Dbs Exhaust Full System - Ninja 250

[Richie1971]

Hi,

A couple of guys on this forum have asked me for my views on the DBS Full exhaust system which I have had for 3 months.

First off, I went for the Stainless Steel system instead of the carbon fiber system, the guy who makes them a Mr Grim () seems to be of the opinion that they are more durable.

I contacted the guy and he said delivery within 7 days, of course this being Thailand in turned into 12 but I did receive it.

He makes each system to order by the looks of it and does not have a ready stock at the factory.

A local guy down here in Hua Hin fitted and charged me the princely sum of 300 baht, it should be noted that the mechanic and had to make a hole on the system a bit bigger as it was too small. (Not being very au fait with the terminology it was the holes used to bolt the system to the frame)

Performance wise it can't faulted, it sounds good and it looks good.

It is very loud, people can certainly here you coming and the backfire pop pops (another technical term) are in my view a bonus - the Police aren't overly keen on the noise but when I have to stop for them they seem to forget about the noise and have a chat about the bike - once they are told that the bike is made in Thailand and 100% legal.

Overall, a good and affordable mod that enhances the bikes looks and the riding experience - recommended for the Ninjette

Cheers

[thaicbr]

"backfire pop pops"

That could be one of 2 things. ever an air leak at the joint OR it's running slightly lean (not good).

It might pay to invest in a power commander. I have been told that the power difference is worth it.

[Richie1971]

"backfire pop pops"

That could be one of 2 things. ever an air leak at the joint OR it's running slightly lean (not good).

It might pay to invest in a power commander. I have been told that the power difference is worth it.

Thanks for that - Just been speaking to the local big bike guy and he say's almost all bikes backfire with a custom exhaust, it's only the design of the stock exhaust that prevents you from hearing them anyway?

As for a power commander, where can they be acquired, any idea how much?

Cheers

[dave_boo]

"backfire pop pops"

That could be one of 2 things. ever an air leak at the joint OR it's running slightly lean (not good).

It might pay to invest in a power commander. I have been told that the power difference is worth it.

Thanks for that - Just been speaking to the local big bike guy and he say's almost all bikes backfire with a custom exhaust, it's only the design of the stock exhaust that prevents you from hearing them anyway?

As for a power commander, where can they be acquired, any idea how much?

Cheers

Thanks for the writeup.

In answer to your backfire (technically it's an 'after-fire' since a backfire is when the flame front travels up and out the intake tract but I'll continue to use the term since that is what is used by pretty much everyone) question; actually it can be caused by overly lean or enriched mixtures.  The leaned out mixture is the most common and likely what you have since modern emission requirements necessitate the tuning.  Basically what happens is that there's not enough fuel to ignite within the manufacturer's design time.  As it is pushed out it has more time to burn and hence 'explodes' outside of the combustion chamber.  Add in a closed throttle which cuts off air, and if the fuel injectors don't stop opening quickly enough, the injected fuel will actually cool the chamber off enough to prevent a combustion cycle (the alternative is much more frightening in that the mixture is so lean the chamber remains hot enough that you have popping all the time not only on off throttle--a recipe for disaster).  With a stock exhaust these pops are hardly noticeable to non-existent simply due to the tightness of joints and the catalysts installed.  I.E. there is no air that is combined with the unspent fuel and a lot of the 'potency' is taken off when passing through the cat (although this also decreases the life of the cat).  Most after market exhausts are not as sealed up and definitely don't have a cat, combined with the leaning action of higher flow you start hearing the pop-pop you're talking about.

In regards to the power commander question I have purchased a  PCV (power commander 5) from the States.  Some 365 USD.  On a stock exhaust it doesn't do much of anything except make the mid-range a bit fatter.  It may have also smoothed out the on-off nature at lower throttle openings or perhaps I'm simply getting a bit better at modulating it.  I'll have to boot up windows and then take a couple of screen shots so that you can see the + and - amounts that power commander makes over the stock map and then the map they offer for the Yoshi pipe if you're interested.

[dave_boo]

 Double post removed.

I forgot to mention; perhaps a low cost fix to your problem would be an exhaust pipe sealant.  High-temperature silicone maybe?  After all you do have some 8 joints in the system that all could be letting in air....

Edited May 4, 2011 by dave_boo

[Richie1971]

Thanks for that much appreciated - actually am thinking about exchanging it for a KLX or D-Tracker - £ for £ I think the Ninjette is better but the roads in Hua Hin are getting worse and worse and the Ninja dosent like being man handled across pot holed byways and highways

Cheers again

[KRS1]

apart from the sound how much power did you lose/gain?

[Richie1971]

apart from the sound how much power did you lose/gain?

Haven't noticed any loss or gain