SOLUTION! Rapping the PE says you don't touch any other fueling then PE it and blow the car out the door.....

Thanks for the input though

Ed M

[smithers]

Tuning all you can and then using the PE to fill in the top end when you just run out of MAF is not a HACK SOLUTION! Rapping the PE says you don't touch any other fueling then PE it and blow the car out the door.....

Thanks for the input though

Ed M

Its a hack job because your 'guessing based on the belt driven boost characteristics. If your MAF is maxed, how do you ACCURATELY know the ingested air? You don't.

I would never, especially since I drive around at 3300ft elevation and then drive to sea level often... and you would be comfortable with your PE adjustments because you have maxed out all abilities to measure or calculate the ingested air? Yea, no thanks. to save a couple hundred bucks to go SD for example... why? (don't answer that, I don't care about your answer)

I call it a hack or a band-aid because that IS WHAT IT IS, when you SHOULD be looking at other proper alternatives BECAUSE THEY ARE AVAILABLE! - it would be completely different if there was no alternative and you were truly limited, but we ALL KNOW he is not.

Look, I know people suggest it, and it does make sense, but its not PROPER when there are other solutions. You know it, I know it!


lol, roll the eyes? yea, you too buddy.

[smithers]

Rapping the PE says you don't touch any other fueling then PE it and blow the car out the door.....

Ed M

Blow the car out the door? Rapping the PE says what? PE talks?
Man, calm down.
lol, no clue what your saying, gibberish or hack talk? lol

[LSxpwrdZ]

I personally do not like adjusting the PE to compensate for max'd airflow or frequency. In a way it is no better than adjusting fuel injector flow rate to alter fueling. If you command a richer mixture then airflow tables should be calibrated to match those commanded F/A ratio's. If the airflow tables get max'd frequency or flow wise then it's time for SD! I'll go ahead and tell you it's right around the 500-520rwhp range on the flow side of things. Scaling the airflow tables will allow a broader range on that power but with no scaling the 512g/sec limit put's your power around there.

My NA 403 max'd out the frequency and the flow on a 85mm MAF so I ditched it and kept it SD. On customer car's that make above 500hp I usually have them convert to SD as well cause it's only a map sensor and the custom OS license to make it happen!

[06Chev5.3]

Thanks for the replies folks. I guess my initial ask was to make sure the tune I put together is conservative enough for initial logging.

Given the car is cat-back and S/C only, I doubt I will max the MAF. Once I replace the LS1 manifold and get headers it sounds like I will need to seriously consider going to SD setup.

Regardless I am going to hold off on driving the car until I get my WB02 bung welded in.. (I bought one, and it is here just not installed).

[smithers]

Given the car is cat-back and S/C only, I doubt I will max the MAF. .

10psi supercharger alone on a stock motor is enough to max the MAF on the early vetts... just make sure you keep tabs.

[smithers]

On customer car's that make above 500hp I usually have them convert to SD as well cause it's only a map sensor and the custom OS license to make it happen!

Exactly! I would never do a PE 'PATCH' (perhaps a better term than hack, as some get offended) on ANY Customers ride if they maxed out a MAF tune.
I will not do that on my own cars either.

[mowton]

10psi supercharger alone on a stock motor is enough to max the MAF on the early vetts... just make sure you keep tabs.

I agree, I went back and did the calculation and it looks like he will be at 650 g/sec or so based on approximately 175 kPa (9 lbs boost) at sea level, 120% VE, 6200 rpm and the 5.7 stock engine. This is too much to make up in PE.

I agree with you 100% and retract my rolling eye's and would definately go with the Speed Density approach ...sorry

Ed M

[06Chev5.3]

So.. if I want to get one bar and go SD. Do you all recommend anyoen close to Houston? I have no experiance going that route.

[Z06SUPERCHARGED]

I agree, I went back and did the calculation and it looks like he will be at 650 g/sec or so based on approximately 175 kPa (9 lbs boost) at sea level, 120% VE, 6200 rpm and the 5.7 stock engine. This is too much to make up in PE.

No it is not...
I'll throw in my results...

I'm at 15 psi and 752 rwhp and using the stock LS6 maf. My maf hits its limit at 4800 rpms so pe table is "raped" from that point on. I tune in Lambda but will use afr numbers for reference for everyone so its easier to see for those who dont use Lambda #'s.

I command 11.0 to 4800 and then have to rape pe cells after 4800 to make up for non calculated airflow through maf. I end up with commanding something like a 7.0 afr at 6400+. Im out of state now so don't have exact pe cell numbers to share but they begin at like 10.0 at 5200 and so on to 7.0 at 6400+.

I have over 100+ logs wot through the gears and my afr's stay within 11.0-11.4 in ambient temps of 50-75 degrees at sea level ALWAYS.
I always drive at sea level and very seldom drive in temps colder than 50 or warmer than 75 (I live in Ca so these are whats normal for me when I'm out).
These afr results are well within my safe zone and have no problem raping the pe table to get to them as they stay constant and have stayed constant for last 2 years. They do not wander ever from this range. Once I max my maf my psi vs rpm vs airflow will stay the same for any given rpm or psi at wot. For instance wot at 12 psi at 6000 will be the same airflow today as it will be next week for me and any other wot rpm vs airflow will be as well and so on. Nothing changes much to make any difference in afr to worry about. I spent 2 years logging and watching afr changes in temps, humidity and any other factors thrown at me and never saw afrs wander out of that range.

Now if you drive in 30 degrees one day and 95 a week later or hit the 6000 feet mountains sure the afrs are gonna wander away from the "safe" zone at wot lean wise cold temps and be fat pig rich on hot days but for people in climates like mine with basically same elevation driving and 25 degree max temp swings its gonna work and afr's will be well within the wanted range.

YES SD is the way to "correctly" go, but I have shown in my logs and tuning it works with maf also.

Not trying to start a pissing match here on what is best or why it works or not but it works for me and I see no log results saying I need to fix or change anything. Someday I'm sure ill go to SD when I'm bored and nothing else to do just to do it for no other reason to just compare dyno number results.

[smithers]

Mowton, thanks for the calculations! - it clarifies the whole picture.
no worries, cheers!

o6Chev5.3. - You want a 2 Bar sensor and a 2Bar SD OS applied. A common sensor used is what comes out of the Cobalt SS - BAP sensor, it has the same 5Volt linear, and plug in.
(A 1 bar sensor covers vacuum up to just past sea level (just beyond) - its actually more than 1 bar as 1bar = 100kpa, just shy of 1 Atm. In actual, the stock 1 bar sensor would read 0.5psi before maxing out) Roughly 14.7psi is sea level and 105kpa is 15.22. Unless of course, you live below sea level, where you use up that headroom.


Gmpartsdirect.com may be a decent price for you.

[smithers]

No it is not...
I'll throw in my results...

.

Thanks for your input.
Its personal choice i guess
a) for a customer, I will never do that
b) for your own car, its purely your choice, but is it tuned to its max efficiency? no. one day at sea level, you could hit a good PE, another day somewhere else, its off, way off. what if you hit belt slip? (or you dont even know its happening) lots of wasted fuel , no way of knowing if the slip is past your maf limit....inefficient. Is the car at its best performance? no. Its variance that can be avoided, and its not that expensive overall.

How would one tune a car at 3000ft and adjust accordingly, then the customer drives to sea level... its a shot in the dark, and leaves some on the table.

I know these Patches can be done, and they 'work - sort of'
Is max potential being left out worth a couple hundred bucks? its a sensor and an OS upgrade. Many here or shops would say, hey, time for SD when you max out your MAF or go with a bigger MAF (slot)...

No pissing match! - lol, sure it works, but your car vs a finely tuned larger MAF or SD car would have a bit more power, every day, any elevation, just saying, your leaving some on the table... well, not like you need any more...


06Chev5.3 - its up to you.... do some reading, you can do either...,

Cheers

[mowton]

No it is not...
I'll throw in my results...

I'm at 15 psi and 752 rwhp and using the stock LS6 maf. My maf hits its limit at 4800 rpms so pe table is "raped" from that point on. I tune in Lambda but will use afr numbers for reference for everyone so its easier to see for those who dont use Lambda #'s.

I command 11.0 to 4800 and then have to rape pe cells after 4800 to make up for non calculated airflow through maf. I end up with commanding something like a 7.0 afr at 6400+. Im out of state now so don't have exact pe cell numbers to share but they begin at like 10.0 at 5200 and so on to 7.0 at 6400+.

I have over 100+ logs wot through the gears and my afr's stay within 11.0-11.4 in ambient temps of 50-75 degrees at sea level ALWAYS.
I always drive at sea level and very seldom drive in temps colder than 50 or warmer than 75 (I live in Ca so these are whats normal for me when I'm out).

Can you post one of your WOT logs, I'd like to check my math and assumptions....at 15 pounds of boost your MAP is 213 kPa assuming sea level (105 kPa). At 4800 rpm, 5.7 litre and an estimated charge temp of 100, you are only attaining a VE of like 95% to yield 512 g/sec (actually 517) or MAF saturation.... Is that correct?

Math isn't my strong suit

Thanks

Ed M