Engine mods S3

[HarriS]

On 2005-10-02 18:20, Lenz wrote:
The most immediately obvious problem with the std 05 S3 exhaust is the 1 - 2 branching before the cans. The right side pipe is on the outside line of a larger radius bend and gets the bulk of the gas flow. The left side is virtually non functioning. Without a full autopsy on the upstream exhaust to find restrictions caused by emission controls and join/weld inaccuracies I'd take a bet that a disappearing act performed on the CATs, rework the 1 - 2 branching and upgrade the cans would show results.

That´s exactly what I thought also before I saw the Arrow exhaust dyno curves. They have a new very nice looking link pipe in their half system but it nets the same 3hp increase in peak power and 5hp mid range like all the rest including TORS. A single 2" can might get better results but that is to be seen.

The bore/stroke ratios of the 05 S3 and the Daytona are different. Small shifts in this ratio mean big changes in the location and range of torque, top end horsepower and revs. These engines have not been engineered by muppets. Bore/ stroke and cams have been matched to the approximate expected usage of the bike. My ideal engine would be a 90deg V4 1200 with a bore/stroke ratio at 1.12 - 1.15 in a chassis like the S3. Tweaking the last bees dick of power out of that would be just a waste of good riding time!!

So the Triumph engine cannot be tuned and changing the cams would get very poor results?

[ This message was edited by: HarriS on 2005-10-03 00:38 ]

[Martin_R]

On 2005-10-02 18:20, Lenz wrote:
The most immediately obvious problem with the std 05 S3 exhaust is the 1 - 2 branching before the cans. The right side pipe is on the outside line of a larger radius bend and gets the bulk of the gas flow. The left side is virtually non functioning.

That's what one would think by just using common sense and by looking at the split, but actually with TORs the left muffler seems to exhale noticeably more than the right one.

I have no idea why this is, but at least on idle and moderate revs with a cold engine and moisture in the cans this can be easily seen. Or if you just put your hand in the way of the exhaust gasses you will notice that the air pressure on the left is higher.

Its good to see plenty of theory offered but has anyone actually dared to meddle with the 05 S3 yet. There is undoubtedly potential for improved performance HarriS. Judging by the number of times this thread has been viewed there is a lot of interest in the subject so I guess the sooner you post your dyno results the better.

For my own expectations of the bike, Crashmasterd's first 2 posts is pretty much where I'm coming from. Dyno charts from Staintune would be interesting given their claim of +9hp and broad torque gains. The 05 S3 engine management appears to work on a collective basis as opposed to individual cylinder management so a PC III installation should be reasonably straight forward.

Stay cool

[Legman]

Crashmasterd wrote:

Legman in Melbourne has promised Dyno charts for the Staintune half system here in the next few days. Keep an open eye.

I met the guys from Staintune at the Melbourne Motorcycle Show two weeks ago. At my request they sent me copies of the dyno charts for the 05 S3. These charts show a 7.6hp increase and a healthy increase in torque right through the range.

The dyno figures for both stock and modified are lower than you might expect but the Staintune factory (and their dyno) is at altitude. Figures would be better at lower altitudes.

I am very happy with the Staintunes. Staintune claim no remap is required, and the my experience confirms that. The bike runs as well as it did on the stock pipes...... except for the extra grunt and the glorious exhaust note




I don't know what the weight savings are but the staintunes are significantly lighter than the stockers, and they don't appear to get as hot as the stockers either.

[ This message was edited by: Legman on 2005-10-03 21:02 ]

[crashmasterd]

Thanks, John

All I can say is that's a whole lot better than the dynos I've seen from other manufactures. It looks like it cleaned up both the HP curve and the Torque curve a bunch too.

The only problem I can see is that it dropped the bottom basement out of both the HP and Torque by a couple 100 RPM- which was to be expected. Who rides below 2200 RPM anyway?

What altitude is Staintune at? They dyno we use here at Portland is about 320 feet, or roughly 100 meters above sea level. If I buy I'd like to compare.

[Legman]

Hi Crash,

I'll find out the altitude and let you know.

[HarriS]

On 2005-10-03 21:29, crashmasterd wrote:
The only problem I can see is that it dropped the bottom basement out of both the HP and Torque by a couple 100 RPM- which was to be expected. Who rides below 2200 RPM anyway?

Nah, they just opened the throttle at ~2000rpm. It is not very wise to load the engine at very low revs.

At last some credible dyno data - thank you Legman. There is some difference between Staintune's claimed +9hp peak gain and the graph data so I took a shot at correcting the data to the standard hp rating at sea level at std atmospheric conditions.

A Google search turned up a conversion site thats worth a look : http://www.csgnetwork.com/relhumhpcalc.html The dyno data shows the runs were done a couple of days apart at approx the same time of day so if we make a few guestimates at the local conditions we can plug them into the converter and come up with a ball park estimate of the delta HP at standard sealevel. The converter site gives explanation in greater detail of the std/base input data.

Temp 87F, Sea Level Air Pressure 29.235 in Hg, Rel Hum 60%, Altitude 2073ft (632m) - Google - Mittagong NSW

Out pops a Correction Factor of 1.142 to be applied to the raw dyno data and 1.142 x 7.6delta HP = 8.7HP @ sea level and standard atmospherics. Allowing for a little inaccuracy in the input estimates I'd say +9hp @ sea level std is a fair call from Staintune. I have absolutely NO connection with this company or any interest in this business except fact finding.

I have no idea if this factor can be applied to the torque figures.

Cheers guys

[HarriS]

The dyno software should correct the atmospheric conditions to standard anyway so correwction factors should not be needed afterwards. Otherwise the two graphs are not comparable at all.

I agree - the figures should be corrected to a std sea level power rating but I have seen a fair amount of published dyno results that have an attached comment regarding ambient conditions at the time of testing to the effect that - "it was a hot humid day/ at altitude so the results were affected blah, blah blah"
Dale Walkers Hole Shot exhaust site is very credible yet still makes these statements. Even at the raw delta hp and torque figures there is a significant increase over the average gain of 3 - 4 HP. I'd be inclined to give Staintune the benefit of the doubt - the check from the conversion is too close to their original claim to ignore.

Cheers guys

[ This message was edited by: Lenz on 2005-10-04 21:15 ]