Brandonbrwn3

OK guys I have read similar posts on here about this subject but hear me out.. I have a 2008 5.3 z71 silverado I decided to delete the AFM and ordered the delete kit from summit racing. While it was all torn apart I did the fallowing upgrades.

-Comp cam 222 234.
-Dual comp cam springs.
-7.4 trick flow hardened pushrods.
-Summit racing trunnion rocker bearings.
-gm performance lifters
-ls non AFM valley pan
-k&n intake
-custom dyno tune.

As the post states I have ran into a big problem. My truck is SLOWWWW has no b**** I got beat by my buddy's stock Yukon xl ..

I know everything was installed correctly and I aligned my cam timing, my question is, can a bad dyno tube make my truck slow? Because it runs good but no power I feel like I'm driving a 92 Camry.. I am planning on doing 3.73 gears and a 3000 stall but this is rediculous. Should I have it retuned by someone else because if its gonna be this slow I don't wanna put any more money into it.. Please any tips or suggestions on why its so slow but sounds so healthy

Bowtie316

iTrader: (1)

With that cam and no stall, it's going to be a turd from a dig regardless of how good the tune is. Does it run out good once you get the rpms up?

thunderstruck507

iTrader: (18)

As stated above, a large cam with stock gears and stock converter is going to blow. When my LS1 was first swapped into my car it had bolt ons and a 230/224 cam and it wouldn't spin from a stop until it hit 3000rpm in first.

Do you have the dyno graph? It could be partially the tune as well but not likely. It's not really hard to get wide open throttle tuning right. Where did it make peak HP?

My guess is it's just bogging down so bad down low and then falling out of the power band on each shift so hard that the extra power at the top of the powerband isn't enough to overcome those flaws.

KW Baraka

iTrader: (7)

Yeah.....the engine and the drivetrain are (and will be) mismatched until you install the gears and stall.

KW

KW Baraka

iTrader: (7)

No need to guess.....it's a fact!

KW

Brandonbrwn3

Thanks for the responses guys, I ordered a tci 10" 3200 lock up stall and gears so hopefully it wakes it up. As far as the questions go, it is OK in down shift when it hits 4500-6000 rpm but when it shifts it falls on its face hard. Oh and another weird thing I forgot to mention, I have to press the gas a little for it to start or it will just crank over.... But other then that it runs good just slow.

Dyno Junkie

Tune is "off""
Either have current tuner rectify this or find someone who can!

Brandonbrwn3

What do you mean by "off "

Dyno Junkie

It's no good.
Shouldn't need to touch accelerator to start the engine.

gagliano7

Without a stall that is a big cam for a 5.3 in a truck. You will have to have it tuned again when you put the stall in.

Kip Fabre

I have a question if you don't mind me asking? Did a cam guy pick that cam or did you? How did you come up with that grind? Thanks

Brandonbrwn3

Summit racing tech picked it out for my build...

Kip Fabre

That explains it. Thanks for the reply.

Brandonbrwn3

I am gonna order a different cam I'm thinking about the howard 218 224 .604 .604 at 112lsa. Any thoughts on that cam

UpstateZ28

iTrader: (2)

I think the best thing you could do is talk to kip from cam motion.i sent all my info for my car with specs on my drive train etc. with my my intended use and goals and he speced a cam for me. Sometimes you get what you pay for and his knowledge is available to you and he will personally discuss what you need. Just my .02 cents. Good luck in what ever you decide.

1989GTA

"I think the best thing you could do is talk to kip from cam motion"

X2.

LLLosingit

iTrader: (4)

I know everyone pointed out that you have a mismatch cam/converter/gear combination but I wanted to add this. The reason your friends stock Yukon beat you is because you have a big heavy truck that needs all the low end torque it can muster to get it moving. The stock cam was designed for that and for emissions. The cam you listed moved the power band up quite a bit so you actually lost power down low where it's needed most. The stall and gears will help regain what you lost. If you don't have headers and free flowing exhaust you may not see the gains you might expect.

03EBZ06

not enough data. how about timing, plug gap, plug pics, AFR? Datalog??
Almost sounds like it needs a tune. Also, is your cam set on ZERO?

Kip Fabre

This one will be to BIG. Look at our website. Go to 5.3 truck you will see cams that will make more torque & power they do not have big lifts and durations. Your 5.3 can not support cams that are made for larger engines like 5.7 6.0 6.2 7.0 You will need a cam much smaller than you think.

Brandonbrwn3

Thanks for the replys guys, after looking around for awhile I landed on the comp cam low lift 212 218 @ .522 .529 114lsa. Since I have dual springs and hardened pushrods and all that good stuff I decided to go with this one. I would have went slightly lower then this one but I didn't want my dual springs putting to much stress on the valve train if I went any smaller.