Here's the sub frame connectors I made for my 89 IROC. They're made from 1 1 1/2" square tubing with 1" dog leg to clear the exhaust. Note that I used the 1" tubing to tie them in to the inner sub right at the cross member and to tie them to the pinch weld along the door. I welded plates to the factory pans for reinforcement and to improve the weld to the bars. Also check out the home made lower control arm relocation brackets and the boxed in lower control arms. This car runs 7.98 1/8 mi @ 93 with these mods and an otherwise stok suspension. Total cost was about $40.

These pics are the passengers side.

 

More pics of passenger side. It's hard to tell from the pics but the tubing is "stepped" up to clear the exhaust. I overlapped the tubes about 5" and got a good weld to tie them together. You can't see but there are many filler pieces tieing the connectors to various places in the floor pan and to the pinch weld under the doors. The "Y" bars actually tie right at the transmission crossmember, connecting both sides together.

 

Here's the drivers side. I made the LCARB's out of 1/4" cold rolled steel and have plans for them if anyone wants. Note how the main tubing is capped on the rear with a 1/4" L bracket. This bracket has a hole where the front lower control arm bolts through. Thereby reinforcing the area that actually "pushes" the car forward and transmits all that stress through out the sub frame system.

 

This side was pretty straight forward. Again, it's hard to see but I welded every place I could along the floor pan. I especially tried to get the heavier plates by the rear suspension supported.

 

I made sure I had them tied in well using tubing, patch plates and gussets. Notice in the first image how the floor pan had already started to crack from all the stress!

 

Wow, they look really good. Can't beat your price either. I would ask for the plans but I already bought Spohn SFC and UMI LCARB. Imagine all the money I could have saved...

 

Nice work, I'd love to see some plans, I will have to build my own SFCs because shipping is just to expensive for me to buy them.

 

I also wouldn't mind some plans for these...email to carl.pence@yahoo.com if you are interested in sharing the plans

 

actually, could you just post the pics or send a link of some sort? I'd like to look them over too.

 

Well most of the plans were on a legal pad but I still have it. I'll see if I can get it scanned or recreate it in Autocad and post later. At least take some better pics! Thanks for the interest.

 

those look very nice, I was considering on making my own sfc's, just wasn't sure on how to go about it. I would really appreciate it if you could send me those plans. E-mail is csmethie@gmail.com. thanks

 

Looks good. I've not seen a better example of a homemade set of SFCs. The LCARBs look especially nice.

 

could you please post plans for those, they look great

 

nice work but welds could be a bit better, anyways congrats it is better to do sfc by yourself then buying aftermarket ones because each car is a bitt different after few years of usage

i'm wondering why all you guyes need plans ?? those are only couple of tubes welded to the car, all you need is 4 collumn lifter, tubings and some one who knows how to weld

 

i would like some plans of those as well they look great. could email to michaelwgreta@bellsouth.net please.

 

The reason I'd like to see the plans is because in order for me to be able to get the steel and access to the MIG my teacher needs to see the project on paper. That way I can get the steel for way cheap and I get a grade for it.

 

to get the sfc's over the exhuast did you just have to weld that bar on top or did you need to grind it down to make it fit?

 

sorry to dig up an old thread, but were those plans ever scanned or put on computer in some way? it would be nice to have something to go by when/if i make mine