2009 5.3 LY5 performance question
 

Hello all,

I am new to the forum but I had a question about my Silveraaado.
This may be a difficult question to answer based on I have not the tools required to log data.
Long story short, there may be few enough AFM cams that someone can give an educated guess.
I'm trying to figure out what cam I have. 4L60 tranny, recently installed new ring and pinion also.
Old gears where 3.73s which where great if you wanted to do 150 on the interstate. I settled for4.56s.
So far this 7000 pound extended cab is skeetin on F250 diesels from around 2010 or close, 2015 hemi single cabs and stayed dead even with a 2015 GMC 2500 diesel if not pulled on him slightly. My uncle listened to the idle and said cam for sure. My question is, which one lol

So it still has DoD active?

They do have a lope at idle with stock exhaust, it's just not very loud and more so there on a cold start.

And the truck only weights around 5400-5500lbs, 7,000 is likely the weight of the vehicle plus passengers that it can hold. The curb weight is always lower.

It is still active. GVWR off the door so I was guessing the weight.
The exhaust is stock, minus the muffler, just dumps on the ground past rear axle.
The truck also faults the maf if given WOT. At least that's the code that shows via auto zone. When it goes to speed density is when it comes alive most.

I forgot to mention, 3k to almost 6000 RPM is the cams range. Its easily noticeable. It does have a small lope at idle. Super smooth motor, no lagging or misses. What surprised me was hanging with that GMC diesel last week. I'm ridin Mickey Baja 35s.
I also installed a potentiometer inline with the IAT. Major difference in power when you give it the fuel for a 0 degree day.

Your thinking a stock Silverado gen4 LY5, extended cab on 35s and 4L60 tranny will hang with a 2015 GMC diesel?
Nah lol

Why wouldn't it?? 35's aren't that huge of an increase in tire, and a stock diesel pickup (yes, even the new ones) are not "fast". Your truck isin the low 5k lb. range, with around 300hp?? A stock 2015 duramax should be between 6500-6700lbs, and around 100 more hp.

I don't see why you are thinking it's modded. If the 2008-2010 6.4 powerstrokes are modded, as in dpf and egr deleted with any kind of custom tuning on them, they are low 13 second to high 12 second trucks. Stock...they are mid-high 15 second trucks. Easy to beat stock, and if you were whooping them modified..there wouldbe no question to mods on am extended cab .5.3 truck.

What is your overall question you are asking?

Did you just buy the truck and are trying to figure out if it's modded?

MAF code can be due to a CAI and not having been tuned or tuned properly it throws off the expected airflow through the MAF at certain RPM ranges and can set a MAF code for airflow greater than expected. You have to rescale the MAF

Nah, I've had it about a year. The maf code stays off unless it's WOT. Pretty sluggish too until it does trip because of how lean it runs until then. Also what got me to thinking about it. Once it faults, it runs speed density doesn't care about the maf and adds no less than 30 to 40 HP while turning off AFM.
This truck also pulled another 5.3 silverado of the same body style, twice in 2nd gear alone before he could shift, when I had the 3.73s.
A tune alone would not accomplish this ;)

My question is what AFM cams are popular for swaps between say, the 6.0 that are very agressive starting at 3000 RPM all the way to 6?

Remap the MAF is a good idea. I've tried 3 of them all with the same behavior and none of them providing enough fuel.
It is aftermarket induction setup but no air leaks.
The IAT was the best choice for adding the needed fuel. Altering the MAF signal worked but still didn't add enough fuel and screwed up my shifting.

What has been done to the truck mod and tune wise complete run down.