More Yoshi ...

I'd like to replace the stock exhaust on my naked SV K6. There are lots to choose from but it may be a Yoshi and it's interesting reading bbartx's earlier thread on this.
I've had a few conversations with various folk and one told me that I wouldn't need any Dyno or fuelling/mapping work done - effectively it's a straight swap of the cans.
I'm not an expert but if the electronic injection is informed by a sensor placed inside the exhaust, doesn't the change in gas flow resulting from a change in exhaust require the fuelling to be looked at. Or is there really little difference??

Any thoughts and apol's if I've missed something obvious.

[northwind]

The SV doesn't have a lambda sensor, at least, the K6 doesn't, so it's not a problem. It'll probably lean out just a wee bit with an aftermarket can alone, the headers are also quite restrictive. Some people do have some slight issues but lots of others just ride on quite happily.

I'll ponder a bit longer but I'm still a bit confused about the electronic injection, if there is no sensor forming a feedback loop then I guess the system is running on a fixed injection map irrespective of exhaust output.

Thanks anyway Northwind ... it helps.

Fitting a system or end can such as the Yoshi will normally require at least a check of the fueling. Some bikes as standard can benefit from a tweak as they bed in.

Its worth getting the fueling checked and altered to make the most of the exhaust. There isnt much point in putting one on for performance gains if you dont actually maximise what it can do. Every bike varies on how it reacts to an exhaust, there is no hard and fast rule. Some wont gain anything and run fine, some run rich or lean and some are just off from the start.

That's clear. Thanks for this, Racer - I'll make sure the fuelling is looked at when I fit the new can.

Cheers.

[northwind]

I think it's partly down to the fact that a lot of people just plain won't notice if it's running badly, my bike never felt more powerful than when I fitted my full system but hadn't rejetted... The midrange was totally limp, so the contrast felt really strong, there was a big jump at 6000rpm. Course, it was making less power everywhere but it felt mint. When I fixed it, it felt neutered (and gained more than 5bhp everywhere and about 15bhp in the mids compared with the pre-rejet results). Funny old thing, the brain.

So I guarantee that there's a load of people on here saying "No need to remap" who would benefit from it. Then again, chances are in most of those cases it's doing no harm, so if they don't mind why worry? You need to run fairly lean to have a long-term ill effect.

But fitting an end can for performance makes no real sense anyway, the cost/benefit is terrible. Think of it as a cosmetic mod and you don't go far wrong.

Don't underestimate placebo power! It's just as good as real power for road purposes, and usually cheaper.

[yorkie_chris]

Worth it for the noise alone IMO

[dizzyblonde]

Do they just slip in easy(scuse the pun), but Im Indoors was going to nick A Full Yoshi system from a TL1000 on his Raptor when he first bought it cause he was told tey would fit perfect, til they tried it and they went nowhere near....He got a set of M4 cans in the end( his obsession with loudness is as bad as mine). They are earsplittingly loud!!!
I have an Art can on the yellow one which Suzy was Dyno'd for but the black one has a Scorpion that didn't need it. Both different, no obvious flat spots in performance on either one, apart from the Art can has a superb deep throat and the black one sounds like a can of baked beans in comparison to it..

Thanks again for the comments, Folks. After asking around some more it's clear that your posts are right on the button (and why wouldn't they be ...). There's a clear view that having the fuelling looked at is important.

The options when fitting a Yoshi can, seem to boil down to two:

1) Fitting a Power Commander and doing the full Dyno thing, more pricey but with all of the downstream flexibility that a Commander gives, or

2) connecting to a "Yoshi-box", which Crescent Suzuki in Verwood can do (this is a Dyno exercise that uses proporietary analysing kit from Yoshi), the result is a re-programming of the fuelling that matches the new can - it's fixed and not infinitely adjustable like the Power Commander option but costs much less.

Voila ...!

[fizzwheel]

if it were me I'd go down the Yoshi box route, it gets your fueling sorted and cost less than a PC.

Unless your an expert and wanting to race, I don't see the point in the power commander, I mean who continually wants to mess with your fueling at home all the time.

I would have thought that Crescent would set it up and get it right and then once its set it wouldnt need fiddling with again...