OK, Let's talk Dakota frames...

[ramenth]

I think what REALLY appeals to me about this is, it solves a couple of issues I have. Big block in an F-body is no big deal, but the Dakota frame strengthens the structure,

Greg

How do you figure?

I guarantee you that a set of well built frame connectors and a set of torque boxes will take the flex out of the unibody to standards that full frame vehicles don't have. The transfer of power to the ground and keeping the weight transferred to the tire that needs grip in cornering will be such to the point that mounting a unibody car to a full frame, with rubber, or even urethane biscuits, you'll be giving up any advantages of getting tube control arms.

Even if you just subframe it in, like the GM's did, you'll be giving up any and of the so-called advantages you're looking for. Drive a Camaro or Firebird, then drive a stock Chrysler t-bar set up. You'll see an immediate difference. There's better road feel in the Chrysler, better handling characteristics built in. Why? Because of the unibody.

As for the rack, the only advantage will be weight savings over the current set up and you lose that savings with the weight of the frame. Firm Feel's stage 2 and 3 boxes negate that issue without the work of converting to a full frame.

Guys, remember, that when it comes to building a car it's a complete package. You don't just look through a Summit catalog and start reading the descriptions of engine parts with the idea that manifold A will give me 40 bolt on horsepower, camshaft B will give me another twenty horsepower, these headers will give another 15 bolt on horsepower. Guaranteed mismatch of parts and for all the money you've just spent, all the time you've got into it and the engine will fall flat on it's face.

I'm afraid that's what you guys are looking at here. The body and the suspension has to be built as a package. The unibody is tight. There's a reason there are no more full frame pass cars out there. My wife's Hyundai XG350 is so tight I can put a floor jack on the left rear rocker pinch weld and lift the entire back of the car.

That's what needs to be done here and I've explained it in using frame connectors and torque boxes. There are things which need to be overcome with our F/M/J platforms and that means getting rid of all the rubber. Now you guys are talking about using a full frame, either all of it, or cut in half, which facilitates the need to use even more rubber!

Explain to me again how eliminating all the rubber in our cars gives us better handling, better power transfer, better grip, and then telling me how using even more rubber than what you need to get rid of gives you an advantage?

 

[bill55az]

I wouldn't. I've rebuilt more of those than I ever had 8.25's. Most of 'em in Daks.

There are a lot of the 9.25 on the roads and they hold up fine. They are stronger than the expensive and hard to find 8 3/4.
Racing use, I cannot say anything from experience.
Normal driving, towing, hauling, it is the first choice.
Dodge put some 8.25 in Durangos with the towing package, and via recall they replaced them with 9.25....around year 2000 IIRC. I bought one of those 8.25 axles cheap, sold off all but the big brakes, which I still have....saving for a future project...

 

[Mr.Lopar]

How do you figure?

I guarantee you that a set of well built frame connectors and a set of torque boxes will take the flex out of the unibody to standards that full frame vehicles don't have. The transfer of power to the ground and keeping the weight transferred to the tire that needs grip in cornering will be such to the point that mounting a unibody car to a full frame, with rubber, or even urethane biscuits, you'll be giving up any advantages of getting tube control arms.

Even if you just subframe it in, like the GM's did, you'll be giving up any and of the so-called advantages you're looking for. Drive a Camaro or Firebird, then drive a stock Chrysler t-bar set up. You'll see an immediate difference. There's better road feel in the Chrysler, better handling characteristics built in. Why? Because of the unibody.

As for the rack, the only advantage will be weight savings over the current set up and you lose that savings with the weight of the frame. Firm Feel's stage 2 and 3 boxes negate that issue without the work of converting to a full frame.

Guys, remember, that when it comes to building a car it's a complete package. You don't just look through a Summit catalog and start reading the descriptions of engine parts with the idea that manifold A will give me 40 bolt on horsepower, camshaft B will give me another twenty horsepower, these headers will give another 15 bolt on horsepower. Guaranteed mismatch of parts and for all the money you've just spent, all the time you've got into it and the engine will fall flat on it's face.

I'm afraid that's what you guys are looking at here. The body and the suspension has to be built as a package. The unibody is tight. There's a reason there are no more full frame pass cars out there. My wife's Hyundai XG350 is so tight I can put a floor jack on the left rear rocker pinch weld and lift the entire back of the car.

That's what needs to be done here and I've explained it in using frame connectors and torque boxes. There are things which need to be overcome with our F/M/J platforms and that means getting rid of all the rubber. Now you guys are talking about using a full frame, either all of it, or cut in half, which facilitates the need to use even more rubber!

Explain to me again how eliminating all the rubber in our cars gives us better handling, better power transfer, better grip, and then telling me how using even more rubber than what you need to get rid of gives you an advantage?

for my application, the whole frame would be wrapped in 1/4" and 3/16" steel, and would be mounted with polly bushing, this would virtually eliminate ANY flex. i have frame connectors, but when we painted it, on the reight rear quarter panel right around the vinyl top area, you could see where its been flexing from three wheeling. but im goin for a different route other than race handeling.

btw, all the lincoln town cars/mercury grand marquise, crown vics are still full framed cars

 

[ramenth]

for my application, the whole frame would be wrapped in 1/4" and 3/16" steel, and would be mounted with polly bushing, this would virtually eliminate ANY flex. i have frame connectors, but when we painted it, on the reight rear quarter panel right around the vinyl top area, you could see where its been flexing from three wheeling. but im goin for a different route other than race handeling.

btw, all the lincoln town cars/mercury grand marquise, crown vics are still full framed cars

You're forgetting a few things.

1.) urethane still allows for flex (I know, you said virtually all the flex.)

and

2.) The Grand Marquis and the CV are dead. The last year for the Grand Mark was 2010, the last year of the CV was fleet sales only, and the Town Car is for a niche market. :icon_biggrin: Really, how many young Town Car buyers are out there? The Grand Mark and the Town Car were throwbacks to an earlier time with mostly folks in the 65+ range owning them. That was my experience at the Ford dealerships anyway.

But I'll go on to address the first issue. I have poly bushings on the radius arms on my F150 4X. If you're familiar with the set up you'll see know that rear radius arm bushings are essentially a ball socket, flexing with the suspension. If they didn't flex, they'd rip the mount right off the frame.

Same goes with using urethane mounts on full frame bodies.

Think about it. What's the best set up to use on the K-frame of one of our F/M/J's? The old cast biscuits or using the new aluminum ones available. This stiffened up the ride considerably, no need for urethane. Why? urethane still flexes, just not as much. Eliminate the iso mounts on the rear and get rid of the big rubber eyelet on the springs. No need for urethane, eliminate the flex. You can do this because it's a unibody car. Full frames? Uh-huh.

Pick ups usually get away with solidly mounting the box to the frame, but still isolating the cab, because in order to haul a certain payload, under torque, the truck has to flex. Watch where the flex is. Solidly mounting the cab to the frame would start flexing the cab so much it would break welds and buckle sheetmetal, depending on the flex needed to move said payload. One of the reason Heavy Duty trucks still have open frames, to give 'em even more flex. The box, being open at the top, has a lot of flex built in. Put urethane biscuits on it, like I'm doing with my F250 2X, the flex is still there, it just translates to a better road feel in the overall characteristics of the truck.

You're car is a different story than most of what's being talked about here. Under no circumstances did the factory ever think about doing to your car what you're doing. You're obviously more into the hopping scene than I am, but it seems to me that's one of the reasons the full frame Chevy's are more popular. When the frame hits, the body, mounted on biscuits, is allowed to flex. Urethane or not.

No, I think I'd try a different approach with your car, and that's to eliminate just about any flex in the body it would have. And there are easier ways to do that, in my opinion, than trying to tie in a full frame. Floor hugging frame connectors, tied to the floor and the rails is a first step, but an x-brace coming off the above mentioned connectors where they tie in at the rails would be a start. Pulling a page out of Ma Mopar's book and doubling the rockers like they did on the E-bod convertibles would help, with the inner doubled up rocker being tied in to the torque boxes. I think I'd want to keep the rubber K biscuits and the eyelets, so the suspension would have that cushion, isolated from the body. I'd have to study the workings of your car more, how the body actually flexed when you pull a wheel off the ground to get more ideas.

 

[Mr.Lopar]

i got a 02 towncar

i have removed the rear iso mounts (went through 3 7.25s) and have a ford 8.8 with a-body shock plates, have cudazappas aluminum soild k-frame biscits, and frame connectors thats are solidly welded to the frame and floor boards where they touch. before i saw this i was thinking about adding torque boxes and cuting open the rockers and welding in a 3/16" or so pipe in em and welding the rockers up. i have thought about making an X to weld up between the frame connectors, but my driveshaft would hit, and i cant have that lol

as for the full frame chevs that are hoping, trust me, them frames dont flex one bit, cuz they wrap the frames with 1/4" steel front to back and some of em do all 4 sides. i helped my buddy wrap his frame for his 85 lincoln towncar with 1/4" steel last winter, and that frame has absolutly no flex. so when i saw this, now its got the gears turnin in my head.

 

[ramenth]

as for the full frame chevs that are hoping, trust me, them frames dont flex one bit, cuz they wrap the frames with 1/4" steel front to back and some of em do all 4 sides. i helped my buddy wrap his frame for his 85 lincoln towncar with 1/4" steel last winter, and that frame has absolutly no flex. so when i saw this, now its got the gears turnin in my head.

Yes, they've wrapped the frame, and yes, the frame doesn't flex, but what attaches the frame to the body?

 

[bill55az]

Anybody here good at photoshop? how would it look to graft the back half of an F body wagon onto the dakota, keeping the cab, of course....

 

[Greg55_99]

Robert, you've made your opinion pretty clear on this topic, but, how about if I challenge you? IF (and I say "IF"), you were to attempt mating an F-M-J to a Dakota frame, HOW would YOU go about it? Like I've said, this is a friendly challenge.

http://www.schwartzperformance.com/projects.aspx?projectid=41

Greg

 

[ramenth]

Robert, you've made your opinion pretty clear on this topic, but, how about if I challenge you? IF (and I say "IF"), you were to attempt mating an F-M-J to a Dakota frame, HOW would YOU go about it? Like I've said, this is a friendly challenge.

http://www.schwartzperformance.com/projects.aspx?projectid=41

Greg

Friendly challenge? I'm up for that.

First of all, me being me, the rails might be a starting point. But nothing else. Take the body completely apart and start fresh, with my own design. It definitely wouldn't be what they're showing in the link you provided. I'll get to that in a moment.

No, if I'm going through all this work, no matter what the platform, starting at the bottom of the alphabet from my E-body going to my M-body this is the way I'd do it:

http://www.legendarymotorcar.com/site/552

Check out all 200 plus photos from beginning to end.

I might, just might use the Dak rails to save myself some work of having to build an entire rail system from the ground up. Do away with the crossmembers, do away with the floor boards and mate everything together from scratch. That would mean adjusting the height of the car to get the center of gravity low, even if it meant running new crossmembers through the floorpans, kicking the floor of the trunk higher, lower, whatever, but it would definitely not be just sitting the car down on a frame and calling it good. Everything, and I mean everything, but the exterior sheetmetal would be built from scratch. Hypothetically, if I'm doing it, it's not just trying to figure out how to mount a frame under a car, or even pieces of a frame under a car. The frame and the car would be so meddled together you'd have a hard time seeing where the full frame stops and the body begins.

Use it as a subframe? Drive a Camaro, Nova, anything GM with a subframe and then take a ride in an E-body or an A-body. You'll notice a difference right off the bat. Sure, I guess you can weld it all together under the floopans, taper it back, and weld it in like the factory rails, but now you have to eliminate all, if not most of the formerly welded in attaching points to the inners, the core support, etc. You'll also need to build some reinforcements into the existing structure as the rails you're using will be heavier, thicker, and more cumbersome right off the bat. None of the under hood sheetmetal is really tied together on a GM F-body. And of the reasons for that is to allow for twist. That's why the core support is mounted in rubber, the inner fenders are mounted with rubber straps, etc. One of the reasons the ride is so, for lack of a better term, squishy compared to other comparable Mopars.

Now take a look at the link you provided with the link I gave you. Sure, the one from legendary motor car is designed to work with Viper pieces, but take a look at all the chassis that's involved. Now take a look at the B-body set up with the Viper engine sitting on it from the link you've provided. See the difference? One is definitely going the whole nine yards, the other looks Mickey Mouse in comparison.

As a matter of fact, let's take a look at XV versus the link you've provided. Where's the chassis dyno to prove their system is better than the unibody? (Stated on the first page of the link you've given.) XV's done it. They've taken the unibody and placed it on a chassis dyno to see where and what improvements needed to be done. Take a look at Motor Trend's comments on XV's Challenger. One g in the slalom. Not bad for "just" a unibody. Nowhere on the site you've given us is there any dyno information about how this has been such a marked improvement over the factory unibody.

As a matter of fact, I'd like to see how it stacks up against something like Ehrenberg's Green Brick Valiant. That simple unibody A-body has taken on some of the best in the world and sent a lot of 'em back on the trailer.

 

[bill55az]

I learned a few things while looking at frames, the 4x4 frame is the one!!!!!
Once you pull out the center section of the front axle, there is enough room for just about any engine you can think of....the xmember in the 4x2 runs right under the oil pan. The 4x4 is naked in that area, so it is clearly the best choice. You could put a front sump pan in it....
Only thing is, how to lower it? I see people chagning "keys" to jack up the front of a 4x4, are there keys to lower one?
Lowering the back is easy, swap to a 4x2 rear axle and leaf spring mounts and you are there...

 

[Greg55_99]

Ahem......

http://www.summitracing.com/parts/DJM-CA2397L-2/

This is for 2WD. Don't know about 4WD....

Greg