Dekelvic exhaust for the Valkyrie

[Bagger John - #3785]

Saw these on FleaBay while perusing various parts listings.

Anyone ever try a set? If so, did you gain anything in terms of performance?

The 21" version appears to be roughly as long as the OEM exhaust with OEM tips installed. Is that the case?

[mark81]

I remember a post somewhere about a guy who bought that off eBay I think he was in Japan. He was not happy with the sound fitment or quality of it

[RWhitehouse]

I can't speak to the Valkyrie exhaust specifically, but I've run several Delkevic systems on other bikes in the past and was always impressed with the quality and fitment, especially considering they're usually 30-50% cheaper than some other "name brand" exhaust systems. They're made in the UK, not China or something as people tend to think because they're cheaper.

[98valk]

a response from them indicated the ID of the head pipes are slightly larger than OEM. so will pick up some HP and lbs.ft.

[MarkT]

This has been discussed at length.  It was proven at that time higher velocity in the headers increases torque.  Meaning smaller diameter headers is better for street pipes.  The Honda engineers knew this and thus the headers are the size they are.  For Delkevic to claim the opposite is just wrong.

[RWhitehouse]

That's the issue with aftermarket parts and performance claims. Sure, that big honking exhaust might gain "up to" whatever they claim- also given ideal conditions, and the right supporting mods. Slapping one part on an otherwise stock bike rarely gives much if any improvement, and is often a negative.

A slightly larger exhaust may emphasize peak RPM power at the expense of low to mid-range torque. For a supersport on the track that would be desirable, for a heavy cruiser, not so much.

[98valk]

the benefit of a slightly larger header pipe. This is for the Viking exhaust.

[MarkT]

There's a lot more at play here than just the header size.  In particular, the Vikings are 6 into 2 creating scavenging while OEM's are 6 into 6, and the OEM's have a LOT more backpressure due to the muffler baffles wasting a lot of power.  Also note how peaky the torque curve on the Vikings is largely due to equal length (or close) headers - not good on a street bike - that big torque bump coming on while accelerating in a sweeper for example, can mess up your line through the curve.  The Honda engineers knew what they were doing designing the pipes for a cruiser.

[98valk]

There's a lot more at play here than just the header size.  In particular, the Vikings are 6 into 2 creating scavenging while OEM's are 6 into 6, and the OEM's have a LOT more backpressure due to the muffler baffles wasting a lot of power.  Also note how peaky the torque curve on the Vikings is largely due to equal length (or close) headers - not good on a street bike - that big torque bump coming on while accelerating in a sweeper for example, can mess up your line through the curve.  The Honda engineers knew what they were doing designing the pipes for a cruiser.

Non Sequitur

[MarkT]

If you can't follow I can explain it to you in simple terms.  eg there's multiple other factors besides header diameter affecting this so your dyno printout doesn't prove your statement - that is, a "Non Sequitur".  

[wirral_biker]

I can't speak to the Valkyrie exhaust specifically, but I've run several Delkevic systems on other bikes in the past and was always impressed with the quality and fitment, especially considering they're usually 30-50% cheaper than some other "name brand" exhaust systems. They're made in the UK, not China or something as people tend to think because they're cheaper.

Actually ( been there and saw it for my KLR650 )...engineer/welder makes exhaust to fit a particular model and then sent off to China for a batch to be made for that model.
Quality was very good and an excellent service.

[wirral_biker]

So, still cannot find anyone who runs Delkevic exhaust ( please NO MORE piss boiling graphs or qualified opinions etc etc )
I just need to know from someone who HAS actually fitted a Delkevic system.    If I go for their system, I will obviously post back up on here....from the horses mouth, so to speak.    
Just didn't want to 'lose' £450 if not much difference or poor fitting.
Found this:- https://www.youtube.com/watch?v=xqlEo0XCR6M
Thanks guys    

[RonW]

Delkevic being in England, wouldn't they have a test exhaust for you to try out?

[wirral_biker]

Delkevic being in England, wouldn't they have a test exhaust for you to try out?

  being England....NO !         They are a genuine company, been there for an exhaust on my KLR650 which they made up whilst I waited.

[RonW]

explain to them that this is for the Valk forum.

[wirral_biker]

explain to them that this is for the Valk forum.

Delkevic haven't replied to my email as of yet..I'll update accordingly

[BorderLineRider]

  I bought the Delkevic system back in June 2018 and didn't install them until September that year. I only bought it because something about my stock exhaust was driving me nuts. The pipe on the right was always a little higher than the left when looking at the bike from the rear. The bike had never been laid over and both pipes were perfectly straight. I think the factory screwed up and welded the rear bracket on the left pipe in the wrong position. Upon installation someone must have pushed down and forced the bracket onto the mounting stud. I have owned the bike since it was new ('98 Standard) and after 3 years the collector cracked and I had to have it welded. I think forcing the pipe into place put a large amount of stress on the collector causing it to eventually crack. Anyway, having one pipe higher than the other was driving me batty so I looked for a used left pipe and did not find a suitable one. A new one from Honda was too expensive. Most aftermarket pipes didn't appeal to me because I don't like loud pipes. The stock ones sounded perfect to me. I found the Delkevic system and it was reasonably priced and they claimed it wasn't louder than stock. I installed it and thought the fitment was pretty crappy and then rode it for 25 miles or so and my Valkyrie was down on power. The exhaust was also too loud for me. The next day I put the stock system back on and the Delkevic has been lying on my workbench ever since. If anyone wants to buy it let me know. Make an offer.