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Post Info TOPIC: New build


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New build
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IMG_20180829_200708596.jpg

After three years and only 10 races it is time to retire the old 321 car in favor of something lighter, smaller, and hopefully more comfortable.  This one measures at 8 ft long (which is over 2ft shorter than the old car) and will have full suspension.  Fitting everything inside such a small package may prove a challenge especially as I intend to stick with lead acid batteries.  (Although the Open Class is getting kinda lonely in this part of the world as Advanced Battery takes off)

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looks good! id be interested to see how it turns out with a body



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Got my suspension on.

Using a sliding pillar style on the front and a more traditional

swing arm on the rear. It's only about an inch of travel but

hopefully enough to keep me from feeling beat up at the end of the race

IMG_20180902_193140337.jpgIMG_20180902_192810840.jpg



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Progress is still being made...

I'm unsure if I'm going to fully enclose it like my last one.

Building a body is a lot of work and I question it's aerodynamic benefit at a max of 40 mph.

IMG_20181231_083158740.jpg

 



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Look at how top fuel dragsters do it, some are open, others are closed, I think if you keep it open you'll be a lot more comfortable, and if its not a difference at 300+ MPH then I think you'll be fine

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Yeah, but I don't have 5000 hp pushing me for 4 seconds... I have 2 hp pushing for 1 hr. If there is any sort of aerodynamic benefit from being fully enclosed I would be foolish to ignore it. ...but it does get awful hot in there...

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Well my thought was at 300 mph a small improvement in aerodynamics would help about 1000x more then at 30 mph, so for them a small increase in aerodynamics would help a lot for a dragster. However some of them don't fully enclose their driver, so I was thinking that if done correctly you could have a open top car.


However the more I think about it with so much speed the air around a dragster probably creates a bubble creating very little drag. There might be a point on a "level of closed-ness vs. aerodynamic advantage" curve where there is nearly no benefit to being fully enclosed, so having a small opening might be a valid option.



-- Edited by Nitoragro on Saturday 12th of January 2019 02:06:55 AM

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Electrathon and drag racing very much are opposite ends of the performance spectrum. Thinking about things very simply, the balance is in the proportional effect of accelerating the mass, against holding speed due to aero drag.
If you think about where Electrathon's hard-fought-for power is used, in drag cars it's about getting them to speed super fast and perhaps holding it there briefly.

The balance of drag vs acceleration is even more apparent in human powered vehicle racing. Battle Mountain speed record vehicles have comparatively heavy bodies, with efficiency as high as physically possible, so that they can hold as high of a speed as possible with low power. However, they get a 5 mile run-up, so the acceleration requirement is very, very low. Vehicles hence have gearing set up for top-speed and nothing for accelerating, visibility that's totally useless for anything other than the event and other items that help in the critical performance areas. The same for events like the Solar Challenge and other long distance, low power formulae; efficient aerodynamics for up to around 1/10th the speed of sound.

On the other hand, drag racing has a monumental power availability over a very short distance.
The propulsive power to get a heavy drag car from 0 to ~250mph is much higher than the power to overcome friction in the short time that the car is creating turbulent air behind it. These machines have anywhere from 1500-5000hp; even a huge drag factor can be overcome by power.
Also, they are much more worried about having to sling extra weight up to speed, so an aero body would overall definitely slow them down. Extra mass at the start means they're behind by the time they're up to the speeds that aerodynamics can help; drag racing is won and lost in the reaction time and the first 50 yards, not the last 500.

Think about aerodynamics in Electrathon as being a "sapping" factor. Any aerodynamic deficiency is held all the way through the event. But then balance that on having to speed back up out of a corner, and bolting on an 80lb body to get your 5% aero improvement then obviously goes too far as you'll not be able to get it back up to speed effectively.

Weight reduction gets you up to speed quickly, an aero body helps you hold it at speed.



-- Edited by Brendan_Smith on Monday 14th of January 2019 04:19:51 AM

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