Speed Demon Wind Tunnel Test

[wobblywalrus]

Disregard the previous post.  The Rocket Seals square o-ring was rubber.  This morning I read the Hot Rod articles about big motors.  That is quite impressive.  It make sense for Duttweiler and others to give out this info from a business viewpoint.  Folks need to know about the things they do and sell in order to buy their services and parts.

[racergeo]

    Just wondering what some of you that posted on this topic think after the result George and Speed Demon had at last years Speed Week. Aero must be petty good, two wheel drive not the worst and single non hemi engine.  I know that He has a Liberty 10 speed trans on order and Craig Liberty is doing the engineering for it right now. That's right TEN SPEED. Clearly George is trying to get another quarter mile or so in top gear to take the absolute wheel driven record.

[handyguy]

  MY LIMITED UNDERSTANDING OF HOW TO GO REALLY FAST IN A  LIMITED DISTANCE ( 5 MILES )  HAS A LOT TO DO WITH TRACTION IN THE FIRST SEVERAL MILES RELATING TO SPEED IN THE REMAINING DISTANCE  .. IF YOU NEVER CAN REALLY HOOK DOWN   , THAN YOUR SPEED WILL REFLECT THE RESULT ..     ME , I ONLY WILL RUN ABOUT 120 MPH THIS YEAR , SO TRACTION NOT MY ISSUE  , EVERYTHING ELSE IS  !!    I AM SOOO
 LOOKING FORWARD TO THIS YEAR  .. EVERYTHING IS APART TO MAKE IT AS GOOD AS IT CAN BE ANY NOT HURT  ITSELF ..  EVERY FALL I THINK I WILL UP GRADE A FEW THINGS   HA HA  , ITS ALWAYS MORE . NEW WIRING  SO WILL START AND RUN  , ENGINE APART  , CHECK EVERYTHING , WHAT CAN I MAKE A ITTLE BETTER ..    BOOOST WILL STAY AT 6 / 7 LBS.  ,, GASOLINE  ,  CAM TIMING HAS BEEN A BIG AWAKENING , 90 DEGREES ABDC FOR INTAKE SEATING , SURE WOKE UP TOP END  !! I WILL SEEE ..    I KNOW LOTS OF RACERS ARE DOING THE SAME THING  ..    STEVE

[Jack Gifford]

Why are you shouting?

[trimmers]

     Clearly George is trying to get another quarter mile or so in top gear to take the absolute wheel driven record.

I'll bet what he's really after is a wheel-driven record at (or above) 500!

Jeff in Boise

[ronnieroadster]

The addition of more gears will certainly help keep the engine in the needed power band to get more top end. But while that area is going to be changed the next issue then will become more of a concern that's traction. Oh the fun of trying to go even faster its an endless addiction for sure.
 Ronnieroadster

[tallguy]

With a significantly less-massive car, getting more traction will require aerodynamic methods.  I wonder whether
the Speed Demon team has consulted with the Carbinite team, who appears to be pretty knowledgeable.

[Rex Schimmer]

Assuming that they used 3000 hp to go 480 they would need a additional approx 400 hp to make 500. Just a 1/4 turn of the boost control!
It is interesting how much down force they must be generating as they certainly appear to be able to go 500 with two wheel drive, and at one time it was "written in stone" that to go really fast you must have 4 wheel drive.

Rex

[stay`tee]

What was the reasoning that you required 4 wheel drive to attain high speed ?

[racergeo]

   
  I have always thought that a neglected area in LSRing was tire rubber compound. I've only recently given it more thought because of a conversation with Marlo. He told me that his car basically ripped up the Mickeys, much as you see the Speed Demon do on every run. He somehow got ahold of some 30" Goodyears with enough of a different compound to keep from spinning the tires and not throwing or spinning the rubber off. He had the tits still on them after the last time it ran in Au.
   The reason I believe this is as a former drag racer I am aware of the huge amount of compounds available to drag racers through several manufactures. As a NASCAR fan I know they are always messing around with different compounds for different tracks. It is the same for nearly ever form of racing. If you have been around for any time at all, you know that in LSR we are lucky to have any tires at all. If someone did have enough money they could get a run of a softer tire from M/T and maybe even an extra 20 thou or so rubber just to give it a go. I know, wish full thinking

[John Clutch]

   
  I have always thought that a neglected area in LSRing was tire rubber compound. I've only recently given it more thought because of a conversation with Marlo. He told me that his car basically ripped up the Mickeys, much as you see the Speed Demon do on every run. He somehow got ahold of some 30" Goodyears with enough of a different compound to keep from spinning the tires and not throwing or spinning the rubber off. He had the tits still on them after the last time it ran in Au.
   The reason I believe this is as a former drag racer I am aware of the huge amount of compounds available to drag racers through several manufactures. As a NASCAR fan I know they are always messing around with different compounds for different tracks. It is the same for nearly ever form of racing. If you have been around for any time at all, you know that in LSR we are lucky to have any tires at all. If someone did have enough money they could get a run of a softer tire from M/T and maybe even an extra 20 thou or so rubber just to give it a go. I know, wish full th inking

No clue if its been tested or not but what about nitrogen in the tires? It must be a temperature issue.

[BSTER]

We have been running nitrogen in our tires for years.  Less fluctuation due to temperature

[Rex Schimmer]

The reason that nitrogen can have an effect on tire pressure is that the way nitrogen is refined out of the air. It has an extremely low due point i.e. very low water content. Heat in tires is generated by tire flex and slip, if you have any water in the tire it will expand at a faster rate than a normal gas because it is turning to steam. A dry gas expands proportional to its change in temperature (in degrees kelvin ). When water changes to steam at 212F it expands at a ratio of 1700:1. You can get the same affect by using air that has been compressed and then dried using a desiccant dryer which typically reduces the due point to -40 degrees F, a refrigerant air dryer reduces the due point to 32 degree F at best. So you can certainly use compressed air for your tires but the compressor needs to have a desiccant dryer, or just use nitrogen.

Rex

[noboD]

I've heard of local tire dealers pushing nitrogen for an extra cost saying it is safer.  Street cars have run on air for over a century. I understand race cars are different.

[salt27]

Costco uses nitrogen and green valve stem caps to indicate it.