HDI Active Exhaust
#1
#3
HDI always means non-domestic versions, California market bikes often have their own changes such as canisters
I'd like to know if the active valve could be useful to enhance torque when closed, horsepower when open--- any Aussies, Brits or other Int'l riders have a thought on that?
Mike
I'd like to know if the active valve could be useful to enhance torque when closed, horsepower when open--- any Aussies, Brits or other Int'l riders have a thought on that?
Mike
Last edited by mkguitar; 09-19-2011 at 09:12 PM.
#4
#5
HDI always means non-domestic versions, California market bikes often have their own changes such as canisters
I'd like to know if the active valve could be useful to enhance torque when closed, horsepower when open--- any Aussies, Brits or other Int'l riders have a thought on that?
Mike
I'd like to know if the active valve could be useful to enhance torque when closed, horsepower when open--- any Aussies, Brits or other Int'l riders have a thought on that?
Mike
#6
I've owned Harleys since the 70s. For those of us in Europe the bikes we get, I was told back in the late 80s, are influenced by Swiss regulations, that have more severe noise limitations than in North America, so we suffer from different exhausts and other things that limit performance, to keep noise down.
I also have a recent Buell and Sportster, which are stock, but to give you an idea of what the changes are, this is how my 1990 FLHS differed from US spec. The mufflers were quieter, the airbox was quieter, there was a restricter in the inlet manifold, overall gearing was higher with a 61T rear pulley, ignition timing was retarded at low engine speeds. So for us to do a proper stage 1 required undoing all those things!
So the HDI exhaust on current bikes is not something to be lusted after! Around the World owners, like our North American brethren, look for ways to disable or replace the restrictive system! If you have a factory parts list you can see where there are HDI parts.
I also have a recent Buell and Sportster, which are stock, but to give you an idea of what the changes are, this is how my 1990 FLHS differed from US spec. The mufflers were quieter, the airbox was quieter, there was a restricter in the inlet manifold, overall gearing was higher with a 61T rear pulley, ignition timing was retarded at low engine speeds. So for us to do a proper stage 1 required undoing all those things!
So the HDI exhaust on current bikes is not something to be lusted after! Around the World owners, like our North American brethren, look for ways to disable or replace the restrictive system! If you have a factory parts list you can see where there are HDI parts.
Last edited by grbrown; 09-20-2011 at 01:34 AM.
#7
Thanks GR,
I was just wondering about that, and if there might be any advantage ( you know like the muffler cut out on early bikes)
61T--- that's what I used for the overdrive on my FXRP in 1990. With a Softail belt.
( bike has a lot of grunt so overdrive no problem)
Still running it all these years later.
Best, Mike
I was just wondering about that, and if there might be any advantage ( you know like the muffler cut out on early bikes)
61T--- that's what I used for the overdrive on my FXRP in 1990. With a Softail belt.
( bike has a lot of grunt so overdrive no problem)
Still running it all these years later.
Best, Mike
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