Fitting tuning parts

[fuzz]

What process do you go through when fitting aftermarket exhausts/jetting kits/air filters? By this I mean if you're fitting them yourself, how can you get the fueling right, as obviously altering any of the above will affect this?

A dyno test would sort it out I know, but what about riding there with your fueling set incorrectly. If you add a filter or exhaust system, surely the engine would run lean as a result, and therefore be hazardous to ride any great distance.

Would it be more feasible to fit a jetting kit with an exhaust system at the same time, then get a dyno test done to get the fueling sorted in the right places? In fact, where are the dyno testing stations located?

I'd just like these things clarified before I start meddling as I'm prone to do
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Bikes: '99 NSR125R, '00 SV650S, K1 GSX-R600, '97 CB500, K3 SV1000S, '16 VFR800

[mr.z]

What are you trying to achive by tuneing?

Even propperly set up filter/jet/exhaust will in most cases loose you power low down and beef up mid/top rev power..

Depending on how you ride your bike you might get no benifit from it other that being open to a buggering from any police that pull you for your illegal can


Fuel/air mix can be tweaked to optimum useing a £99 mix analyser, but dyno operators will
A: have FAR better equipment and
B: more experiance useing it.

However something bendy wrote sticks in my mind, at a dyno shootout sort of thing the bikes that hadn't been messed about with (filters/jets and exhusts) were MORE powerfull that those that were...

IMO money is better spent makeing it more rideable, ohlins rear shock, ohlins front suspension innards/progressive springs, better tyres, improved brakes/braided lines...

Depends where you think your bike is lacking in the handleing/rideability department..
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>RidingSkills<->Tech Tips<->MyBikes<

[bish777]

The newer the bike is the less that can be gotten out of it.

Newer superbikes (anything in the last 10 years) are very highly tuned from the start-there is not much to be gained in tuning before getting into bore jobs and turbos etc.

Older machines (like my GSXR1100) respond well to a bit of fettling-for instance, on my bike, dumping the airbox and fitting pods, then rejetting increases power by 7 or so horsepower off the bat, and a free'r exhaust adds almost the same again.
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GSXR1100J

[Kickstart]

Hi

Ride gently and you will probably be fine. Most of the time with 4 strokes you will probably not run dangerously lean with just a pipe and slippers (well, filter), although it might well not appreciate a long run..

Problem is that it might well be rich in some areas and lean in others.

On most modern bikes you will probably only get a 5% improvement from a pipe and filter properly jetted (and a loss of power if you do not get the jetting right), and that is too little to be noticeable on its own. What most people are probably noticing is not the extra top end power, just how the power feels like it is coming in as the revs rise out of a hideous mid range flat spot they have introduced.

Some bikes do have badly designed exhaust silencers. 1200 Bandit is meant to be pretty awful (and weighs a ton), which is why they get a healthy gain from exhaust mods (Akrapovic claim a 20hp gain for their system). Most of the time though an aftermarket exhausts main advantage is being able to piss off the locals easily.

Half the issue with fitting a jetting kit is adjusting it correctly. For example I think there are 5 notches on the stage 3 dynojet kit needles in my Bandit, so you need to choose the right one of those. You also need to find someone who not only has a dyno with an exhaust gas analyser, but who also knows how to use it properly and understand the results.

Fitting a filter is hardly a big issue. After all the airbox will probably need to come off to fiddle with the jetting anyway.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[fuzz]

I've been thinking about it for the SV. There is a flat spot between 4k and 5k revs, but to be honest, I spend most of my time between 3k and 4k.

I agree that money may be better spent on handling, and I'm just considering what I might possibly do at some point in the near-ish future at this stage. (Can't afford anything at the moment ) I'd like some rearsets for a start as the footpegs are a little awkwardly placed for sporty riding, and I'd like to start messing with suspension settings aswell, so a rear shock might be a wise investment. I'm starting to notice the how the bike responds to particular situations better now (in and out of corners, under acceleration and while braking etc)

The original question about tuning was less to do with gaining loads of performance and more to do with my curiosity regarding engines and the tuning of.
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Bikes: '99 NSR125R, '00 SV650S, K1 GSX-R600, '97 CB500, K3 SV1000S, '16 VFR800

[fuzz]

Don't you also have to tell your insurance company if the bike is modded in any way?
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Bikes: '99 NSR125R, '00 SV650S, K1 GSX-R600, '97 CB500, K3 SV1000S, '16 VFR800

[craigs23]

I've cheated a little with the setup of my bike. I found a few people who had similar modifications (half system, free-flowing can) and asked what settings they had made to their jets/airbox. Installed the new system myself, along with the jets, made a few modications to the throttle springs, air holes, added a cdi unit - and then checked all the settings on a dyno.

Recomend telling your insurance company, some finer details to do with the changes may invalidate/change your insurance agreement.