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Discussion Starter #1
One of the biggest mis-conceptions:
If I have the same parts he/she does.... I should run the same time.....


Drag racing is more than just a pile of parts and money. Its easier to say you ran an 11 second 1/4 mile than it is to actually run one.


The number 1 part on in a drag race is the rider/driver.

Tighten the nut behind the steeringwheel/handlebars first. Then go buy parts... otherwise its hard to get the main nut to learn how to handle the rest of the power parts.


Launch tech:
1. Body position is key. Heavier riders should choke up on the tank as much as possible while trying to keep a low center of gravity. An upright rider causes too much weight transfer and will end up with a 12 o'clock wheelie. Light weight riders can cheat this a little by sitting toward the middle of the seat and just leaning forward as to keep some weight on the tires for maximum controlled grip out of the hole.

2. Bike setup can kill a race.
a. Lower tire pressure equals more grip and less roll out. More paddles equal more grip and more weight. Wider paddles equal more grip and more weight. Higher tire pressure equals less grip and more roll out. Less paddles equals less grip and so on.... you get the idea..... So which tire do you need? That is the Million Dollar question. To maximise your current setup. You can play with verying pressure to meet the conditions of the track. Wet/tacky sand = more pressure or Dry/dusty sand = less pressure. How much exactly.... each tire differs.

b. Resistance is futile. Free up your vehicle as much as possible.... Weight can be trimmed by removing un-needed parts and materials. It can also be saved by replacing stock parts with aftermarket light weight performance units. Rotating mass is probably the most critical in low horsepower vehicles (sub 500whp). There is a huge debate as to how much effective weight is being saved. I've heard numbers from 1lb of rotating mass = as high as 9lbs of dead weight. And as low as 1lb of rotating mass = as low as 3lbs of dead weight. One thing all the engineers, keyboard physists, and shade tree mechanics all agree on ....... Its one of the first places to start shaving weight. Here is a neat lil article from Velo news : http://www.velonews.com/tech/report/articles/9662.0.html

The next place to fee up would definately be all rotating assemblies. Engine, trans, hubs, axel carriers, chain, etc. The vehicle that rolls the easiest is also going to be quicker than one that is not easy to roll. This starts off as simple maintenance and keeping your machine clean and lubed. It can also migrate to faster bearings with higher speed ratings and using exotic materials and coatings. Not to mention the rule of weight savings also helps here too....

3. Finding the "groove". Every track or lane has a "groove". The sweet spot in the track. In some cases it can be pretty small. In others it can be very wide. Tire selection affects the size or the type of groove. The type of groove can be key too. This is an acquired sweet spot to find. For example.... My skat traks performed best in wet sand, groomed sand and did not do well in rutted or light fluffy sand. Now that is compared to my STU Brats. The Brats can take off really well in just about anything but really wet sand. In the really wet stuff the Skats pretty much eliminated any advantage the brats had.

Now here is the bad part..... Just like the tire controversy, The groove is subjective to rider style, experience, and comfort; Tire selection, pressure, paddle shape and size; Rider weight, position on the bike, etc etc etc.....

Bottom line....... Take a hand pump and a pressure gauge with you out to the dunes. Start off with launching the bike as it sits. This will tighten the nut behind the handlebars. Then move on to the other stuff.

And don't forget to have fun!!!



More lessons to come later.....yes I'm very bored right now....
 

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WOW Rich...that is awesome. Maybe after reading this I will be able to beat you a few times...for a change! :first:

Great information...only thing I could possibly think about adding is how drastic sand conditions can change throughout a day...from higher temps, wind, etc. all will change the moisture content making the ideal tire pressure you worked so hard to find a 10 am not being ideal at 5 pm. Oh and by the way, it rained 2 days ago so today's ideal pressure at 10 am will not be ideal at 10 am tomorrow!!! Good stuff!

I sure wish you would get a Nitrogen generator so we can fill our tires and change pressure easily! :devil:
 

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Discussion Starter #5
WOW Rich...that is awesome. Maybe after reading this I will be able to beat you a few times...for a change! :first:

Great information...only thing I could possibly think about adding is how drastic sand conditions can change throughout a day...from higher temps, wind, etc. all will change the moisture content making the ideal tire pressure you worked so hard to find a 10 am not being ideal at 5 pm. Oh and by the way, it rained 2 days ago so today's ideal pressure at 10 am will not be ideal at 10 am tomorrow!!! Good stuff!

I sure wish you would get a Nitrogen generator so we can fill our tires and change pressure easily! :devil:[/b]

ha ha ha yeah.... And don't forget to check and set your pressure before every run to try and maintain consistancy (I do it when drag racing my car but not my quad). Running down a hot track and creating rolling friction will also raise air pressure..... (for those who didn't catch it... thats why rob mentioned using Nitrogen).

You can have your tires filled and then get a 5 gallon air tank filled at any "big truck" repair place.
 

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From Mixxer on another site:
static weight...sprung or unsprung....10lbs ~ 1HP

rotational mass is both part of total weight and also part of flywheel weight, you have to carry it AND spin it in its own accelerated orbit..... 1lb rotational~7lbs of static
 

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Let's try pinning this and see where it goes :)
 

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One of the biggest mis-conceptions:
If I have the same parts he/she does.... I should run the same time.....[/b]
Man i could not agree more with this one ......

a. Lower tire pressure equals more grip and less roll out. More paddles equal more grip and more weight. Wider paddles equal more grip and more weight. Higher tire pressure equals less grip and more roll out.[/b]
how about this for thought. I have spoken to others about this and some feel the same way. More air pressure more traction and less air pressure less traction ..... to an extent. Here is the thought ..... When the tire is inflated more MORE of the paddle will dig into the sand offering more traction and when less air pressure is in the tire the tire will start to fold or crinkle offer LESS paddle in the sand and less forward traction. I found this to be very true with some sand stars i tested last year. Just a thought for controversy ...... great post RichS

FUELATV
 

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Great stuff....Cowbell worthy IMO
 

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Fuel, that is very true in damp or clay applications, a good friend of mine from Port Magic explained this to me. On the damp or clay tracks it does exactly what you said, fold over and and not grip with the less pressure, but in the sand (dry) with the skinny tire, when you have less pressure the tire sits "flat" in the sand and as you accelerate it grows like a dragster tire and your only using a small portion of the paddle, requiring less work from the engine. Well thats how it was given to me from Rudy.
 

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Tire pressure on stock tires around here gives you more traction with less pressure and less traction with more pressure. It really depends on the type of terrain you are riding on. I couldn't speak to sand and paddles though. I'm getting ready to go to a drag strip Sunday though that they say you need to run paddles on. I'll have to see if they guy that owns the drag strip will let me borrow the paddles off his Honda if I don't do to well.

I know around here you want your fronts to be hard as a rock when drag racing (less rolling resistance).
 

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Fuel, that is very true in damp or clay applications, a good friend of mine from Port Magic explained this to me. On the damp or clay tracks it does exactly what you said, fold over and and not grip with the less pressure, but in the sand (dry) with the skinny tire, when you have less pressure the tire sits "flat" in the sand and as you accelerate it grows like a dragster tire and your only using a small portion of the paddle, requiring less work from the engine. Well thats how it was given to me from Rudy.[/b]

To add to that, I know when I ran 6psi in my 20x10x8 extremes at st. anthonys my bike would trap about 30mph up choke and with 3.5psi my bike would trap 34mph up the hill. I think the less pressure i had in the tire, let it expand more, therefor letting the bike keep its momentum up because of less drag. I dont remember the lauches very well but I do know it pulled up the hill much better with less pressure. Seems like the sand there is very loose.
 

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Nice post rich...
I race my Quad how i Race my Cars...Drive the Living shit outta of it...
I wont sit then and keep revving my engine when im at the starting point, ill keep it pegged and Drop the Hammer and call it a day. Full throttle all the way down the track never letting off quick shifting....
KUTSUJU STLYE!!!
 

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very nice post.my question to you guys that like drag racing,is this,i have a ltr with the follwing mods 1.full rs5,power commander,velocity intake,and iam also working on the motor,iam going to port it,and get a higher comp piston with web cams mid to top.my question is,i want this as a strong dunner,should i go with a plus six swing arm?how will that affect my dunning?i order a lonestar plus 4,but i have till monday to change my mind.i know that ill be fine with a plus 4,but here is the thing,i want to dyno the bike,and get 2 different maps 1 for race gas,and 1 for methanol,now with methanol i know ill be needing a bigger swing arm[by the way would that even be possible,to run methanol with an after market injector?]let me know what you guys think. :devil: :devil: :devil: what happens is when i go to glamis ill spend saturday all day at the hill,and sunday is when we end up going all over the place.thanks. :mafia: :mafia: :mafia: :mafia: :mafia: :mafia:
 

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very nice post.my question to you guys that like drag racing,is this,i have a ltr with the follwing mods 1.full rs5,power commander,velocity intake,and iam also working on the motor,iam going to port it,and get a higher comp piston with web cams mid to top.my question is,i want this as a strong dunner,should i go with a plus six swing arm?how will that affect my dunning?i order a lonestar plus 4,but i have till monday to change my mind.i know that ill be fine with a plus 4,but here is the thing,i want to dyno the bike,and get 2 different maps 1 for race gas,and 1 for methanol,now with methanol i know ill be needing a bigger swing arm[by the way would that even be possible,to run methanol with an after market injector?]let me know what you guys think. :devil: :devil: :devil: what happens is when i go to glamis ill spend saturday all day at the hill,and sunday is when we end up going all over the place.thanks. :mafia: :mafia: :mafia: :mafia: :mafia: :mafia:[/b]
+6 would be for a drag bike. Even a +4 is abit extreme. If you are making a drag bike then sure go all the way with the length. However, with the mods you listed, you really dont need to upgrade the rear yet. You have a powerfull engine, but not that much. When you have bored it to 520, mid high cams, modded crank, turbo/nitro, etc., THEN go 6" hardback rear because you will have a drag bike. What you have is an slightly modded dune bike. If I were to match a length to those mods you listed, I would go no longer then a +2. You will effect the "dunability" by going much longer.
 

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+6 would be for a drag bike. Even a +4 is abit extreme. If you are making a drag bike then sure go all the way with the length. However, with the mods you listed, you really dont need to upgrade the rear yet. You have a powerfull engine, but not that much. When you have bored it to 520, mid high cams, modded crank, turbo/nitro, etc., THEN go 6" hardback rear because you will have a drag bike. What you have is an slightly modded dune bike. If I were to match a length to those mods you listed, I would go no longer then a +2. You will effect the "dunability" by going much longer.[/b]

Goint to long on the swinger will also cause a loss of traction. It puts the weight to far forward. I wouldn't touch the swinger till you can't keep the front end down anymore. I've found that the ltr has a very nice layout stock. Its alot easier to leave the line hard on then my buddies 450r.
 

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Discussion Starter #17
good added info on the tire pressures guys.


As for the swingers..... I wouldn't mind a +2 on mine but I've seen a couple duners with +4's and +6's....

the longer swinger also makes it more stable at speeds... but the longer the swinger the slower the quad will react when changing direction. In dunes like glamis you could probably get away pretty easy on a +4 - +6. But in LS oklahoma in the trails, a +2 to +4 would probably be it.

And yeah longer swinger also = need more paddles..... you might find yourself needing a 9 paddle brat or 8-9 paddle skat.
 

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I would stay with the stock swing arm if you want a "modified" duner, with the 21" tires it is already a little difficult to slid, and adding more swing arm to the bike will just make it a little harder to turn. if you want to keep the duning fun, I would leave it alone.
 

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Man i could not agree more with this one ......
how about this for thought. I have spoken to others about this and some feel the same way. More air pressure more traction and less air pressure less traction ..... to an extent. Here is the thought ..... When the tire is inflated more MORE of the paddle will dig into the sand offering more traction and when less air pressure is in the tire the tire will start to fold or crinkle offer LESS paddle in the sand and less forward traction. I found this to be very true with some sand stars i tested last year. Just a thought for controversy ...... great post RichS

FUELATV[/b]
i know this does happen. my new 21"s at dumont racing with 4 psi, you could see wrinkle marks in the sidewalls just like a drag slick does
 

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I would stay with the stock swing arm if you want a "modified" duner, with the 21" tires it is already a little difficult to slid, and adding more swing arm to the bike will just make it a little harder to turn. if you want to keep the duning fun, I would leave it alone.[/b]
i will go wth the +4 swing arm,iam going to get a lone star square tube super lite its what they called it.iam also going to add the lighter rear hubs,and the sprocket carrier.ill be fast iam sure of it so kraker bring your blue wheels over to glamis.jk.thanks for the info guys. :devil: :mafia:
 
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