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If the ECM can compensate for a Hot Cam and 1.6:1 rockers that were in the kit without a tune, I would say no, you don't need to do anything. It should handle the slight performance improvement just fine. Even if it has a Hot Cam in it by chance, the ECM will handle it.
Did you remember to re-calibrate for your rear end differential ratio ? OR do you by chance have gotten lucky and have a 3.07 rear gear ? Your speedometer and shift points (maybe, I would need to go back and look again) and any other setting controlled by speed instead of RPM would be off.
G44 - Rear axle 3.07 ratio
G92 - Rear axle performance ratio
are the 2 RPO codes that indicate 3.07
Under the Tools tab is a Speed Calibration selection that will allow you to recalculate what is needed.
That was one thing that we really didn't finalize when I changed the VIN and sent you the stock file to reload.
YES there are MPH transmission related tables. I just went and looked. If you do not have the 3.07 rear diff ratio, you will have to reprogram for that.
As a matter of fact I did, thank you. It seems like they had already reprogrammed the fans, which explains why I was on high alert when they would kick on differently, when I first got it. I pretty much got the cooling fans figured out. I'm guessing it's the "fan threshold on" option. I'm going to adjust it accordingly, then install a 180 thermostat. Any tips on adjusting fan Temp? So could I really install an LT4 hot cam and not have to reprogram it? I know heads are basically bolt-ons. But a cam???? It is a mild cam imo... so it makes sense. I just got my CATS. I'm going to pull the data from the obd1 pcm. Maybe it'll help someone in the future. And reprogram the obd1. There's a '94 TA in town that I have my eyes on. It's been parked for some time now, And I'm sure it has an obd1. Well, I finally got to lay my doubts about the tranny to rest. I figured it was a bad tune. What I did notice is that the vette seems to run much more mellower and smoother.
yes a bolt on, but if not stock and flow better will require a reprogram.
use this for a Google search
does a lt4 hot cam package require a tune
and do some reading. the ECM will handle it, but a tune would get the most out of it. you could purchase a mail order tune from PCM4LESS out of Stow Ohio
now that you have it back working again and get the most out of it,
why do you ask about 1.6:1 rockers ? does it already have those, or are you going to do that ? if it already has those, that is why I speculated that maybe the previous owner also put in the Hot Cam.
The PO put them on, but no cam. When I first spoke with the original tuner (and after the PO claimed that a scanner caused the issue). He claimed the issue with the tranny was tune related, but wouldn't explain how or why. He also explained that he only added the rockers and tuned it, but upon inspection. There's new gasket maker around the intake manifold, which raises a few flags (porting maybe). But anyhow, when I turned it on after returning it to it's factory settings, I noticed a difference on the smell of the exhaust. No bad, but different. Maybe not as rich??? Who knows, I drove and idled it for an hour and a half with no issues. Which is why I asked about the rockers. Any good books that you might recommend? Thanks!
Originally Posted by drcook
yes a bolt on, but if not stock and flow better will require a reprogram.
use this for a Google search
does a lt4 hot cam package require a tune
and do some reading. the ECM will handle it, but a tune would get the most out of it. you could purchase a mail order tune from PCM4LESS out of Stow Ohio
now that you have it back working again and get the most out of it,
why do you ask about 1.6:1 rockers ? does it already have those, or are you going to do that ? if it already has those, that is why I speculated that maybe the previous owner also put in the Hot Cam.
I really like this one. It has lots of useful information in it and helps you to understand the LT1. I have this one myself. I have read it front to back and back to front. Then what you can find on the forum, you should be able to deal with the engine.
