what could be some things that would cause spark retard? Datalogged my car, and in some spots i was getting 15* of spark retard, and was getting a constant .4 at all times, even idle

 

knock sensor picking up loud noises which sound like knock. Such as LT's. You need to get a tune to desensitize the sensor or get an LT4 knock module.

 

alright, thats what i was thinking. I am going to put in some poly motormounts too because my exhaust hits on my driverside floorboard

anything else that could be causing it?

 

The hitting of the floorpan is problaby a cause, along w/ the general loudness of aftermarket headers. Almost every LT1 will pick up some retard with headers. The best route is probably a tune from MadZ28 costs around $100 but will get you like 10-15rwhp, and will take care of the knock for good. I'm not too sure if the LT4 will get rid of all of it, probably not, but it would lower it to around 6-10??

 

I actually have a local guy doing the tuning, and he is quite good at it, i will tell him that so we can get that all adjusted

 

Constant knock retard can be the result of a faulty knock sensor. Scan it for codes, looking for DTC 43.

Before you jump into desensitizing or eliminating the knock sensor, make sure the knock isn't "real". Consider things like:
-low octane fuel
-running lean
-excessive coolant temp
-excessive inlet air temp
-too much spark advance
-carbon buildup in cylinders increasing compression
-hot spot on heads

 

Header and roller rockers are the big culprit for false knock. 15 degrees is a ton of KR, gotta fix that banging on the floor.

 

anyone have any other ideas? It will only do it in opened loop, not closed loop.

 

So its constant, but only in open loop? Confusing.......

 

well, okay, let me clear that up
i have like .2-.4 at all times, open and closed loop, but it will only sputter when it is warmed up

 

okay, i ordered new motor mounts to try to get rid of the exhaust hitting the floorboard.

Since it only does it when its warmed up, does anyone have any other ideas?