LOL! All of them were so slow they did realize how slow 🐌 they all were...they just raced each other normally...until a dyno day and a bolt on T/A LS1 blew the doors off of one of those "500hp" cars.

 

I looked at the tune.
Its set up MAF only. Not an issue, they run fine that way. Easier to tune.
Timing table seems normal.
AFR commanded is set to 12:1, but I image right that was done to get the AFR at the tail pipe to what the tuner wanted.
Tourque management is mostly tuned out.
Good catch on brake torque management.

The only way to tell exactly what was rubbed on is if you have the stock tune.

 

Thanks folks, I’m keeping a list of this stuff to share with whoever I find for another tuner.

RonSSNova I don’t know what’s going on with my private messages, it won’t let me send you one either. Wish I knew a way to get in touch. Sounds like you’re a good local resource.

What are y’all’s opinions on adding Tri-Y headers? Typically they are helpful for lowend torque. As I’ve said, I don’t want long tubes (noise, install hassle, smog problems) but maybe Tri-Y (like Thorleys) would help this cam on the exhaust duration, and help wake up the low RPM torque…thoughts?

 

I know it's not what you want to hear but short of boost the 4.8 is a turd of an engine down low. I've had three trucks with 4.8's and I daily drive 4.8 2wd 09 Silverado I also have a 2003 5.3 power Z71 and it runs circles around the 4.8 powered trucks. As cheap as 5.3's if I wanted more low end power I would just swap in a 5.3. Swapping in the 5.3 is probably easier than changing the cam.
It's not that the 4.8 is a terrible engine but it's gutless under 4,000rpms after that it pulls hard for it small displacement.
If I keep my 09 it will get a 6.0 swap, I like the truck but I don't know why they bothered to put a tow hitch on it when the 4.8 can barely tow an empty trailer lol unless you want to run the **** out of it keeping it in a lower gear constantly.

 

The question of torque really depends on expectations, what you're trying to do with the truck, and how much you are willing to spend to get it.

Tri-Ys are proven to increase low and mid-range, and Thorley is a good quality brand. Their true tri-y are midway between a shorty and long header in length, so fitment may be easier. Don't know if what it will impact in terms of noise or smog problems. But it's not going to be leaps and bounds, since it's still a 4.8L.

Other ideas would be advancing your existing cam 4 degrees. But that's really a band-aid fix to having chosen the wrong camshaft for your desired power range. You'd be better off going with a different camshaft (again, we're still talking for the 4.8L).

On the higher side of cost, would be swapping in a larger engine as noted by others, or adding a positive displacement supercharger like a Magnuson. Either would compliment your existing camshaft, so you could swap that over to the larger displacement or 4.8L with blower.

But perhaps before you start down those paths, give a different tuner the chance to work his magic. And look into what gearing you have in the truck. A set of 4.11s (assuming factory height tires) would really help. As would a mild torque convertor.

 

5.3's are exactly a low torque monster either. My 5.3 is kind of a dog down low but that might be because of the stock tune.

 

If it was mine, ID go with TSP headers a 3,200 to 4,000 stall converter (a different tunner) and 4.11 or 4.56 gears and don't worry about the torq. Let the RPM do the work.

 

I left a message in your Visitor messages.

Give me a call. Leave a voice mail. Text works too.
I'm sure I can help with the surging. At least log it and see what's happening.
I'm in NE Portland.

Ron

 

As an Australian, I find it interesting that in the USA, people seem to directly compare different dyno runs from different shops down to the last few HP as if they are even. We can't do that here. There's always too many variables and a dyno print out is only a tuning tool, really. Handy for comparing certain things but not something that you can religiously stick to. We can't even directly compare Dyno numbers between the US and here as there's a general 10-15% difference.

I'll give you an example. I lost nearly 50 rwhp with a cam change in a 5.7. If you go just off the Dyno print out. I changed a 214/217 .600/.587 112 Comp Cam to a Cam Motion 218/226 .595/.587 116 cam. Cam Motion assured me I would gain power going bigger and I'm sure everyone else would expect that too. Instead, I went from 392 rwhp to 345 rwhp! Car was much slower as you would expect.

Was Cam Motion exaggerating? I don't think so. What this doesn't tell you is that the shop who ran both numbers (years apart) changed their Dyno type. They installed a new 4WD Dyno of the same brand but it reads lower. So, anything not run on the new Dyno reads differently. This Dyno also reads generally much lower than other Dynos in the area. In fact, the Cam Motion ran 20 rwhp less on this Dyno than a similar Dyno at another shop.

I ended up changing the Cam Motion for a TSP 216/220 .600/.600 112 that made an extra 14 rwhp over the Cam Motion back to back but felt so much better to drive due to how it made the power. I think if I stuck it on other shops Dyno, it would make around the same power as the original Comp cam but it's all just numbers really. It's about how it drives for me. Comparing Dynos for exact numbers is a fools game to me. It's just a guide.

 

What gear? My truck has 3.42 and will literally roast the tires from a stop, Pulls a trailer much better than the 4.8 with the same gear. Both are bone stock down to the factory style mufflers. I'm not saying it's pulls like the newer 6.2 or a diesel but I don't have to drop all the way to second gear on hills like the 4.8 does.

 

Now see...THIS is how this forum is supposed to work. A local guy willing to help. Outstanding Ron.

 

I'm not sure of the gear. I'd guess 3.42. It's a 2009 Z71 4wd.

 

Give me last 8 digits of your VIN, I'll tell you whatever you need to know about the truck.

 

I'm pretty sure it's 3.73 gear, but here are the last 8 of the VIN: 4Z121818 Thanks that'd be great if you can verify rearend ratio.

I've gotten in touch with RonSSNova (a super nice guy and only a few miles from me) and we're going to see if he can do a "laying of the hands" on the tune, maybe next week.

 

Message boards are amazing...

 

We will get together when it’s not pouring rain.

We do get an occasional nice day in Portland this time of year. 😊

 

Now that's a good dude right there, I still say when it's sorted out change the gears and converter, then let it eat. Small cubes (rpm) and good gearing can make a world of difference....

 

Just in case you are looking a Doug's Tri-Y headers. I put a set on my 2002 4X4 Sierra back 2007 when they were ceramic coated. Had to cut back the Y pipe to move the cats back to make them fit. Only headers I could find to keep stock ground clearance as they fit where the stock pipes go. Just a few bottom rust spots from scrapes.
Performance wise, never had the truck dino-ed , but it runs good.
Hope this helps.

pic below is the cut back Y pipe


you should see the grass fly!

 

Hi folks I'm pulling this cam out and starting over. RonSSNova, bless his kind soul, tried his darndest to tune it and get it to stop surging, but the surge continues. So, I'm now humbly looking for your input on a new cam choice. As a reminder, this is a 4.8 with 706 heads, cold air intake, stock exhaust manifolds and true dual exhaust with X pipe and flowmaster 40-series. I'd like to retain the Tick dual valve springs that are in the truck. This is a daily driver and I just want it to have more low end grunt, right off idle. I do Not Care about top end gains, I spend my time from idle to 3k (usually closer to 2-2500k). I also don't want to have to make any other changes such as torque converter, long tube headers, or any other exhaust changes. With that said, the cams I'm considering are:

BTR Truck Cam Stage 1 V2. SPECS: 206/212 .553/.553 112+0
https://briantooleyracing.com/btr-ca...r30612120.html

BTR Torque cam SPECS: 202/202 .511/.511 111+1
https://briantooleyracing.com/btr-ca...-30202112.html

I would greatly appreciate your input on which of these two you'd suggest, and why. Or what other cams you might suggest, given my goals. Thank you!

 

This:
BTR Torque cam SPECS: 202/202 .511/.511 111+1

Because of this:
This:
With especially this:
And finally this:

As long as the above characteristics are truly what you're looking for, there's nothing fundamentally wrong with the engine, and your expectations are realistic (it's not going to throw down high numbers on the top end), this sounds like what you're looking for. If this doesn't idle smooth and pull harder than stock right off the convertor with a proper tune, something else is going on.

The dual springs would be usable, but way overkill. Downside to that will be additional parasitic losses. You could either sell them and go for inexpensive GM beehives12499224 and still come out ahead (Beehives<<$100). Or accept a small loss in efficiency and torque.