Check out the tune I pulled from my customers car.

[n8dogg]

Just for learning purposes and curiosity I pulled the tune out of one of my customers cars. The tune was performed by a reputable GM Tuning shop. Take a look at it!

Car Info: 2004 Corvette Z06, 12,000 miles.

Engine Mods: Halltech Intake, LG Motorsports Pro Long Tube Headers, Stock TI Mufflers, Throttle Body Bypass, Race Radiator with integrated oil cooler.

Vehicle Useage Mainly used for Trackmasters events at Watkins Glen Intl. Raceway, Mosport, VIR.... Driven once in awhile on the street to Corvette Club meetings, joy rides, etc...

Things that I found...

Probably tuned with out a WB02. I say this because look at the PE A/F. Commanded quite rich in my opinion. And why does it go leaner with the increase in RPMs. Don't you want to go richer?

The MAF calibration is very close to mine, and I don't have long tubes. I bet it needs a further adjustment. I guess I would need to log the LTFT's and see whats going on.

High octane table was copied and pasted to low octane table. I guess this is OK because of how rich it's tuned? I think I would prefer the protection in case I got bad gas. Notice the few cells that jump 4 degrees? Hmm, shouldn't the map be gradual?

AIR settings are stock, why not lower the RPM limit?

Fan settings seem quite low for a factory thermostat.

This car put down 385hp. I would think with the intake, headers, radiator, and tune 400 is attainable.

hmm... opinions?

[LS1_Dragster]

I've always tuned richer at peak torque and leaned it for HP as the RPM climbs.

Lee

[WeathermanShawn]

Just for learning purposes and curiosity I pulled the tune out of one of my customers cars. The tune was performed by a reputable GM Tuning shop. Take a look at it!

Car Info: 2004 Corvette Z06, 12,000 miles.

Nice..Low Miles.

Engine Mods: Halltech Intake, LG Motorsports Pro Long Tube Headers, Stock TI Mufflers, Throttle Body Bypass, Race Radiator with integrated oil cooler.

Vehicle Useage Mainly used for Trackmasters events at Watkins Glen Intl. Raceway, Mosport, VIR.... Driven once in awhile on the street to Corvette Club meetings, joy rides, etc...

Things that I found...

Probably tuned with out a WB02. I say this because look at the PE A/F. Commanded quite rich in my opinion. And why does it go leaner with the increase in RPMs. Don't you want to go richer?

Different opinions on this. Lately I have just been using one Commanded AFR (easier to tune). There are a lot of PE Tables that go 'leaner' at higher RPM's as cylinder pressure decreases. Perhaps best verified by dyno.

The MAF calibration is very close to mine, and I don't have long tubes. I bet it needs a further adjustment. I guess I would need to log the LTFT's and see whats going on.

Good read on that. It could be close, but need a log. I believe the VE Table is stock.

High octane table was copied and pasted to low octane table. I guess this is OK because of how rich it's tuned? I think I would prefer the protection in case I got bad gas. Notice the few cells that jump 4 degrees? Hmm, shouldn't the map be gradual?

See, I am not sure if the ZO6's really need that much spark. It is a 'common' Spark Table in that spark drops near Peak Torque. I always keep my Low-Spark 4-6 degrees lower. Why not..like you said, better to have some protection if KR occurs.

AIR settings are stock, why not lower the RPM limit?

Yea, a lot of people do not mess with it until you start camming. There is room for improvement.

Fan settings seem quite low for a factory thermostat.

Yes. Unless there is a 160 degree Thermostat, Fans would be blowing all day. Just enough to heat soak the IAT readings..:grin:

This car put down 385hp. I would think with the intake, headers, radiator, and tune 400 is attainable.

Sounds right.

hmm... opinions?

I think this is pretty typical of a tune one would have for the mods. I always wonder how they determine the MAF Calibration though. Just guess? Who actually logs them with a normal dyno tune and adjusts the MAF accordingly. I would always want to start 'polishing' the VE Table. Especially with the MAF adjustments. Would make the transitional fueling better and contribute to an overall smoother ride.

So, are you actually in the tuning business? (if that is not too personal).

[n8dogg]

I think this is pretty typical of a tune one would have for the mods. I always wonder how they determine the MAF Calibration though. Just guess? Who actually logs them with a normal dyno tune and adjusts the MAF accordingly. I would always want to start 'polishing' the VE Table. Especially with the MAF adjustments. Would make the transitional fueling better and contribute to an overall smoother ride.

So, are you actually in the tuning business? (if that is not too personal).

Hey Shawn,
Not too personal at all. You have been a tremendous help in my education in Tuning, I consider you a friend. I am the (only) technician for an established used Corvette dealer in Western NY. We're a small business, just 5 full time employees. We sell only clean low mileage Corvettes, no auctions, no junk. My job is the service end. I am the only mechanic, if I'm not wrenching away I am either on the phone with a customer, typing up customer bills, or calling around for parts. My position is very difficult this time of year due to the volume of customer work. At my age its quite extraordinary and I am not ashamed to be proud of where I am.

So as far as your question goes, I have not implemented tuning into the shop....yet. I have a lot to learn, when I first signed on this board I had very little knowledge in tuning, other than what I have read in books and learned about EFI in Schooling. For now I am playing around with my Z06 tune. I have gathered enough knowledge to be able to adjust for a more free flowing engine, as well as do some timing advancement and fuel adjustments (while being safe). I really can't wait to start using my wide-band.

Actually, the customer who's tune I posted would like me to tune his car with a Wide-band. So I may just play around with his. I will surely be posting some more questions as I go along. The most confusing part for me right now is creating maps. I haven't attempted to do so yet, nor read up too much about it.



Alright, so as far as this tune I posted, how does his current fan setting create the risk of IAT heat soaking?

[WeathermanShawn]

Thanks for the compliment and friendship. I will always take another friend!

On the Fan/IAT Heat Soak. Not to long ago I did a test where I set FAN 1 to engage at 220F (and one where I set it lower, and one higher). My theory was that engaging the Fan drives up the IAT disproportionately. I.E., the higher you set your Fan Temp engage, the less likely you are to drive up your IAT. I consider IAT to be the real enemy of performance.

I still need to sift through a lot of data, but here are my preliminary conclusions. Having your Fans kick on too soon, does nothing but drive up your IAT to crazy temps. I prefer to let the ECT climb to ~208-212, then engage the Fans. Try it sometime and if you are really motivated look at the 'Charge Temperature' Formula and see how much IAT contributes to airmass and fueling.

Well, anyhow here are a couple of screen-shots. Same ECT, but IAT just keeps climbing.

Bottom line, for my Thermostat I keep my Fan engage temperatures about stock - 10F.

EDIT: This is a preliminary study. I picked 3 Fan Engage Temps (at Idle). The only time my IAT soared was when the Fan engaged. Not engaging the fan kept the IAT near ambient for the longest period of time..

[n8dogg]

Thanks for the compliment and friendship. I will always take another friend!

On the Fan/IAT Heat Soak. Not to long ago I did a test where I set FAN 1 to engage at 220F (and one where I set it lower, and one higher). My theory was that engaging the Fan drives up the IAT disproportionately. I.E., the higher you set your Fan Temp engage, the less likely you are to drive up your IAT. I consider IAT to be the real enemy of performance.

I still need to sift through a lot of data, but here are my preliminary conclusions. Having your Fans kick on too soon, does nothing but drive up your IAT to crazy temps. I prefer to let the ECT climb to ~208-212, then engage the Fans. Try it sometime and if you are really motivated look at the 'Charge Temperature' Formula and see how much IAT contributes to airmass and fueling.

Well, anyhow here are a couple of screen-shots. Same ECT, but IAT just keeps climbing.

Bottom line, for my Thermostat I keep my Fan engage temperatures about stock - 10F.

EDIT: This is a preliminary study. I picked 3 Fan Engage Temps (at Idle). The only time my IAT soared was when the Fan engaged. Not engaging the fan kept the IAT near ambient for the longest period of time..

You know what, I noticed my IAT was rising after I came to a stop and checked my log today. Now that I think about it, I am pretty sure my fans were on. Once they clicked off the IAT came down to a normal temp. Right now I have Fan 1 on at 200 and off at 196, and Fan 2 on at 205 and off at 206. The ECT stays right at 194-196, but my IAT did get up to 116 at one point. Granted it was a 90 degree day today I still think that's a little high from just hot engine temps.

I need to drive this car and log, I swear my car with just intake and mufflers and my own tune pulls much harder than his even though he has long tubes and cooling mods.

[WeathermanShawn]

Here is another way of looking at it...

A Stock 2002 ZO6 does not start pulling Spark until its ECT gets to 230F. But, it will start pulling Spark as soon as its IAT gets to 95F. Pulls a whole lot more spark with IAT climbing than ECT. So, it is inferring the dominant role that IAT has in engine performance vs ECT.

So, perhaps better to have a 225F ECT and 90F than a 200F ECT and 115F..Something to ponder.

Yea, your car is fast. Whenever I scan logs I always look at how many MPH is gained in 1 second. Your car really accelerates. An interesting PID if your OS has it, is under Performance..CALC.Power. It is essentially your 'Net HP'. Might be interesting to see what yours comes out too. You have to make sure your vehicle weight is entered properly. You don't have any KR issues, which may explain a lot.

Well, good luck in your endeavors. I am in it just for the hobby, but I like to think things out..sometimes to excess..:).

Later..

..Shawn..

[n8dogg]

Wow, so I was probably seeing a good 4deg retard in timing at my highest IAT, and a retard of at least 1 deg the whole log. Hmm... Although my fans come and off quickly, and from what I can tell don't seem to come on when I am driving. I will have to play around a bit and see. Here is my latest log... I've never been able to chirp 3rd, and I can do it with ease with sticky Nitto Invos. I am still not happy with my MAF Freq. When I do a log with my customers car it should be interesting to compare. :cheers:

Edit: Make that at least 6deg in retard due to the 130 deg IAT! Wow! Yet she still pulled hard... hmm

[WeathermanShawn]

Yea, its pulling real good.

Your Trims look perfect. I should mention there are a host of Spark IAT/RPM Modifiers that add some complexity to that Table I posted. But, you get the idea.

It is weird (but understandable) about your MAF Frequency and oscillations. I see you CYLAIR Airflow 'jumping' around at WOT, but luckily it never effects your spark load values.

We will really know when we see how the wideband shows if your AFR is constant. Perhaps it will be no big deal.

Later..

[The Alchemist]

""customer came in today concerned about knocking from his engine and oil consumption. Said it had been "chipped" by the previous owner and wanted me to check it out. He was refered to me by the local Holden Dealer.

The ECU wasn't locked, obviously, and the tune in it just blew me away!!!.
Have a look and do a comparo with a standard tune.

Check the skill in the spark map lock timing to 25deg the whack it back to 20deg flat to rev limiter...may as well have a distributor!!!

The "minimum spark" set to 18 deg even at 1000rpm!!!! no wonder it knocked when you nailed it. Also even if it detects knock, which it was, the knock spark retard amounts have all been reduced etc etc I'm sure you can work it out.
The only half decent thing was the VE table....at least some work had gone into that.
I did a quick compression test with the scope and 3 cylinders are down so its coming back for a leak down test next week .....
Mike ""

Hi N8dogg,
heres a quote from a post I made in the tuners lounge months ago.....such tunes, unfortunately, are commonplace. I have many examples of professional tunes like this one pulled from customers cars, that were not worth a cent and in my opinion have lead to substantial engine damage.... sad but true I'm afraid :(

[Gordy M]

Just for learning purposes and curiosity I pulled the tune out of one of my customers cars. The tune was performed by a reputable GM Tuning shop. Take a look at it!

Car Info: 2004 Corvette Z06, 12,000 miles.

Engine Mods: Halltech Intake, LG Motorsports Pro Long Tube Headers, Stock TI Mufflers, Throttle Body Bypass, Race Radiator with integrated oil cooler.

Vehicle Useage Mainly used for Trackmasters events at Watkins Glen Intl. Raceway, Mosport, VIR.... Driven once in awhile on the street to Corvette Club meetings, joy rides, etc...



I have a 2000 LS1 Corvette that I use mainly for tracks and autocrossing. I have set similar fan settings because of the car use. When running HPDE and time trials, I am more concerned about oil temperature (about 260-280F) than IAT, but my logs show the IAT is pretty constant 20-25 deg over ambiant when on the track but the lower fan settings cools the oil faster when running your cool down laps and cooling the car in the pits. If the Corvette was mainly street driven, then I would agree it is too on too low for the motor. The stock Corvette thermostat is set for about 185F deg and the normal running down the highway is 196 deg. but driving around town it is different.

[WeathermanShawn]

All good points Gordy..

My main point of testing was to challenge the near-obsession of street driven vehicles who endlessly 'chase' lower ECT temperatures in lieu of IAT. My main goal is to attempt to get IAT as close to ambient temperature as possible.

It becomes even more of an interesting challenge as Denver's Boiling point (water) is ~200F, and up in the mountains it drops to ~ 190F. So the combination of ECT/IAT is just somewhat of a natural hobby to observe and try to fully understand.

As a side note, I also have the SLP Manual Fan Switch. That comes in real handy. I am not sure if it allows for the FAN 1 and Fan 2 IAC Correction (B4301, B4302) that EFILive software allows, but it is nice to have.

I take it you can monitor oil temperatures? That sounds like a nice feature.

Thanks for the input.