Early dyno results: GS intake tubes on R1100S + prediction.

[HerrFlick]

The dyno run:

As the local dyno shop was preparing to relocate it's dyno, I was able to get only a single run, principally to see the shape of the torque curve. No correction factors were applied, but note the ambient temp of 36.C (been a bit warm out here lately .

Circumstances didn't permit before/after runs but I'll be back for those later. (Have to undress the beast to get at the airbox to remove GS runners).

After that I'll be fitting Lennie's RocketSprockets.

The torque curve reflects the seat-of-the-pants feeling, particularly the intital lift at 2500rpm.

What these graphs don't reflect is the smooth rideability across the full rev range as well an urgency in the power delivery above 4000rpm. (Not present in the stock 1100S power delivery).

Note also the steady power delivery from 6000-8000rpm.












Putting my money where my mouth is:

The Prediction

Below are my torque and power curves overlaid on another dyno chart of stock 1100S:

These are the before/after relationships I think I'll get at the next dyno run.


NOTE: If you think these 'predicted' curves look a bit too good, I can tell you the bike runs like those curves look.

Now have a strip of rough rubber around the centre of the back tyre. Was previously smooth.

Always looking for the 7th gear.












Another important chart:

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[oyster]

It looks to me like you have lost about 30 HP since 2003?

[HerrFlick]

It looks to me like you have lost about 30 HP since 2003?

Nope. Not being a dyno operator I have no idea what they did re setting up. As I said above they had just enough time to give me one run to see the shape of the torque curve.

You can't pull 200kph (125mph) with panniers fitted. Or rip up the centre of the rear tyre.

Patience - I'll be back with the before/after charts in a week or so.

[HerrFlick]

It looks to me like you have lost about 30 HP since 2003?

PS: don't take my word for it. Take Mike B.'s from the other thread:

Well the sun was shinning this morning so I got the bike out for the first test ride with the GS tubes. Wow! there was certainly a difference. As soon as I started it I could tell it sounded different.

The exhaust note is louder and much sharper sounding when you rev it.

The rush of power that it normally gives in the last couple of thousand revs, now comes in much sooner. I would say about 4000 rpm. The low down power is definately stronger but more importantly it's much smoother.

But as the revs climb passed about 3000 revs all hell breaks loose and it really takes off. between about 4 to 6k I found myself having to lean forward and hang on.

The induction noise is much louder at those revs too. On a few occasions I actually thought I was in a gear lower than I was, simply because it was pulling too strong

[SAS Tom]

It looks to me like you have lost about 30 HP since 2003?

Nope. Not being a dyno operator I have no idea what they did re setting up. As I said above they had just enough time to give me one run to see the shape of the torque curve.

You can't pull 200kph (125mph) with panniers fitted. Or rip up the centre of the rear tyre.

Patience - I'll be back with the before/after charts in a week or so.

I am looking at doing this myself but you seem to be making out like it turns the bike into some sort of monster. All it does is give you a bit more mid range at the expense of top end. It's only a few hp here and there.

I doubt your shredded rear tyre is to do with the little bit of extra torque as tyres for this bike go on much more powerful machinery. Much more likely It's to do with the road surface or your suspension set up.

I would be interested to see before and after runs for the real difference.

[Mike B]

It may only seem like a bit here and there but it makes a very noticable difference when you ride it.

It's no monster ok, but it will catch you out.

Mine has rocket sprokets as well ,that may make it even stronger in the mid range.

I cant tell by the seat of my pants dyno if it has lost anything at the top end of the rev range, but I very rarely visit that end of the rev range anyway.

For the road, it makes a nice difference, not only to the mid range power, also the smoothness on roll-on and roll-off. Like I said in the other post, you can buy em second hand for under £20 a pair, and mine will be staying. Unlike some so-called great mods that make bugger all difference in the real world.

My advise? try em, see what you think.

[HerrFlick]

It looks to me like you have lost about 30 HP since 2003?

Nope. Not being a dyno operator I have no idea what they did re setting up. As I said above they had just enough time to give me one run to see the shape of the torque curve.

You can't pull 200kph (125mph) with panniers fitted. Or rip up the centre of the rear tyre.

Patience - I'll be back with the before/after charts in a week or so.

I am looking at doing this myself but you seem to be making out like it turns the bike into some sort of monster. All it does is give you a bit more mid range at the expense of top end. It's only a few hp here and there.

I doubt your shredded rear tyre is to do with the little bit of extra torque as tyres for this bike go on much more powerful machinery. Much more likely It's to do with the road surface or your suspension set up.

I would be interested to see before and after runs for the real difference.

Hi Oyster.

No - this doesn't turn the bike into a Hyabusa or an S1000RR - but I'll bet after you fit the GS choobs you'll you'll come back with a grin you won't lose for a week.



Anyone live near Oyster who could verify this?