chassis lightening question

I did a search and couldn't find much tech info on lightening a chassis. It's a stock '54 Chevy frame that will be 'z'd front and rear but I'm also trying to take some pounds off.

Does anyone have any guidelines of how and where I can go to work with a holesaw on this frame without impacting rigidity or structural integrity?

Thanks,

Rich

 

Those frames are the TopHat type. They look like a hat if viewed as a slice. They're pretty thin metal, but really rigid because of their boxed design. I wouldn't cut into them though. Seems like you would ruin the rigidity and strength of the frame. They're not that heavy, relatively speaking.

The straight six is the really heavy piece of those cars.

 

dude, going on a diet is a lot safer that swiss cheesing a frame, think about it, and clean the schitt outta the trunk too!

 

Also, get yourself a holesaw and cut a 3" or whatever circle out of a piece of scrap steel. Weigh it. Multiply by the number of holes you were considering. Think about how much fun the cutting was, and how much is gone from the teeth on the $aw already....I think you will find the cost benefit ratio to be pretty poor. If you pay for the hole saw blades cash in one dollar bills, the weight loss from your wallet might exceed that from the frame.
Find a thin girlfriend, and remember to ask her if she's been putting on weight every couple of days. You'll save a lot more...

 

Better places to loose weight than your chassis.

Try lighter brake components, lighter wheels anything that is unsprung.

There is probably lots of meat that you can loose on the body, zoom the core support full of holes, cut some of the braceing out of the package tray, or even some of the crap out of the inside of the doors etc.
Have someone hammer you out an aluminum deck lid, loose some upholstery, or the radio and the heater. get an aluminum radiator.

 

Make it a carson top. That way you can adjust the weight if you girl gains a bit.

On a serious note. Aren't those frames riveted? Also I would worry about cracking due to metal fatique and drilling? I may be wrong though.

 

I used to laugh at the entry level drag car builders,they would spend days scrapeing the sound deadener from the trunk of a car to lighten it up and then fill the tail light housings full of lead so it would get better traction.

Thats like the racers who would take off the charging system and water pump to get more H.P. and then add another battery,battery box , electric pump and 7 foot of 00 cable so the car would start and cool all day ,Never mind the $400 generator to charge the battery between rounds.

Don't make this stuff any more difficult than it is.

Just my opinion ,I could be wrong

 

Thanks guys, for the laughs as much as the tech advice.

I haven't made my mind up to swiss cheese the frame or anything, I just wanted exactly the kind of input you have given. I was under the impression that within reason, you can cut holes out of the sides of a top hat section frame (or box section) and not loose strength, but even if that is the case, it's probably more trouble than it's worth.

I guess I've been looking at too many pictures of old Bonneville racers and thought the same trick could work for me.

Porknbeaner, I'll be losing some of that inner sheetmetal as you suggested, and I'm considering fabricating an aluminum floor, I've thought about the deck lid too.

I posted last week or the week before asking for these ideas and had some great advice. I have a article in one of my old mags on making aluminum bumpers and grilles using the original steel as a pattern, and a friend of mine has offered to cast some hollow aluminum grille teeth for me using molds made from the original teeth. This should be good for some pounds off the front end, and they will polish up great too.

It will be a chopped and dropped leadsled, in the full traditional sense, but I'm building a 302 to be mated to a wide ratio Muncie 4 speed, 5.13 '64 Pontiac rear and some tall tires, its a combo that has some good performance potential for good quarter mile times and to be opened up at a dry lake bed close to me, but I need to get the curb weight down to about 3000lbs to take full advantage of it.

This may be wishful thinking, but according to the ratio's if I can push the engine to 9000rpm at the lake bed (wind resistance is also a factor) I should be able to push 167mph. I remember seeing a '67 Charger once that clocked 168mph and that's probably more of a brick than a lowered and chopped '54 Chevy as far as aerodynamics are concerned.

According to desktop dyno 2000 (I have no idea how accurate it is) the 302 should peak at 532HP @ 7000rpm, and 454lbs/ft torque at 5500rpm, it should be good for over 400HP all the way past 9000rpm. As you all know, a engine built this way has little low end torque, it doesn't start making real power until 4000rpm, but I also want to race it at the local track.

This is why I am wanting to get rid of weight everywhere I can, if I can get the car down to 3000lbs, I am hoping to be able to run a mid 11 sec q/mile. This car is intended to be a real sleeper, a wolf in sheeps clothing, a traditional custom on the outside, but a monster when you stomp on the go pedal, saying all this, it will be mostly street driven.

That's the background. I hope ya'll can find some method in my madness. I won't take offense if you trash my idea, or bring some sobering reality to my project.

Back to the subject of swiss cheesing my frame...

Thanks for the help!

Rich

 

just wondering but even if it makes the most power at 7 grand whats the point of pushing it to 9? arent you just losing hp the further you go past 7 then?

just wondered

 

lightening holes on airframes are "belled",to restoresome of the strength from losing the parent metal.

if you could bell the holes,it might be ok.

they make chassis punches,easier than hole sawing,
but a good sized punch that bells the holes ain't CHEAP!

i like the cut out some scrap,weigh the piece,and multiply theory.

fill up the tires with helium.

 

The only reason to do this is to see what I can open it up to on the dry lake, sticking at 7000 in fourth should get me to 130mph, but I'll have no more gears. According to the predicted power and torque curve, I'll still have 460HP available up to 9 grand, and the motor will be built to take that, not every day, but it should hold up fine.

So the power should be there to push past 130mph without a O/D gear and the motor will handle the rpm. How far past I'm not sure because it starts to get more complicated at those speeds in terms of wind resistance and aerodynamics, but I would hope I could break 150mph. If I could hit 160mph I'd be really happy, and the numbers dictate a maximum of 167.7mph because under no circumstances do I want to take the motor past 9 grand.

Maybe a better solution to see just how far I can push it in a straight line is a five or six speed box to keep the revs in the peak part of the power and torque band, but nothing I have bought for the car is newer than about '65 so far and I'd like to keep it that way. I've been looking at one of those planetary O/D units, it would compromise keeping the car built purely from 60's speed gear and parts, but perhaps its a compromise I could be forgiven for in this case.

Stealthcruiser, good call on belling the holes! Didn't think of that but you're right, that would be way better than just cutting holes straight.

I can probably just do some math, multiply the area of a 3" circle by the weight per square inch or foot or whatever of the steel that the frame is made of, and multiply that by the likely number of holes, and see what I'm likely to loose, might not be worth it.

Rich

 

I am certainly not the smartest person on here so take this for what it cost you.

I have built and raced drag cars for over 40 years.H.P. does not power the car ,Torque does.

In my opinion a #3000 car with a 302 inch motor is spending money very foolishly.I think a 406 chebby with a 308 gear at 5400 would be a faster car and could be built for thousands less.And will probably stay together for years.

I hear daily about 500 to 800 h.p. engines and 9 second cars,but when they are put on the dyno quite often they will not put out more than a crate engine does.

A high rpm ,small inch ( low torque),deep geared car is fine ,but it should weigh 1800 lbs.

The key to building anything is the combination,period .If one or more things in the combination is off the whole project suffers.

9000 rpm smallblocks ,where do I start.$500 valve springs replaced probably after two or three top speed charges. $1500 cam and lifters,$650 connecting rods, replaced very often ,and don't even think about using a Chevy crank ,yep $ 1500 to $ 2000 more .


Just my opinion .