GTS1000 Horsepower
Finally got some real horsepower
Sat 14 Oct 2006
New improved GTS1000A... a SuperSportsTourer is born! How to tune a GTS...
make some bigger holes in the airbox,
fit a less restrictive exhaust & silencer
and then modify the internal inlet snorkels (early airbox shown, extra oversized external holes inside the airbox can be seen). The internal snorkels are removed at the base and radiused with a Dremel or similar.
and life is a big gas
Notice the start of a bell shaped curve (red one)...yippee... just needs a fuelling tweak and it'll be awesome vs standard!
Peak horsepower now at 113 RWHP, or around 125 crankshaft (DIN) HP estimated, but the real surprise is there are no losses compared to standard, and the average horsepower is 22% greater than before, which translates into 22% more acceleration, and the gains are huge, especially from 7000 rpm.
Just lost a major criticism of the GTS having poor top end power, compared to it's FZR engined cousins, and the best bit is I have seen 118 horsepower, but I couldn't run the bike like that...not yet anyway..
I'll dig out the curve for you naysayers.
make some bigger holes in the airbox,
fit a less restrictive exhaust & silencer
and then modify the internal inlet snorkels (early airbox shown, extra oversized external holes inside the airbox can be seen). The internal snorkels are removed at the base and radiused with a Dremel or similar.
and life is a big gas
Notice the start of a bell shaped curve (red one)...yippee... just needs a fuelling tweak and it'll be awesome vs standard!
Peak horsepower now at 113 RWHP, or around 125 crankshaft (DIN) HP estimated, but the real surprise is there are no losses compared to standard, and the average horsepower is 22% greater than before, which translates into 22% more acceleration, and the gains are huge, especially from 7000 rpm.
Just lost a major criticism of the GTS having poor top end power, compared to it's FZR engined cousins, and the best bit is I have seen 118 horsepower, but I couldn't run the bike like that...not yet anyway..
I'll dig out the curve for you naysayers.
Comments
GTS1000 SuperSports Tourer
Sat 08 Jul 2006
What a difference a few hours make, and the red curve was the finished result.
Earlier in the morning on the dyno, I was at the green curve stage, come the afternoon I was sitting pretty on the red curve, and when you compare the gains from each improvement, you can see a GTS responds well to modification. If you look at the standard curve and where I am now, there are virtually no losses, and huge gains, between 22-36 hp more than standard, and no camshafts, engine mods or porting has been done to date. Talk about free horsepower.
Earlier in the morning on the dyno, I was at the green curve stage, come the afternoon I was sitting pretty on the red curve, and when you compare the gains from each improvement, you can see a GTS responds well to modification. If you look at the standard curve and where I am now, there are virtually no losses, and huge gains, between 22-36 hp more than standard, and no camshafts, engine mods or porting has been done to date. Talk about free horsepower.
Renegade vs DIY EXUP exhaust
Sat 08 Jul 2006
After fitting the Renegade exhaust, which was an obvious improvement on standard, I have to say I was slightly surprised at the lack of horsepower that replacing the standard restrictive silencer with a more freeflowing straight through noise absorption silencer had actually produced.
According to the Renegade website,
I should be getting a second wind at high rpms, but on examining the Renegade exhaust, I made an interesting discovery...it had not been butt welded as I had thought, but there were blades of metal from the inserted tubes used in it's fabrication sticking into the exhaust flow, and undoubtedly causing back pressure or reversion.
So whilst England were losing on penalties against Portugal, I decided to mod an FZR1000 EXUP exhaust to replace the Renegade in a back to back test on the dyno. The reshaping of the exhaust to clear the centre stand came from various donor parts from the breakers near me, welding was carried out using a MIG set, a flange to mate the Lambda sensor to the EXUP cavity was fabricated and the whole exercise was completed after a few hours.
Then it had to be fitted...what a pig this was. A weekend later it was fitted and then it was off to the dyno again.
To be honest the bike didn't feel any different, but your butt is the worst dyno in the world, anyway you'd expect a 4-1 system to gain top end at the expense of bottom end compared to a 4-2-1, all things being equal. I wasn't surprised to see the hp down at low-mid rpm, but I was surprised to see no change at the top end, and more importantly nothing like the Renegade dyno results.
So what was causing this.
The green curves are the two exhaust systems, Renegade and homemade EXUP versions... nothing in it... and the red curve was a few hours later.
According to the Renegade website,
I should be getting a second wind at high rpms, but on examining the Renegade exhaust, I made an interesting discovery...it had not been butt welded as I had thought, but there were blades of metal from the inserted tubes used in it's fabrication sticking into the exhaust flow, and undoubtedly causing back pressure or reversion.
So whilst England were losing on penalties against Portugal, I decided to mod an FZR1000 EXUP exhaust to replace the Renegade in a back to back test on the dyno. The reshaping of the exhaust to clear the centre stand came from various donor parts from the breakers near me, welding was carried out using a MIG set, a flange to mate the Lambda sensor to the EXUP cavity was fabricated and the whole exercise was completed after a few hours.
Then it had to be fitted...what a pig this was. A weekend later it was fitted and then it was off to the dyno again.
To be honest the bike didn't feel any different, but your butt is the worst dyno in the world, anyway you'd expect a 4-1 system to gain top end at the expense of bottom end compared to a 4-2-1, all things being equal. I wasn't surprised to see the hp down at low-mid rpm, but I was surprised to see no change at the top end, and more importantly nothing like the Renegade dyno results.
So what was causing this.
The green curves are the two exhaust systems, Renegade and homemade EXUP versions... nothing in it... and the red curve was a few hours later.
GTS1000 hp & torque mods to date
Sat 15 Apr 2006
Went on the dyno again today, and did some more tweaks. Finally got some data with the new Renegade 4-2-1 collector and larger bore Renegade downpipes fitted, which have now replaced the OEM catalytic converter and drinking straw OEM downpipes.
Mods to date include, bigger inlet holes in airbox base, Renegade downpipes and collector but still running OEM silencer.
Green top curve is rear wheel horsepower to date, red curve below the green one is standard unmodified bike.
Other curves are torque curves for the two hp curves above.
Mods to date include, bigger inlet holes in airbox base, Renegade downpipes and collector but still running OEM silencer.
Green top curve is rear wheel horsepower to date, red curve below the green one is standard unmodified bike.
Other curves are torque curves for the two hp curves above.
First horsepower gains with a modded airbox
Tue 04 May 2004
After double checking my bike's performance against another GTS1000, it was discovered I had an HT fault, not a head gasket problem, although I did find I had a coolant fan switch fault later. Below is a curve with the airbox off and with the airbox on.
After doing the essentials, I noticed that the holes into the airbox were mighty small compared to say a a well fed 250cc four stroke, so I removed the top lid of the airbox and I got a bit more horsepower than this.
The green line is what I ended up with after putting back the stock lid and air filters. Not a bad gain for a little work with a holesaw,
and the blue line is the unmodified bike's rear wheel horsepower plot.
After doing the essentials, I noticed that the holes into the airbox were mighty small compared to say a a well fed 250cc four stroke, so I removed the top lid of the airbox and I got a bit more horsepower than this.
The green line is what I ended up with after putting back the stock lid and air filters. Not a bad gain for a little work with a holesaw,
and the blue line is the unmodified bike's rear wheel horsepower plot.
