PontiacBonnevilleClub.com

I've been following the development of the Cadillac ATS, and one of the things they were doing in order to drop weight was drilling holes in all manner of parts.

Lo and behold, someone thought of that before:

http://www.modified.com/features/0611ss ... index.html

So, given that GM built cars to survive several degrees more stress than they normally would see in 5 lifetimes, I'm wondering if anyone here has gone the route of drilling out parts to drop weight? Brackets and such wouldn't seem to be that difficult to modify, but things like Kmembers and strut towers might need to be thought out beforehand.

Hot Rod Magazine did it on the LS7 Solstice they built back in '06. Things like the master cylinder bracket, washer fluid bottle bracket, etc they drilled a bunch of weight-reduction holes. They lost a good bit of weight by doing that and using a bunch of carbon fiber parts. The car was like 40 lbs heavier when they were done, which was incredible considering they doubled the cylinder count and tripled the horsepower.

00Beast wrote:Hot Rod Magazine did it on the LS7 Solstice they built back in '06. Things like the master cylinder bracket, washer fluid bottle bracket, etc they drilled a bunch of weight-reduction holes. They lost a good bit of weight by doing that and using a bunch of carbon fiber parts. The car was like 40 lbs heavier when they were done, which was incredible considering they doubled the cylinder count and tripled the horsepower.

I would suppose that the tricky part is deciding which pieces could have holes cut safely into them, and which would end up landing you in a ditch.

Given how overweight these vehicles tend to be (not a slight, just an observation) one could concievably drop some serious weight here. I'd like to do that for MPG reasons, however it would also increase performance a bit.

If you really want to dump weight, you can do a lot before you start drilling holes. Remove all your crap from the trunk, the spare, etc. I keep at least 100 lbs of crap in my trunk, tools, parts, etc. If I was really concerned I'd remove all that. Then you can get into removing things like seats, carpet, accessories, etc. You could also lose some mass by going to a light-weight wheel and Low Rolling Resistance tire. It all depends on how far you want to go...

00Beast wrote:If you really want to dump weight, you can do a lot before you start drilling holes. Remove all your crap from the trunk, the spare, etc. I keep at least 100 lbs of crap in my trunk, tools, parts, etc. If I was really concerned I'd remove all that. Then you can get into removing things like seats, carpet, accessories, etc. You could also lose some mass by going to a light-weight wheel and Low Rolling Resistance tire. It all depends on how far you want to go...

The cool thing about drilling holes would be that most of the car would appear to be stock, and you wouldn't have to change the appearance much at all.

The uncool thing about drilling holes is getting to the parts you're going to drill holes into.

Plus, I'm not after a track car, just a lower mass daily driver that gets a little better MPG.

That would be A LOT of drilling to lose even 100lbs, which in turn wouldnt grant you much of a MPG gain. Your best bet is just to keep your car in good tune, lay off the go pedal, draft, use cruise control whenever feasible, etc, IMHO.

And they are also using a lot of light weight materials in the ATS, Im sure.

Easiest weight reduction technique: different car.

Or more HP

01bonneSC wrote:That would be A LOT of drilling to lose even 100lbs, which in turn wouldnt grant you much of a MPG gain. Your best bet is just to keep your car in good tune, lay off the go pedal, draft, use cruise control whenever feasible, etc, IMHO.

Lol, yes that would be a lot of drilling, and most of it beyond the ability of a shade tree mechanic.

And all the internal parts would have to be re-coated in order to prevent rust.

Guess it's time to contact a body shop to spit-ball this idea from a cost standpoint.

yourgrandma wrote:Easiest weight reduction technique: different car.

Someone always comes up with great ideas on car forums....

No body shop in the world is going to do this for you. Could you imagine the liability? Someone smashes into your car, it crumples like a pop can and your family sues them for having altered your car?

Also:

kstills wrote:

yourgrandma wrote:Easiest weight reduction technique: different car.

Someone always comes up with great ideas on car forums....

Its not like I'm against thinking outside the box. I just have a certain grasp on the basics of physics. A big car built as a luxury flagship model isn't going to get very light and you'd end up loosing anything that made the car tolerable to begin with.

Cutting holes in stuff is a last step. Before doing that, you'd get way more out of removing excessive weight elsewhere. Nothing in these cars was built to be light. The seats alone weigh as much as a small cars engine.

Not trying to thread Jack but has anybody tried a set of nice leather racing buckets? as stated above these seats weigh a ton getting rid of those bastards would definately help I've Bern looking into getting some myself. lighter weight wheels is where you will notice the biggest difference large/heavy rotating mass means slower car. that's why I got rid of my Goodyear triple treads they weigh twice as much as my wheels. spare tire/Jack, if its only a track car get rid of stereo equipment, or other electronics you wouldn't need in a usual drag car I.e. hvac, evap system, etc. I think 600 pounds could easily be shed if your looking to go all out but that's not the case here.

The only bonneville I've seen with racing seats was BadSSEi, and that was a track-only car. Most SLE/SSEi's have air-bags in the seats, which would kill the system if you removed them, plus then you'd have seatbelts to figure out, since they're in the front seats on these cars. That wasn't a big deal on BadSSEi, as it was 'caged and used a 5 point harness that attached to it.

yourgrandma wrote:Easiest weight reduction technique: different car.

I went that route, and lost about 700 lbs, 2 cylinders, and 2.4 liters of displacement. Careful not to cut too much...

Best weight reduction would be ditching the spare/jack and getting some lightweight wheels.

I didnt get a chance ev to weigh my 5 spokes but when I put my snows on them I was impressed at how light they already are.

The enkeis im putting on are fairly light at 21.4lbs each at 18", id bet the stockers are withing a pound or 2.

LeSabre in Buffalo wrote:
Best weight reduction would be ditching the spare/jack and getting some lightweight wheels.

Sounds like the OP want to lose weight and keep it as a daily. Losing the jack/spare would be the dumbest thing, hello flat tire. For the, track sure! And the "work" to remove it isnt worth the gain.

Not sure how I got quoted there...

As things would have it, I do not have a spare tire, not to save weight but because my brakes are kind of a big deal.