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View Full Version : Question regarding chassis upgrades on a convertible



93vert
05-31-2001, 05:46 PM
I just bough a '93 240SX convertible and would like to know what modifications I can do to stiffen up the chassis. I have seen strut tower braces but are they effective and which ones are the best? Also, has anyone installed subframe connectors? I have a supercharged Mustang and when I installed subframe connectors on it the handling improved tremendously. I am curious if they have the same effect on the 240SX's.

Any other useful modification tips are welcome. I'm not looking to turbo charge it or turn it into a road warrior, just basic effective mods. The car is an automatic.

**DONOTDELETE**
05-31-2001, 07:54 PM
I don't know about the convertible 240sx in particular, but the convertibles in general have the most flex across the middle of the car, where the passengers sit. There's no roof, so only the floor pan provides rigidity against twisting. The best thing you can do is install a roll bar. It should stiffen things up a lot right where you need it, and makes things safer too.

**DONOTDELETE**
06-01-2001, 12:13 PM
Hey, just now outa curiosity I did a search for info about that foam stuff. From what I found, I wouldn't bother with it. It doesn't form a complete seal, so water can penetrate it. When that happens it gets trapped right next to the frame, and slowly rusts away at the chassis. Bad stuff, I wouldn't use it.

06-01-2001, 11:54 PM
You can get chassis foam from these guys: http://www.itwfoamseal.com/auto_aftermarket.htm

Supposed to be pretty effective. I think a front strut brace will help, but it'll be hard to find one for the rear because I don't think one from an S13 hatch or coupe will fit (the top gets in the way probably).

You can probably get so-called "ladder bars" from Japan (made by Do-Luck). They're basically like strut braces except they go underneath the car and brace the frame rails.

Asad

<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by 93vert:
I just bough a '93 240SX convertible and would like to know what modifications I can do to stiffen up the chassis. I have seen strut tower braces but are they effective and which ones are the best? Also, has anyone installed subframe connectors? I have a supercharged Mustang and when I installed subframe connectors on it the handling improved tremendously. I am curious if they have the same effect on the 240SX's.

Any other useful modification tips are welcome. I'm not looking to turbo charge it or turn it into a road warrior, just basic effective mods. The car is an automatic.<HR></BLOCKQUOTE>

**DONOTDELETE**
06-02-2001, 09:52 AM
<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by Ben:
Hey, just now outa curiosity I did a search for info about that foam stuff. From what I found, I wouldn't bother with it. It doesn't form a complete seal, so water can penetrate it. When that happens it gets trapped right next to the frame, and slowly rusts away at the chassis. Bad stuff, I wouldn't use it.<HR></BLOCKQUOTE>


whats the source of your information??...i'm seriously thinking of using this stuff...

**DONOTDELETE**
06-03-2001, 02:20 AM
Well, I found a couple discussions about it. One from the Miata mailing list and another on a Pantera mailing list. This stuff is basically the same as the foam flotation they use to fill empty spaces on boats in case of a capsize. The Pantera guys mentioned that a bunch of pantera owners used it back in the day and every one of them had serious chassis rusting problems later. They said it was because the stuff doesn't dry right away. It will actually take a couple years to completely dry, and as it does that is slowly shrinks and cracks. That allows water in and rust everywhere. The miata guys said it was because the foam itself is slightly perforated and slowly soaks up water like a spunge. That holds the water next to the chassis. Either reasoning you want to use, you get the same result. So it's up to you, but I wouldn't risk it.