[n02]

Hey guys,

Apologies in advance as I’m a bit of a rookie in many respects.

Recently purchased 2018 NSC that has full system. The exhaust has bluing on it and I thought this was maybe intentional? But I’m not sure.

I’m looking at putting the stock exhaust back on anyway and so I went round to a local shop and the guy advised he didn’t believe it had been tuned when he had a look at it but said it shouldn’t be a cause for concern either way. Turn it in had a listen to it etc. The bike is very smooth. Doesn’t stutter or have any problems or jerkiness.

So, I thought the bluing was normal. But bit of researching suggests It can be a sign of it running lean, which would make sense with full exhaust and no tune ? Or is it simply a by-product of a full exhaust system either way.

I know at times people do it on purpose so I’m really just trying to gain an understanding if it should be a cause of concern. I’ve started down this path as I was wondering wether I would not need to get it tuned again if it had been tuned in the first place, in order to revert back to stock with no issues.

I’ve sent an enquiry to get a link pipe for the muffler to the stock headers/cat from sc-project.
Thanks

 

[Bevo]

Akrapovič warns that full exhausts need a tune or engine damage could occur.
I had a 2014 with an Akrapovič open slip-on (cat delete). Akrapovič had two downloadable maps for the Power Commander for my setup.

Akrapovič | World Championship-Winning Exhaust System Technology

Akrapovič | World Championship-Winning Exhaust System Technology

www.akrapovic.com

 

[n02]

Yeah I saw that. Other than volume of the pipe that’s part of my push to put it back to stock exhaust. The bluing makes me think it’s running lean the more I read about it.

Interesting to think if the previous owner was willing to pay $3000 AUD almost for full system but didn’t get a tune or power commander/ rapid bike. The original pipe looks worn in and the bike has done only 2800km when I got it so pipe must be very recent.

 

[Bevo]

The bluing makes me think it’s running lean the more I read about it.

Exactly. A full exhaust will run lean that's why a flash or tune is required. The open slip-on I had on my 2014 ran lean.

 

[Ghostrider.1127]

For 18718 you have lot of opportunity to reflash the ecu ( or a rapid bike evo)

 

[n02]

For 18718

?

 

[Bevo]

?

Might be referring to the replacement value of the bike. I'm unsure as well.

 

[Ghostrider.1127]

18/19

 

[Oregonian]

OP - you can ship your ecu to EDR Performance in Oregon and have them flash it.

 

[Bevo]

?

He means that there are a lot of options for a tune or ECU flash on the 2018/2019 year models.

 

[oldcorollas]

OP - you can ship your ecu to EDR Performance in Oregon and have them flash it.

Why send halfway around the world, when there are tuning shops locally that use Woolich gear?

 

[doser]

So, I thought the bluing was normal. But bit of researching suggests It can be a sign of it running lean, which would make sense with full exhaust and no tune ? Or is it simply a by-product of a full exhaust system either way.

dude, you got me thinking: what actually causes blueing. I'm a chemist, but honestly, I ( still) don't know! something to do with the chrome plating and temperature. but i'm pretty sure you're right about running lean (therefore, too hot), and that can't be good for your exhaust valves... but - pardon the thread jack - the internet 'research' (about the hardening properties of chrome platings) led me to a Reddit site featuring a lot of machine guns. not my thing, at all - I'm not American! but there was a delightful little piece of humour kinda randomly interjected:

Enjoy the New Year. Damn, I can't wait for riding season to return.... maybe two months?

 

[oldcorollas]

The "blue" is a result of the thickiness of the oxide ayer that grows with heat, and is more a rainbow of colours.
The oxide grows faster at higher temperature, but you can reach he same oxide thickness, and same colour, at lower temperature with longer time.

Is the same process as "temper colours" for steel, except in that case it is iron oxide, not chrome oxide.
Also same process as the rainbow colours on titanium.

what causes the colour is "thin-film interference", due to the different lengths of the light paths of the light that bounces off the outside of the oxide film, compared to the light that bounces off the oxide/metal interface.

there are different orderes of interference, and for some materials you can get multiple rainbows. (eg SiO2)

for the exhaust above, starting at the springs and going toward the head, you can see the same progression fo colour as in the image below.
ie, at springs, approx 400 on the X-axis, and at the head is around 1000.
for chrome oxide, above that oxide thickness it turns black, rather than going through the next order (and next rainbow)

 

[oldcorollas]

and.. if the headers are titanum, they are much more likely to get funky temper colours without getting stupid hot, compared to getting same colours on stainless steel (which most comments on internets about colour and heat are probably related to)

Aren't they titanium?

Titanium Headers

what is really good, is that each of your cylinders is changing the pipe colour at the same rate.. so at least they are all even

If you get bored, or change tuning, you can polish them back to bare Ti metal, and watch them colour up again.

some nice images of new vs coloured Ti headers on this site

Kawasaki Ninja H2 & H2R Vandemon Polished Titanium Exhaust System 2015

Kawasaki Ninja H2 H2R Vandemon Polished Titanium Exhaust System 2015-23. We at Vandemon bring you the benchmark of exhaust systems. Shop online now.

vandemonperformance.com.au

 

[n02]

and.. if the headers are titanum, they are much more likely to get funky temper colours without getting stupid hot, compared to getting same colours on stainless steel (which most comments on internets about colour and heat are probably related to)

Aren't they titanium?

Thanks so much for your time and detailed explanation. Yeah they are titanium. I’ve reached out to sc-project and looking at a few options either way. That puts me at ease a bit surrounding it. Much appreciated cheers to everyone for the replies