Easy Header Question - Please help......

[NZ440RT]

I am going to order some tti headers BUT, I am confused.
I'm not 100% sure about what size my collectors should be?

This is what I want or have been told will suit my stock 440 1970 Challenger, these headers are not for the strip just want my engine to breath easier and get a few extra horses and sound a little "chunkier". I will not be adding any mods to this car after this so am not worried about "but if you add this or that later the ?? is the way to go...."


HEADERS: TTI 1-7/8" primary tubes with either 3" collectors or 2-1/2" collectors. Ceramic coated with thermal barrier insides.

EXHAUST: TTI 2-1/2" Exhaust system with an X-Pipe using Dynomax Super Turbo mufflers.


I'm confused about my collector size.

Is 3" collectors to big for my 2-1/2" exhuast system or does it make no difference what size the collectors are?

I'm no car guy but I would think that 2-1/2" collectors to a 2-1/2" exhaust system makes more sense? Well it looks better on paper but I don't know shit. LOL!! ;D

Please help I need these headers/exhaust ASAP.


Cheers,
Carl

[Coil]

If there are no more improvements, stick with the 2.5"
Why not use 3" all the way out the back?

The 3" is not too big, the exhaust shop will need to put a reducer pipe in it. If you will be installing it yourself, just use the 2.5"

Again, why not improve the breathing and just use 3" to begin with?

[NZ440RT]

Won't the 3" will be too much for my 400hp (max) output? I won't be adding any mods in future. Plus the 3" will be too loud. ;D

Is there any harm in going 3" collectors to 2-1/2" exhaust system? Or is there no difference?

[Coil]

I know its just a bow tie bomber, but my 87 suburban with stock 350 is running 3" exhaust. With mufflers and cat, it was pretty quiet. Got a bit louder when I removed the cat. Whats the problem with being loud? Remember, Loud Pipes Save Lives......and let the ricers know to get the hell out the road

[NZ440RT]

Thanks for your help but I've been told more than once that the 3" system is over doing it for a stock 440 engine. Don't wan't a loud droney noise well I lurk the streets. The stock engine was good enough for me but the headers and exhaust will give it that extra snarl and performance.

I've decided to get this combo:

Headers = tti 1-7/8" Primarys Tubes to 3" Collectors with Ceramic Coating and Thermal Barrier Insides.
Exhaust = tti 2-1/2" Exhaust with X-Pipe and Dynomax Super Turbo Mufflers.

Plenty enough for a stock 440 and daily driving.

Thanks once again.
Cheers,
NZ

[ajmopar]

Do you want the Summit Racing/Mopar Muscle Magazine answer or the truth?

400 hp requires a 1 5/8" primary tube diameter, 34 to 36" long with a 2 1/2" collector. Ask Don, his 318 runs 1 5/8" tubes and makes over 400 horse. There is an argument to be made for a larger displacement engine needing a little bigger tube, so fine, run a 1 3/4" primary.

For a basic street machine (naturally aspirated, 13.5 in the 1/4 or slower, 3.55 gears, 2800 stall converter) 3" exhaust is overkill. for what you gain in top end power, you lose it lower down in torque. Guess what throws a heavy street machine down the road? low to midrange torque, that's what.

Yah, those TTI headers sure are pretty, but the big block ones are nowhere near to being equal length, and they sell them in sizes way too big for near stock motors, which most of them end up on. What you end up with is a very free flowing exhaust manifold, not a cylinder scavenging header. They will actually cost you torque on the low and midrange, and give you a few hp right where never drive. But boy are they shiney!!

So you can see, there are no "easy" header questions, unless you are after looks and nothing else. If you want to improve the power output of your engine while increasing efficiency, size the tubes right and run and exhaust system with an X pipe that will keep the velocity up, right to the tips.

[ajmopar]

Do you want the Summit Racing/Mopar Muscle Magazine answer or the truth?

400 hp requires a 1 5/8" primary tube diameter, 34 to 36" long with a 2 1/2" collector. Ask Don, his 318 runs 1 5/8" tubes and makes over 400 horse. There is an argument to be made for a larger displacement engine needing a little bigger tube, so fine, run a 1 3/4" primary.

For a basic street machine (naturally aspirated, 13.5 in the 1/4 or slower, 3.55 gears, 2800 stall converter) 3" exhaust is overkill. for what you gain in top end power, you lose it lower down in torque. Guess what throws a heavy street machine down the road? low to midrange torque, that's what.

Yah, those TTI headers sure are pretty, but the big block ones are nowhere near to being equal length, and they sell them in sizes way too big for near stock motors, which most of them end up on. What you end up with is a very free flowing exhaust manifold, not a cylinder scavenging header. They will actually cost you torque on the low and midrange, and give you a few hp right where never drive. But boy are they shiney!!

So you can see, there are no "easy" header questions, unless you are after looks and nothing else. If you want to improve the power output of your engine while increasing efficiency, size the tubes right and run and exhaust system with an X pipe that will keep the velocity up, right to the tips.

[ajmopar]

Do you want the Summit Racing/Mopar Muscle Magazine answer or the truth?

400 hp requires a 1 5/8" primary tube diameter, 34 to 36" long with a 2 1/2" collector. Ask Don, his 318 runs 1 5/8" tubes and makes over 400 horse. There is an argument to be made for a larger displacement engine needing a little bigger tube, so fine, run a 1 3/4" primary.

For a basic street machine (naturally aspirated, 13.5 in the 1/4 or slower, 3.55 gears, 2800 stall converter) 3" exhaust is overkill. for what you gain in top end power, you lose it lower down in torque. Guess what throws a heavy street machine down the road? low to midrange torque, that's what.

Yah, those TTI headers sure are pretty, but the big block ones are nowhere near to being equal length, and they sell them in sizes way too big for near stock motors, which most of them end up on. What you end up with is a very free flowing exhaust manifold, not a cylinder scavenging header. They will actually cost you torque on the low and midrange, and give you a few hp right where never drive. But boy are they shiney!!

So you can see, there are no "easy" header questions, unless you are after looks and nothing else. If you want to improve the power output of your engine while increasing efficiency, size the tubes right and run and exhaust system with an X pipe that will keep the velocity up, right to the tips.

[ajmopar]

sorry for the double reply, my browser just had a seizure.

[NZ440RT]

I was told by HEAPS of people from Moparchat and beyond, ED and Chryco etc etc.......that my set-up was fine. It's no 318 pumping 400hp it's a bigblock 440 pumping 400hp. If I had the same size collectors as my exhaust it would just be an extension of my headers. Yes I will be getting an X-pipe either custom made or I'm waiting for an email from tti to see if they have them in stock and just don't display them on there website.


Thanks once again but my mind is made up,
30 to 2 replies is a little better. ;D

[MoPower]

For a street vehicle, you realy aren't going to see a difference with equal length headers. The last time I looked, equal length headers were very expensive and at least one tube had to go through the fender well.

The TTI headers will look great, perform very well, will not cage the starter, are reasonably priced, and don't need any body cutting.

As far as the pipe size goes, I believe that you were stating that agains what coil is saying. Taht is because NZ is wanting 2½" pipes, not 3" pipes.

The only issue that I really have is the 3" collectors going back down to 2½" pipes. I would think that would cause turbulance in the exhaust.

[NZ440RT]

Thanks for your input MoPower. I was told from a reptuable source that having the same size collector as the exhaust size basically means all your doing is putting headers straight through the whole car, in other words expanding the headers. I thought you might need that extra 1/2" of collector size to force that pressure into the 2-1/2" system therefore creating backpressure. ;D

Not sure but I know I won't be going 3" exhaust to loud and too much kill for a stock daily street car. I'm not talking racing I'm talking to town and back (hours drive).

Cheers,
Carl

[ajmopar]

Your argument makes no sense regarding wanting to have 3" collectors reduced to 2 1/2". Yes it will work, but it is not optimal. I understand the need to keep things affordable and workable, but yes, you would see the differnce with equal length headers that are properly sized on the street, maybe moreso there than at the track (driveability, low end torque, fuel mileage etc).

TTI makes a nice and pretty high flow exhaust manifold and a nice exhaust system to hook up to it, but lets not fool ourselves into thinking they are a well tuned header design.

Who is your reputable source, BTW?

[NZ440RT]

Lets just say my reptuable source is well know in the mopar board circle. Not going to drop names but he visits this site on the odd occasion the other is from Moparchat.

[Coil]

Your original question is quite confusing. You want the engine to breath, get extra ponys and sound "chunkier"? OK. But you dont want it louder. I think you should by a Honda. Want to change the sound? = change the muffler. Want extra ponys? = use a GOOD set of headers (equal length tubes, etc...) I have known those who try to make it breath better and loose torque. And since when is a BB Mopar NOT supposed to be loud? Remember....loud pipes save lives......and scare women, childern and the ricers.
One more thing.....you want it to breath better but yet you want to restrict the flow from 3" to 2 1/2" ?? This is gonna create some back pressure and may not clear the cylinders. Thats ok....when my tired old worn out SB 71 Nova leaves you breathin my oil burning cloud at the stop light and you cant even come close to me on the freeway........just remember.....it breathes so much better and those headers look good.....