Not happy with dyno tune on supercharged ZL1 - poor drivability - Need Help!

[nighttowl]

To make the long story short, I took my car to have it dyno tuned (ID850 injectors, 11% OD pulley, headers, CAI, Ported TB, upgraded HX) on 91 octane, NGK TRIX - 574 rwhp 536 rwtq), and I'm not happy with the tune. I brought this up with the tuner, and sent a log, but he said it looked OK. The guy said to bring it back if I'm not happy with it, but Its pretty far. He has done an excellent job of tuning my old car in the past, but this one; not so much.

The issue is the drivability is poor. Log shows it is lean, as LT fuel trims are really maxed out at 25% in the lower throttle areas, particularly between 1700-2800 rpm at low throttle under load. I was told this is because of the DFCO.
I can feel the car surging. according to my wideband, it looks like its a little lean for part throttle under load when the surging happens.
If I hold the throttle steady, it actually feels like the car slows down when it gets around 2800 rpm, and from the log I can tell that the mph acceleration slows down through that range in first gear.

There is no knock.
I changed out the spark plugs yesterday to NGK BR7EF (#3346), and the problem worsened.

Can someone take a look at this to see if there is any explanation for this, possibly point me in the direction for a fix?

Thanks.

[5FDP]

Post up logs too, others might have more knowledge to give.

One thing I noticed was that it looks like he more than doubled the knock sensor level (that's if the table is similar to the truck tables I'm used too), a change I don't feel that should be done. I've never had to do it. It might be worth comparing what he did change with a stock file to see his exact changes, and that knock table might just be a reason it never shows knock.

[nighttowl]

I tried to, it will not attach.
I have an additional thread in the "lounge" to find out why I cannot attach an HPL file.
when it gets fixed, I will post up a log.

It does look like the knock thresh holds were raised significantly.
This is most likely why I do not see any knock.

I have attached the stock file.

zl1 2-22-16 3.0 stock.hpt

[jsllc]

I have a ZL1. To better help please make sure you have a complete list of changes. Did you change injectors? Looked at tune. Some things do not look good.

[Auto-Hentzschel]

Your tune need bigger injectors. You don't wrote that in your change list!
also without logfile, its not possible to see any issue.

[GHuggins]

Tune shows considerably larger injectors being installed - what brand and size? Also confused on the knock tables - in one section he has made the knock sensors considerably more sensitive then turned right around and made the knock reference bleed off quickly in the higher rpms and higher engine loads then on top of that made the sensitivity in another section near impossible to start registering? Lots of things didn't make a whole lot of sense on the knock? VE needs to be tuned - lots of timing has been pulled in the lower rpms - bet your fuel economy has dropped hasn't it? There's nearly no need at all to pull a lot of timing like what's been done for just a 10% over crank pulley... Also at this build - really no need to go with different than OE plugs - just tighten the gap on them up to .035"... Plugs alone will help with drive-ability issues... Just some quick observations...

[nighttowl]

I forgot to add that in, they are ID850's.

[jsllc]

So to make sure:

ID850 injectors
11% OD pulley
headers
CAI
Ported TB
upgraded HX

No top pulley change?
No size change on TB like to a 90mm?

Just so we can give you good advice

[nighttowl]

So to make sure:

ID850 injectors
11% OD pulley
headers
CAI
Ported TB
upgraded HX

No top pulley change?
No size change on TB like to a 90mm?

Just so we can give you good advice

only a bottom pulley, no top. no on the larger TB.

Still unable to attach a log.

[jsllc]

On the attach. If you are using IE (the blue E) I have seen issues. If you can try FireFox.

[nighttowl]

Log attached to first post.
I had to cut it in half.

[jsllc]

in looking at the tune:
Idle, startup air was changed and the follower. I have no idea why as it should not need it with your changes
MAF is changed but should be. Not correct if trims are way off.
Car is being forced into MAF only mode.
Virtual VE needs to be adjusted as you changed injectors.
Raised the Rev Limiter
Changed the O2 sensor operation (may be cause if some trim issues)
Changed Power enrichment ( interesting config here)
Removed CAT protection. I assume you have CATs
Destroyed your timing table ( do not know why )
Changed idle timing
Changed all of the adaptive idle adjustments ( was there an issue with the car in idle )
Changed knock sensors and how knock is managed
Change TQ management.

Yep it was all hit. Do not know the logic behind some of the changes.

[jsllc]

Log attached to first post.
I had to cut it in half.

So if your widebands are correct you are getting down to 10.5 while commanding 11.8

[GHuggins]

Your fueling is adding anywhere from 7 to 30some percent at all times - this is what's throwing off your wot fueling... I saw at times it adding 32 percent while increasing in rpms - that's definitely not dfco... Has something happened to it since it was tuned - it's almost like it was tuned in with "rich after flash" not being taken into consideration - your tuner has been tuning for awhile hasn't he? Was it running OK when you picked it up? Possibly had a vacuum cap or something blow off? Just thinking of possibilities for the extremely large amount of fuel being added now... Was the exhaust valve bypassed and not capped - resulting in a vacuum leak at the rear of the car below 3000rpms?

[nighttowl]

The guy who tuned it has been tuning for about a long time.
I haven't made any changes since tuned.
I will check for bad line connections at the muffler valves (lol - muffler valves), I haven't checked there yet.

[nighttowl]

front O2s weren't very tight.
I found no leaks.

I noticed drivability issues later in the day after it was tuned.

[schpenxel]

Wow, those fuel trims look horrible. WB readings aren't much better.

It's going quite a bit richer than commanded. 10.5 or so when commanding 11.8:1

Some areas go as log as nearly 10:1. If I remember correctly PLX's widebands bottom out at 10:1, so its possible it's even richer than that...

This has nothing to do with DFCO. If the tuner told you that then he's just giving excuses

I wonder if Greg is right and they didn't account for the whole "rich after flash" thing or something? I'm not sure..

[nighttowl]

Possibly, I was there when it was tuned, but mostly just standing around twiddling my thumbs.
Supposedly there is a fix in the works for rich after flash, but my OS was not covered yet.

[GHuggins]

The rich after flash still won't fix your problem - it will just make things easier when you do go to fixing it yourself... That way you won't have to wait or worry about it effecting your tune adversely...

[schpenxel]

Not so much a fix as a "now you don't have to wait so long between flashes before data is usable.."

What you're getting right now is the same as you'll get after changing the new table you'll eventually have access to. It will just get there right after startup vs. 10-15 minutes of driving around.