Cobra six into six question

[Heinno]

Hi All

Got the pipes today - wanted to install, but the holes in the bracket that bolds onto the head seems too close - it should be an easy fix, but I was wondering - is this normal?

Also, does the baffles in these pipes make a huge difference in sound - thinking of going straight pipes.

Any advice welcome, I am new at this

Thanks

[wdvalk]

Mine bolted up nicely.had to play with the hanger bolts a little,you will lose back pressure ,resulting in less hp if you take the baffles out,but it will be louder,mine are loud with the baffles in

[Bugslayer]

Are you using new gaskets? It sounds like you're either using the same gaskets, or none at all.

[Heinno]

The bolt studs (on cylinder head) do not line up with the fastening plates' holes on the pipes. Seems to be (holes in the plate) about 4mm too narrow. I can ream the holes, but it seems rather strange that this would be needed.

[SCain]

If the plates are curved just slightly, thats your problem. Try straightening the plates and they should bolt right on.

[Redline +]

Also, does the baffles in these pipes make a huge difference in sound - thinking of going straight pipes.

Yes, considerable difference in sound. Personally, as an old hot rodder/drag racer, I loved the open pipes... but not for long distance.

On my bike, on the dyno, removing the baffles increased both hp and torque by 5.

I now use stock pipes.

Redline 

[Heinno]

Yes, considerable difference in sound. Personally, as an old hot rodder/drag racer, I loved the open pipes... but not for long distance.

On my bike, on the dyno, removing the baffles increased both hp and torque by 5.

I now use stock pipes.


[/quote]

Did you rejet? Everybody seems to be saying that removing the baffles would reduce HP.

[Heinno]

If the plates are curved just slightly, thats your problem. Try straightening the plates and they should bolt right on.

Thanks, I have noticed they are slightly curved, but did not think that would be enough effect the hole positions - will see if I can straiten them out, and if solves the problem.

[Brad]

I take the baffles out every year when street vibrations comes to town.  Lot's of HD boys making lots of noise during that rally so I have to show them that the Hondas can make some noise too.     If I am riding a distance I put the baffles back in.  It takes less than 10 minutes to remove or replace them.

[Heinno]

I take the baffles out every year when street vibrations comes to town.  Lot's of HD boys making lots of noise during that rally so I have to show them that the Hondas can make some noise too.     If I am riding a distance I put the baffles back in.  It takes less than 10 minutes to remove or replace them.

Do you notice a power difference in baffles "in" vs "out?"

[Redline +]

Yes, considerable difference in sound. Personally, as an old hot rodder/drag racer, I loved the open pipes... but not for long distance.

On my bike, on the dyno, removing the baffles increased both hp and torque by 5.

I now use stock pipes.

Did you rejet? Everybody seems to be saying that removing the baffles would reduce HP.
[/quote]

The Cobra pipes were installed by the original owner. I don't think it has been jetted, it may have adjustable needles. I've had no reason to look at the carbs yet so I don't know.

I could feel the difference in power with the open pipes and the chassis dyno confirmed my butt dyno.

Redline 

[Heinno]

Redline

Thanks, sounds like your carbs was tuned with the baffles out by the previous owner. How many miles do you get on a tank?

[Bugslayer]

My bad. I thought you meant the bracket's were too close to the head..... Duh.. 

[Redline +]

Redline

Thanks, sounds like your carbs was tuned with the baffles out by the previous owner. How many miles do you get on a tank?

Miles per tank will vary widely depending on tank size, how full you fill your tank and of coarse your right wrist.

I average probably 37 miles per gallon, close to 40 a few times, can't stay outa the throttle!

I have put 5.1 gallons in my 5.2 tank twice at just under 200 miles... filling stations sometimes are few and far between.

Redline  

[Brad]

I take the baffles out every year when street vibrations comes to town.  Lot's of HD boys making lots of noise during that rally so I have to show them that the Hondas can make some noise too.    If I am riding a distance I put the baffles back in.  It takes less than 10 minutes to remove or replace them.

Do you notice a power difference in baffles "in" vs "out?"

I do not notice any difference in power.  My neighbors car alarm notices a difference in the sound 

[Heinno]

I do not notice any difference in power.  My neighbors car alarm notices a difference in the sound 
[/quote]

LOL - THAT IS ALWAYS FUN! ESPECIALLY IN AN UNDERGROUND PARKING LOT!

[Heinno]

My bad. I thought you meant the bracket's were too close to the head..... Duh.. 

NOPE - The holes seem too close to each other - the stud screws seems to be further apart than the holes in the plate - will ream them, should not be too hard. The pipe ends fit nice and snug into the heads - cant wait to hear her roar!

[shank]

 are you trying to put your pipes on assembled? two of them stay together the other one removes from those two. i had the same problem. basically had to separate to get them to line up. kind of a pain, you will need an extra hand. make sure to put new exhaust gaskets in. use a little bit of grease to hold them in place. tighten the back last. and personally i like the sound with baffles out. long ride or short i want to hear it. lol

[olddog1946]

I have cobra pipes and when I did my first rear tire removal I took the exhaust off the bike...(didn't know any better) and had trouble putting them back on..had to install one at a time, which worked fine..there were no gaskets in the pipes, just about a pound of red rtv, which was a bitch to remove..I installed new gaskets and had one hell of a time putting the nuts on..could just barely get them started. Don't forget to recheck the nuts a few times or you will be losing them..ride, check , ride, check..
Personally the bike sounds like a porsche on steroids, but I find it a bit loud for an old fart..I added some muffler wrap to the baffles, which knocked it down a bit..still pretty loud..

I must also mention that my splines were bone dry..I doubt they had ever had any kind of grease/paste put on them..SO, DO INDEED, check yours..

[Heinno]

are you trying to put your pipes on assembled? two of them stay together the other one removes from those two. i had the same problem. basically had to separate to get them to line up. kind of a pain, you will need an extra hand. make sure to put new exhaust gaskets in. use a little bit of grease to hold them in place. tighten the back last. and personally i like the sound with baffles out. long ride or short i want to hear it. lol

No, the pipes line up, even if assembled - the 2holes on each fastening plate do not line up with the bolt studs next to the exhause outlets on the head. I can fix it, but is seems strange - almost like the plates is made for a different kinda bike. All the other screw holes line up well with the pipes in place.

[Bone]

Wonder if the plate was put on upside down before welding during mfg. ?

[Hoser]

If you want the noise, you lose power, to each his own, you won't notice it without a dyno, or if you race your buddy with the stock pipes on his Valk!    hoser

Stock pipes

[Heinno]

If you want the noise, you lose power, to each his own, you won't notice it without a dyno, or if you race your buddy with the stock pipes on his Valk!    hoser

Stock pipes

Naah, not enough Valks around my neck of the woods - just a bunch of Harleys - no problem then LOL!

[Hoser]

You are correct, sir, as I said, to each his own.     Hoser

[Heinno]

You are correct, sir, as I said, to each his own.     Hoser

Thanks for the dyno pic - does your bike (the one on the dyno) have bigger jets, or just cobra pipes?Seems a small difference. Except for power building.

[Reb]

If they are new pipes, For a couple extra $$$ you can get the inside of the pipes ceramic coated, which will greatly decrease the amount of bluing that takes place on them. I don't know how well it  works, but always wanted to try it.

[Hoser]

You are correct, sir, as I said, to each his own.     Hoser

Thanks for the dyno pic - does your bike (the one on the dyno) have bigger jets, or just cobra pipes?Seems a small difference. Except for power building.

That is a stock 99 Valkyrie with stock exhausts, piggies cut, with a truck stack exhaust cover and grumpy's tips.  It turned 94 horsepower with out the grumpy's tips on it, so I'm leaving them on, 5 hp gain.  Thanks Bill!  Hoser