08 Silverado Truck Norris cam

[That_guy]

I personally set the misfire rpm up around 2800 to 3400 that way if it's got an actual miss, it'll still pick it up, but on extreme cams I've seen even raising the counters quite a bit will still cause random misfire codes which is why I started raising the rpm threshold so it won't look for them below that point.

I set up a misfire config that has every single misfire monitor PID whatever current PCM I'm tuning will offer me. Then I multiply all the misfire tables by 1.5 until I get the computer OK with the cam being there, even at idle.

I know that make take a few more minutes to do but I've seen a lot of dead holes during compression checks on account of a misfire being driven / raced on too much and the driver had no idea it was that bad because the computer couldn't tell them.

[Alvin]

Alvin I know you've been in the game a long time and know your stuff but I'm going to have to respectfully disagree with you here. Disabling the PCM's ability to see a real misfire is never a good thing. I've seen a lot of blown up engines that didn't have to be because tuners turned off misfires and the driver had no way of knowing their engine was breaking up because of a real problem. It's all about numbing down the tables enough so they'll ignore the cam, but still alert the driver in case a real misfire is occurring. The P0300 needs to stay at 2nd mil, and the tables need to be multiplied until they're a touch over ignoring the cam on the scanner. I've tuned cams with 30+ degrees of overlap this way that still had active misfire monitors and no issues at all with false P0300's.

It's ok to disagree..

My thinking is

cars got along just fine in life before misfire counters.

I can't imagine a way a misfire would cause any sort of mechanical damage.

It should be fairly easy to notice a miss and that should alert you before a light would

I've seen plenty of OEM vehicles with a severe or complete miss.. like a wiped camshaft and still not throw a misfire light. I mean honestly so many wiped out camshafts with zero misfires reported.

Lastly.. I do far too many cars to have them come back because one bumped a misfire timer with a cam.

XXXXXX

But the method you describe sounds useful. I'm always open to other ideas.

[GHuggins]

A lot of people probably aren't aware but the OE raised the misfire counters on a lot of setups to where they wouldn't show misfires unless it was a dead miss - another reason why I started changing the rpm setting cause you never know what you're really working on.

If you have a vehicle that had this update it basically won't report misfires at all at idle through 11 or 1200 rpms and then has to have a constant miss for 12000 counts before it will turn the light on. Granted you have to have one of the updated cals and even certain vehicle platforms such as colorado's and traverse's and some of the newer silverado's. Basically anything that has a "recall involving a reflash" for a mechanical issue has probably had something like this done to it to help get them out of warranty... Not uncommon for GM to do things like this and since they never get caught or anything said to them - well, they'll just keep on doing it. Just like all the diesel's that were getting in trouble - GM was doing it much worse all though a recall where they killed the emissions DTC's themselves then they conveniently came out with a "possible fuel economy issue" reflash that turned them back on when trucks were getting to or out of warranty. Traverses with all their timing chain issues - flash update to reset the "0" position every time power is pulled - no longer kept it in memory - lets them stretch till they have serious issues before turning on any lights.

Agreed raising the counter is usually better, but I wouldn't necessarily raise all of them that much (maybe leave the higher rpm stuff lower) as you never know what the OE has done in the background of a cal. I have seen misses overly stress other cylinders in race applications, but usually knock sensors and everything has to be killed to cause damage and even more so it's usually timing and fueling related right from the getgo that caused the original miss. I just don't like raising everything 2 or 300 percent - focus that more to idle and pre3000 rpm's.

Don't know which is truly best - I do it both ways and kill it 100% if that's what the customer wants or detune if that's what they want.

[Claimingthe808]

Hey how's your tune going on this? Do you have a tune file that was working good with the original truck intake? Or your most current. Having trouble in my own setup

[blackbeauty435]

Hey how's your tune going on this? Do you have a tune file that was working good with the original truck intake? Or your most current. Having trouble in my own setup

I took the new intake off and put the stock one back on
Still running rich. I?ve given up on trying to figure it on my own. I?ve been working way too much to be able to get to the tune. I know it?s running rich but being new to tuning I still don?t know what to change exactly to get it right.
I figure when I get time I?ll take it to a tuner and try to get it right.

[Claimingthe808]

I took the new intake off and put the stock one back on
Still running rich. I?ve given up on trying to figure it on my own. I?ve been working way too much to be able to get to the tune. I know it?s running rich but being new to tuning I still don?t know what to change exactly to get it right.
I figure when I get time I?ll take it to a tuner and try to get it right.

Besides running rich how is it? Does it stop go drive pretty normal?

[blackbeauty435]

Besides running rich how is it? Does it stop go drive pretty normal?

Yes

[Cory21c]

Give this a try. You will still need to dial in your fueling but it should be much better.

Cheers.

[blackbeauty435]

Have someone helping me get the tune finished.
Been working on the VVE. No matter what we do it still pulling fuel on bottom end.
I?ve checked for vacuum leaks. Replaced MAP sensor. Replaced accelerator pedal as it was throwing P2138 code randomly.
I?ve done multiple logs and taken those numbers and copied and pasted into the editor and multiplied by % half but it still shows anywhere from -10- -19 under 1000 rpm.
Am I missing something here?
I can post a latest log later today, I?m currently at work.

[JakeSullivan]

Hey there, folks! I've been lurking around this thread for a bit, and I've got to say, the enthusiasm about the 08 Silverado Truck Norris cam is real! Personally, I'm a big fan of those cam swaps – they can really bring a whole new life to your ride. As for tuning, I've had some experience messing around with different setups, and yeah, it can be a bit of a trial-and-error game sometimes. By the way, quick side note – anyone ever considered looking into Lift Truck hire for those heavy lifting jobs? Just a thought, especially if you're wrenching on your trucks and need to move some serious weight around.