Why no 4 into 4 exhaust?

[Anonymous]

Ok, the black art of exhaust is totally unknown to me. Everybody talks about doing up their GS with a 4 into 1 exhaust. Neat, cool, alrighty...

But then I saw a Magna, which is a hot looking bike. 4 into 4 exhaust, which to me looks rather cool. I'd probably do an upswept thing if I did it, since 2 stacked pipes would make saddlebags and comfortable 2-up nigh impossible.

Anyway, why is 4 into 4 so unheard of on inline 4-bangers? Is it common and I missed it? Does it turn into a pumpkin? What gives?

[Anonymous]

Does it turn into a pumpkin?

Yup, that's it.

Actually, it is not seen largely because of packaging and cost issues. It is hard to put four pipes on a bike and not pay a serious weight and ground clearance penalty. And no OEM wants to make FOUR pipes and install them.

Performance-wise it is a good thing, and is much easier to tune than a 4-1 system, but the gains over a good 4-1 are not normally worth the packaging issues.

Mark

[lhanscom]

Actually a 4 into 4 wouldn't work well for performance either. The reason for combining the pipes is so that the exhaust pulse from one cylender will help pull the exhaust out of another cylender. By keeping them separate you lose the scavaging effect. You may be able to remedy the problem by having a crossover tube though, if you want to experiment.

[jhw84]

I have the stock 2 into 2 on my bike with the crossover, and have no dead spots. Some people complain about a dead spot at half of redline (4750 for me), but I have never experienced this.
Personally, I will never go to a 2 into 1 on this bike, and if/when I get a bike with a 4-banger, I will keep the stock exhaust or return it to stock because I believe the Japs got it right the first time.

[Jethro]

Personally, I will never go to a 2 into 1 on this bike, and if/when I get a bike with a 4-banger, I will keep the stock exhaust or return it to stock because I believe the Japs got it right the first time.

Kudoos to you. Everybody tells me to ditch the Anti-dive units on my bike. I like having the total experience of the 83 1100ED, just like the engineers planned. If I didn't, I'd get another bike.

[crag antler]

Personally, I will never go to a 2 into 1 on this bike, and if/when I get a bike with a 4-banger, I will keep the stock exhaust or return it to stock because I believe the Japs got it right the first time.

Kudoos to you. Everybody tells me to ditch the Anti-dive units on my bike. I like having the total experience of the 83 1100ED, just like the engineers planned. If I didn't, I'd get another bike.

Damn it does a heart good to see you're turning into such a fine 83 1100E owner 8) 8) 8) 8)
I know everyone has their own ideas for their bikes as varied as our opinions here, but I really love it when us diehards keep them stock looking.
Hell, if I wanted a bike to tweak, I would go like skip[ and buy something new. 8O :twisted:

[WesV]

Hell, if I wanted a bike to tweak, I would go like skip[ and buy something new. 8O :twisted:

Problem is Skip is so obsessed that he doesn't stick to that fancy smancy new bike of his, that poor little GS on Nitrous and everything else.... poor Skip....poor bikes under Skip's ownership... :P :roll:

[crag antler]

Hell, if I wanted a bike to tweak, I would go like skip[ and buy something new. 8O :twisted:

Problem is Skip is so obsessed that he doesn't stick to that fancy smancy new bike of his, that poor little GS on Nitrous and everything else.... poor Skip....poor bikes under Skip's ownership... :P :roll:

8O 8O :roll: :roll: :roll:
It seems like ole skip[ gets a year on his bikes and has to buy something new.
Maybe he ought to go back to Suzuki 8O 8O 8O 8) :? :? :?

[Jethro]

Heck, I even still have the hunt on for a stock exhaust, and I have a V&H, D&D and MAC systems to chosse from already!

[Poot]

Personally, I will never go to a 2 into 1 on this bike, and if/when I get a bike with a 4-banger, I will keep the stock exhaust or return it to stock because I believe the Japs got it right the first time.

Kudoos to you. Everybody tells me to ditch the Anti-dive units on my bike. I like having the total experience of the 83 1100ED, just like the engineers planned. If I didn't, I'd get another bike.

Damn it does a heart good to see you're turning into such a fine 83 1100E owner 8) 8) 8) 8)
I know everyone has their own ideas for their bikes as varied as our opinions here, but I really love it when us diehards keep them stock looking.
Hell, if I wanted a bike to tweak, I would go like skip[ and buy something new. 8O :twisted:

damn...it seems like the feeling has spread!!! apart from the handlebars, my bike is staying stock! (maybe a new paint job when some $$ comes my way)

got the stock 4-2, which gives me a nice quiet ride for most of the time, but comes alive when i want it to :twisted:

poot

[crag antler]

got the stock 4-2, which gives me a nice quiet ride for most of the time, but comes alive when i want it to :twisted:

You know I feel the exact same way there poot. I like the fact that the stock pipes are fairly quiet for putting around town with a nice growl but once I let her loose, she sounds quite nice without deafening me.

[bradleymaynar]

Build to suit! Make it yours and to he!! with the rest!!!

Brad tt

[Nerobro]

Well, Honda did a 4 into 4 on the first cb750's. 4 into 1's are popular due to tuning benifits. They are the best way to generate the lowest pressure's in the exhaust system.

Straight pipes work, but you are giving up a LOT of preformance by not tieing into the other cylinders exhausts.

4-2-1 exhausts can be more compact, and provide the ability to tune for two different exhaust lengths, versust the one for a 4-1 exhaust. 4-2-1 ehxausts are much more difficult to build...

MV agusta's actually have a 4-2-1-2-4 exhaust on the F4's . Both the 750 and the 1000's have that exhaust. There are bikes out there with 4-2-1-2's such as the hayabusa and the CBR1100XX.

[Anonymous]

Well, Honda did a 4 into 4 on the first cb750's. 4 into 1's are popular due to tuning benifits. They are the best way to generate the lowest pressure's in the exhaust system.

I have to disagree with the thought that 4-1's are much superior. Yes, you can tap into the pulses from the other cylinders, but that also adds many problems with the other pulses interfering with the desired results as well. Running 4 individual pipes lets you tune the engine like 4 separate singles running together on a common crankshaft. You can certainly generate good scavenging with 4 separate pipes and the tuning is MUCH easier because of no cross-cylinder interference. There is a reason why Honda (and others) ran separate pipes on the GP bikes in the 60's. Given the weight penalty and packaging problems of having 6 separate pipes on the 250-6, Honda obviously thought there was some benefit or they wouldn't have gone to all the trouble.

I forgot to mention one other reason that you don't see 4 pipes - fashion. It is simply not cool to have a 4-4 system on a new sport bike and they are what drive the design and manufacture of exhaust systems (our old bikes are really an afterthought to the pipe makers). It would also be a major problem finding room for that many pipes on a new sport bike. Take a good look at any of the latest generation bikes and see how tightly they are packaged. I couldn't fit a custom 4-1 pipe with megaphone onto my ZX-9 without moving components and the new bikes are way worse than it is in that respect.

That said, I think a custom 4-4 megaphone system would look great on a GS. Someone here should go for it and build one just to be different.


Mark

[shaftzuki]

That said, I think a custom 4-4 megaphone system would look great on a GS. Someone here should go for it and build one just to be different. Mark

I'm doing just that .... here's the conceptual sketch 8O



If it's not showing up, go to the flatline garage link below 8)
Da%$ photo hosts ... 8O