Last week I acquired a 1994 Civic Ex coupe that will serve as my daily + pull auto-x duty while my sedan is in paint.
While ST rules are fairly strict there is some decent weight reduction that can be legally done, but you won't see the triple digit reduction #'s like you see in more stripped cars.

This weekend I swapped in a fresher Z6, and weighed a bunch of stock parts compared to the replacements, and parts I added.
My EX did not come with A/C so unfortunately I can't provide that weight loss, I'll see if a buddy has the components I can weigh tho.
I used a bathroom scale so weights are approx.

Replace exhaust manifold/b-pipe with stainless header.
Stock piece 25#'s, header 11#'s. 14# loss.

Relocate battery to trunk and replace with "lawn and garden' battery. Old 30#'s, new 16#'s, plus about 1# wire.
13# loss

21mm? JDM EK9 rear sway bar and brackets +9#'s

Replace crank pulley with DX version. ~3# loss

Tein coilovers- too close in weight to originals to tell, maybe ounces heavier.

15" wheels and tires-nearly identical weight, but went from 14" steelies to 15" aluminums and azenis.

Spare tire, jack, tools, floppy cardboard thing and trunk carpet. approx 30# loss.


Note that the header and battery relocation take alot of weight off the nose, where you want to lighten up. The DX crank pulley will also help the motor rev quickly but is non-dampened. I've heard longivity issues with such pulleys but it's contraversial...I may opt for using the stock one with underdrives on the accesories instead.

When/if funds allow I can replace both front and rear LCA's(someone is making chromoly tubular front lca's now) and still see another 20# loss.
Heat shields can also go, and I will add some more #'s when I get an exhaust.

 

Only 300lbs to go!

Make sure you don't remove the heat shields that bolt to the chassis as that would not be legal.

Put the battery back where it is stock, and use the 6lb variant that's out there. Less weight is better then better weight balance, and you aren't going to ever really impact the 52-53% left heavy weight of the car.

I would not use the tubular control arms in a Solo car. They were designed for drag racing and might not hold up to the lateral loads from Solo.

I used an underdrive crank pulley on my z6. 325k miles on that motor, still shows good oil pressure. I'm gonna go out on a limb here and say that the guys who think underdrive pulley's kill engines are wrong. Now, overtightening your accessory belts or the timing belt is a sure fire way to toast the #1 main bearing (and cam journals if you overtighten the timing belt).

My 93 Coupe was 2250lbs with stock seats, battery, and b-pipe + axle back muffler. 2190lbs was an easy mark for that car to hit. If you get under 2250lbs, then you're doing pretty good. My 93 Si was 2090lbs, again with stock weight seats. It could have gotten down to 2050lbs if I'd tried harder.

 

^ I have the rules here that state heat shields may be removed to facilitate aftermarket exhaust installation.
I haven't got the battery yet, but had it all picked out. I'd like to relocate even the 6lb battery because my tray is all rusted to hell anyway and I have the cable already.
That's nice to know about the pulleys, I'd been procrastinating on buying a set because of what I heard.
On the belt tension issue, I will slack things up some and see if they slip, I could have set them a little tight...I didn't drive the car today because after the camber kit install I have mad toe out.
There isn't much more to be done legally for weight loss unless I'm missing something....

 

Replacement seats and mounts
Inconel thinwall header
Aluminum exhaust w/ turndown at rear axle (don't go all the way to the bumper)
Go over every single bolt on the car and cut off the portion extended past the nut when fully tightened

And I almost forgot an old favorite, "accidentally" power wash the entire undercoating off the car, including the wheel wells.

 

The seats are coming out tonight for vacuuming, I'll weigh them and see. There is a 28# per seat rule...

 

25#

 

ops my bad.

 

Heat shields that are bolted to the exhaust, not the ones bolted to the chassis. Basically, the ones on the exhaust are open as they can be considered part of the exhaust, but the ones on the chassis are chassis heat shields, ie, not part of the exhaust.

Don't bother with front camber kits, you loose more suspension travel then they are worth. Use the washer trick on the rear to shim out rear camber.

Cutting the exposed threads off all fasters would be considered illegal. As would removing the factory applied chassis undercoating. Any aftermarket "Zeibart" undercoating can be removed with a pressure washer more or less.

Al body dampers are good for ~1lb per corner.

Stock seats were 33lbs each IIRC. And unless the rule changed again, min. seat weight is 25lbs.

The intake was worth a couple of pounds. No stereo or speakers is worth about 10lbs over aftermarket stuff, 7lbs over OEM.

That's the easy stuff. If you want to get hardcore, Ti header and exhaust dumping in the tunnel, 9lbs/ea wheels, cross drilled rotors turned down to min. thickness, almost worn out pads, shaved tires, custom hollow front bar, Al upper shock mounts, no wing, aftermarket headlights with plastic lenses, remove trim and emblems, strip paint off the car and paint with only a single coat of paint, short shifter out of Al, replace hood, fenders and doorskins with aftermarket parts (thinner sheet metal), same with the windshield and a few other odds and ends. Don't forget, simply powerwashing the undercarriage (withOUT removing undercoating) will usually drop 1-2lbs. Same for removing the interior to vacuum and clean it. I've actually found 4lbs in a car once by removing the interior and cleaning it well. (helped that the po had left behind various tools and fasteners all over the car)

 

dry ice the sound deadening material on the inside of the car, strip the carpet and rear seats etc etc and touch the black sound material with dry ice. let it sit for a bit then whack it with a hammer and chisel!

 

Sure, if you wanted to make an illegal ST car, that would be a great idea.

 

Possibly a hollow integra front bar would help...
X2 on the interior cleanout, I removed the rear seat in my 4dr and found crayons candy silverware change all kinds of crap in there.

Solo-x, the washer trick is done on the back, I used 2 washers each for about 1/8" thick stack. I actually have a upper link kit from a car I gutted, but they were so heavy I opted for washers.
I installed the camber kit up front but left them near max negative camber so the upper control arms just clear that seam inside the wheelwell. It still offered more camber correction than not installing them.

 

I'm not opening up the rulebook here at work (and I hate PDFs), but I swore that fasteners were open. I could very well be wrong though.

I should apologize there. I meant the undercoating part as somewhat of a joke.

As a real suggestion, pull the swaybars off the car and make up for the change in roll stiffness with more spring. My 25mm solid rear ARB is not light...

 

The rule is that fasteners can be replaced with fasteners of a like kind. One or two fasteners shorter then stock? Fine. All of them shorter then stock? It would be clear that you were forging into an area that is neither black nor white, and at the big dance, you _might_ get paper thrown at you for it. That said, it'd be really hard to discover if someone had done that. Of course, it would also be really hard to know if someone is using a 13lb flywheel (stock is 18lbs), Ti flywheel bolts, a lightened clutch cover, a bunch of hidden "non-critical" fasteners that could be replaced with Al versions if one were inclined to do so, and so on. Thankfully, that's not the discussion!

 

Oh, and you won't be able to get the handling and driveability where they need to be without swaybars. To get the appropriate roll stiffness, the spring rates would be too high to work on anything but the smoothest of surfaces. I was running a 900lb front spring with ITR 24mm front bar on my car. You'd need something close to 1400lb springs to make up for the lack of a bar to get that roll stiffness. At that point, you get into another interesting point of the suspension tuning spectrum where spring decoupling is major concern. (think of decoupling a spring as droop limiting the suspension. zero droop front suspension on a fwd car is bad. In all caps. Bold. With a 120 font, in red, and flashing.) A shame really, as that 24mm bar was 12lbs (the 21mm stock bar is 8lbs). Fortunately, the weight is really low and paid off in more grip. And yes, I tried no bars on more then one occasion.

 

Really? Wow. I was shooting for 2150'ish with my 93 Si. You removed the AC I guess too which is about 30-40lbs. Any website that shows your build? Or is it a secret?

 

Sorry, I guess I'm not fully aware of the rules of ST, it just seems with all the other things you can do, you would be able to do that. Im learning the AutoX ways still so I'll keep my mouth shut, HAHA.

 

even thought all the rules are black and white, it's still hard to understand them sometimes. for me, atleast, i went to a couple of national tours (and asked a lot of questions here. good help here) , and it helps to see what everyone is running, and how they are running it.

like say you have some front canards (ricey spoilers on the corner of your front bumber) for show/look purpose. they have no real function what so ever. it just looked really nice. well in the rules you can't run anything like that in ST. could get in trouble for that

my advice, go to a couple of national events. some of the closer ones to watch. go and look at some of there setups. compare and take notes. for sure they won't give all there secrets, but if you're not comptitive to them they probably will. or if they think you're in a different class.

 

I finally got it out for a test drive and had some issues. 1st the tire ate a fender liner so I have to stuff it back in and zip tie it.
2nd the tranny I pulled off a JDM D15B-VTEC(the good one like the Si not the vtec-E), turned out to be a damn VX tranny and the car is a dog for acceleration, that's gotta come out.
The Z6 tranny with the 4.88's will be coming apart and getting the 4.25FD stuffed back in it, and I'll swap the tranny out again
Overall I took a couple of turns pretty fast and it felt pretty good, just enough weight transfer on/off throttle to let the brakes work but the sways keep it nice and flat.
ST class is filling up with pre-registered's..a legacy 2.5i and WRX both dual driver cars, and a 2006 GTI. My work is cut out for me..

 

just don't drive with your head up your butt, and you'll do fine.

 

Update...turns out the fuel filter wasn't flowing too well and that's why it was so slow. I drove it to work friday and it got bad enough to throw a CEL.
I already have had several options to cheat, but did not. IF I do well in my class I'd like to know it was done legally. I already had to take the fidanza flywheel out and install that big stock POS
My last question, the car still seems a little slow. I've been driving a B20 swapped car daily though so I'm not sure if it's just me or...
Would it be worth it to get the local crome pro tuning guy on my ecu before the weekend to take advantage of the bolt ons?
I've tweaked timing fresh plugs done everything I can to get a few more HP out of it.
Overall I'm very pleased with the handling, the teins(basics) are intermediate enough that it still has decent weight transfer for good braking, yet the bars keep it fairly flat, and my favorite part, lift on the throttle while going thru a turn and rear rotates nicely

 

Are hybrid transmissions legal in ST? I thought not?

 

I was thinking the same thing. Tranmissions has to be the original type tranny that comes in that year and model car. No changing of gears, syncros, final drives, etc.

 

That's correct the tranny must be stock, no LSD no light flywheels. My Z6 engine swap I installed was originally for a H4 class EG. I expected the D15B-VTEC tranny to be the same, but being it wasn't I removed the aftermarket 4.88 from the USDM tranny which I know is a Z6 trans and put that one in.

^^^I think if you read the rules(I printed them and studied them before I bought my car) they allow wear items to be exchanged with like type provided there is no performance gain...i.e. you put steel EK shift forks in your EG tranny for realiability...

Tires came in today....got mounted..now I gotta borrow my buddies fender roller...

 

ughhhh im pretty sure you cant replace shift forks.from ek in a eg... especially in ST

if it doesnt state that u can in the rulebook its not legal, even if they provide no performance gains... anyoen can make an arguemnet aluminum shift forks to steel or steel to aluminum....

kind of a like a mysterious valve shim (only real ST guys know about this )

 

Haha, poor Hollis.