Rubicon beats SP500HO in Drag Race... not once but twice???
#21
Thor,
What you have said makes sense, and I would agree with you if it were not for the fact that I have tested the SP500 both ways. I really think my bike is a little quicker on the sand drag with 27" mudbugs than it is with stock tires. I understand that it is not a fair and accurate comparison between my bike and the HO, that is why I posted it as a Rubi VS HO sense they both had the same size and width tires.
I am not sure how rich the HO is from the factory, but it took a K&N and a 2" snorkel to get my mixture where it should be. Before I made the mods, Tazgrizz could run off and leave me on the street. After making the mods, I pull him by about a lenght or so.
Greg
What you have said makes sense, and I would agree with you if it were not for the fact that I have tested the SP500 both ways. I really think my bike is a little quicker on the sand drag with 27" mudbugs than it is with stock tires. I understand that it is not a fair and accurate comparison between my bike and the HO, that is why I posted it as a Rubi VS HO sense they both had the same size and width tires.
I am not sure how rich the HO is from the factory, but it took a K&N and a 2" snorkel to get my mixture where it should be. Before I made the mods, Tazgrizz could run off and leave me on the street. After making the mods, I pull him by about a lenght or so.
Greg
#22
Greg & Tex Mud,
Thanks for your honest observations & postings. There appears to be some unhappy HO owners veiwing this thread.
Does this mean these results will happen every time? NO! But they did this time so people should just get over it.
Results can & will vary dependin on many factors.
My question is has any one seen dyno numbers from an independant source on the HP of a SP & SP-HO to see if it does truely develop 20% more horsepower. Or is it just a marketing scheme?
Thanks for your honest observations & postings. There appears to be some unhappy HO owners veiwing this thread.
Does this mean these results will happen every time? NO! But they did this time so people should just get over it.
Results can & will vary dependin on many factors.
My question is has any one seen dyno numbers from an independant source on the HP of a SP & SP-HO to see if it does truely develop 20% more horsepower. Or is it just a marketing scheme?
#23
Tex and Greg,
watch out,im leaving in a few minutes for Texas,look for me.I'll be the guy on the Xplorer.I have to give us Polaris guys back our proud reputations of high performance.
A HO losing to a Ruby and a stock Sportsman?Your next post will read,
Just got blown away by a 400cc Xplorer,
LOL,[just kiddin]
Bill
watch out,im leaving in a few minutes for Texas,look for me.I'll be the guy on the Xplorer.I have to give us Polaris guys back our proud reputations of high performance.
A HO losing to a Ruby and a stock Sportsman?Your next post will read,
Just got blown away by a 400cc Xplorer,
LOL,[just kiddin]
Bill
#28
TexMud,
thats what this whole thing is about,FUN.And it sounds to me like you guys allways have plenty of that.
Texas,from Mich is a LONG haul,but I certainly appreciate the invite..I really enjoy reading about Gregs evaluations,he seems to tell the story exactly the way it happened,not the way he wishes it were,and that adds to a persons credability.Keep up the good work,
Bill
thats what this whole thing is about,FUN.And it sounds to me like you guys allways have plenty of that.
Texas,from Mich is a LONG haul,but I certainly appreciate the invite..I really enjoy reading about Gregs evaluations,he seems to tell the story exactly the way it happened,not the way he wishes it were,and that adds to a persons credability.Keep up the good work,
Bill
#29
Gregg
"Thor, What you have said makes sense, "
+ Yes, it is all basic physics and applied mechanical application.
and I would agree with you if it were not for the fact that I have tested the SP500 both ways.
+under specific tractive conditions not pertaining to true accelerative ability.
I really think my bike is a little quicker on the sand drag with 27" mudbugs than it is with stock tires.
+ This is a traction issue and does not pertain to pure acceleration on hard pavement.
I understand that it is not a fair and accurate comparison between my bike and the HO, that is why I posted it as a Rubi VS HO sense they both had the same size and width tires.
+ Have you considered the fact that the Rubicon is geared lower than necessary and will actually gain speed from an increase in tire diameter?
+ With an HO in the garage, I know for a fact that it is faster with stock tires than it is with 26" Mudrunners, due to gear ratio change of the tires and the amount of power required to turn more rotating mass.
+ Was the air filter on the HO clogged? Did the driver weigh more than the other two drivers involved.
"Thor, What you have said makes sense, "
+ Yes, it is all basic physics and applied mechanical application.
and I would agree with you if it were not for the fact that I have tested the SP500 both ways.
+under specific tractive conditions not pertaining to true accelerative ability.
I really think my bike is a little quicker on the sand drag with 27" mudbugs than it is with stock tires.
+ This is a traction issue and does not pertain to pure acceleration on hard pavement.
I understand that it is not a fair and accurate comparison between my bike and the HO, that is why I posted it as a Rubi VS HO sense they both had the same size and width tires.
+ Have you considered the fact that the Rubicon is geared lower than necessary and will actually gain speed from an increase in tire diameter?
+ With an HO in the garage, I know for a fact that it is faster with stock tires than it is with 26" Mudrunners, due to gear ratio change of the tires and the amount of power required to turn more rotating mass.
+ Was the air filter on the HO clogged? Did the driver weigh more than the other two drivers involved.
#30
>>>>When you guys race with the auto do you just push the throttle to the bar? Some people have told me they go quicker by not just slamming the throttle wide open from a dead stop. <<<<<<
One of the variable factors involved in acceleration is to attain the highest possible air flow velocity through the carburetor. All of the internal settings of the carburetor are calibrated off of throttle position/air velocity.
If a person changes venturi bore size and goes with a larger carb, he will loose air velocity at lower rpms, minimizing the venturi effect through the carburetor necessary to create power.
At the maximum rpm, the engine will draw more air through the engine with the large carb IF the cam and ports are capable of pulling more air through the engine. Again this is a big if.
Have you ever noticed all of the reports of "bogging" usually involve, carbs, cams, and exhaust? These three items have to be synchronized for proper operation. Certain mods upset this balance and reduce performance.
Which is why all of the mods for Honda 450 don't work. The Honda engineers did not leave any power laying on the table for the "back yard/swamp" mechanics to pick up.
But anyway, back to your original question, nothing is lost by nailing the throttle on a stock machine. On a modified machine; who knows, it will vary.
I hope this helps.
One of the variable factors involved in acceleration is to attain the highest possible air flow velocity through the carburetor. All of the internal settings of the carburetor are calibrated off of throttle position/air velocity.
If a person changes venturi bore size and goes with a larger carb, he will loose air velocity at lower rpms, minimizing the venturi effect through the carburetor necessary to create power.
At the maximum rpm, the engine will draw more air through the engine with the large carb IF the cam and ports are capable of pulling more air through the engine. Again this is a big if.
Have you ever noticed all of the reports of "bogging" usually involve, carbs, cams, and exhaust? These three items have to be synchronized for proper operation. Certain mods upset this balance and reduce performance.
Which is why all of the mods for Honda 450 don't work. The Honda engineers did not leave any power laying on the table for the "back yard/swamp" mechanics to pick up.
But anyway, back to your original question, nothing is lost by nailing the throttle on a stock machine. On a modified machine; who knows, it will vary.
I hope this helps.