Hi. I have a 2018 C7 Z06. It has tubular exhaust headers and Xpipe. It does not have any catalytic converter. It also has a replacement air filter. KN.
The electronics are stock.. except for the V4 V8 disconnect, some fan adjustment, catalytic converter protection, and the faults related to the catalytic converters have been eliminated.
Can any wise person check my LOG to see if everything is correct or if there is something wrong with the exhaust and I need adjustments?
It does 60 to 130 mph in 7.55. According to Dragy
I'm sure that with a good adjustment it would be faster.

I attached 2 tests.
a 60 to 130
and a slightly more extensive test

 

Looks like you need some VVE work and some MAF work just to get started. Likely fuel enrichment for WOT needs work as well.

Are you sure the tune is otherwise stock? Normally things lean out slightly after your mods but yours is all over the map and generally waaaaaay rich although you do have a couple crazy lean areas as well.

 

I would say it is original.
Unless the previous owner modified something.
I am attaching the "original" and the one I have modified as I said before..
Let's see what you think.
I heard somewhere that some original versions were very rich. They even made explosions in the exhaust when decelerating when it is hot. "I have good explosions, very nice haha"
This was corrected with a SW update.
Maybe it is my case... or not..

 

VVE, MAF, and VTT are all stock. Looks like someone messed with the E85 tables. CAGS is tuned out in your original file, and a few other things.

While I do agree that the factory runs a little rich.....your log is showing corrections of more than 20% in some areas. Makes me think you have an upstream exhaust leak that's fooling the o2 sensors.

Having said that, many of the experts on the HP Tuner forum say that even if you've turned off all the aft o2 sensor related "stuff"....there are still various checks and test running in the background that you can't see. When the PCM doesn't get the expected response, weird stuff can happen.

 

Thanks. I checked the exhaust manifold gasket to see if it has any leaks.
I would like to know if I have to disable anything else, regarding what you say about other background tests.

 

You can decide if you want to turn back on the rich to lean (and vice versa) diagnostics for the front sensors. P015A thru D codes. I try to leave on as much as possible to take advantage of the diagnostics. You have the tests running, but the MIL turned off.

Otherwise, I don't see anything else to turn off. The background tests aren't accessible to my knowledge. HP Tuners "shows" about 15% of the actual code. There's a whole lot going on that us mere mortals don't see/have access to.

A couple guys on the HP Tuners forum have access to some background stuff (I have no idea how they get that) but none have (or admit to having) access to background emissions control tables that can be changed.

 

Ok. I didn't notice those codes. I didn't disable them. It was probably the previous owner who installed the exhaust system.
I also think that it's better to leave those 4 codes active.
Will I get a lot more HP compared to now if I do the tune?

How can you see that it's very rich? What value are you looking at? If I don't have wideband installed?

 

The only way you're getting "a lot more power" is to get it on a dyno so you have a controlled environment and can tune wide open throttle. Your EQ ratio....ie power enrichment (PE) stuff....is all stock. As such, there's certainly power to be gained there.

Base spark table is stock except for one small corner of the table. Someone screwed around with the min spark tables as well as some of the other spark multipliers. The changes are so seemingly ad hoc in some cases I'm not sure what they were trying to do. Given all the changes in the E85 table, it makes me think a prior owner was running E85 and then removed it prior to the sale.

The mods to the car are minor enough that you could just have it tuned for WOT. I'd guess you'll pick up 30-40hp with a reasonable tune. Unlike the old days, the factory stuff is pretty good and the software is so integrated in these cars that often times "less is more" when it comes to changing it. Like most mass produced things, you can usually make the data look better but that doesn't necessarily translate into anything you feel or notice.

Tuning Gen 1/2/3 stuff is equivalent to Grade School. Gen IV was High School with some college classes. Gen V is college level with some Masters courses. Now there's Global B in the C8 and other current cars which is PhD level.

As for how I know it's rich....I'm looking at the part throttle data. I'm using filters to get rid of data in spurious fueling cells, cold temps, etc



At the other end of the spectrum, you're showing lean in the upper RPMs. Usually the PCM adds fuel at WOT for positive fuel trims but I'd have to look more closely to see what's going on before you enter PE mode.



I say all this with one HUGE caveat. Your logs are very short. One is 35 seconds and one is 58 seconds in length. Really need longer logs to truly assess part throttle but again....there are so few mods that just having someone tune WOT is probably fine and you'd pick up noticeable improvement.

 

very difficult haha.
is it possible that some SW are like this?
I mean the small corner of the spark table.
the minimum spark. and the deleted flex fuel table..
I say this because I also saw it strange. and I asked a friend who has a 2016 Z06 for his original file, to compare.
and like mine, it has the flex fuel table deleted and the base spark table is identical.
There may be some differences depending on the SW..
I have seen other times some strange changes, from one SW to another..

I would like to adjust it well in WOT. for me that would be enough.
Is there a way to do it myself? I live in Spain and here nobody knows how to do it on this model..

I attach the original from my friend.

 

I got another stock from 2018 at HP Tuner..
For comparison and it is also the same as mine except for the minimum spark.

add

 

Tunes can be different between years and even within a given year.

If you're going to tune WOT, you need a wide-band o2 sensor or you need to rent dyno time so you can use their sensor.

 

​​​​​​​ok, i think a nearby shop has a dyno and o2 sensor
Can i do it myself? is it a difficult task?
or will i have to ask someone for help?

 

unless you’ve tuned a Gen V before, I’d recommend you ask for help

 

No, I haven't done it. Who can trust me and do it online?

 

You should ask on the HP Tuners forum. There are several guys over there that remote tune.

I'm not sure of how much they charge or if they'll tune a car in Europe. Since tuning is their business and therefore livelihood, they may have concerns about laws, taxes, etc.

 

I'll talk to Ben Charles and see if he's interested.

 

Greg Huggins is another really good one