Plugs didn't help. It looks more like its random than anything

 

Still having the issue. It looks like the timing is steady and then will drop about 5 degrees even with steady throttle. Any ideas?

 

Been mentioned, but check plug wires closely. I had similar problem under hard acceleration missing and found plug wire was contacting header and burnt through rear one. Hard to see unless you closely inspect them.

 

Ok just got my Z06 back from the tuner, and he did remove 3 TR6 plugs from #2,#3,#8 cylinders.. "NEW Tr6 pulg came up bad" he changed them out and problem went a way..He did ohm meter the wires and all new plugs and all came up good now, so im out of the woods for now.

 

Finished mine up late last night. We switched to a speed density tune and used a 2-bar MAP sensor that ECS sent us. They also sent us a tune to try with the new MAP sensor and it was pretty much spot on. ECS helped me and stayed with me to make sure that everything worked out. A big thanks to East Coast Supercharging and G.R.E.A.D Tuning out of Corydon IN.
From what I understand, the LS7 MAF sensor is too sensitive with the added FI and needs to be out of the equation while tuning the car.

 

Sounds like my problem with the maf... There are pros & cons going with a SD tune from what I was told.

 

What's the cons besides maybe getting slightly worse mpg?

 

I was going to say that it sounded tune-related to me. I'm going to have to disagree about the MAF, though. I have the same one on my LS3, and we had no problem doing a standard tune using the MAF. I think the key is having someone who is experienced with tuning this style of engine. Mine was done by someone who I consider one of the best in the business, though.

We did Speed Density on my LS1 a few years back, but that was almost a requirement due to the limitation of the MAF on those engines. The new card-style sensors have a much higher limit and SD is really no longer needed.

 

From what I understand is that the SD tune will not compensate for fuel and timing during changes in the weather so for example: if you do a SD tune during the winter time, the tune will be set for those conditions. Once it's hot summer time, the tune will have to be looked at again for the differences..

Correct me if I'm wrong.

Maf tunes will compensate for all changes.

 

ECS said the MAF on the LS7 is too sensitive for FI and we had to go with a speed density tune. We tried stock tune from the car and changed to compensate for the fuel injectors and also tried a tune that ECS sent that wasn't SD and both came up with the same thing, timing drop very fast for no reason and a stumble that sounded like a miss. After only changing the car to a SD tune, it went away.

 

That is one of my concerns with going SD but I don't have a choice.

 

...or go with a different MAF that is more forgiving to turbulence such as the Lingenfelter 100mm or abaco.

 

Glad I could help you out, congrats on the nice numbers.


When properly tuned, I have not seen any downside personally.

Although when supercharged I'm not as focused on fuel economy, but our cars that are SD get good mileage from what has been reported back to me.

Incorrect Jeff, an SD tune can, and in our case, still is ran in closed loop. The car will absolutely compensate for weather/altitude ect.


Another possibility, but persoanlly I feel we get the C6Z's to run as if it came from the factory in SD (as many cars have in the past) that there's no need for it.

Most of the people who are against SD tuning are HP tuner users who do not have the same easy capabilities to tune the VE table, so they have to MAF tune the car. I prefer a closed loop (auto correcting) SD tune for supercharged cars because a MAF can easily be covered with dirt or an oil film that collects dust etc, which will cause the car to fail lean. An SD tune IMO is more of a performance oriented tune, and a performance oriented build should be tuned that way. There are zero negatives to the performance and general drivability of the vehicle, and most owners do not even realise they have been tuned in speed density after leaving here, all they need to know is that the car is performing correctly and safely.

 

I use HP tuners and it is very easy to SD tune the car with their custom OS. I have a 2.5 bar setup with a full VE table that is scaleable. I agree with Doug that an SD tuned car can run just as well as a MAF tuned car if not better. You can run OL and CL.

From what I am reading... I had the same problem with my green car. I changed the plugs, wires, coils and pulled my hair out for weeks. I then was told to bring in my spark plug gap and my miss fires went away.

Try gapping your plugs at .030 instead of .035. You might lose a little power, but it may fix your issue.

Thanks,

Adam

 

I agree with this in principle but what happens when you to modify your build, experience significant changes in outside temperatures, or changes in altitude. Would not a Maf be more forgiving especially when you can tweak with hptuners.

 

I agree. I've been running mine in SD open loop from 35 degree weather to the 80ish we've had lately for the past 6 months. I log almost every drive and it hasn't really changed that much fwiw. I'll probably leave it in SD mode and just enable closed loop once 100+ F summer hits. I plan on ditching the MAF completely when I get it 'charged.

I am tuning an older ECU which is much easier since it's a VE table instead of equations. I haven't got around to figuring out the VE equation thing.