Hotrodding the GS

I'm thinking it has something to do with the vectors.

Dang... that doesn't suck, exactly.

<table border="0" cellpadding="5" width="650"><tr><td>Yes, that doesn't exactly suck. I think it would be great, but that much of an increase in top speed doesn't seem very likely.

What were the before and after velocities on Bigdave's bike, 116 and 127? How much of an increase in power does that represent? Let's use 100 horsepower as the starting point. That's about what the 1200GS motor produces. And we'll shortcut our way to saying that at terminal velocity all 100 horsepower are being used to overcome drag.

Some of you will already know this part. If you increase the velocity by a factor of 2, the power it takes to overcome drag increases by a factor of 8. The factor of 2 is cubed, and becomes a factor of 8.

Working the formula, if 116mph on the GS requires 100 horsepower, then double that speed, or 232mph, requires 800 horsepower. Not that the GS could travel 232mph, but here's another example. To travel at 126.5mph the Bugatti Veyron requires 125 horsepower. Double that speed to the 253mph top speed requires 125 times 8, or all of the car's 1001 horsepower.

That's all very exciting, but what about the horsepower difference between 116mph and 127mph on the GS. Working the formula, those 11 miles-per-hour require a little over 31 horsepower. From 100hp to 131hp. And that's what I mean. It doesn't seem very likely that a Y-pipe and an IICE Air provided a 31% increase in horsepower.

I sure don't disbelieve the report, there are many variables that could account for the speed increase. For example, changes in wind direction and speed, or slope of the road, could each account for an 11mph difference in top speed, without requiring 31 horsepower to do it.

Bigdave-gs had himself a lucky tailwind!
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I took the time when I installed the Y-Pipe to make sure I didn't have any leaks. Everything was fully seated and clamps were snugged down to spec. Ran the bike on the lift and ran my hand down around the connections while the bike was still cool, feeling for and exhaust leaks. None detected, so I feel sure as it heats up the fitting will only get tighter. As for the top speed increase, could be a factor of partialy clogged cat. The bike was run on the same roads I always ride. It has more "punch" in the upper RPM's and it seems to run smoother than it did before I changed out the exhaust and installed the IICE AIR. As for the popping up through the TB's, it seems to have a flat spot and run very lean from idle to 2200 RPM. After it rolls past 2300 to 2500 the engine really pulls hard to red line. I also feel that the peak power curve of the engine was moved up in the RPM range because of the better flow throught the engine exhaust and the installation of the IICE AIR. Just my 2 cents.

Very simple...unplug the IICE Air...plug in the stock wiring and go for a ride...this is not that difficult..
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Same, same with your CCP...just remove all the adjunct items you have added to your bike [one at a time!] until the "problems" are gone.. Perhaps you have done this and I missed that post.
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On induction leaks, we used to use either WD 40 or propane [using unlit small propane torch] on areas of suspected leaks [Chevy SB intake manifolds etc] and note RPM changes, watching out for starting a flame!
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On exhaust could you spray on a soap solution if surface is not too hot to look for leaks/bubbles?<o></o>

I use brake cleaner myself. Mostly because it leaves no residue

JJ

One way as mentioned in Wallowa's post to eliminate the IICE Air from the equation is by removing it or changing the plug jumper to the stock (-0º) position.

Increases in useable power are always good, knowing what caused them is also.

JJ

When I unplug the IICE AIR and plug everything in stock, problem goes away. Plug the IICE AIR back in, popping at low RPM but the bike runs better at mid and upper RPM range.

Well, Lucy. Let's go 'perimenting on all 4 settings. Only way to know fo' sho'. BTW folks, this a 1150 GS Adventure. 126.5 on the GPS rocks.

Wallowa:
How effective for small leaks?

Oh. Almost forgot. To get a full understanding of that GPS verified 126.5 mph....

here is an artist's conceptualization of BigDave's aerodynamics.

Ok so this begs the question…

Since you are all from Texas and we all have heard that EVERYTHING in Texas is bigger than life, faster than a speeding bullet, more powerful than any mere mortal could possibly imagine etc etc…

Perhaps the GPS readings are of a similar bigger than life proportion?

And this is just your way of trying to get the focus back on Texas ever since Alaska stole your thunder?

JJ

Since my 1200 will only do 126.8 by GPS with a full remus and a widget (on it's best day level ground) , I can only say.......the test is on.

The test day I rode with him he didn't have a GPS. I was on my XR1200 Harley that will run exactly 122 mph (and the speedo is spot on, too, at that speed with my Garmin). Day in, day out. Uphill or downhill. (That's when I hit the rev limiter in 5th.) So, I can attest to that much speed.


But I'm sure there is some way we can find out the numbers.

First the description of what constitutes a small anything [] is open to discussion. Next since internal combustion engines are best described as "air pumps"; so the displacement and type of fuel management could result in different degrees of sensitivity when you blow a little propane onto an intake leak and the fuel/air ratio changes from lean to richer....I forgot to mention that we did this at idle speeds, so if you have an idle circuit that also goes into the mix...bottom line, if RPMs vary at all, there is a leak...not something you need a tach for, you listen for the sound of the engine to change.

Brake cleaner, that also makes sense.....and although I did live for decades in Humboldt County and did not smoke, my friends tell me that pot smoke also changes the song of the engine when blown over an intake leak...or perhaps they just lost interest?​

Thanks, I have heard tell of it making the exhaust note more mellow

uhhhh.....whoa... Lost interest in what? I forget. <!-- / message --><!-- sig -->

Dang, this thread is surging all over the place. I just got back from three weeks in Italy, lusting over small Diesels and women in high heels... but in that time, have PS and JJ come out with any new products?

I hit 453 mph on my DRZ once. Well my GPS said it did. I was impressed when it cracked the ton.

lol. My 2610 says something like that , too. Must have been on in a very fast plane.

Has anyone posted some pics of the final location for a GSA 2009? Velcro, Double Sided tape or zip tie?
Thank you.