Connecting frames

[stangstevers]

I have the opportunity to borrow an F350, enclosed trailer and a race car shop to work on my car. With that, I can do mini-tub for larger tires (would love that eventually) but I'm thinking connecting frames. I could pay $500+ for steeda ones but why bother, it's not hard to fabricate. Here's the question, how about going nuts and doing through the floor connectors and strengthen the torque boxes. I realize it changes what the car is but not a lot of people can do this or even afford it (to be blunt, this isn't cheap if you pay a fabricator to do this). I'm not doing a cage, just reinforce the twisty old fox. I do want a strut tower brace and make a brace between the shock towers in the back.

Pics:
http://i486.photobucket.com/albums/rr226/Mustng408/MustangBuild1003.jpg

http://griffinracecraft.com/images/733_Young_011.jpg

http://i316.photobucket.com/albums/mm338/z7turbo/zephyr%20pics/100_1953.jpg

Not what I'm talking about but pretty cool:
http://store.kennybrown.com/files/imagecache/product_full/29550%20Extreme%20kit%20installed%20red_0.JPG

Goal is stupid solid car, adds some weight but I think the benefits outweigh that. I'm almost tempted to start measuring it. I can almost do it at home too, just need a mig welder. I think my arc will burn through the floor plans and I'd end up with an ugly botched shitbox.

[Scott]

I would go for it as it clearly stiffens everything up. While S197's are a little more rigid than Fox bodies I added BMR Sub Frame connectors to my car in the spring. Glad I did as they make excellent points for jacking and jack stands. Very easy now to lift the whole side of the car with one floor jack.

http://i955.photobucket.com/albums/ae40/Scott_GT_CS/Suspension/IMG_9072%20Medium_zpsjrh0o8pj.jpg (http://s955.photobucket.com/user/Scott_GT_CS/media/Suspension/IMG_9072%20Medium_zpsjrh0o8pj.jpg.html)

http://i955.photobucket.com/albums/ae40/Scott_GT_CS/Suspension/IMG_9078%20Medium_zpsjouf2aiy.jpg (http://s955.photobucket.com/user/Scott_GT_CS/media/Suspension/IMG_9078%20Medium_zpsjouf2aiy.jpg.html)

[stangstevers]

Looks killer too! Thanks for the pics.

[TheMustangShow]

Steeda make one for the Rear, cheaper than fabbing one: http://www.americanmuscle.com/steeda-shock-tower-brace.html

[RedSN]

*discretionary warning: the following is just my opinion, and may be refuted by several experts.*

That's a lot of extra weight for what? Ask yourself how does a unibody work? Where does it's strength come from? And where are it's weaknesses?

Connecting more steel between the front subframe and the rear subframe does not transform a unibody into a body-on-frame chassis. Nor would you want it to. Why would you want model-T technology? You would have to weld in a truck frame size section in order to connect the front and rear in this manner.

So the front subframe carries the engine and front suspension, while the rear subframe supports the axle suspension components. Between the two is a rigid shell, the car body. Adding steel to the bottom of the shell provides more strength and stiffness to the portion of the shell that is under tension during flexing. That's why the SFC's can be round, square, or rectangular, really doesn't matter. Could be a flat bar for all that it matters. Unfortunately, the top portion of the shell, the roof, is never reinforced.

To be honest: most of the "car feels more solid" feeling comes from the seat connectors. Normally, the seats are bolted to a flimsy floor pan. The seat connectors add a huge amount of rigidity to this connection.

As for the truss-style ladders ....what exactly are they supposed to be adding to the unibody? Side impact resistance? From what I gather, they are intended primarily as a jacking rail and look cool.

[stangstevers]

Ha! I'd have to trust your input RedSN. Valid points. And here's an experiment to prove your point: http://www.mustangandfords.com/how-to/chassis-suspension/mmfp-0909-why-subframe-connectors-benefit-your-mustang/

So now I can have the same "feeling" just by adding some flat bar to the floor pan where the seat mounts lol. Everyone swears about connecting frames preventing torque twist, but now I'm thinking the bars will just twist with the body since they aren't connected with each other to prevent them from moving independently. I'm sure the extra rigidity comes from more than the butt-meter though?

But the tension you're talking about is looking at the side profile and preventing it from flexing (banana shape), the torque flex from sticky tires and big engine, the connecting frames will just twist with the body. You'd need x-bracing from door to door top and bottom to keep the body "square". So if I understand, it's like building an ikea cabinet, it's flimsy until you add the cardboard backing (x brace), but the connecting frames aren't that backing we think it is, it's just another shelf? Hard to put in words but I assure you, the mental image makes sense to me lol.

But some extra metal around the typical fox "stress crack" areas such as where the control arms bolt up, is not a bad idea though.

[tulowd]

http://www.torontomustangclub.ca/forums/showthread.php?547-87-Convertible-GT/page8

I looked into all this - on a vert the rocker panels are double width from the factory for additional stiffness; also has a big ass L channel riveted along the bottom. and had a chassis shop custom make thru the floor connectors to the trans X member. They also re enforced the lower control arm pickup points by welding in some "Battle Boxes" I had purchased. They also redid the rear bulkhead with /.125" plate and welded in my old 6 pt roll bar.

I fabbed up and welded in the rear shock tower brace and the front SFC extensions to the fire wall myself, shoulda done everything myself in hindsight. I also seam welded everything I could get my hands on, laid down about 150 ft of welds into the chassis.
Its not enough, but it made the car way better; along with upper and lower MM K member and strut tower braces.

The side jacking rail/garden trellis doesn't likely do anything; but have at it. Use a good Mig with a bottle of Autoweld and .025/.023 wire for best results. A lot of that sheet metal is paper thin, coated in crap, rusted and somewhat galvanized. Way more work than it looks like prepping everything.

If I was to do it again, I would buy and weld in the MM or Steeda full length connectors and BB's myself, saving a bundle of time and money. You can add in the thru the floor part yourself or buy it from Griggs.

The prep work is brutal, especially with no hoist or rotisserie.

[ZR]

Hart to beat what the Steeda connectors add to your ride, quality product.

[RedSN]

Hart to beat what the Steeda connectors add to your ride, quality product.
No doubt. But I'm certain now, more than before, that the main difference between the homemade connectors on my Fox versus the Steeda connectors on my SN are the seat braces.
Having said that, I'm extra glad I went with the Steeda's because they are a nice solid piece of steel to attach the torque arm to.

[ZR]

At one time I'd have agreed but after cutting off lesser versions (yes including the odd set with seat braces) and feeling the amount of difference has me taking the opposite stance. Material they are made of, way they mount and how they are welded does matter. Steeda's rear mounting plate, surprised all of the other mfg's haven't followed suit.

[hsousa88]

I hate this topic.

[RAT ATK]

Did infloors on my ride. Made a noticeable difference to my car.

[Slick_89_Hatch]

I have the MM connectors that Rick Installed. It is not just a "Feeling in the Seat" difference. I can jack up the car from lets say the RR and the entire ass end will come up almost entirely straight where as before with home made jobs the car would twist and the LR wheel would not come up. You can't tell me that they do not offer a significant change in rigidity. Now, going through the floor, not sure if that offers any more than something from MM or Steeda other than ground clearance. Id also add that my car drives really solid and has little to no squeaking or rattling.

[stangstevers]

If I jack the front driver side, the rear tire comes up just as high as the front... it's pretty solid for a fox... no connecting frames.

[Slick_89_Hatch]

I probably get a little more twist being a hatch. I've only driven a couple Notches but notices they seemed fairly solid without connectors.

[ZR]

Fairly solid without, a whole lot better with.

[BOOOSTD]

My very first mod on the SN were the Steeda FLSFC's and they made a noticeable difference. Next to a gear, its one of the best bangs for the buck IMHO!

[stangstevers]

some system that re-enforces and makes better use of the trans tunnel and rockers would be nice. Definitely more expensive and more work than blasting in connectors.

I'm planing something, hold on.