Moddoo

iTrader: (4)

I'd like to throw something in here.

I have searched a lot on the pacsetter LTs.
Many people express a noticeable increase in tire spinning torque after installing them on a 5.3.
We all know they are 1.75" primaries, and fairly long.
Most people run the 3" ORY with them.
Another thing I found is that Stainless Works makes a LT with 1.75" primaries, decent length, and choke them down to 2.5" at the collector. I dont understand this 2.5" collector idea.

I know this thread is about an 8.1. I am only hoping to pull out some more "general" header info.

RoosterMcCandles

iTrader: (4)

This is an interesting topic but I would have to agree with Yelo. Many people go with things that are too big for their engine (ex. cam, headers, exhaust) and then are amazed that they didn't get the results they expected. LT's are designed to help and promote scavenging of the cylinder whereas shorties/stock manifolds are not.
Scavenging>No Scavenging
LT's = Scavenging
Shorties/Manifolds = Minimal Scavenging
Therefore, LT's>Shorties

Yelo

The LS1 is an extremly efficient engine...for it's size it flow MUCH more than a traditional smallblock (go find a head-flow comparison..the differences will blow you away !!) and can make use of a bigger primary tube on a long-tube header...IMO 1.75" is still too big for a 4.8/5.3 but people are always seeing low-rpm gains with them so apparantly it's not TOO BIG for the motor. The 8.1 is a different beast altogether, it's a traditional big-block design and a 1.75" or a 1.825" primary tube is sized just about right for it

shawn calvin

iTrader: (3)

Originally Posted by Sanderson Headers website
Smaller diameter pipes flow less volume than large ones, but the exhaust in the smaller pipe flows faster. Until you reach the RPM where the sheer volume of exhaust gases require bigger primaries, smaller tubes scavenge far more efficiently. If you're using the engine in the 1,500-3,500 RPM range, which is typical for a street driven car, you definitely want 1- 1/2" to 1-5/8" primary tubes for a small block and 1-3/4" to 1-7/8" for a big block. Any bigger and you'll lose plenty of low end torque. Beyond 3,500 RPM it's a question of where you want the power peaks. As you can see from the chart above, small tubes don't lose their edge in horsepower or torque until you get above 5,500 RPM.
this is what i am talking about.that sounds like that is what you need for towing. wene towing you should be in that rpm range

Yelo

I agree....and you will typically find properly sized primary tubing in a long-tube header, NOT a shorty. Shorties were designed originally to provide increased exhaust flow while remaining street and emissions legal....they DO provide an increase in flow, but they are NOT tuned to increase scavenging and build torque.

seadoo

I agree with Yelo...
when i build my race cars (drag or road race) i always re-do to my headers... most SBC like 40" primary lengths to maxiumize trq and useable hp.
LT's will give more 1000-4000 rpm trq and HP than a mid or shortie can dream of AS LONG AS you use the correct size diameter primary. for our trucks, i feel 1/2 stepped to 1 5/8 headers is the best. i wish someone would make them (eddy makes for fbod's)

TravisH

iTrader: (1)

Hey Shawn,

I never said you have to be a seasoned member to know anything, I just stated that you cant earn the respect of other members and have them actually listen to you if you dont bring FACTS along with your reply. Your right, There are not a lot of "kids" on this site that just argue about everything they can, like I too have noticed elsewhere. There a few younger guys on here(me and a couple others) but I would not say that we dont know **** from shoeshine. Hell, when I joined this site I didnt know ****,I wasted a lot of money on crap that doesnt work, but I kept reading and reading and reading and then buying the stuff that does and learning A LOT along the way. I too am not saying anything to make enemies, Im sure you do have alot of knowledge that will be very helpfull to someone.

Well, you probably heard that from a salesman. Like Yelo said, tell you anything you want to hear, they know how to sell their product to a consumer. Its business.

Im interested in see what the R&D guy says.

You also have to remember that these engines(genIII) are COMPLETLY different from the old SBC's. A lot of the things that worked well on them doesnt work so good with our engines. Lets just say, for example: A throttle body spacer. On the old engines they deffinatly made a difference, but on a genIII? No.

Why?
Because the fuel used to go throught the carb or Throttle body and when it was spaced out, blah blah blah Im sure you know the rest... But on GenIII's the only thing going through is air... ok thats enough. I went way off topic.

Back to the headers!

Take it easy man

shawn calvin

iTrader: (3)

have you guy heard of [westers garage]?there are in canada and they know there ****, they do almost 250 custom tunes a month,and they mostly do chevy.you can check there web site it is westers garage .com , or give them a call,i dont know the # but the guys name is lydon, he does all the tunes.and is on top of his game. please call them and ask them and ask what headers work best for towing. wene i called them they said to use the shorties, if you are going to tow and want low end torque.and also they do not sell headers.and also hooker sells shorties and long tubes , so why would they tell you to buy shorties that are less money than long tubes. did you think about that?
and i am not saying that lts are bad, i am just saying for towing the shorties are the way to go.

Yelo

I'm pretty familiar with Westers Garage and thier tunes...they're pretty respected in some circles (we're more Nelson and W4M oriented around here though). I'll give 'em a call either later tonight or tomorrow and see what they have to say.....

TarheelZ

It's actually Lyndon, but you're right...he does know his stuff!