Weight

[Dynoroom]

How do you mount your ballest in your race car? Do you bolt it down or put it in a box? What other ways do you add weight to your car?

[SPDRACR]

Mike, How much does the roadster wiegh now? Eric

[John Noonan]

How do you mount your ballest in your race car? Do you bolt it down or put it in a box? What other ways do you add weight to your car?

It is bolted down and also in a box for Bonneville...depends on where and how much you need.


J

[Dynoroom]

I might want to add about 1000 lbs. 

[SPDRACR]

Are the lower frame rails rectangle or round tube? I would aim for no more than 65%rear bias. If you have ingots drill and bolt, if you are going to mold your own use standard rod coupling nuts , on one end weld a piece of 1"x 3" x1/4" flat strap, like a T and cast into your mold. Try and mount under axle center lines and between the front and rear axles.

[Stainless1]

We bolted the rear shot boxes to the frame rails, the front piece is a poured ingot inside an aluminum tube (didn't have a steel one the right size) also bolted to the frame.

[jl222]

How do you mount your ballest in your race car? Do you bolt it down or put it in a box? What other ways do you add weight to your car?

Dynoroom
On our Alston chassis camarro they put  weight boxs behind the rear tires low just above the lower body line and the batteries mount on top of the box. We melted old lead wheel weights into small blocks and bolted the lid on.I forget the size but a little wider than the battery and about the same length, forget how deep but about 6''. The big intercooler tank (abut 38 gal) and the water tank below it.
 Come by and see us and take a look at bville.

                    JL222

[promachine]

Hi Mike, we pour lead shot into the frame rails. When we build the frame on the 511 we put bulkheads in the frame rails so we could make adjustments. The rest of the weight gets bolted down where we need it with 1/2 inch bolts. Also using 1/4 plate for the floor and firewall helps to have a good secure surface to bolt lead to. In the 811 we have 800 lbs. bolted down here and there.
 In the new blown fuel roadster everything is heavy, really heavy
Hope to see you on the salt

[MCR]

Informational only:

Home Depot has lawn tractor suitcase weights.  These are 43lb 12x12x3" cast iron weights with a convenient handle.  About $50 ea, IIRC.  We use them for sled pulling ballast.  Sand is the cheapest weight but not legal for many forms of racing.  Last pulling event I loaded up 1,700lb of 50lb sandbags for under $60?  Just don't let the cats get to it...

[Cajun Kid]

If I wanted to add weight to the front of my car.  Could I put lead shot in the front spreader bar (as long as I seal it so none could come out) ?

Also my weigh balance with me in the car is 52% Rear and 52% Left... (with out me it is 50/50 front/rear and 50/50 Left/Right) within .1 % each direction... I am thinking the rear needs to be just slightly more % thna the front but don't know what the magic number is??

Charles

[Sumner]

If I wanted to add weight to the front of my car.  Could I put lead shot in the front spreader bar (as long as I seal it so none could come out) ?

Also my weigh balance with me in the car is 52% Rear and 52% Left... (with out me it is 50/50 front/rear and 50/50 Left/Right) within .1 % each direction... I am thinking the rear needs to be just slightly more % thna the front but don't know what the magic number is??

Charles

Personally I think you are probably fine.  Are you concerned about this for running Maxton or B'ville?  How fast do you think you are going to go on the salt if that is the answer?  Did you ever read the stuff on CG/CP?  You could then decide if you think it applies to you.

c ya,

Sum

[Cajun Kid]

Sum,  I read the CG/CP info and it is a good read... I think I understand it, but I may have a bit of confusion, either way I am now confused at much Higher level... LOL

Most folks who have LSR experiance tell me the body style I am running would be most difficult to reach the record in class (201.xx)  I do feel in E/CGALT  that my motor sure has the stuff to do it (assume it stays together at Maxton the next two meets)  I think I will take the "E" motor out of the 33 Vicky and build a more AREO classic body style for the salt,,,,

For Maxton, I currently hold the record and feel once I tech for the higher speeds this fall I can comfortably move the record up again (as long as she holds the bumps well and with no major cross winds)..

Last weekend,,, I did a 147MPH pass down the bypass near my house,,(6000rpm's in High Gear) She should pull all the way to the 8200 chip with no problem (made power to 8400 on the dyno) 

Based upon my current tire, tranny and rear gear set up your speed chart shows that 8200 in high would be 205MPH...

By the way your speed chart is within 50 rpm's of dead on all the way from 30mph up to 147mph,,, thanks so much for the chart,,, it has helped me with my gearing and tire size etc...

Hope to have my new wheels and tires on for Maxton in Sept.

Charles

[Sumner]

Last weekend,,, I did a 147MPH pass down the bypass by my house,,, at 6000rpm's in High Gear... She shoould pull all the way to the 8200 chip no problem (made power to 8400 on the dyno) 

Based upon my current tire, tranny and rear gear set up your spped chart shows 8200 in high at 205MPH...

By the way your speed chart is within 50 rpm's  from 30mph all the way to 147mph,,, thanks so much for the chart,,, it has helped me with my gearing and tire size etc.........................Charles

The chart isn't off your tach, tire growth, slippage, etc. is  .

There is one small assumption you are making about pulling all the way to 8200 in high gear even though you made the most HP there that will prove to be a problem.  Let me try and explain:

On our record run we averaged 239.7 mph in the 5th mile and our exit speed was 241.2 at 7100 rpm, so we weren't going to run any faster even if the course would have been longer. On one of the previous pages we showed that we needed about 700 HP at the crank to run 240 mph and that is what the motor puts out at 7100 rpm (240 mph). Our motor makes maximum HP at about 7400 rpm, about 740 HP. So why couldn't we run up to 7400 rpm and maximum HP. Seems logical that we should be able to. I gave away the answer in the last paragraph. Our speed at 7400 rpm with the gearing in the car would be 250 mph. The answer lies in the fact that if it took us 700 HP to run 241 it would take 781 HP to run 250 and we didn't have that much so there was no way we were going to get to 250. We might have crept up to 245 or so if we would have had another mile or so and the motor would have stayed together.

So the moral of the story is try and be realistic about your top speed and try and get your gearing set so that you are at or near max HP at that speed/rpm. Use the spread sheets I've listed.

That was from ......................

http://purplesagetradingpost.com/sumner/bvillecar/bville%20-%20LSR%20Thoughts-5.html

.......... page 5 of your "required" reading  .

I'd like for you to run 205 with that car, but I'll wager some of my meager income that it won't happen  , but that just may make you want to prove me wrong.

c ya,

Sum

[Cajun Kid]

SUM,, also I am working on the scrub radius and caster (to ease the high speed wandering we discussed prior)

SR was off --- the intersection was to near the inside of the contact patch,, so if I read your stuff right and am using a narrower, taller tire and a narrower wheel with more BS.  That should put the line at the center of the contact patch (or very close within 1/4 inch, it is currenty 2 inches inboard of the center)

Caster is 4 degrees and once new tires/wheels are on, I will have the alignment done..


Thanks again for all your help and that cool website,,,,

Keep up the good work on your build,,,, it is awesome,,,  Hope you and Hooley have a great time at SW...

Charles

[Cajun Kid]

Sum,,, I do agree with you that the 33 Vicky ("that car")  would probably not go 205,,, my guess would be 175...

When I said bump the record, I was referring to the current record (mine) at Maxton,,, it is a soft record,
I was not referring to bumping the 201.xx record at B'ville, (did not mean to confuse the two ) I have no hope of the Vicky going that fast... The areo is just not there,,, neither is the handling (yet)



That is why I think a 80/81 Trans Am, FireBird or Camaro would be a better choice since I will only run in Classic Category...  My search is for a Trans Am, I  think it has better front area than a Camaro.