Kevlo already has a great thread with installation info and photos, so I'll just put up a few photos and explain how my installation differed.

I installed these on June 3 with much help from my friend Broaner (Org member who now has a VQ35ed S13 240SX). He did all the welding and I helped wherever I could. I believe I was the first to install Truax SFCs without using a lift. I borrowed 4 ramps and we jacked the car up and lowered it onto the ramps, front wheels first. Didn't want to mess around with driving on and having them scoot across the floor.





We scraped off the factory undercoating and then used a wire wheel to get the last bits off. Then we held the main rails into position with one clamp and my hands while Broaner welded the rearmost tabs. As I recall, one side was a perfect fit and the other was not too far off. I think we used a jack at the front end to bend the rail after it was welded at the rear point.

It's a b!tch to weld upside down in cramped quarters, but for this particular job it's doable. Broaner only caught on fire once.

 

The job took an extra hour or so because I wanted him to seam weld the main rails for added strength and stiffness. After doing this I read that it can cause problems with temperature changes, but I'm a bit skeptical of that since it's all steel and even slightly different grades of steel should expand and contract pretty uniformly. Anyway, regardless if whether you think it was a good idea or not, it's a site to behold:





I was interested in getting the job done quickly so I told him, as long as the welds are strong, I don't care how pretty they are. But most of them came out really nice:



We decided to grind down the outermost part of the Truax welds on the crossbracing so we could mount it for maximum ground clearance. I don't recall exactly how we mounted it but maybe you can tell from the photos.

 

I undercoated with 3M undercoating, which is about double the price of other undercoating so I hope it really is better. I used one can and it was barely enough. I know I probably missed some of the tight spots due to the bad angles I was working at. I'm not too worried about rust since I don't drive the Max in the winter.

Doors open and close perfectly. Car feels significantly more solid, but I wouldn't say vastly more solid. Interior rattles over small bumps are definitely reduced, but I was quite disappointed that the car still rattles a lot over larger bumps. In my mind I had built up SFCs to be so amazing that they would transform the car into a luxury car that felt like a tank, but obviously that was more than I could hope for. I guess this will motivate me to do the next steps: chassis foaming the rocker panels and pillars, and then sound dampening the floor and doors.

I have driven the car for almost two months now and have yet to scrape the SFCs on anything, including speed bumps, speed humps, and steep driveways. I am lowered about 1.7" front and 1.5" rear (roughly). Wheelgap is 2.0" front, 2.3" rear.

More photos here.

 

A few more shots of the welding. Broaner is omg teh man!

 

Awesome. keep us updated on whether or not the welding to the main rails does anything in temperature changes. I would hope it doesn't because I bet it would be quite a bit stiffer and better for handling like that.

 

Very nice review Vquick

2 things

1 did you every fix your sp2 from hanging low? and does it effect the SFC?

2 how common is it for the doors not to close properly with the SFC?

 

1. Nope, the B-pipe is nowhere near the SFC crossbracing so I wasn't compelled to fix it. I hope to someday but it's not a pressing concern since I've never even scraped it. The only thing I had to do was remove the rear heated O2 sensor (replaced with a bolt) because the Greddy SP2's bung points down for some idiotic reason. The center of the cross bracing is right there where the O2 is so I have the sensor off the car right now, resulting in a Service Engine Soon light. But the rear O2 does nothing except monitor the catalytic converter so I'm just living with the light for now.

2. If you install SFCs properly, you don't have to worry about the doors not closing right. You just need to have the car resting on all 4 wheels at the time you weld the SFCs on. If you have the car jacked up from the frame rails, the chassis is going to be flexed differently and the frame would be held in the flexed state by the SFCs.

 

VERY NICE WELDS!!!!!!!

 

Thanks a bunch Kev. It was definitely tight. I was a bit dissatisfied with some of the beads but generally it was alright.

I will say to all out there that this is definitely doable in any level garage so don't be scared off SFC's by the requirement to put your vehicle in the hands of another. At this point I'll put in my shameless plug. I'll be glad to do this install for anyone.

 

Welds look good. Did you guys think about doing any seamwelding inside the car where the panels meet with industrial glue?

Thanks for the pics VQuick.

 

I've done that every seam in my S13. Its had a huge result. Tom and I kinda discussed it but for a DD that kinda overkill. I'm sure he'll chime in. Foaming is the next best thing to seam welding.

 

If I had my own welder and lots of free time I would do seam welding. I suspect that 10% of those welds would make 90% of the structural difference because they're at the stress points, so the rest is definitely overkill and added weight. But without instruments and mechanical/materials science knowledge that's just guesswork. Foaming will be my last major chassis work. Except for the RSTB that Broaner's going to weld to my strut towers.

 

So aside from your being dissappointed with the difference it makes in sound, how do you feel about the change in ride quality, as far as taking corners and what not?

 

How much more work and time would this seam welding take? It may be overkill. But who doesn't want the car at full potential? Sure the car will probably never be used to it's fullest potential with the stiffening of the chassis, but I would still love to have it all seam welded.

 

You refering to the whole car Hacim or just the seams related to the SFC's? Doing my whole car easily took me 60hours of @ss busting work. And a Maxima is significantly larger than an S13. Doing the seams on the SFC's adds about two hours.

 

Yes I was talking about the whole car. Are all these welds done from inside the car?

 

Yes, a majority of them are done from inside. I did it that way at least. Its really a PITA to weld upside down on your back cramped under the car. Sitting in the drivers compartment is much easier. Eventually I plan to do the bottoms of the seams on my S13 but I need to flip the chassis over to do that. Also, sorta another heads up. Don't do seam welding on a rotiserie. I've seen it done and I'm appauled every time.

Tomer, lookin back at the pics I'm realizing you got some awesome shots with the slag flying. Sweet!

 

Ride quality is significantly but not amazingly better. As I said, well worth it but don't expect miracles.

Broaner, did you do all your seam welds with the 240's suspension loaded or no?

 

Unloaded, including the weight from the powertrain, drivetrain and subframes.