Trying to generate some interest in subframe connectors.

[25psi]

http://forums.maxima.org/showthread.php?t=425928

"Okay, subframes connect the front and rear of your car together. Our cars are uni-body. That means that our thin, and weak floor pan serve as a link between the front and rear of the car. Look under you car, you will see a jacking rail under the front and back, but nothing between the two.
That is where the subframes come in. They connect the two together and serve to reinforced and stiffen the chassis. I had a 88 t-top Fox and after i installed them the difference was night and day.
I suggest this as a first mod to anyone.


Sub frame connectors connect the rear of the car to the front of the car. The front & rear both have small frame type areas that the suspension bolts to and only floor pan between them. When installed sub frames connectors it ties the front with the back, hence making the car stiffer with less flex. Convertibles are worse that coupes, since they do not have a top that helps stiffen up the body, verts with sub frames have a noticeable difference in body flex. Body flex is not good.


Another reason a car or truck won't respond right away when you step on the gas or turn the wheel is because the vehicle is trying to twist itself. This is wasted energy, reducing your fuel economy and your vehicle's responsiveness. Fortunately, accessories that stiffen your vehicle--including subframe connectors and strut tower braces--will reduce this body flex, so your car or truck will respond to your commands more quickly. Install sub-frame connectors and improve traction, handling and help eliminate squeaks and rattles. "

Trying to get some interest going, I think these would be a valuable tool an DSM's.

From what I've read it will make the car feel MUCH more stiff, like a german car.

 

[boostedinaz]

First off our motors are "side to side" not " front to back" so no matter what you do they wont really twist the car. If you have ever seen the underside of an AWD car you will see that these aren't really needed. I can jack up a front tire a few inches off the ground and it will bring the other rear wheel with it in no time. Seems stiff enough to me. If anything they can be made at home for a fraction of the price a "kit" will charge.

Just my .02.

 

[25psi]

First off our motors are "side to side" not " front to back" so no matter what you do they wont really twist the car. If you have ever seen the underside of an AWD car you will see that these aren't really needed. I can jack up a front tire a few inches off the ground and it will bring the other rear wheel with it in no time. Seems stiff enough to me. If anything they can be made at home for a fraction of the price a "kit" will charge.

Just my .02.

Read the thread I posted, in it, it explains that it can benefit FWD/transverse mounted uni-body cars greatly. It helps by increasing chassis stiffness as a whole, not just from the engine twisting forces.

 

[boostedinaz]

Read the thread I posted, in it, it explains that it can benefit FWD/transverse mounted uni-body cars greatly. It helps by increasing chassis stiffness as a whole, not just from the engine twisting forces.

But again, have you seen the underside of an AWD car? Have you even jacked one up by just a single corner? They are talking about FWD cars that have a piece of tissue paper holding them together not a car with numerous bracing and other smaller subframes already on it.

Yes, I have seen older muscles cars and some new F bodies and Fox bodies buckle fenders and scrape right rear bumpers, but I have yet to see an AWD DSM do any of that or even come close.

 

[jtmcinder]

As soon as you read the thread-starter's suggestion that the strength of a unibody car comes from the floor-pan, you should have moved on to the next thread.

The strength of our cars comes from a stretched monocoque unibody. The whole darned car is the frame. Yes, there is some boxing here and there for added strength, but they are just parts of the whole and a lot of that crap underneath is to keep the floor from flexing when someone big climbs in. A frame-based car, on the other hand, often needs connectors because you don't have the benefits of a 3D shoe-box-with-lid design.

Put another way, you don't see DSMs (at any power level) popping out sunroofs or buckling roofs or quarter-panels when they launch. We have no need for connectors. If you want to add some weight to the car, knock yourself out, but our real problem is torsional stiffness, so you'd be much better off adding a 6- or 8-point. Having the weight transfer to the outside rear wheel would be useful. Having the car flex and allow the weight to transfer up front is holding us back in turns, especially if you have a sunroof.

- Jtoby

 

[MNGSX]

The cage will stiffen more than just torsionally.... Not that most ppl need it..

 

[jtmcinder]

Agreed. The rule of thumb is that the unibody must have 10x the torsional stiffness of the suspension. So only with high springrates (and a lot of diagonal weight transfer) would you need one for handling.

- Jtoby

 

[zephyr_8]

I had actually considered fabbing up some subframe connectors for my car, but after i really thought about it I realized that it would not be a big enough difference for the amount of work(at least in my car, its seam welded). It might help but i think there are better ways.

Oh and by the way, if you think your awd is stiff, well consider this, after i seam welded my car it handles more precisely, doesnt understeer (much) and just in general is more controlled. It rides smoother too. I wish i had a way to explain how much difference there is in the stiffness of my seam welded chassis and a stock one. I wouldn't rule out stiffening up the chassis as a worthwhile thing to do. I plan to finish bracing the chassis/stiffening it, before i even add shocks/springs/swaybars/bushings. The car as it is, is already a huge improvement over stock.

 

[25psi]

As soon as you read the thread-starter's suggestion that the strength of a unibody car comes from the floor-pan, you should have moved on to the next thread.

The strength of our cars comes from a stretched monocoque unibody. The whole darned car is the frame. Yes, there is some boxing here and there for added strength, but they are just parts of the whole and a lot of that crap underneath is to keep the floor from flexing when someone big climbs in. A frame-based car, on the other hand, often needs connectors because you don't have the benefits of a 3D shoe-box-with-lid design.

Put another way, you don't see DSMs (at any power level) popping out sunroofs or buckling roofs or quarter-panels when they launch. We have no need for connectors. If you want to add some weight to the car, knock yourself out, but our real problem is torsional stiffness, so you'd be much better off adding a 6- or 8-point. Having the weight transfer to the outside rear wheel would be useful. Having the car flex and allow the weight to transfer up front is holding us back in turns, especially if you have a sunroof.

- Jtoby

It sounds like AWD DSM's have plenty of bracing from the factory from what I've read, but can the same be said for FWD's?

I didn't claim that a unibodied car's strength comes from the floorpan either, it was part of the quote.

 

[jtmcinder]

The unibody is more than enough, given you're talking about a a front-engine, front-heavy, front-wheel-drive car. And, again, if you detect any buckling, you'd be 10 times better off with an 6- or 8-point than subframe connectors. (Not that a FWD has a rear subframe.)

- Jtoby

 

[Defiant]

Camaros and Mustangs need SFCs. Rather desperately, in fact.

DSMs don't. I don't know what a Maxima would do with them, either. Although they would add some road-hugging weight.