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Mike, Glad you had a good time, but. And this is not a knock, what the heck?

With all the stuff you have, and stuff you did. Why are you so slow?

I know GT speedo's are not that accurate, and the tachs are notoriously unreliable, but I've done better than that on the Interstate in Texas.

I didn't have three miles either.

Or all that aero stuff, but I suggest your gains there are slight, because a GT is a slippery beast to start with.

Is it the extra weight in your car, of the cage and all those cameras? Or is something wonky with your combination, IE: cam, gearing, tire size, whatever?

I'm sitting here scratching my head, because I figured you would have been at least eight, or so MPH faster than that.

Oh well, it is what it is, and like I said, this was not intended as a knock.

But just for the heck of it. When you do your post run, and the next pre race inspection, you might want to check throttle travel, and see if it opens all the way.

Cause something just don't add up.
I think I can help with this one a little: Bonneville is, well...Bonneville. If it was easy everyone would do it.

You've got a road surface that can change day to day. It can be hard like concrete, can have standing water on it, or it can 'give' like beach sand. Never consistent.

You also have that elevation thing. 4000 feet above sea level. So figure 16% less power or so than you make at sea level.

Higher temps, also less power.

Weight doesn't affect top speed. Only how long to get there.

Gearing is important though. Fall out of your powerband and you're not going fast. A Getrag (and stock 4-speed) have horrible rpm drops between shifts. Judging by Mike's speeds and the rpms he was spinning, he would have a higher top speed in 5th gear with a 3.89 final drive. It would rev a little higher and put the engine back into its' powerband. 4200 rpms would turn into 4700+ rpms in 5th at the same speed.

I ride a KLR 650 dual sport bike. Not fast by any means. Maybe 105-107 mph top speed. I know of a guy with 'The worlds fastest KLR'. Makes about 60% more power than stock. Full aero bodywork. The bike goes 112 mph at Bonneville. That's it! It took him years to go that fast, the first two times he went he was slower than a stock bike.

Bonneville is NOT easy...
 

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Discussion Starter · #44 ·
Mike, Glad you had a good time, but. And this is not a knock, what the heck?

With all the stuff you have, and stuff you did. Why are you so slow?

I know GT speedo's are not that accurate, and the tachs are notoriously unreliable, but I've done better than that on the Interstate in Texas.

I didn't have three miles either.

Or all that aero stuff, but I suggest your gains there are slight, because a GT is a slippery beast to start with.

Is it the extra weight in your car, of the cage and all those cameras? Or is something wonky with your combination, IE: cam, gearing, tire size, whatever?

I'm sitting here scratching my head, because I figured you would have been at least eight, or so MPH faster than that.

Oh well, it is what it is, and like I said, this was not intended as a knock.

But just for the heck of it. When you do your post run, and the next pre race inspection, you might want to check throttle travel, and see if it opens all the way.

Cause something just don't add up.
I agree. I was expecting more, and in fact, we've gone a little faster on a closed course.

It could be the salt, which was smooth and hard but not asphalt. Our tires were pumped up to 40 psi and it felt like I had little grip, even going in a straight line.

There is also the altitude, 4200 feet. We did not do any tuning one we got there. A/F was around 11.5 at mid-RPMs and would rise. Back at home it would be at 12.5 and mostly steady.

We don't have a speedo and our Autometer tach seems to work fine.

Now I really want to get the car on a dyno.
 

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Nice pics!

Hey Mike, Nice Pics! I don't know if it means anything, but the first day results list your run just before Dave Brant's run. Dave is renewing his license and had to make a pass between 150 and 175 to bump the category up. His 170+ did that and the next day he ran a 180+ to get his 175 license. If all went well, he was set to run the first half of the record this morning (existing record is 219 so he can go 225 for his licensing run). The next morning, Randy qualified for a new record at 162+ (record was 149) and ran 166 for his 2nd half - new record is 164+ for a 2000 cc pushrod motorcycle with a sidecar. His early start had him in line 6 places before you. It turns out that a 3rd one of my designs (Derek McLeish) ran his SideCarStreamliner (SCS) with a 1000 cc Buell motor to a 159+ (no previous record in that class). Randy was planning on taking the sidecar off today (9/9) and running as a motorcycle (I think Partial Streamlined) while Derek was adding a bit of Nitrous and going after a "Fuel" record instead of the "Gas" one he just set. Should be a busy day for those 3 as they help each other on their runs! Hopefully there will be 5 new trophies in the various trophy cases at the end of the day! -- Doug

Here is a link to the USFRA web site for more pics and tabulated results for all the rest of US who stayed home rather than going out and going fast! Usfra home page

PS - Dave runs a Honda CBR600 motor in the 750cc class streamliner!
 

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Bonneville isn't for wimps!

I agree. I was expecting more, and in fact, we've gone a little faster on a closed course.

It could be the salt, which was smooth and hard but not asphalt. Our tires were pumped up to 40 psi and it felt like I had little grip, even going in a straight line.

There is also the altitude, 4200 feet. We did not do any tuning one we got there. A/F was around 11.5 at mid-RPMs and would rise. Back at home it would be at 12.5 and mostly steady.

We don't have a speedo and our Autometer tach seems to work fine.

Now I really want to get the car on a dyno.
Hi again Mike, To answer part of your questions, the density altitude on a hot day (85* F or so) can be in the 8500 foot range. That "eats" as much as 25% of your sea level horsepower (but it does help with the drag level also). As you said, the salt is hard, but it is not asphalt. If you walk around barefoot (highly NOT recommended), you will notice that the salt is ALWAYS wet. We have seen motorcycles that were "taching" 20+ mph more than they were running (in the larger engine sizes) and 5% is almost a given, even for smaller engines (but not as small as my 100cc toy). Slippage is always with you! Your numbers are not record breakers, but you knew that going in. The closest equivalent to what you are running would be Grand Touring Sports in the SCTA-BNI rule book. (" ... street cars you can by from a dealer ..."), the record for a 2000cc GT is 166+ mph. I don't know what the car was. -- Doug
 

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I think I can help with this one a little: Bonneville is, well...Bonneville. If it was easy everyone would do it.

You've got a road surface that can change day to day. It can be hard like concrete, can have standing water on it, or it can 'give' like beach sand. Never consistent.

You also have that elevation thing. 4000 feet above sea level. So figure 16% less power or so than you make at sea level.

Higher temps, also less power.

Weight doesn't affect top speed. Only how long to get there.

Gearing is important though. Fall out of your powerband and you're not going fast. A Getrag (and stock 4-speed) have horrible rpm drops between shifts. Judging by Mike's speeds and the rpms he was spinning, he would have a higher top speed in 5th gear with a 3.89 final drive. It would rev a little higher and put the engine back into its' powerband. 4200 rpms would turn into 4700+ rpms in 5th at the same speed.

I ride a KLR 650 dual sport bike. Not fast by any means. Maybe 105-107 mph top speed. I know of a guy with 'The worlds fastest KLR'. Makes about 60% more power than stock. Full aero bodywork. The bike goes 112 mph at Bonneville. That's it! It took him years to go that fast, the first two times he went he was slower than a stock bike.

Bonneville is NOT easy...
Now that makes sense, most of Texas is pretty close to sea level, our roads are paved with solid grippy rubber due to all our truck driving friends, and yeah, there is a difference in power between a hot afternoon, when it's 107 in the shade, (and 120+ on the Interstate). Versus late at night when it's cooler.

Maybe, since you don't have any rules to follow. You could rig up a water injection system with a fine spray, and somehow rigged to rpm, as to density, or pressure.

Food for thought.
 

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Now that makes sense, most of Texas is pretty close to sea level, our roads are paved with solid grippy rubber due to all our truck driving friends, and yeah, there is a difference in power between a hot afternoon, when it's 107 in the shade, (and 120+ on the Interstate). Versus late at night when it's cooler.

Maybe, since you don't have any rules to follow. You could rig up a water injection system with a fine spray, and somehow rigged to rpm, as to density, or pressure.

Food for thought.
I've used Snows Boost juice before...taint bad stuff
http://www.summitracing.com/search/...SortBy=Default&SortOrder=Default&autoview=SKU
You'll for sure will need to do a few spark timing adjustments.
 
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