I did not write this, I found this on a local site and thought this information was very useful and want to share it with Monte Carlo Forum,
Here is a link to the original thread, all credit goes to xWOODx on mnclubgp.com
www.MNCLUBGP.com • View topic - *THE header thread* [ Guest ]
You will notice there are alot of names for 2 brands of headers. If you see a type of header for sale, but its not listed here LOOK at the pictures im posting and the picture of that header, if they look the same - they are.
With all headers -
- Most do not come with cats, they have an "off road pipe". Even though we do not have emission testing in MN it is very illegal to not have a CAT, it can be up to a $30,000 fine (10k for you, 10k for installer, 10k for shop if there was one). It is up to you if you want to take that chance. Your exhaust will be louder, raspier and smellier without a cat. If you do want to run 110 octane LEADED gas you cannot have a cat.
- This is a problem alot of people installing headers for the first time have. They start installing it and just keep bolting down parts as they get them, DO NOT do this. You need to fully assemble and install the headers in your car LOOSELY. Put the bolts in a few turns, just enough to hold the part there as you will need alot of slop and movement to get all the parts in correctly to avoid leak issues. Once every part is in then start to bolt down pieces, but do it a little at a time, so do not fully bolt down one part while the rest is very loose. Tighten a little on every piece untill they are all very snug, then start to torque them down. Also, when tightening the actual headers to the head as with all other parts, start with the middle bolts and work your way out.
- Put high temp RTV in all slip connections, then put band clamps on top to eliminate any leaks. If this is not working because the slip connection is very close to a collector or something that is not perfectly round, try wrapping it TIGHTLY with header wrap
- Napa is the most popluar place to get band clamps for slip connections. A properly installed band clamp should be so tight that the clamp material actually forms to the pipes under it to eliminate leaks, easiest to use a impact gun on the bolts to do this. dont go overboard and break the bolts though.
- Most headers are coming with header gaskets for mating up to the head. Throw them away, stock are reusable MLS gaskets and will last pretty much forever unlike the paper tinfoil gasket they are giving you. Its WAY to hot at that point in the exhaust to use anything but a metal gasket. Further down the exhaust on your 2 bolt and 3 bolt connections you will use a paper type gasket. Even at this point its to hot for a paper gasket and its recommended that you get one that has a metal seal ring on the inside. If the gasket is all a composite material without a metal ring on the inside chances are it will blow out soon - especially if your more modded.
- All headers use there own downpipe. If you have an aftermarket or larger downpipe on your car now with your stock exhaust manifolds you will get a new downpipe with your new headers, so you will just have to sell your old downpipe to help offset the costs.
- Stainless steel is the preferred material for headers. It doesn't rust (welds may though) and it holds heat in better then mild steel. a GOOD set of stainless headers will be cool to the touch after 15-20 minutes while mild uncoated headers will still be very hot. Take note that there are different grades of stainless steel, 321 being the best then 304 is another common grade used. Header gauge is also important as it refers to how thick the metal is. Mild steel headers WILL rust out if they do not have a ceramic coating on them, especially if you drive the car in the winter.
Ceramic coating helps to keep the heat in, lowers underhood temps. There are different levels of coating, and you can get them coated on just the outside, or the inside and outside. Do you need it? well, are your headers stainless or mild steel? do you drive in the winter? Mild steel headers will eventually rust out with no coating, especially if you drive in the winter. It may take 5 years, but it will happen. I would recommend coating 100% if you get mild steel headers, its just an added bonus if you get stainless.
Exhaust Velocity / Scavenging effect
So the pimpled faced dumbass at Checkers told you that you have to have backpressure if you want to have torque. Guess what? he is wrong. Backpressure is NEVER good for performance. What you need for a torquier more responsive engine is EXHAUST VELOCITY. A smaller pipe gives you more velocity then a bigger pipe so you need to figure out how much air your motor is going to flow. basic bolt on setup with no more mods? smaller headers, s&s would work the best. going to add an intercooler? something a little bigger, maybe ssac's. going to add a cam and every other damn mod as well? pacesetters would be better then ssac's because of the bigger primaries. Its important to have as much velocity as possible with as little backpressure as you can get - things like mufflers (especially baffled mufflers like flowmasters) add backpressure and kill velocity, as do big body catalytic converters. As far as performance goes, a moderate sized pipe with no mufflers would yield the best results but sound like ***.
A cloth like substance you can wrap around exhaust parts. Once the wrap is on you can touch that part and not even burn your hand, be careful though as it can trap water in it and speed up the rusting out process. very useful if your exhaust gets dangerously close to a fuel line or anything for that matter.
Fuel Line concerns
Your headers will now be much closer to your throttle body then your stock manifolds were. with my pacesetters and modified zzp fuel rails needed for my intercooler my fuel line was probably 1" from the header, 1.5" after i tweaked the fuel line for more clearance. Even if its not touching that header puts out enough heat to burn right through that fuel line since its only a nylon type rubber. I ended up changing that fuel line for a steel braided AN line for more saftey.
Spark plug wire concerns
Your headers may now touch the spark plugs boots, you need some sort of heat shield/sleeve to protect them. Usually it touches on just 2 or 3 plugs. You can get sleeves made specifically to protect your plug wires, they are not real cheap but if you need them you need them.
Pacesetter / OBX Headers
One of the most asked about because they can be found very cheap
1 3/4" Primary size
3" downpipe section, 2.5" reducer at the end to bolt to stock catback
Can be had in Stainless or Mild steel
My least Favorite headers, they are the headers i had on my car. As far as design/performance goes they work very well, but they are difficult to get to seal - especially if you have to take them off and reinstall them while working on something else. Mine sealed ok the first time, then after taking them out i couldn't get them to seal around the Y pipe area ver well. There isn't much room for clamps in that area, but you need band clamps on those Y connections. These are probably the biggest PITA to install correctly
SSAC / XS Power
(and DPP headers if you've been around for that long...)
1 5/8" primaries
3" downpipe section - 2.5" reducer
These headers are often listed as "mild steel" when they are for sale. They are infact stainless steel headers, from what ive noticed a thin and cheap stainless, but stainless non the less. Headers like the zzp and togs are a thicker gauge
For budget headers these are considered the best you can get for under $350. they have the least amount of fitment and leak issues. It is highly recommended that you get wide NAPA band clamps for the crossover on these headers. They are around $11 and will help to seal the slip connections so they dont leak.
TOG Headers / Tog Extremes
Considered to be one of the better Headers for quality and fitment, they were expensive but you do get what you pay for.
1 5/8th primarys
To my knowledge these are no longer in production and like all SLP products they were spendy. Most people installing these headers had issues with the flex pipe leaking and causing a ticking noise. This design was later copied by DPP and the SSAC / XS headers are essentially the same, but they dont have the flexpipe problem
These headers can use the TOG downpipe, all other headers have there own specific downpipe.
Smaller 1 5/8" primaries AND a 2.5" downpipe these are not considered "optimal" headers for Supercharged 3800's, they are much better for N/A setups. For this reason they are not very popular, but they would perform fine on a basic bolt on supercharged 3800