Advantage/disadvantage of switching from 4-2 to 4-1 exhaust

What are the advantages/disadvantages of switching from a 4-2 to a 4-1 exhaust?

My main concern is cost - I can get a new MAC 4-1 for $350 vs a 4-2 for about $450

 

There is a single advantage in that you are scavenging from all 4 cylinders.

There are some that like the sound of all the exhaust going out through the 4 into 1.

Some don't like the unbalanced look of the pipe exiting out just the right side.

Really, it is just personal preference. I have a buddy that rides an XS11G and likes the 4 into 1. I prefer the 4 into 2.

The jetting process is the same, though.

 

I've heard "scavenging" before - but don't know what that means. Is 4-1 louder, or just a different sound?

 

it tends to be louder, its definately a different sound too, i recall you saying you want to be quiet...

you will save weight, though some people say you can feel the weight on the right side.. idk about that.

as long as you run the stock intake system... you shouldnt need to jet.

I'm looking forward to someday getting a 4-1 for my seca 750..

 

I don't mind alittle louder, just not wake the neighbours loud.

 

Re: Advantage/disadvantage of switching from 4-2 to 4-1 exha

I think most systems are 4 -1 based on cost. I have no idea if original XJ systems had a "Balance box" between them - but most Japanese fours had them - and they rotted like ****.

I personally like 4 into 1's.

The only thing I found with my exhaust (Already fitted by previous owner) was that it covered one of the bolts I needed to remove to overhaul the rear monocross linkages (Not a problem on yours!). This meant I had to remove the system to do the work!

 

I've got a MAC 4-into-1 (with megaphone) on my bike, plus I run a K&N air filter in the stock airbox -- I did have to re-jet in order to get the bike running right.

Went with the 4-1 simply based on cost, now I kinda wish I'd gone with the 4-2. In the ~12 years since I replaced it, the cost of the MAC systems hasn't changed.

The 4-1 makes the bike look unbalanced (to me) - visually heavy on the right side, missing something on the left.

The 4-1 also lowers your ground clearance -- the bottom, collector portion of my pipe has taken many a beating, grinding, etc even from some speedbumps in parking lots.

The 4-1 is louder than the stock exhaust, but not obnoxiously so. It's also a very different tone, but again not something that bothers the neighbors. I can't compare to the 4-2, as I've never heard it in person.

 

What does it mean to re-jet? IS this referring to having to alter the jet settings in the carbs? I'm new and I'm also set to tackle a carb cleaniing shortly.

 

Re-jetting is the process of taking the carburetors apart, replacing the jets and needle with different ones to improve fuel mixture, and usually modifying the slide piston as well.

On mine, I replaced the stock needle with an adjustable model, drilled the slides for greater air flow, and replaced the jets with 2 sizes larger to account for the greater airflow caused by the exhaust and air filter changes.
Usually all the parts and instructions come in your "jet kit" -- mine was a kit from K&N.

 

Altus, do you have any pics of your bike?

 

Scroll down to "Exhaust Scavenging"

http://en.wikipedia.org/wiki/Manifold_(automotive)

Or the way it was explained to me is
The exhaust pulse from 1 pulls exhaust out of 3 which then pulls exhaust out of 4 which then pulls exhaust out of 2 which then pulls exhaust out of 1, etc, etc.

Note to all you engineer types:
I know my description really describes a properly designed 4 into 1 exhaust, just trying to keep it simple.

ab

"How bout them Cowboys!"

 

Sorry about the delay - wasn't home last night. I'll put one or two general pictures up in my albums tonight.
I can get some pics if you'd like - anything specific?

 

4-1 can quite often change the power characteristics of a motor as in move peak power up in the rev range usually a 4-1 is designed for higher top end power which isnt necassarily what you want from your engine.A lot of aftermarket exhausts have to be removed or shifted in some way every oil filter change which personally gives me the s@#$s.
A friend had a CB1100 Honda first thing he did was put a 4-1 on it a few years later he was offered stupid money for the 4-1 so he sold it and wacked the stockers back on expecting to change it as soon as the right deal came along but what he found is that the bike was much more pleasant to ride, power came in a lot lower down the rev range,his girlfriend liked being a pillion a LOT more because there was a hell of a lot less vibration they both commented on how much smoother the whole riding experience was AND the cops couldn't hear you coming from a couple of K's away.
The XJ does a have great howl through a 4-1 though.
Having said all that I love the way my 4-1 sounds even if it is a tad loud but I have just found myself a 4-2 and will be changing it over.

 

Horsepower - the engine breathes better no bottleneck in the exhaust

works the same for cars dual exhaust more Horsepower.

 

Re: Advantage/disadvantage of switching from 4-2 to 4-1 exha

hey eman, Check my gallery n youtube..i hav a XJ700 Maxim with stock pipes and also a Maxim X XJ750 with 4 in to 1 HINDLE exhaust. Videos dont really justify the real sound..personally after using both i tend to like both time to time. 4 to 1 sounds nice while idle especially..n take off too. Mine is not rejetted and running it a bit rich give me great power like stock exhaust..NO difference..Some listers have said about losing power at 4k band which i havent experienced..again every bike is different sometimes you may need a rejet. Like Altus said..when i move both my bikes up in to my shed..i realise 4 to 1 is a bit low at the collector area than stock Collector (is Flat).

 

i just bought a pair of used "screaming Eagles" for $22.00.
the sound is fantasic.
no re-jetting, lots and lots of power not there before.
prob because i modified the stock pipes and lost a bit of
back pressure.
these still run 4 into 2 but if i can get this kind of performance
boost imagine what a good 4 into 1 will bring.
oh, if you can afford vance and hines i'd go there. top notch.

 

Re: Advantage/disadvantage of switching from 4-2 to 4-1 exha

You can get a jet kit from K&N?? I wonder if they have my jets in stock.
And what do you guys think about a custom 4-4 exhaust? Good idea? bad idea

 

i like custom 4-4 exhausts.... do it, theres so many things you can do...

 

yah, the right set-up might look real good.
what style were you thinking of? shot gun, staggered,long,
short, straight or muffled?

 

I'll have to draw a picture up. Headers will be the same. All four will come under the bike and connect to the bolt that our collector box is connected to by either, a new collector box, the old box, or all 4 pipes will be welded to a strip of steel that I can put the bolt through. THATS where I'm undecided.
And then the pipes will come out, the curve 90 below the passenger footpegs, then 90 again back towards the rear tire, ending in a slash cut.
They'll probably be super loud so i'm going to throw some wire mesh in the pipes to hopefully absord a little bit
Back pressure is what I'm worried about. I'm hoping I wont loose any horsepower or torque. Thats why I cant decide what to do with the collector box. Keep it for jetting purposes? Make a simplier 2-2 box? Or just the 4 pipes.
Ideas?
-Chris

 

sure, forget the collector and just run straights.

yes you will have to add something to muffle the sound
at least to a tolerable level.

the auto parts sell bendable exhaust that can be run under
the bike and up to the striaghts.

just a thought.