Bonneville America Forums Forums Technical Forums Exhaust cross over pipe

i was looking at my stock exhaust i have removed all the baffels and cut them short about to the front of the back tire. i was wondering what would happen if i remove the cross pipe?

There's a discussion of this issue here:

http://www.bonnevilleamerica.com/forums/...rt=all&vc=1

What I took from it was if you have chambered baffles, you need the crossover.
With open pipes, you don't.

This is an open item with me today too.
I'm having some alignment issues, and the presence of the crossover doesn't help.

i thinking of cutting mine off and plug my pipes are open no baffels, by the old discussion it seems to be one of those factory things. hell after all the other removed items: airbox, ai's, rejetted, handlebars, turn signals moved and replaced finders cut, seat cut and lowered why not take somethingelse off.

Dog,

Read the last couple of comments on the thread that rhnstn mentioned in his above post. Buddy from the old board plugged his cross over pipe and I posted his comments.

Gene

I figured I would add a reply here rather than on a thread from last year. I recently had my balance tube removed, cut off and blanks weldd over the holes. Performance wise I cant notice any difference, this doesnt mean it isnt different though. It could be and it's so slight I just dont feel it.

Exhaust note wise it's very different, certainly louder. Which is good, I'm all about loud pipes.

Cross over is used to let the gases of a cylinder have more way of escapement.

Thats good if the mufflers have a restrictive baffle.

With an open muffler theorically the cross over is no more needed.

Removing the crossover has been an estetical issue for Harley owners with that ugly pipe in front of the cylinders (early big twins and Sporty).
But if you remove the cross over with still restrictive baffles there's a small loose in torque and power and some more vibrations.

The sound of course get better without cross over because the two exhaust notes don't mix.

With a cross over the exhaust gases of a cylinder that is in exhaust phase go out from that cylinder's main pipe but with a short retard due to the smaller diameter of the cross over tube, from the other pipe too.
The sound of every exhaust phase become a bit mixed.

Without cross over every exhaust phase note is more distinct.

Harley owners know better about it. And it's an important issue for them.

Finally did it. I’ve had a bug up my butt to remove the crossover pipe ever since Buddy did it on the old board, so I had it cut off and plugged today.

My first impression is it does not give you any enhancement in performance. However it does change the tone of the exhaust note. The best way to describe it is it’s a crisper note. It also increased the loudness of the pipes. I’ve had D&D’s on my bike for about 5 years now, which I thought were loud. All I can say is unless you want to ride with earplugs don’t do it. However I really like the new sound of the scooter….


Gene

I plugged my crossover pipe with a 30mm expansion plug. It took me about 45 minutes, minus the trip to the auto parts store and the explanation to my father that I was, in fact, not going to blow my motor up.

Difference? My pipes are mostly wide open right now, which is to say stupidly loud, so I doubt plugging the crossover has any net effect - but I sure do like tinkering with my bike.

did you have to weld the plugs or just knockem in?

was off work last week and cut the crossover out, it sounds great thanks for info.

i've read both threads again and again. i can't figure out where exactly is the crossover?

right now i'm running specialty spares with the baffles out. taking the crossover out will bring it to a deeper tone? AND if i put the baffles back in with the crossover plugged will the bike still perform.

Right now the speedy is dripping with hp and performance loosing a few horses won't hurt. just want to focus on getting the sound right.

thorn

look under the engine.

ok, so plain and simple. i'm going to take the crossover out (or plug it actually). should i take the baffles out or leave them in... there isn't much batting left on them. OR does it even matter? i noticed someone mentioned how the sound even out and dulls at cruise speed. i want a good sound all the way through. not only when i accelerate.

help?

thorn

p.s. please respond in layman's terms. thanks.

Well if you plan to remove the crossover in my opinion remove most if not all the restriction in the mufflers. The crossover pipe is there to equalise back pressure and give the exhaust a little extra room to escape with restricted pipes.

Picked up a plug this morning. Butt-o-metre no dif. Red lines to limiter. Sound more distinct. 2 hrs including trip to shop with pipe to select the plug. Do I like the new sound. You bet!

SpeedyKiwi, what plug did you use? Did you cut the crossover out with the headers still on the bike?

Best thing to do is take the headers off to do the job. Cutting will be easier and putting the plug in with a knockometer will be easier too.
I haven't done mine yet but it's on the to do list. I would imagine a freeze out pluf to close the hole. Right? I'll probably weld mine in after it's in place. Then a little high temp paint to prevent rust.

My question is... What is between the header and the head for a gasket. Since I want to be prepared to do the job all in one shot and not have to wait for something as stupid as a gasket.

I took the pipes off altogether. Then I took them down to a local auto shop. There I matched the diameters with a couple of “Frost Plugs”. I ensured they would be a tight fit. A quick smear of Locktight Blue and I tapped them in. I was very careful not to disturb the flange gasket. At least I assume that’s what it was. All in all it took 2 hrs including the trip to the shop. I was very suspicious of the join at the headers but there seems to be no leaks. Just got back from a ride. No leaks. Running fine. There doesn’t seem to be any change of power. Just the exhaust note. A bit sharper and flatter.

On my racing full Akrapovic for my ZRX1200 croos over pipes are still there but they are half in diameter than the ones on the stock pipes.

On twins if you remove cross overs you obtain some more vibrations and less smooth middle-to-high revs transition.
But the sound is way better due to a more distinct exhaust note into every pipe.

Can't wait to have my first Triumph so I can build my own stainless steel pipes.

Yesterday I went for a test ride. I've tried Bonneville standard, America and Speedmaster.

I like Bonneville standard like an all around performer for european roads, but the saddle is heavy and my girlfriend didn't like it and the seat position.

I like Speedmaster too but America is more relaxing to drive. And the girlfriend likes America so much expecially with high sissybar.

So now we can't choose between America and Speedy...
If I buy a Speedy I'll be obliged to buy the high and soft seat for travel...

Powerful brakes on Speedy!

Hey Dog it is a copper gasket type flange for a better word mine measures approx 45 millemeter yep where a metric country lol
Benny

sorry i should mention i have a 04 795cc speedy yep i got a "yellow" one very nice thank you for asking hehe

thanx. Have you guys been reusing that copper gasket with no leaks? Or buying a 2 new ones?

I didnt a fit new gasket. Checked for leaks. Was ok. Went out with the guys at 10am. Got back at 3 pm. The bike got a bit of a caining at times. Dam those rockets. Checked again. OUCH THATS HOT. Looks and sounds ok. But I will pick up some next time im over near the dealer for peace of mind I guess.

i opted for new 1's that way i would'nt have to do replace the reused 1's if they were to leak,mind you from the local stealership,$36 plus a week to get them maybe i should have gone with the silicon option on the old 1,s

I love the results for cutting the crossover out, i think it looks good and the sound is great, i took about 6 inches off my pipes and removed the baffles and cutthe fiberglass pac also. i will post pictures soon.

Just finished cutting the crossover out of Wendys exhaust.I couldn't find a freeze out plug that fit inside the cross over pipe tight enough. It was either a loose fit or too big. So I got 1 3/8 and used them like a cap. Tight fit over the pipe had to tap them on with a wooden mallet. Then I welded them all the way around.Tomorrow if it isn't still raining they will get some high temp paint on the area prone to rust.

I cut the cross over pipes so just enough was left when I drove the freeze out plugs on they just touched the origonal weld.I ground the chrome off before driving them on. Then welded.

We will see how they sound in the next day or 2 and a road test for any preformance changes weather permitting.

Cross over pipe job done on Wendys bike. Not sure it was worth it. I like the new sound you can hear the individual cyl. more but not any louder and I don't see anything as far as performance one way or the other.

I think I'm still gonna do mine since I do like the new sound and the parts cost me $1 with my commercial acct.

tv commercials?

i just reused the old ones i cannot find any leaks, i am work the valve adjustment might take the pipes off to see how the inside of motor looks.