First off, the original idea was restoring a '94 Civic VX Hatch back to completely stock form with a couple underbody aero and structural upgrades like stainless hardware, however I purchased the car in rather rough shape. It runs, drives, etc, but needs quite a bit of cosmetic work and odds and ends. Knowing this, I seeked out some junkyards and found parts, but I couldn't find a hatch locally, as I would rather just get a new bottom tail gate, since the tailgate and hinges on it now is rusted pretty badly.
While looking for some parts cars, I had a friend's car available. It's a 93 Civic Si project car that has a clean frame and body on it, but it's been gutted. So this leaves me in a decision conundrum.

-Let's start with pics of the Red VX I have and the 93 Si, I am picking up first.
1994 Red VX
Significant rust around rockers, tailgate, and rear quarters, but the rest of the frame isn't too bad. Obviously the badly rusted areas will need cut out and either replaced with panels from rustrepair.com, but I'd rather just swap it over from a shell as the rust is over such a large area, plus I need a tailgate anyways.








Left rear inner fender towards rocker.


Left rear rocker with cover taken off.



Needs a new downpipe and muffler

Underbody isn't as bad as the outside looks...most is surface rust.

Probably needs some new bushings and poly

Compensator arms are smoked


93 Si





So here is the predicament. Should I swap the clean Si panels over to the VX chassis and then paint(and take car of the rest of it...or should I take out the VX engine, tranny, wheels, trailing arms, brakes, instrument panel, etc. and put it in the new Si chassis?

The plus of the Si chassis is it is already stripped, so I could do a more thorough painting and rustproofing all the way around. The downside is I know very little about the Si and see it weighs a down, which I'm guessing is because of power accessories and the like. This Si has a moonroof. Would there be any way to hook up this moonroof to the VX's power terminals? Are there differences between the Si chassis as a whole compared to the VX? This Si already had an integra disc conversion all the way around from the Si disc brakes, but I can't use those with my 13 inch VX wheels, so it's pretty worthless there. I will probably just keep the VX wheels and rear drum setup unless there is a disc setup small enough to fit up in the VX wheels.

The other idea was just swapping the panels and tailgate off of the Si and welding them on to the VX frame then grinding and treating the remainder of the rust.

It's going to be a LOT of work either way, but at least it will be thorough and done correctly and better than OEM when done.

 

That VX xhasis looks like it is done.

 

Use the Si chassis. That VX chassis looks like it went down with the Titanic

 

Are there any differences between the Si chassis and the VX chassis or are they fundamentally the same? I know I will have to swap the VX trailing arm over to the Si so I can keep the drum brakes, but what about the lower control and compensating arm? Will I still be able to hook up the power moonroof with all the VX equipment?

I noticed the Si weighs substantially more, but I'm presuming the engine and all the power features on the Si is what makes it so much heavier than the VX?

 

It's not really that bad. If I bought the rockers and quarters from rustrepair, the body work would be 90% done(minus the hatch tailgate). The only pain is the parts that the replacement panels don't fit in, hence why I got the Si to POSSIBLY just zip out the panels on it and transplant it instead trying to fabricate the curves around some of the sill and upper left rear quarter area.

 

Use the Si. VX is toast.

Everything (and I mean EVERYTHING) will swap over. Basically you will be building a new VX from scratch on an Si frame. This is great! You get a nice moonroof in a VX. Don't sweat the electrical. Moonroof harness is a separate harness that will remain in the Si and plugs in to the fuse box.

Also, the Integra rear discs will fit the 13" wheels. Only the fronts won't fit if they are from an integra. In which case, just swap over the ones from the VX since these are the same as the original Si's anyway.

You are kinda embarking on a project similar to this guy: http://ecomodder.com/forum/showthrea...5z1-23433.html , only he put his into a sedan but many of the concepts are the same. Have confidence that this will work and is a good idea, frankly.

 

Is there a spot in the VX fuse box to hook up the moonroof though? Outside of that are there any other differences between the Si and VX like anti-roll bars, chassis bracing, etc.

I actually didn't know the rear Integra disc's fit the 13" VX wheels, because I had only heard otherwise, but like you said, I could just put the VX fronts on if the Integra rears work, although I might have to do some fiddling with proportion and disc size possibly, so the rears don't have too much bite to them.

About the only part of this car that will remain "Si" is the power moonroof, and the rear disc. Everything else will be converted over using the original VX parts for maximum fuel economy down to the instrument cluster. Other misc. parts like the L front fender, windshield, etc I can find for dirt cheap at local junkyards, so not too concerned with that aspect.

 

For all the trouble it's worth, you always want to get the chassis with the least or no rust!! It will save alot of time and trouble

 

Yes, the VX fuse box will happily accept the moonroof subharness. Fuse boxes are identical (just need to add the 30A fuse). Bodies are identical save for the moonroof and the holes for the body mouldings. And there is a front anti-sway bar on the Si that connects the front control arms, that's about it for differences.

Possibly, though I doubt even that the proportioning valve was changed (check). Functionally and practically, Integra rear discs are identical to Si rear discs so I actually doubt that the rears were swapped or if they were it is same for same.


Fun! Does the Si have its original electrical harnesses? One thing to think about is adding wiring for VX-specific features if you want to keep the current Si harness because it is pre-wired for Cruise Control (you DEFINITELY want this for max fuel economy) as well as the rear wiper, trunk light, and power mirrors. Having done a similar type of swap before, adding the VX features to the existing Si vehicle will be an easier process than going the other way (to keep Cruise Control, etc.). Don't do away with some of these little luxuries; you will find them quite handy.

If you want to do any other functional improvements to your ride, now is your chance. To get some ideas, check my DIYs in my signature.

 

You'll also have a bigger gas tank with the Si. By 1.9 gallons I believe. Also those VX rims won't fix with the integra brake setup.

 

^ Truth.

Get familiar (if you aren't already) with the unique features of the VX and be sure to swap them over to the Si. A couple of things that come to mind right away are: Front lip, rear under-bumper diffuser, shift-up light ... there are more.

 

The front lip or a version of it will be going back on. The shift light will be retained along with adding an MPGuino. The underbody diffuser, I may eliminate to save weight, because I am going to make my own underbody tray and rear diffuser to help with aero. I find that to be the biggest problem with the car is the aero underneath it. I think there can be a substantial improvement in that area.

 

If you decide not to use the moonroof I will gladly buy it off of you I went through a similar build and ended up cutting the car in half and welding on another half because the rust was sooo bad.

 

The only real difference is the lack of body molding on the CX/VX, the channel is actually shaped a little differently.

Most of the weight comes from the moonroof. The only other power features the Si has are power mirrors. The locks and windows are manual. The engines weigh roughly the same, rear discs add a little weight, but nothing substantial overall

You're way, way further ahead with just using the Si shell. And yes the VX is that bad. Once you start cutting into it you'll figure out it's a lot more rotten than you think. Believe me I'm familiar with this.

The Si has a front swaybar. If you plan to use it you need the Si front LCAs

You don't have to do any screwing around, the '92 - '93 Si came with the same small front brakes the VX did along with rear discs.

 

So, I'm making a little headway with this project after a 6 month hiatus. To put all concerns away, I am using the clean Si shell, although I have realized some problem areas I have to cut and weld since riceburner extraordinaire thought it would be DUM as fuq to hack it to attempt a right hand drive conversion and other stupid crap. Anyways, I can work those issues out with my welder. I do have some questions though.

1: VX wheels fit the Si rear disks, but they don't fit the fronts. Can the VX front rotors and discs swap right over seamlessly?

2: The VX and Si use different brake boosters. I believe the Si uses a 9" and the VX uses an 8". Is one a better option than the other?

3: I want to keep the VX manual steering rack. I realize the crossmember for the VX is different from the Si, but can the VX manual steering rack fit right up to the Si crossmember without problems?

 

Hey it's OK, sometimes life gets in the way.

If the front brakes don't fit the 13" rims then it means they've been swapped for larger brakes. ALL 92-95 Civics (non-ABS) had the same size front brakes. Swap over the VX ones to go back to stock.

Brake booster swapped because front brakes swapped? Makes sense, but don't quote me. Check part numbers online.

Can't help with #3.

 

Yea, a lot of crap has been going on, so it's nice to get on with it.

It's possible they are integra front brakes. The previous ding dong did a real handful cutting out one of the engine mounts, multiple holes in the firewall, weapon R coilovers, and cut out the transmission tunnel. He also did a stellar job of hacking the dash/steering wheel support as well, so all that jazz needs cut out of the VX, lined up, and welded in.

I'll check the part numbers for the brakes again. I think the caliper was actually an Integra caliper, but I just haven't had time to check and I'll be gone for about a week as I am traveling down to Road Atlanta for the NASA Championships this weekend.