GSX-S1000 Exhaust System upgrade
(Now with sound clips)
The standard GSX-S1000 exhaust system is reasonably good, with a great noise, however it is a bit restrictive and quite heavy. Huge improvements to the GSX S Exhaust can be made with the right upgrades. 5Kg can be saved with a only slip-on and GSXS decat, as well as a good power increase, GSX-s1000 Tuning is quite easy and the engine rsopnds very well to exhaust changes and tuning.
There are 4 main ways below to upgrade the Exhaust System
There is an exhaust valve, that is controlled by a solenoid system and the ECU, it is designed to enhance low throttle running and it helps to reduce noise emissions to cope with Euro 4. There is also a catalyser and large underfloor silencer on the stock GSX-S Exhaust.
The header system is a 4-2-1 system with 1-4 and 2-3 interconnected,this should produce good torque, however the secondaries are very short causing a major dip in the torque between 4,500 and 6,000 rpm. There simply isn’t room for a decent 4-2-1 system with a cat and underfloor silencer.
There is a narrow band 02 sensor just in front of the exhaust valve and catalytic converter.
There are various different GSX-S1000 slip-on’s available, however the standard slip-on is not particularly restrictive (although it is heavy) so slip-on’s or end cans don’t make much difference to the power or torque and just a slight difference to the sound, although they can also look better. Huge variety in price from cheap copies at 50GBP to expensive cans at over 600GBP. Power upgrade, maximum 1 or 2 BHP
Yoshimura do a range of slip ons for the GSXS, Yoshimura and Suzuki go together like bread and butter..
M4 slip on, small and light and available with an option of 2 dB killers for when you need to be quiet.
Many other such as Akropovic, Arrow, Black Widow etc.
Decat or Link Pipe
A decat or link pipe replaces some or all of the underfloor exhaust components, some link pipes replace just the heavy restrictive silencer whilst a decat usually removes the cat and silencer. Most link pipes leave the Exhaust Valve (EXCVA) in place but it can be removed as well. The decat is the most cost effective GSXS-S1000 exhaust upgrade. GSX-S1000 tuning or reflash will help the bike to run better after this mod.
Decat Exhaust Benefits
The main advantage of a decat is weight saving and power increase at a very low cost. (100-200 GBP) Power Upgrade approx 10 – 15 BHP
As can be seen the silencer is large and heavy and causes most of the exhaust restriction and does most of the exhaust silencing, removing the Cat will add a bit more flow and power.
The exhaust valve can help the bike to run more smoothly at low speeds and quietens the bike around 5000rpm but also reduces the flow at the top end
Link pipes can be home made (if you are a competent welder), made at a local exhaust shop or they can be bought. My first decat was made locally as there were not any available to buy.
They can now be purchased quite cheaply ( and well made) from Oli Jones through the Suzuki GSXS Owners UK facebook group. They are designed to fit the stock slip-on at the rear, at the front you need to cut through the Cat (then remove the rest of the cat) and it just clamps on no welding needed. It leaves the Exhaust Valve in place and functioning.
They can also be bought through Ebay
Full off the Shelf System
Full Yoshimura System Sound
There are a number of retail off the shelf full systems which means full headers, link pipe and end cans, although you don’t have to have all parts from the same manufacturer (i.e. Arrow headers and Akroprovic Can) as long as they are designed to fit i.e. same bore (standard GSX S1000 silencer is 51mm)
When you fit full headers you generally remove the exhaust valve (EXCVA), the exhaust valve servo gives feedback to the ECU on its position (so the ECU can check that the position of the valve is what it should be) and if it doesn’t get feedback it throws an FI error – lights on the dash (code C46), to prevent this error some manufacturers supply a physical rotor arm, or preferably an electronic servo eliminator or a re-flash as the servo itself weighs nearly 1Kg and is worth removing.
Full headers and a good end can can give a significant power increase over stock, but will only get the full benefit with a tune from a PCV or Re-flash, Power Upgrade 10-20BHP
Black widow Headers are very reasonably priced and flow well but have very short secondary pipes, similar to the stock headers
M4 headers have longer secondaries helping with mid range torque
Arrow headers have cross over pipes between the primaries, are more expensive than M4 or Black Widow
Yoshimura headers are a 4-1 system, this is designed for maximum power at the expense of low end torque
My custom exhaust system sound
To eliminate the dip in the torque curve between 4,500 and 6,000rpm so I decided to build my own full custom exhaust system, with tuned headers and a generic GSXS Titanium Exhaust end pipe
I initially built a system with stepped headers and a proper matched and designed 4-2-1, Using 1.5″, 1.75″ and 2.0″ (39, 44 and 51mm) stainless pipes with 460mm primaries and 420mm secondaries. This had an SC project end can, however the 2.0″ main pipe was restricting the top end so I amended the initial build. Power Upgrade 10-20 BHP plus a torque increase and no flat spots
I’ve now upgraded again to a larger bore GSX S Exhaust system with a generic GSXS Titanium exhaust end pipe with 1.5″ Primaries, 2.0″ secondaries and final pipe is 2.5″ (39, 51 and 63mm)
The GSXS Titanium Exhaust end pipe and can are extremely light because of the use of Titanium.
The 39 and 51mm pipes are full stainless and the 63mm pipe and the End Can are Titanium. This increase in size was to allow more power at the top end as the 2.0″ pipe was restricting the top end, the rear pipe is now longer than standard smoothing the bottom end of the rpm range.
The stock System weighs 10.4Kg and my system 5.1Kg saving 5.3KG over stock.
The new GSX S exhaust system is awesome, producing more torque throughout the entire rev range and filling in the large dip in torque around 5000rpm. It is now difficult to keep the front wheel down. I often find myself 1 or 2 gears higher than before and it pulls away beautifully. The ECU is now also re-mapped and has produced a sublime engine that produces smooth power everywhere and makes a great noise.
Sound Levels GSX S Exhaust
1 metre behind exhaust with calibrated sound meter
|GSX S Exhaust Volume||Idle||5000 RPM||Max|
|Stock Exhaust||82dB||92 dB|
|GSXS Decat – stock slip on||85dB||97dB|
|GSXS Decat with M4, dB killer||87dB||106dB|
|GSXS Decat, M4 no insert||89dB||108dB|
|GSXS Decat, no tailpipe||90dB||114dB|
|GSXS Custom Headers, SC Project||87dB||106dB||123dB|
|GSX-S Custom Headers, SC, dB killer||82dB||101dB||107dB|
|GSXS New custom Headers Firetorch Titanium||89dB||108dB||124dB|
Custom headers with Firetorch Titanum 2.5″ end pipe