While i am waiting for my new FG XR8 ute to arrive from QLD i have been looking at full exhaust systems and its starting to do my head in with whats out there

but my biggest problem is do i get the Tri Y or the 4 into 1
now i know the tri Y are better for low down torque and street aplication and the 4 into 1 are better for high reving top end power but what do i do???

its a manual and i will be (later on in a year or 2, maybe supercharger ) doing more than just cold air induction and full exhaust system (looking at twin 2.5" system stainless with hotdog mid mufflers)

also trying to pick which brand as there are lots out there

most of my driving will be country with stints around perth and maybe a drag or 2

any help will be great

cheers

tri-y

On a 290...4 into 1.

just to add my bit. while working at ford the nicest boss 290 i ever drove had try-y's instead of the 4-1. also was a 5 cogger. it actually had some pull and would squirm while accelerating in 2nd, instead of just putting ur foot down and waiting for the power to come.
maybe the do with only being a 5 spd, dunno, but it changed my perspective of pipes on the boss motor

Tri Y's for sure

My 393 clevo performed better with Tri y's over 4-1
4-1 are really only good if your driving it W.O.T all the time,
i found the tri y's gave me more streetable torque.. thats just my experiance with my combo
and my combo aint no slouch !!

ok i also see pacemaker do 2 types of 4 into 1 ....which one and why do you blokes recon tri Y over 4 into 1 or the other way round

PH 4007
FORD FALCON XR8 –GT 5.4 Litre V8 “FG MODEL”
Tuned Length
Primary Pipe: 1 ¾"
Secondary Pipe:
Outlet (flanged): 2 ½"
Y Branch


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PH 4009
FORD FALCON XR8 –GT 5.4 Litre V8 “FG MODEL”

Primary Pipe: 1 ⅞"
Secondary Pipe:
Outlet (flanged): 3"
Y Branch:

--------------------------------------------------------------------------------

PH 4019
FORD FALCON XR8 –GT 5.4 Litre V8 “FG MODEL”
Tri-Y Design

Primary Pipe:1 ¾"
Secondary Pipe:2"

Outlet (flanged): 2 ½"
Y Branch:


looking at most brands for headers atm just thought id put up the pacemaker ones

If cost ain't an issue then go di filippo, there stuff works the best, they are 4 into 1 but they are dyno proven as being the best for achieving power, if you want more low down go then there are other avenues to explore

been doing more research and found this write up ...very interesting

http://www.popularhotrodding.com/tech/0 ... index.html



and found this from a 4 cylinder web site (yeah i know its not a V8 but its half of one )

So now we come to the 4-2-1 – Tri-Y – and the 4-1 header designs. First the Tri-Y:

As the name Tri-Y implies, the four runners (the tubes attached to the engine block) are arranged in such a way that three groups of “Y” shaped runners are formed. Runners one and four form one Y section, runners two and three form a second Y section, and finally those two Y sections (now forming two new runners) dump into a single section of the header called a collector. This is why it’s called the 4-2-1 – four runners collect to form two runners which collect to form the final pipe that runs to the cat then exhaust, or for cat-less systems, straight to the exhaust.

In contrast is the 4-1, where all four runners form into a single short collector; four runners into one, the 4-1. Simple enough, right?

On Honda headers, Honda Tuning magazine (thanks guys, awesome job) mentions several other design criteria that can be altered to affect performance. They don’t test each of these in turn, but here they are listed. With either primary design, you can change both the primary and collector tubing diameters. With the tri-Y, the secondary tubing’s diameter can also be altered. Again, remember that these tubes can’t just be increased because you think that will open up the exhaust…it’s all about balance, figuring out the exact combination to improve the exhaust’s velocity out of the combustion chamber. Bigger is NOT always better people, let’s all remember this concept because it’s the same with intakes!

So how did the tests turn out? Tri-Y designs by and large have a much broader RPM spectrum so increases showed up throughout the range on the B16 rebuild tested by Honda Tuning Magazine, but the 4-1 passed it up in the peak range because the 4-1 design is mostly used for high RPM (they have a narrow range of effectiveness) racing applications. Note how we all have 4-2-1 designs because our cars aren’t race cars!! The tri-Y design for our cars is definitely the best even though the 4-1 will beat it up top; the key is that the tri-Y hangs with the 4-1 all the way through the RPM range, giving more torque and whp at the low end than the 4-1, only losing at the very top and only by a small margin (3 whp and 2 torque). Since we all don’t drive our cars daily at 7,200 RPM, my guess is that this won’t change the trend for tri-Y headers being chosen over 4-1 for our application.

I know the theory on headers and normally I would say that 4-2-1's are the way to go.
However, after looking into the actual performance gain including bottom end, on the 290 engine it seems that the difference down low is so miniscule between them and the mid and top end was markedly better with the 1 3/4" Difilippo with the pinched collector so I got them. I've just managed to find some FG cats to modify and the rest I will make using 2 1/2" 304 and stainless Walker Ultraflow mufflers.

xr9ute do you have any graphs to back this up or is it just talk from bloke to bloke
what model number were the difilippo extractors that you got and how much $ is one looking at for the extractors (cant seem to find much on price of them)

are you finding it difficult to get an exhaust to match up with these or you just making your own..wouldnt mind catching up sometime to have a look at it if thats cool or have a chat

Nope, but I've seen the dyno test sheets and talked to the owners.
I'll see if I can find the part#. It doesn't seem to be on the actual headers.
Just remember 1 3/4" 4-1 pinched collector.
I'm making my own because I have that exhaust that I made for my old XE ute. So I may aswell cut it up and re-use it.
Drop me a pm.

cheers mate
will give you a PM when im closer to getting back to perth ..i just got back up to work
wouldnt mind having a chat with you
cheers