Exhaust: 4 Into 1 or 4 Into 2?

O

OneEyeMan

Registered
I've seen a lot of beautiful aftermarket exhausts on all your Busas on this site.
One thing I've been wondering about is my Title question.
Are there benefits of one over the other?
Personally, I like the cleaner look of 4 Into 1; plus, I assume there's a weight savings without the extra plumbing using this setup.
Can I also assume a 4 into 1 is less expensive than a 4 Into 2 due to less hardware?
Is there something I'm missing here?
Now, I'm sure a lot of folks like the balanced look of having 2 exhausts and I definitely see that point of view also.
Just wondering if there were any other reasons for one over the other besides appearance?
Finally, what do you all consider some of the better 4 Into 1 full systems out there? Are there any systems to stay away from?
I'm really looking for a slightly louder than stock system, plus weight savings.
Oh, and it has to look killer! :thumbsup:
And I know I'll need a PC III or V, right?
Please be gentle as I'm still a Busa Newby.
Lenny
 
it's just preference. as far as performance goes I believe the 4 into 1 is better but you are talking a difference that few will notice. both will save a lot of weight cuz those stock cans are so heavy. so it's whatever you like. what color is your bike? if its the blak and gray I really like the yosh full system with the carbon can. Looks great and sound great. but that just what I like. brock's is probably the best for performance but 2 loud 4 me. I really like akrapovic but that's a lot of money
 
I have the HMF 4-2-1 highmount (Luci's in the middle). The 4-2-1 yeilds higher HP than the 4-2-2 like semi has (Lucy's in the back). The highmount exhaust steals some HP becasue of the long midpipes with multiple bends. So if you are looking for the biggest HP bang for your buck, the 4-2-1 low mount is the ticket (Hot Rod Harv's Busa in front). Personally, I prefer the high mounts and am willing to give up a few potential ponies for them.

IMG_1975.jpg
 
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BusaWhipped said:
I have the HMF 4-2-1 highmount (Luci's in the middle). The 4-2-1 yeilds higher HP than the 4-2-2 like semi has (Lucy's in the back). The highmount exhaust steals some HP becasue of the long midpipes with multiple bends. So if you are looking for the biggest HP bang for your buck, the 4-2-1 low mount is the ticket (Hot Rod Harv's Busa in front). Personally, I prefer the high mounts and am willing to give up a few potential ponies for them.
Click to expand...
Sweet I like that tube size...gonna have to start playing with the HMF's some more... :cheerleader:
 
I'm sold on the Brocks, but they are a little louder than the others. Greg sells a pipe that performs as well or better but I can't spell it :laugh:

I'm also sold on the 4 into 1, but that's a preference. No doubt there's some weigh savings in those pipes.
 
BusaWhipped said:
I have the HMF 4-2-1 highmount (Luci's in the middle). The 4-2-1 yeilds higher HP than the 4-2-2 like semi has (Lucy's in the back). The highmount exhaust steals some HP becasue of the long midpipes with multiple bends. So if you are looking for the biggest HP bang for your buck, the 4-2-1 low mount is the ticket (Hot Rod Harv's Busa in front). Personally, I prefer the high mounts and am willing to give up a few potential ponies for them.
Click to expand...


Thats why I got rid of all those bends:laugh:
Its got to be something to here your group riding around with a pack all running HMFs.

DSCN1557.jpg
 
dadofthree said:
I'm sold on the Brocks, but they are a little louder than the others. Greg sells a pipe that performs as well or better but I can't spell it :laugh:

I'm also sold on the 4 into 1, but that's a preference. No doubt there's some weigh savings in those pipes.
Click to expand...
Hang on, I might have my own exhaust system in not too long....it won't be loud..and it will make peak power.. :whistle:
 
BigRod1300 said:
Thats why I got rid of all those bends:laugh:
Its got to be something to here your group riding around with a pack all running HMFs.
Click to expand...

Big Rod please, please, please tell me how you did this exhaust. I have a stock 06 busa and want a shorty exhaust but do not want the slash cuts because of the noise. This would look perfect since im adding a variety of CF components.
 
+1 on the info shared above... either system will benefit you over the stockers--- I just like the look of the 4-2-1 systems...I just upgraded mine with the carbon look too---lot to choose from out there:cheerleader:

My Busa with the Yoshimura TRC-D pipe 050610 002smaller.jpg
 
The 4 into 1 vs 4 into 2 thing was explained to me by a local tuner this way:

Exhaust system are tuned to a certain frequency. At that frequency it sends a negative pressure pulse back up through the header and this aids in getting gas to flow through the engine. A 4 into 1 can only be tuned to one frequency. A 4 into 2 can be tuned to 2 frequencies. What this means is that the 4 into 2 would have a wider powerbande and more torque, all things being equal. This is also why some bikes have cross over pipes between the headers from different cylinders.

Basically bikes that are tuned to a single purpose (i.e. a racing bike is tuned for top end) work with the 4 into 1. Road bikes might work better with 4 into 2 pipes.

Thye Hayabusa makes this pretty much irrelavant though since it has so much power that you can stand to lose a little bottom end with a 4 into 1 and not really miss it.

I would be interested if anyone has also heard this. The guy who told me really knows his stuff and builds street and race bikes and has headers for sale with hours of dyno time so I figured he should know.
 
I have tiforce titanium 4 into 2.

I think a 4 into 1 makes the beauty of a busa look like its missing something from the rear and makes it look uneven. Just my 1 cent
 
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