New build could be overweight...

[John Thawley]

I'm mid-build on a new car. I used the 3/8" tungsten cylinders laterally embedded into the body. COM is perfect... car looks good... but I'm at 138 grams without paint. /images/boards/smilies/frown.gif

I'm looking for areas to remove wood... but what I might be able to get out won't yield much at all. I could shorten axles... again, no big whoop. I'm running 1.8 gram wheels... could go to 1 gram, but prefer not to.

So, it's either try to paint it with 5 grams of paint or figure out how to drill through into the tungsten. I'm guessing the latter is a major undertaking.

Any thoughts... or do I send it to the crusher and start over? This is the first body I've drilled with the block and it's rolling awesome right out of the box.

JT

 

[Obsession Racing]

I'm mid-build on a new car. I used the 3/8" tungsten cylinders laterally embedded into the body. COM is perfect... car looks good... but I'm at 138 grams without paint. /images/boards/smilies/frown.gif

I'm looking for areas to remove wood... but what I might be able to get out won't yield much at all. I could shorten axles... again, no big whoop. I'm running 1.8 gram wheels... could go to 1 gram, but prefer not to.

So, it's either try to paint it with 5 grams of paint or figure out how to drill through into the tungsten. I'm guessing the latter is a major undertaking.

Any thoughts... or do I send it to the crusher and start over? This is the first body I've drilled with the block and it's rolling awesome right out of the box.

JT

First off, FORGET about drilling into the tungsten. You will not get through that stuff with standard drills.

Secondly, if I do my math correctly, that's 0.18oz(approx) left for paint. That's completely realistic, unless you have a heavy hand with the paint can, or tend to use heavier paints in general. If you keep your base (body filler, or whatever you use to seal the grain) to a minimum, and spray light coats of primer and then color, you should be OK. One good option that is relatively light is the Duplicolor "Metalcast" series. With this, you lay down a light ground coat, and then as many coats of color as you think is necessary to get the right look. The nice thing is that this paint is essentially a colored clear coat. Therefore, you won't have to run clear over the top if you want to save weight. Clear can be heavy, and really push your paint weight up.

Alternately, if you are using a more sophisticated paint system (HOK, for example), you can probably stay under weight as well, as long as you don't load on the clear coat.

Finally, you mentioned wheels.....why don't you want to use 1g wheels? I assume that you are using wide wheels as opposed to razor wheels. The Intimd8r's that John sells are the fastest on the planet, and weigh in at about 0.9g. Is there some reason (outside of cost) that is keeping you from using them?

O.R.

 

[John Thawley]

To be honest... if I was building a proxy car, the 1g wheels would not be an issue. We're building a pack car with full confidence we'll get to the council finals. That said, I'd prefer that lettering show on the inside and not raise the "ire" of other parents that find accusing you of buying a win easier on their own ego than giving you and your son credit for doing your home work and busting your butt to get it right.

I'm fairly confident in this case that we'd only go faster with 1g wheels and risk looking like we're piling it on.

Meanwhile, I've taken the car to the belt sander. /images/boards/smilies/smile.gif Believe it or not, it did grind through to the tungsten and even ground some off. I had a layout of three lying parallel to the ground behind the rear axle... three lying in front of the axle and two lying parallel and centered in front of those. I've dug the two out... replaced them with three 1/4" cubes and filled the hole with bondo.

Now I'll be able to shape the body back to near original, paint comfortably (I like high gloss clear) and still have some headroom to tune the COM. It's going to be a bit more aggressive given we've taken weight from in front of the axle.... so with a few small holes and some tungsten putty, we'll be able to get the weight spot on and make some quick tuning adjustments if we're too aggressive.

Thanks,

JT

 

[36racin]

John,
I saw on here someone used a sharpie or some type of marker and used some type of alcohol to rub the lines out from the pen. Might try that if your close on weight and you not looking for a pristeen paint job.

 

[Kinser Racing]

I use a sharpie. It's just an alcohol based stain. If you want to build a sleeper forget the paint. I just painted my street rod body 5 minutes ago, I can do without it.

 

[quadad]

Personally I find having at least 1/4 oz (preferable more) of adjustable weight (margin and space) to be immensely more important to me than a pretty paint job - if you have a track to practice on. You can create some separation from those with equal build skill and knowledge if you have a track, and one of the ways you do that (as you probably know) is to 'tune' the weight beyond standard expectations for COM, side-to-side, etc.

That said, I have never made a beautiful paint job or used more than 2.5 grams for paint. My latest cars with one coat of primer and one coat of topcoat have closer to 1 gram. They won't get any ooh's and aah's, but they are 'in-the-hunt' speed wise. Expecially if this is one of your first builds of this type, don't expect it to be perfect, take advantage of the experience and you will discover ways to build better next time. Best of luck !!!