Quote Originally Posted by atlantadan View Post
Engine specs: 383 forged, -5cc flattop, 11.6:1 compression, TrickFlow 195's, new stock Caprice 3" MAF, 40# injectors, LT4 knock module, 1.6 rr's, RAISS cai, longtubes, new opti, new ICM, coil, wires, plugs, ECT, MAP. Running 93 gas, and tuned for 93.

Cam is 224/230 .560/.544 112 LSA

I've been working with a well respected tuner to get this new build sorted and I am still having loads of knock, and very poor fuel consumption. 10-11 in town. Now, I didn't expect this car to be a miser, but I was getting 16 around town with my clapped-out 350, so I expected something a little closer to that....

I'm attaching a TTS Datamaster log taken this morning. From a stone-cold start through town to warm-up, and then a long run on the interstate. At the end of the log, the knock is easy to see at part throttle.

I don't know if this is a 'no no' here, but could someone look at the log and see if there's anything blatantly obvious that myself and the tuner are missing? At this point, I've got hundreds and hundreds of dollars in tuning this car. Two tuners later (the first one was a comedy of errors), and here we are. I'll pay the right person if this can get sorted out.
If your cam and converter are lugging that cam its not going to get good fuel mileage.

I have a 450 hp V8 sedan that is in the same 4,200 lbs range as your Caprice and I get about the same mileage in-town with my lead foot despite the fact the engine is direct injected and very techically advanced.