How bad is this?
09-17-2012, 09:49 PM
#1
How bad is this? The car in question is a 1994 Z28 with a built 383 Stroker in it. It now has just short of 3 K on it.
I was just going over the previous owner's posts here and on other sites and I came to a conclusion. The owner had a PCMforLess tune put on the car after he put longtubes, a LPE supertube, and a full exhaust on it. (stock motor) I was lead to beleive that the PCM was sent back to PCMforLEss when he put the 383 Stroker in it. Turns out that is wrong.
He apparently didnt get a re-tune. The engine was just rebuilt this last winter after I snapped a crappy eagle cast crank..... and I assumed the tune was good for a while. I haven't beat on it much at all, mostly driving around town.
The motor is a 383 Stroker, 10.5:1 compression, GM847 cam, ported intake and heads, stick sized valves, 1.6RR and higher rate springs. 1 piece stock length pushrods.
Before the rebuild (no main engine specs were changed) I have a dyno sheet that shows it made 380 at the wheels through the auto trans and the A/F was decent all the way through the RPM range. I asked the previous owner, and he admitted that the tune wasnt changed after the 383 was put in, just checked.
I wonder how much power is still on the board? Its going to a proper dyno tuner in a couple weeks, just wondering what to expect. The car dives great right now, no hiccups, just a SEL for a rich condition if I cruise for too long on the interstate.
Thoughts?
I was just going over the previous owner's posts here and on other sites and I came to a conclusion. The owner had a PCMforLess tune put on the car after he put longtubes, a LPE supertube, and a full exhaust on it. (stock motor) I was lead to beleive that the PCM was sent back to PCMforLEss when he put the 383 Stroker in it. Turns out that is wrong.
He apparently didnt get a re-tune. The engine was just rebuilt this last winter after I snapped a crappy eagle cast crank..... and I assumed the tune was good for a while. I haven't beat on it much at all, mostly driving around town.
The motor is a 383 Stroker, 10.5:1 compression, GM847 cam, ported intake and heads, stick sized valves, 1.6RR and higher rate springs. 1 piece stock length pushrods.
Before the rebuild (no main engine specs were changed) I have a dyno sheet that shows it made 380 at the wheels through the auto trans and the A/F was decent all the way through the RPM range. I asked the previous owner, and he admitted that the tune wasnt changed after the 383 was put in, just checked.
I wonder how much power is still on the board? Its going to a proper dyno tuner in a couple weeks, just wondering what to expect. The car dives great right now, no hiccups, just a SEL for a rich condition if I cruise for too long on the interstate.
Thoughts?
09-19-2012, 04:29 AM
#4
Crank is now an Eagle 4340 forged, worked over by a well known builder. Also 4340 H-beam rods and Mahle forged pistons. I know a bump in compression would have made me more power, but that's what the bottle is for 
All the clearances are set up for nitrous, but that won't go on until next year sometime.
I always thought there was a lot more to tuning than a decent A/F curve...... LOL Am I wrong? There's got to be a decent amount of power in there still, as I'm sure the timing events haven't been messed with, and a lot of things were changed.
All the clearances are set up for nitrous, but that won't go on until next year sometime.
I always thought there was a lot more to tuning than a decent A/F curve...... LOL Am I wrong? There's got to be a decent amount of power in there still, as I'm sure the timing events haven't been messed with, and a lot of things were changed.
