• If you currently own, previously owned or want to own an Avalanche, we welcome you to become a member today. Membership is FREE, register now!

Tapping into the hidden power of the Vortec 5.3

Armageddon

Full Member
Joined
Jul 15, 2006
Messages
660
Location
PG County Maryland
Lately i've been constantly trying to figure out how to make use of all the hidden power of my motor. It seems like there's alot left it it but i cant quite figure what i need to do inorder to get it out. I dont know what the Vortec lacks and what the main goals for this engine were in the first place, but i basically am trying to learn out to improve the weaknesses and exploit the strong points.

One thing i know this engine needs is more torque but i have no clue how to improve that besides the long tube headers.

I appreciate any help or info that anyone knows about this engine and what it takes to make it more of an performer.
 
You can start with a good tune. One from a good tuner or get HPtuners and do it yourself. Another would be forced induction(supercharger, nitrous, turbo) but that can get costly. Heads and cam are another way also, or just change to the 1.85 ratio rocker arms.

As far as the headers, the 5.3 will actually give you more low end torque normally aspirated with the shorty headers.

Hope this helps.
 
I would be glad to chime in but it looks like you already have some good advise.  (y)

If you talking about a $500 budget go with a tune.  If it's $5k go FI.

 
trannyman said:
You can start with a good tune. One from a good tuner or get HPtuners and do it yourself. Another would be forced induction(supercharger, nitrous, turbo) but that can get costly. Heads and cam are another way also, or just change to the 1.85 ratio rocker arms.

As far as the headers, the 5.3 will actually give you more low end torque normally aspirated with the shorty headers.

Hope this helps.
This seems like a good way to go since all of it will basically void most of my warranty. At least if anything goes wrong it'll be harder to see the cam. >:D

To my surprise the engine has roller lifters so those dont really need to be touched, now i'm just looking for a good kit for the cam, 1.85 rockers, springs(retainers,shims etc). Comp cam has a cam but there's runs for like $385 for just the cam and nothing more.I've heard of another popular kit on here but i also dont like jumping on the bandwagon before i know why it's popular. I tend to like the stuff that's geared mostly towards towing (low rpm torque) although i do next to none of it. Also i'm not worried about emissions, just strictly a more efficient & powerful motor that wont have any trouble codes.

But if i just deside to change a few things on the top end before the cam, what would be more important between the springs & the rockers? So far this sounds like something that will be perfect for reliable daily driving with alot more power.
 
THE SPRINGS, THE SPRINGS, THE SPRINGS!

Stock springs are marginal even with a stock cam.  I would never do a cam swap unless the springs were done before or at the same time.

 
getting rid of the torque management would be a good start.  Try a tune first, then decide if you want to start spending every last dime you have ( or that you feel you can hide from a significant other ) trying to get one of these HEAVY rigs to go fast.........

Not that I would no anything about what I have said ( see sig below ) , but that would be my advice for what ever it's worth.... just my .02

d
 
trannyman said:
You can start with a good tune. One from a good tuner or get HPtuners and do it yourself. Another would be forced induction(supercharger, nitrous, turbo) but that can get costly. Heads and cam are another way also, or just change to the 1.85 ratio rocker arms.

As far as the headers, the 5.3 will actually give you more low end torque normally aspirated with the shorty headers.

Hope this helps.
If I remember correctly long tube headers will give more top end and shorty's will give you low end(torque).So like trannyman is telling if you want torque go with shorty's not long tubes.The question really to ask your self is how much bang for your bucks...the sky is the limit to what you can do to an avy but how much are you willing to spend?Good luck  :wave:
 
  what they said.  if you want to get serious try the SLP package i.e., assembled heads & cam.  then get you a set of headers & exhaust along with a custom tune, and you will have a beast.

  all the advice above is great.  just remember what KY_BOB said, "...never do a cam swap unless springs are done..."  basically one mod needs to be complimented by another to get the full potential.  good luck.
 
KY_BOB said:
THE SPRINGS, THE SPRINGS, THE SPRINGS!

Stock springs are marginal even with a stock cam.? I would never do a cam swap unless the springs were done before or at the same time.
Sounds like a bet then.. i'll jump on those also. Are there any specific spring you would recommend? The main thing i was thinkin is that the springs might possibly lower efficiency because they would be more internal tension to overcome, and the main think i've been trying to do is raise the total efficiency of the motor. But then again i guess it could actually raise the efficiency if it could move the valves easier..
 
DanV said:
then decide if you want to start spending every last dime you have ( or that you feel you can hide from a significant other ) trying to get one of these HEAVY rigs to go fast.........

Another in the long list of why I'm divorced :laugh:

If you are going to change the cam, you will not need to change to the 1.85 rockers. You will run into problems if you do. And yes to the springs. I forgot that in my original reply.
 
Armageddon said:
Sounds like a bet then.. i'll jump on those also. Are there any specific spring you would recommend? The main thing i was thinkin is that the springs might possibly lower efficiency because they would be more internal tension to overcome, and the main think i've been trying to do is raise the total efficiency of the motor. But then again i guess it could actually raise the efficiency if it could move the valves easier..

I don't mean to sound like a smarta$$ but that would be dictated by what cam you will put in it.

If you plan on going mild, stock LS6 "yellow" springs (stock for a Z06 Vette) are cheap and good up to about .570 lift IF the ramps aren't too extreme.  Comp 915 springs IMO ore only slightly better than LS6 springs and more expensive.  If you want to run a high lift cam with some fast ramps Comp 918 springs are the way to go.

 
KY_BOB said:
I don't mean to sound like a smarta$$ but that would be dictated by what cam you will put in it.

If you plan on going mild, stock LS6 "yellow" springs (stock for a Z06 Vette) are cheap and good up to about .570 lift IF the ramps aren't too extreme.? Comp 915 springs IMO ore only slightly better than LS6 springs and more expensive.? If you want to run a high lift cam with some fast ramps Comp 918 springs are the way to go.
lol no smartassness taken... I'd probably run the Vette Springs just because i'd at least have the lee-way of a GM part in that case. I was just making sure i was on the right page because i didnt think it'd need the rockers AND the cam either if i had the cam already doing the same thing.

How much better is the cam then the 1.85 rocker option? Because that would also keep from having to go through the trouble of changing such a key part if the rockers almost do the same thing.
on a side note check these out :love:

http://cgi.ebay.com/ebaymotors/OEM-GM-LS6-Valve-Springs-16-Yellow-GM-12499224-NEW_W0QQcmdZViewItemQQcategoryZ33621QQihZ006QQitemZ160116854617QQrdZ1QQsspagenameZWDVW

The only way i'd want to run a high lift cam is that if it gave me more torque and power in the 1500-5k range since that'd be perffect for even low rpm hwy driving. I def dont want something that makes the truck more of a race/drag car then just a fast street truck.

Sorry about all of these train questions, but I really appreciate the great help so far by the way, hopefully i'm also getting someone else help thinking about the same stuff. :B:
 
Those are the springs that I was talking about.

I don't have the specs of the stock cam handy but it's roughly 198/200 .500/.500.  1.85 rockers would change the lift from .500 to .540.  That should be a noticeable gain but it's still mild by performance cam specs.

Most of the guys on pt.net that run NA setups run cams with duration of 220/220 or 224/224.  Granted those may be a bit extreme for trucks as heavy as ours and do require a torque converter change.

Also keep in mind the LSA (lobe separation angle).  If you plan on going FI at some point you'll want to go with a fairly wide LSA to reduce overlap.  Overlap in a NA engine helps with scavenging the exhaust from the cylinders but with FI it basically blows some of your boost out the exhaust valve.  I would consider 114deg a minimum LSA if you plan on boosting it at some point.  If you don't, 112 would be good.

In short (too late) if you do a cam swap, you'll be thrilled.  I wish I had the money to do one now but I don't.  :needhug: Maybe by next year.
 
KY_BOB said:
Those are the springs that I was talking about.

I don't have the specs of the stock cam handy but it's roughly 198/200 .500/.500.? 1.85 rockers would change the lift from .500 to .540.? That should be a noticeable gain but it's still mild by performance cam specs.

Most of the guys on pt.net that run NA setups run cams with duration of 220/220 or 224/224.? Granted those may be a bit extreme for trucks as heavy as ours and do require a torque converter change.

Also keep in mind the LSA (lobe separation angle).? If you plan on going FI at some point you'll want to go with a fairly wide LSA to reduce overlap.? Overlap in a NA engine helps with scavenging the exhaust from the cylinders but with FI it basically blows some of your boost out the exhaust valve.? I would consider 114deg a minimum LSA if you plan on boosting it at some point.? If you don't, 112 would be good.

In short (too late) if you do a cam swap, you'll be thrilled.? I wish I had the money to do one now but I don't.? :needhug: Maybe by next year.

Gee, It almost sounds like you know what you're talking about :p  :kidding: Good info  (y) (y) .

I want to see how much the engine has stock before I make any changes. Once I get to the point where I'm ready, I'll do the rockers and springs first. But I don't think I'll worry about a cam till I toast the engine and change to something different >:D
 
trannyman said:
Gee, It almost sounds like you know what you're talking about :p? :kidding: Good info? (y) (y) .

I want to see how much the engine has stock before I make any changes. Once I get to the point where I'm ready, I'll do the rockers and springs first. But I don't think I'll worry about a cam till I toast the engine and change to something different >:D

I'll admit the thought of a set of 1.85 rockers and LS6 springs has crossed my mind too.  It's a lot easier than tearing into the motor.

 
KY_BOB said:
Those are the springs that I was talking about.

I don't have the specs of the stock cam handy but it's roughly 198/200 .500/.500.? 1.85 rockers would change the lift from .500 to .540.? That should be a noticeable gain but it's still mild by performance cam specs.

Most of the guys on pt.net that run NA setups run cams with duration of 220/220 or 224/224.? Granted those may be a bit extreme for trucks as heavy as ours and do require a torque converter change.

Also keep in mind the LSA (lobe separation angle).? If you plan on going FI at some point you'll want to go with a fairly wide LSA to reduce overlap.? Overlap in a NA engine helps with scavenging the exhaust from the cylinders but with FI it basically blows some of your boost out the exhaust valve.? I would consider 114deg a minimum LSA if you plan on boosting it at some point.? If you don't, 112 would be good.

In short (too late) if you do a cam swap, you'll be thrilled.? I wish I had the money to do one now but I don't.? :needhug: Maybe by next year.

I'm surprised i knew exatly what you were saying so quickly. If the cam opens the intake so long that the boost would actually assist in clearing the exhaust gases right through the exhaust valve.  Takin advantage of boost sounds like efficiency to me :love:

But as far as the cam i dont want so aggressive of a cam that it'll actually take away power on the bottom end because that's where i want the power. A TC would just make me burn more gas because i couldnt be light on the pedal when i would need to just cruise along, but still great info for anyone who wants to get max power up through to the redline. :D

I want power but it has to start around cruising rpms which are usually around 1300-1700 around town to 1900-2200 (going 70) on the hwy.  Because as of right now with thes 3.73's i have no power in the lower band exactly where i need it.

But back to the rocker and cam comparo.... if i'm not lookin for that aggressive of a cam (because i def plan on turbo charging anyway) would a 1.85 rocker/spring combo be just as good or close? Because if those spring on ebay arent esy to damage in those bags or anything i'm gonna def grab them. :B:
 
Jethro320 said:
Just bought an 05 Z71 and I am in the same boat as you, lets talk when you have a chance.? My email is rod320@airmail.net, thanks.

When you start talking about adding power it's more like a sinking ship :p

Welcome to the club Jethro.  :welcome:
 
Armageddon said:
would a 1.85 rocker/spring combo be just as good or close? Because if those spring on ebay arent esy to damage in those bags or anything i'm gonna def grab them. :B:

You won't get near the power from just rockers/springs as a cam swap but it is a heck of a lot easier to install or cheaper if your paying someone else to do it.

Look into the Lingenfelfer GT2-3 cam kit that they sell. ?It's on sale for $400 shipped and includes LS6 springs. ?The specs are 207/220 .57x/.57x lift. ?I think the LSA is 118.5.

That cam shouldn't cost you anything in torque but would definitely boost your mid range. ?It also works great with FI.

 
trannyman said:
Gee, It almost sounds like you know what you're talking about :p? :kidding: Good info? (y) (y) .

I want to see how much the engine has stock before I make any changes. Once I get to the point where I'm ready, I'll do the rockers and springs first. But I don't think I'll worry about a cam till I toast the engine and change to something different >:D
I do too but the cost of all these boltons add up would even equal the valve of a cam less alone a turbo. Although i'll still get a turbo first i'm sure the headers would help the sts spool up quicker.
 
KY_BOB said:
I don't mean to sound like a smarta$$ but that would be dictated by what cam you will put in it.

If you plan on going mild, stock LS6 "yellow" springs (stock for a Z06 Vette) are cheap and good up to about .570 lift IF the ramps aren't too extreme.? Comp 915 springs IMO ore only slightly better than LS6 springs and more expensive.? If you want to run a high lift cam with some fast ramps Comp 918 springs are the way to go.


  you do not sound like a smart a$$.  i agree with you 100%.
 
Good info guys I get a better idea on how to do things as well my question is where do I go toget a good tune done I dont wanna go to just anyone and have it suck let me know I'm in wyoming but i travel to nevada several times a year might be able to do it here in casper, wyoming or in reno, nv or denver, co let me know plz if you guys know any good places in those cities thanks guys
 
03_Avalanche said:
Good info guys I get a better idea on how to do things as well my question is where do I go toget a good tune done I dont wanna go to just anyone and have it suck let me know I'm in wyoming but i travel to nevada several times a year might be able to do it here in casper, wyoming or in reno, nv or denver, co let me know plz if you guys know any good places in those cities thanks guys

If you want to mail order one, I recommend:

http://www.nelsonperformance.com/

If you want to have it dyno tuned, I can't help you. 
 
Back
Top