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The Elephant In The Room: unloading the load from a B-body.

Here's the final upgrade in its fullness. All 6061-T6 aluminum and weighing in at 22 Lbs including the clamps. An approximate 36 Lbs removed.
Muff's dump right before the diff. There were several hidden benefiting factors.

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I didn't weigh the exhaust system for my Duster but if I had to guess I'd say the whole shebang weighs close to 100 lbs. And that's for a small block A body! It's awesome and all but when it arrived at my house I was completely shocked and saddened at how much it weighed. The headers weigh a TON.

Here's the current setup - TTI 1 7/8" full length headers, flanged header to X-pipe adapters, full 3" X-pipe exhaust system to the back bumper, Dynomax Ultra Flow muffs, TTI-specific rear tailpipe hangers and stainless band clamps for the joints. Beautiful stuff but HEAVY AF.

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The full-length 3" tailpipes also weigh a ton. To save weight and clean things up in the rear, I thought about eliminating them and dumping the muffs right before the axle. When I mocked it up I found it to be a tight fit and I was not interested in cutting up (shortening the x pipe) my brand-new, ridiculously expensive exhaust system to make it work.

I went back and forth with ditching the tailpipes for a while. I know enough guys out there that deal with dumps but there are also just as many that say they hated it so I ultimately decided against it. With either choice there's no real difference in perfromance so you just have to pick yer packaging poison. Dusters are light in the back so perhaps there's a small benefit to having the weight back there anyway.
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The previous system for my Duster was also fairly heavy but the smaller TTI 1 5/8" step headers I was running weigh less than the larger ones. The old system was all welded together into one piece behind the headers which sucked to remove.

On my next project I might try to do what FMJ did and cobble something together myself. Not sure I have the patience to get it all fitted up nicey-nice like he did though, that's a lot of time and effort!
 
Here's the final math.
If this were to have been a full aluminized steel exhaust stretching out to the rear bumper with tail pipes and all, it would have been conservatively weighing closer to 88-95 lbs installed, so in this case and in theory, 45 to 55 lbs would have been discarded by going aluminum. Basically a 51% weight drop.
With this project first being a steel midway system at 58 Lbs, in actuality, 36 lbs were discarded when going aluminum. Basically a 62% weight drop.

But WEIGHT! there's more.
Measuring at 3-1/2" then reducing to 3" as a midway, I can just imagine what the final weight would have been if it was a typically sized 3" pipe system reducing down to 2-1/2" as a midway. Probably just under 17 Lbs.

It must be stressed that the ability for headers to rid heat more efficiently than factory iron exhaust manifolds is a determining factor behind this. Temperatures vary from car to car, but the temps at a factory manifold flange where it meets the pipes could be much higher than a header collector where it meets the pipes. This is usually because the factory iron exhaust manifolds are shorter and closer to the engine exhaust ports where exhaust flame temperatures are obviously higher and more intense. It could be assumed that high heat tubings such as 321 stainless could work with an iron manifold to help transition exhausts to cooler climates further down pipe, but again it all has to be tested and verified to factor which material-either steel, stainless or aluminum- could-would-should make the cut. Exhaust noise is a whole other field.
The temps on these particular collectors were not high enough to make aluminum soup and the lighter alloy was supposedly able to tone down the exhaust note, so it got drafted in.

The benefits on this project were cooler pipe temps, no rust nor oxidation issues and surprisingly a quieter exhaust note.
It had to be tucked tight and high with snugged clamping to not allow vibration which is any hanging systems nemesis, especially aluminum.

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Cool stuff.....and knowing there was another modified K frame here somewhere, I found it when cleaning out my box trailer.....26 lbs! It has a bit more trimming along with being solid welded like the one in the car now after cutting off the factory spot weld pinch 'lips' AND the motor mount stands since the plan for it was to use motor plates. It does need to have a brace welded to the mount for the steering box so add a pound or so for that.
 
Cool stuff.....and knowing there was another modified K frame here somewhere, I found it when cleaning out my box trailer.....26 lbs! It has a bit more trimming along with being solid welded like the one in the car now after cutting off the factory spot weld pinch 'lips' AND the motor mount stands since the plan for it was to use motor plates. It does need to have a brace welded to the mount for the steering box so add a pound or so for that.
Geeez oh cheese, 26 lbs is light.
 
Geeez oh cheese, 26 lbs is light.
It surprised me for sure! Was thinking that it would be a bit lighter than the one that's in the car (32 lbs) but didn't expect 6 lbs! Just wish I had weighed them both before 'trimming'. I did weigh the one that's in the car and iirc, it was a tad over 40 lbs. Might have mentioned it here in a earlier post....
 
Oh, oh. I spy an aluminum pumpkin in a certain A-Team car.
WEIGHT until you guys get a load of what I've investigated as far as rear ends. The mechanical types that is. LOL.
 
Oh, oh. I spy an aluminum pumpkin in a certain A-Team car.
WEIGHT until you guys get a load of what I've investigated as far as rear ends. The mechanical types that is. LOL.
Well, how strong is the aluminum chunk? Seen them but they seem to be pretty rare.
 
It surprised me for sure! Was thinking that it would be a bit lighter than the one that's in the car (32 lbs) but didn't expect 6 lbs! Just wish I had weighed them both before 'trimming'. I did weigh the one that's in the car and iirc, it was a tad over 40 lbs. Might have mentioned it here in a earlier post....
Well, at least you got some pounds off the K. I basically just cut off the motor mount bosses, reinforced the steering tower and that was it. I could have gone further and for some reason did not think of it any deeper. I guess one of those Magnesium or Aluminum FX factory K's will find its way to my bay. LOL.
 
Well, how strong is the aluminum chunk? Seen them but they seem to be pretty rare.
Those chunks were rare when they first came out as I was having trouble getting one for my then 8-3/4 set up. Heard or read that they saved 11 pounds over the iron unit. Beefy unit it is. Should survive decently behind a light car with a true cheater tire.
 
Those chunks were rare when they first came out as I was having trouble getting one for my then 8-3/4 set up. Heard or read that they saved 11 pounds over the iron unit. Beefy unit it is. Should survive decently behind a light car with a true cheater tire.
I might have been one of the first in the country to get one and subsequently one the of handful of people that pulled the trigger on one. I haven't seen any others out in the wild.

The problem was they were too expensive. I paid $600 for it but the last time I saw one for sale new it was over $900. Too small of a market for them as well since if you had any real power you'd switch to a Dana or 9". I've thought that people failed to grasp what was done to strengthen them though and would pass them off as another 8 3/4 time bomb waiting to explode. Right or wrong, racers would never spend the coin on something they perceived would fail in short order. Sucks for them!

I've run it down the track several times and street driven it plenty, no problems. The caps are through-bolted through the front of the pumpkin, it's stout. The bottoms of the caps are also counter bored into the main housing to prevent cap walk. That fit was TIGHT, like I had to massage the bore a bit to get the caps on, even after putting them in the freezer.
 
I might have been one of the first in the country to get one and subsequently one the of handful of people that pulled the trigger on one. I haven't seen any others out in the wild.

The problem was they were too expensive. I paid $600 for it but the last time I saw one for sale new it was over $900. Too small of a market for them as well since if you had any real power you'd switch to a Dana or 9". I've thought that people failed to grasp what was done to strengthen them though and would pass them off as another 8 3/4 time bomb waiting to explode. Right or wrong, racers would never spend the coin on something they perceived would fail in short order. Sucks for them!

I've run it down the track several times and street driven it plenty, no problems. The caps are through-bolted through the front of the pumpkin, it's stout. The bottoms of the caps are also counter bored into the main housing to prevent cap walk. That fit was TIGHT, like I had to massage the bore a bit to get the caps on, even after putting them in the freezer.
When I found one, it was out of my league but figured they were pretty special....plus I wasn't making a lot of power back then so just went with the 60 as they were much cheaper.
 
In regards to K members, I chose a QA1 tubular unit. I went with their whole front end including upper and lower control arms and adjustable, aluminum strut rods. Switching out all the factory parts for the aftermarket tubular stuff saved 18lbs. off the front end. Other benefits include more room, more available caster and less flex in the LCAs. The strut rods saved the most weight.

Yes, the Flaming River steering box is slightly heavier than a factory aluminum one. What can you do.
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Several years ago I had the idea to trim down a later '73-spool mount K frame I had that somone prior to me tried to cut on. I made a jig for it and started looking at where to trim it but never got the project off the ground. It's a LOT of work to cut the flanges nd te-weld it all back together in a safe manner.
 
Okay, you guys wanna talk rears? Here you go. Yes it's a Dana and NO! it isn't mine. Chew on it for a little and I'll get back to you all about it in a short while.

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When I found one, it was out of my league but figured they were pretty special....plus I wasn't making a lot of power back then so just went with the 60 as they were much cheaper.
Yep, just like I said. I understand why the alum. diff was so pricey but that doesn't mean that the buying public was willing to eschew that for whatever weight savings it offered.
 
Is that the one they were going to start producing some years ago? From around Florida I think.
Yes, it’s from a company called Baxtek. Supposedly it is /was strong and readily available with almost any gear ratio. Most importantly to me was the weight savings of about 80 lbs at best. I was hooked and booked.
I tried in vain to have them slip one underneath this car to do some real world drive and race tests with results being announced in a feature article on the car, but they weren’t having it and wanted me to purchase the whole BAXsket at full price. I walked.
I wasn’t too keen on the over beefed rear cover anyway.
I think they never got it off the ground in any serious way.
Unfortunate.
 
In regards to K members, I chose a QA1 tubular unit. I went with their whole front end including upper and lower control arms and adjustable, aluminum strut rods. Switching out all the factory parts for the aftermarket tubular stuff saved 18lbs. off the front end. Other benefits include more room, more available caster and less flex in the LCAs. The strut rods saved the most weight.

Yes, the Flaming River steering box is slightly heavier than a factory aluminum one. What can you do.
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Several years ago I had the idea to trim down a later '73-spool mount K frame I had that somone prior to me tried to cut on. I made a jig for it and started looking at where to trim it but never got the project off the ground. It's a LOT of work to cut the flanges nd te-weld it all back together in a safe manner.
I modified my lower control arms too....but have no before and after weights and wasn't after less weight when I did them. All that aftermarket stuff is great but wasn't in my budget at the time.
 
I must say that it must have taken a good chunk out of someone's pocket to tool up such an aluminum Dana 60. For them not to get it off and running must have been a huge loss. My argument was that publicity and real world ink is part of getting such things off the ground. Being that those axle tubes were bolt on, any material could have been used including chrome-moly tubing or titanium.
There's other ways to shave a few pounds from an iron 60 to your advantage. I'll explain soon enough.
 
I modified my lower control arms too....but have no before and after weights and wasn't after less weight when I did them. All that aftermarket stuff is great but wasn't in my budget at the time.
Based on my limited experience, I'd say it's hard to get into real weight loss without spending a lot of time and money on it. Generally, the answer is to buy aftermarket parts. Stuff like my 10" drum spindle Wilwood brakes shaved over 60 lbs off my front end. I'm not making my own lightweight disc brakes at home though so it's either pay the piper or do it yourself. Even if you do have the tools, equipment and skill to produce sanitary and safe pieces you're certainly ahead of the game but that kind of ability does not come overnight and it does have a high investment cost if you chose quality tools.

If you don't care about appearance, stuff can merely be yanked out and if necessary replaced with something that conforms to whatever rules you decide to run your car under. That's usually dedicated race car stuff though. Street machines will always straddle the line between race and passenger car identities. An unpainted, brake-bent sheet aluminum dash with three Auto Meter gauges and diamond plate panels riveted to flimsy fiberglass doors is light for sure but that approach won't get you much action on the street.

And then there is FMJ who looks at every single part of his car and tries to ascertain how it can be made lighter while retaining most or all of the particular parts' original strength and appearance. Ashtrays, door handles and strikers, steering wheels all get the treatment. Generally nobody that I know of other than FMJ (myself included) decides they're gonna shave off a a pound or two by RE MAKING their steering wheel out of aluminum while keeping it looking like an original part. That right there is a key element to this methodology. Some people may not see the value of going to that level of detail. Plus, not everyone can sustain that kind of focus and determination either, especially when cars come and go in life. Maintaining that bucks down, DIY strive and drive with one car for thirty years is pretty unique.

I'd say I have my feet planted in both worlds but tend to favor buying stuff over getting too deep into sleight-of-hand trickery. There's a bunch of brackets and such you can't see under my dash that have been massaged. I stripped off all my undercoating and repainted the bottom of the car with factory-style grey dip epoxy primer. I get rid of all unnecessary wiring, creature comforts and whatever dead weight can be jettisoned in the name of better performance but I don't leave that stuff as-is either. I take the time to search out and obtain things like factory correct heater and radio delete plates. Some of those things took me years to track down.

At one point I even obtained an early A body right-side heater delete vent box from someone in Australia because that's what the Super Stock Hemi Darts and 'Cudas had. They were standard production parts down there for several years because Australian cars have the heater box on the left (right-hand drive). I have to think I'm the only person that's ever done that. The guy who sent it to me thought I was nuts since shipping the thing was like triple what the part was. But try to find one in North America!

Conversely, I do have plenty of mail-order pieces like a Kirkey aluminum seat, a pin-on fiberglass hood, a QA1 front end, an aftermarket dash with digital gauges and Wilwood brakes. None of those parts are over the top blingy gee gaws though so even at first glance they can blend in to the background unless you take a second look.

Details, details.
 
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