Do Power Cones Help Or Hinder in Stock pipes with after market Slip ons?

[Hindgrinder]

Any body able to help out with this question?

Stock '89 883 with an S&S.

[andyxlh]

Hello!
Do you mean slip on exhausts with some kind of baffles or drag pipes (which are straight through tubes?) Drag pipes will always work better with some kind of baffle - unless you are using them for what they are designed for which is running close to max RPM on the drag strip. The scavenging effect of the back pressure caused by the baffles allow the engine to breathe better and increases power through the low RPM ranges - which is where you are if you are riding an '89 model with the rigid mount engine (if you want to keep the fillings in your mouth!)
Sometimes I have seen drag pipes without baffles cause lean burning and damage to the exhaust valves - but that might be able to be mitigated with careful jetting. Very long drag pipes have more resistance to the exit of the exhaust gases than the sort ones obviously, and therefore require less baffles. I'd definitely be using the 'power cones', which will also probably reduce the harsh bark to a rumble too.
If you have slip-ons made by companys like 'cycle shack' or the older HD screamin' eagle ones they have baffles built in and they won't need any messing with - and they deliver great results on the dyno. Best value for money swap over the OEM exhaust by far IMHO, and sound 100% better than drag pipes too. Have a look through them - you will see the walls are holed a bit like a cheesegrater and there is a metal 'tongue' which directs most of the exhaust gases through the baffle (the holed bit). They slip on to the end of the stock header pipes - the ones with the crossover under the air cleaner.
cheers
Andy
Sydney
www.youfreeweb.com/andysharleys

[Hindgrinder]

Thanks Andy, yes I was asking about power cones in stock exhaust pipes with the cross over tube and Samson slip on's.

[mayor]

Andy, I think he was talking about torque cones that fit inside the head pipe at the head. 


I've played with power cones a few times in various pipes ranging from stock head pipes to drag pipes, never felt a notice able difference.  IMO save your money. 

[andyxlh]

oh so you call those things power cones on that side of the Pacific, do ya?!
when I was living in the Carolinas on '03 I had many a discussion with my riding buddies about drag pipes and the slip in baffles which I would call a 'torque' or 'power' baffle which they didn't like as it stopped their rides sounding like a DC-10 on take off, guess I just waffled right on down that road!
BTW, do those head baffles you mention work, and if so through which part of the rev range? I would imagine they work in the same way as the crossover and exhaust baffle, but I really don't have any ideas as to how they would make a whole measurable difference if you have the rest of the exhaust system set up right....
cheers
Andy
Sydney

[mayor]

the torque cones look like this:


I think the basic premise is that they add a slight amount of back pressure and limit reversion.  I would be curious to see dyno results showing that they work.  Personally I agree with Andy, baffles at the tail pipe is going to be much more effective than adding these at the head.

[Hindgrinder]

Well, I might have been able to give the results in dyno testing with and without but the guy who owns the dyno expressed to me that first off, it's only an 883, and secondly he's afraid that the engine might scatter being an '89 and an old engine,,,,,,,
The first dyno test that I ran was with a set of old SE slip-ons and power cones in the header pipe.
52.5hp and 49.7 lbs of torque at 6,100rpm.
So where on the net I found the engine specs for an '89, rated 48hp and 39lbs torque.
The main reason for the dyno run was to check carboration with the new S&S super E.
He's got a sniffer linked to the dyno so you can watch the mix through the rpm range.
Once he got the idle mix set he did the dyno run.
I changed out to the Samson slip-ons and went back, that's when he disclosed his fear of scattering my old 883.
I think he's right, and the only time I use full throttle is when I'm riding in town or out on the highway anyway so I'll leave the Samsons on and sell the SE's, and be happy with 52+hp
Thanks for the help,,,,,,,,,