I made it easy for the L67 guys above, no need to be fooled by anything- its a proven method to power on that engine (and to some extent on the L36 too).

Doesn't make a difference to any of the 5th gen + montes, there are only a handful of headers available, and practically all have the same size downpipe, so its non-issue.


The stock manifolds on the 3800s aren't that bad. The ubend is the #1 restriction, followed by the downpipe, lastly followed by the front manifold.

You can buy a used plog and a used 3" dp, and fix all 3 problems for under $200, without having to shell out the $350-1000 for headers. True headers would make a bit more power, but the install is much easier and it will work just as well for someone not looking to go all out.

Also irrelevant to the L67 guys-a larger tb is proven to make more power regardless of what magic test u want to do, so you can't make that blanket statment- it only applies to NA guys.

You need to be specific- the hypertech programmer kinda sucks due to its very limited nature- but you're a moron if you think a DHP PT or HPT programmers are worthless. Box tunes (ie they ship you a tuned pcm in a box) seem to work well for those with minor bolt ons and can be had for much cheaper than even the hypertech programmer.

Not at WOT- 14.7 would cook your engine at WOT. Many box tunes adjust your AFR to better points in the abuse modes, and specifically in PE.

Wrong, you obviously didn't read my post aboveand have never tried to install headers on these cars. Rockers are actually easier to install, not to mention all the other stuff I listed...

 

ok how about 07 5.3 what can i do for any where from none to 100 hp from cheap up to what i gotta spend for 100 gain

 

there isn't much you can do cheap to pick up power... the serious power costs serious money. the best thing to do is get out of the exhuast thread and head on over to Engine & Internal if you ask me.... or Nitrous, Supercharger, and Turbochargers... but you'll probably have to build the engine up a little bit to take the pressure of the turbo, but i've never researched the 5.3

 

I doubt you're going to find that many people on here that are experts on the LSx series of engines- I would suggest going to:
http://www.ls1tech.com/forums/to read up on that specific series of engines. Yours is a little different- but its as close as you're gonna get.

Honestly, for 100 hp gain NA, I really think you're gonna have to look into doing a cam and ported heads. I just don't know enough about those engines to be specific- I'm a 3800 guy.

x2, that engine is going to be more expensive to get power out of than the 3800s because in stock form, it has fewer weak points- which makes squeezing cheap horsepower out more difficult.

The cheapest/easiest way to do 100hp is gonna be a bottle, and people have had amazing results with the LSx engines and bottles, but its not a mod for everyone- it is nice if you are only concerned with dyno #s and track times, but don't care to improve daily speed- which if its your DD, you're probably going to want something more permanent.

 

I guess there is no need to really go any further, because he re-wrote 100 years of exhaust theory and practice.

What was all ready proven by professionals is that if the pipe section behind the manifold output/header collector is larger, then as gases escape, hit this point it tries to rapidly expand and creates a turbulence in doing so. This will destroy the scavenging effect that trying to be formed.

Then again, having multiple ports that exit within the exit pipe, one after the other, it then take turns cutting each other off, stop the pulsation that one would like to create to try to empty each cylinder of all possible leftover gases. Having a separate tube that dumps into a collector/output section does 2 things. One it in itself allows the exiting gases its own freedom ( Non shared ) exit point to allow greater velocity speeds and the merge point allows for a vacuum ( Scavenging effect ) from other cylinders exiting gases, Kinda a play tag type event. Tri Y's take that creation one step further.

Are the headers made for a odd confined space perfect?
No they are not, better than a factory manifold? If you need to ask after reading a 101 of exhaust theory and then say no, well!!!!

Based upon those 2 replies against exhaust 101 via professionals with supporting data of all kinds, the explanation of the other topic points are the depth of reality is beyond even trying to explain.

 

I'm guessing you're trying to say that a 3" downpipe is a bad thing right? Seriously, I don't care what kind of theory you read about- a 3" DP makes more power than a stock downpipe. It has been proven numerous times.

If you knew anything about the stock 3800 downpipes- they have the nasty ubend behind the cat, and the double wall tubing necks down extremely small just after the inlet (smaller than the outlet of the manifold connection).

It makes no difference if it makes sense to you or not- it makes more power, with no noticeable downside (as long as you stick with the 2.5" on stock or mildly modded 3800 NA, and keep the 3" on any s/c 3800 and heavily modded 3800 NA), so I don't see what there is to argue with.

I'm not trying to argue with any sort of theory of what works for headers and what doesn't- the fact is that the 3100/3400/3800 market only has so many headers available, and they are all designed exactly the same, so no one on here has any choice unless they plan to make their own custom headers.

All the headers I've seen for these engines have the front 3 combine to1 crossover pipe, which combines with the rear 3 right before a single downpipe connection. The only headers I've seen that are different are the pacesetters in that they do the front 3 to 1, rear 3 to 1- and both of those two into a Y pipe to single exhaust, but the 1.75" primaries are a little big for most on here, and they're poor quality headers.

You can argue all day that aftermarket header design is so much better- but in the end, you still end up with the same configuration as the stock manifold setup, so there is really no point to argue about it...

 

The point of not to argue is your total 100% lack of knowledge in the field.
A header, even the 3800 ones are in no way close to being the same as a manifold in design or theory.

A manifold has 3 short pipe section that go directly into a larger one and the output section is at the end. They cut each other off trying to get to the output and great mini sections of back pressure points.

A 3800 header had 3 longer pipes that merge at the exact same point, a collector, the gases passing out on one tube creates a vacuum pulling gasses out of the other tubes. That much more efficient for scavaging.

Thats pretty simple to look at and understand once you know that.

OK, now you've asked for it.

Tuning

I'll make this as simple as I can for your knowledge ability.

I don't care if its a Laptop program, a hand held take to a lap top, pure hand held programmer or a send in.

You smart to take in all the variables to DIY?
Do you have a dyno in your back yard?
Answer no to either, well you got problems.

The others, well its pretty simple.

Do they live where you do?

I live in lets say Denver.
Air doesn't hold as much oxygen as it does at sea level in Maine.
Air could be dryer or wetter per each location.
Just 2 simple values for this tuning.

So how much of a enrichment amount is needed in Denver and how much in Maine.

Lets say you can take it to a dyno and watch as level are changed.

One town makes the most power at 11.6:1. the other 13.2:1, so your telling me a generic given table change will work out for everyone to the same degree, I THINK NOT.

Your trying to tell me for $100 bucks they've data logged every type scenerio one could run into in the US weather wise?? DON'T THINK SO.

Besides the fact you all ready don't understand what I said earlier.

Short term determines long term trims.
As you drive like a normal person the PCM is making constant adjustments for weather related, wear and tear etc. When you go into PE it uses the changes it made for that particular driving pattern, weather learning etc period before it went into PE to determine what it would do in PE.


As far as you out reaching on the U-bend.
This has been done 10's of thousands times before and wll documented.
Straigtenig out these minors 1-2 h.p tops.

Couple that with the above stuff about tuning and you've got a mess or real lucky it worked semi well.


I do hope others further along in the learning process will now have picked up something they partically knew etc. Those confused and sold by the miracles of after market and there ability to change data to make their products seem miraclous, well!!

 

I didn't explain myself well enough- and you are right that the front manifold design is pretty different from a front header- but the rear setup is very similar between the two.

What I was trying to say, is that there is no point in arguing the differences between header designs because they are all virtually the same for these engines. All the information you posted above is useless- because we have so few options when it comes to headers, other than very minor variations. The other thing I was trying to say is that the stock manifold routing is pretty much the same as with the headers (with the exception of the front manifold that I forgot to mention), becuase there is no room to do anything different.

Thats not to say that good power can't be made from a stockish setup. Hence why I reccomend two modding paths:

For those looking to do the easiest, cheapest route and don't plan to go deep into modding:

-front powerlog
-3" downpipe w/ ubend delete

This gets rid of the 3 major restrictions: the ubend, the tiny double wall upper DP section, and the outlet of the front manifold. This is a proven setup that makes good power. You can do both mods for $200, and total install time should be 1-2 hours.

For those looking to go further down the road- do full on headers off the bat. You're looking at a $350 minimum, up to $1200- and a much harder install (100x harder on 5th gen montes).

For those doing just the basic bolt ons on an L67 or L36, the extra hassle and price of headers doesn't justify the small power gain over the above setup- the setup I posted above flows plenty well for basic setups (mostly 300 bhp and under- which most basic bolt on L67s do). Sure headers will make more power- but for someone on a tight budget trying to hit 300 bhpon an L67, spending 3x-4x the money isn't realistic.

My knowledge ability? lol, I bet I've got significantly more hours tuning 3800 pcms than you do-do you even own a tuning program?

You don't need a dyno- you can get 90% of the way there with a basic street tune- just as most professional 3800 tuners do. You tune to get your FT's to lock in at 0 at WOT, and be near 0 driving around, then get your O2's where you want them, and then bump timing up while until yo uhit knock and back it off a bit.

You're acting like you start from scratch with a tuner- you don't. You start from the stock tune, correct some of the crappy things that are built in (ie boost dump, etc), and then slowly modify the stock tune to get fuel trims back in line for your current mods.

I agree that buying a cookie cutter, predone pcm will never yield the power of doing the tune yourself- but from looking at a lot of modded 3800 tables, you can see that they do follow a certain pattern. From what I've seen with the cookie cutter pcms is they bump fueling in known problem areas, and bump timing where they know it is a little low- and correct all the crappy things (like boost dump and such). Sure, most of them are on the rich side to be safe, and have slightly negative FT's, and sure they aren't running all the timing they could- but thats just being safe so it can be used anywhere.

I never argued against that did I? Not sure why you posted any of that, because its common tuning knowledge- I never disagreed with any of it.

You can't blanket statement that either, the power gain on a bone stock car is going to be much different from a 300 hp modded car. Youcan't deny its a restriction, even stock- and evensomething as small as a 2whpisn't bad for how cheap/easy it is to replace- especially if you're getting a full downpipe at the same time.

 

so 100 might be little to hard to get what about 50 more?

 

Well Bumping, its not worth the effort to try to debate this anymore you've obviously got a lot to learn.
This isn't 100% track here, street ability, mileage, warranty etc are concerns a VAST MAJORITY will have to contend with. You method is track only and still debatable on that end as to merit.



3800 tuning, yup probably have me there.
Overall, well you got A LONG WAY to go buddy.
Competition Data Systems software here!