X-Frame Member

[Nick Micale]

We all know from the experience of others that the lower control arm frame mountings need reinforcement. There is no question about that. As I looked at the task of reinforcing those points I realized that the thrust load being transferred to the frame through the lower control arms was being carried by the weak C channels of the mid section of the stock frame. I thought it would be better to lessen that load and carry it to the front of the frame through an additional member. It's a well know fact in the chassis business that an X-frame member does wonders to resist frame twist, and it would also do well to share some of the thrust load from the lower controls arms and transfer it directly to the stronger forward portion of the stock frame.
I also realized that if the intersection of the X was done right I could use it as the transmission mounting also. The whole project really started out as a way to reinforce the lower control arm frame mount, and snow balled from there. The question of how much does it help. Hmmm. The main objective was to strengthen the lower control arm frame mounting points. It does that very well. Being a X-frame member, it controls frame twisting. It triangulates the entire mid-section of the stock frame. It adds more structure to transfer the thrust load from the lower control arms. It adds opportunities to mount other items to it, such as the transmission vent catch tank and intake plenum catch tank.
Bottom line it does a lot of things to help. Does it make a difference on the ET slip? Heck, I don't know. It was just one of my crazy engineering projects.

Don, that is very nice work, which is up to your usual high standards!

We did a similar "X" on my cars years ago when we reinforced the LCA mounts, not a classy as yours, but they do stiffen the frame.

Also, the rubber pads from the trans crossmember have been long gone when we removed all the rubber body mounts and replaced them with my kid's hockey pucks. OK, my "roots" in racing go back to the time before Summit and Jegs, when we had to make-do and modify to get by.:biggrin:

Anyway, I agree, hard to give a number, but my car hooks when many other cannot, and certainly stiffens the entire car.

Don, do not see your diaper or belly pan? They are mandatory on ALL 9.99 and faster cars at the tracks here in the state.

 

[Squid4life]

Wow, crazy impressive, as with all your projects.

 

[Alky V6]

Don, that is very nice work, which is up to your usual high standards!

We did a similar "X" on my cars years ago when we reinforced the LCA mounts, not a classy as yours, but they do stiffen the frame.

Also, the rubber pads from the trans crossmember have been long gone when we removed all the rubber body mounts and replaced them with my kid's hockey pucks. OK, my "roots" in racing go back to the time before Summit and Jegs, when we had to make-do and modify to get by.:biggrin:

Anyway, I agree, hard to give a number, but my car hooks when many other cannot, and certainly stiffens the entire car.

Don, do not see your diaper or belly pan? They are mandatory on ALL 9.99 and faster cars at the tracks here in the state.

Yeah, I know. I'll be fabbing up a belly pan for it soon enough. It's on the 'to do' list. My fellow racer buddies keep asking me that too. I tell them, the car ain't gone 9.99 with this new turbo yet. They give me a funny look like, Don trying to skate the rules? Has the magnetic field of the earth reversed?

 

[Louie L.]

Impressive work Don. Are the front and rear legs welded together on each side making it a 3 piece unit (2 sides and 1 center) or separate fronts and backs making it a 5 piece unit?

 

[Dwayne]

How much weight was added to the car ?

 

[Alky V6]

Impressive work Don. Are the front and rear legs welded together on each side making it a 3 piece unit (2 sides and 1 center) or separate fronts and backs making it a 5 piece unit?

The center area of each side are one channel piece that was slit and bent to shape, then the slits welded up. Inside the channels at the center section you'll notice no welds, while on the outside there are welds.

To answer your question, 3 piece. Two sides and the center joining plates.

 

[Alky V6]

How much weight was added to the car ?

I don't know the weight of the X-frame alone. I don't have a weight before the X-frame. The weight of the car with me in it and full of fuel was 3140 lbs after the X-frame.

 

[turbofabricator]

Nice work Donnie. Haven't posted much lately due to CRAZY overtime. One other thing to add to your X-brace is a couple of bracket to mount your safety loop to. I've seen the safety loop RIPPED out of the floor. Simple safety mod for a guy like you. When I looked that the first few pics, I was thinking "I hope he attached the aft end to the front LCA bracket". Later pics proved we think alike. I welded bars from the LCA backets diagonally forward to the cross member mounts, and then boxed the frame in front of the mounts. (on my first GN that was stolen, so if anyone sees a GN with diagonal bars call me) Kinda fun to watch your stuff, and read comments like Nicks statement about doing things with what ever we have laying around. Hockey pucks!.......... Sarah Palin would be PROUD!

 

[Alky V6]

Actually, the front yoke and U-joint of the driveshaft is over the top center section plate. So the plate would help out the loop if there was a front U-joint failure.

 

[Alky V6]

This is what the X-frame looks like after a transmission removal.