Need Help reducing Knock Retard

[beav626]

2008 Corvette LS3 Auto 6 speed

Car only has a Cam 225/230 113 LSA new springs and rods.

Factory NPP Exhaust w/ Factory X Pipe

Got a Mail order tune that wasnt to par so my friend and I began to work on everythihg.

Car is still running very rich at WOT low to mid 11's AFR

in Open Loop it is rich under 2k RPM too.

On my scanner I see a lot of knock retard

so my friend and I tried to lean her out and couldnt...
we adjusted the MAF table and VE table and it didnt make a difference.

How do I lean the car out so I can get my 12.5 AFR at WOT.

Thanks

[IDRIVEAG8GT]

Try my attached thumbnails.

[IDRIVEAG8GT]

Timing is a different story, that could be BKR or anything else. Is the knock audible?

[beav626]

Timing is a different story, that could be BKR or anything else. Is the knock audible?

What is BKR? The knock is not audible but im sure that and the timing have something to do with me running rich.

[IDRIVEAG8GT]

Burst Knock Retard. It's a prediction coefficient concerning where timing should be pulled.

[Ls1c5vette]

2008 Corvette LS3 Auto 6 speed

Car only has a Cam 225/230 113 LSA new springs and rods.

Factory NPP Exhaust w/ Factory X Pipe

Got a Mail order tune that wasnt to par so my friend and I began to work on everythihg.

Car is still running very rich at WOT low to mid 11's AFR

in Open Loop it is rich under 2k RPM too.

On my scanner I see a lot of knock retard

so my friend and I tried to lean her out and couldnt...
we adjusted the MAF table and PE table and it didnt make a difference. How do I lean the car out so I can get my 12.5 AFR at WOT. Knock is not something we need to wrry about right now untill the fueling is right, I only saw 1 deg of retard on our WOT run. Also I am using a LM2 calibrated wodeband.





Correction^^, I could not figure out how to alter his VE table, it was all zero'ed out, he is on MAF only right now, lowering the PE table did nothing and lower the MAF table did nothing so I am stumped on how to make his WOT afr leaner, I am used to the Gen III tuning (my car) but the gen IV's have about 1.5 times as many tables. His OL afr from idle to 2k is in the low 13's, car fully warmed up.

[IDRIVEAG8GT]

2008 Corvette LS3 Auto 6 speed

Car only has a Cam 225/230 113 LSA new springs and rods.

Factory NPP Exhaust w/ Factory X Pipe

Got a Mail order tune that wasnt to par so my friend and I began to work on everythihg.

Car is still running very rich at WOT low to mid 11's AFR

in Open Loop it is rich under 2k RPM too.

On my scanner I see a lot of knock retard

so my friend and I tried to lean her out and couldnt...
we adjusted the MAF table and PE table and it didnt make a difference. How do I lean the car out so I can get my 12.5 AFR at WOT. Knock is not something we need to wrry about right now untill the fueling is right, I only saw 1 deg of retard on our WOT run. Also I am using a LM2 calibrated wodeband.





Correction^^, I could not figure out how to alter his VE table, it was all zero'ed out, he is on MAF only right now, lowering the PE table did nothing and lower the MAF table did nothing so I am stumped on how to make his WOT afr leaner, I am used to the Gen III tuning (my car) but the gen IV's have about 1.5 times as many tables. His OL afr from idle to 2k is in the low 13's, car fully warmed up.

I figured that you guys didn't go enough. I tried 10% off just for fun. I'm doing some research here on why the changes would take no effect.

In essence you might simply want to try a Write Entire.

[Ls1c5vette]

I thought it was not a good idea to do a write entire? Hope we dont have to do that every time cause its about 5 mins a pop!

[FASSTRUK]

The eq% vs rpm ratio(in fueling,power enrichment) should be set at 1.150 for all rpms(this will give you 12.60 commanded AFR)...then put you MAF setting back to stock. Invest in a wideband to properly watch/adjust your afr using MAF from now on.

[IDRIVEAG8GT]

I thought it was not a good idea to do a write entire? Hope we dont have to do that every time cause its about 5 mins a pop!

i know it sounds totally unethical, but when trying to change AFR on my Silverado, no matter what I did it stayed the same until I did a Write Entire. It was sooo weird, but try it, or do what FASTRUK says.

[Ls1c5vette]

Try my attached thumbnails.

Doing this will force PE 100% of the time will it not? I dont understand why all those tables are zeroed out.

[C5 2000]

http://www.hptuners.com/forum/showth...682#post109682

[Ls1c5vette]

^^Makes sense now, we will try that this weekend. So him being a MAF only tune ALL I need to do is set the PE, and then scale the MAF table accordingly to compensate to rich/lean during WOT, correct??

[Ls1c5vette]

Bump for question above ^

[IDRIVEAG8GT]

^^Makes sense now, we will try that this weekend. So him being a MAF only tune ALL I need to do is set the PE, and then scale the MAF table accordingly to compensate to rich/lean during WOT, correct??

Yes sir. You are correct. Don't give yourself a brain aneurism doing this. Remember you're too rich, not lean. And you aren't rich enough to foul plugs.

You guys are doing good, no worries!

[ontarioss]

On those PCM's you have to do a write entire every time. My tbss was a pain.

[04colyZQ8]

Bump for write entire on E40 PCM is this necessary?