VZ Tuning - Knocking at low revs stock?... Pacemarker heads/aftermarket gear?

[bigdaddycool]

Got me a 2006 VZ Executive.

Pacemarker headers, 150 cell racing cats, 2 small resonators after the cats, a central muffler and rear reasonator. (two hole mod, K&N etc)

All together work great with my intake manifold spacer from MACE. I own VCM Suite etc.....

Now.... I've found with the torque at 100% and most other parts of the tune Airflow, VE & Optimal Torque as per normal....... my car knocks anywhere from 800-2000rpm 3 to 7.4degree's.

I've been lowering the spark here.... but i'm lowering it below the stock settings... does this sound right?

Would you say despite the torque being 100%..... this could be caused by my pacers/exhaust setup, it doesn't appear I have any vacumme leaks etc.

[delcowizzid]

what sort of fuel ratio do you have at that area you got a wideband or real wideband readouts off the factory wideband sensors

[bigdaddycool]

no wideband..... narrowband guage (more for a mental note as I drive around what to check)..... and vcm scanning logging my spark/knock/stft and ltft's etc.

I have no idea where or how the air to fuel ratio works on a VZ tune.......... there's nowhere really for it. Alot of cars have spots to set the A/F Ratios in the tunes.......... alloytechs dont.

I've been lowering the spark and smoothing out the fuel via the injector mutli etc.

[delcowizzid]

obviously its way lean a narrowband wont show difference in fuel ratio from 11 to 13:1 they are so inaccurate put the standard fuel settings back in fuel tables are never smooth either allways up and down all over the show

[bigdaddycool]

either way I have no idea how the air to fuel ratio setup works on these tunes....... easy to find on v8's and adjust, alloytechs........... no idea. i assume it's to do with the 'desired air load' area.