44 replies to this topic

[87zc1crx]

on them cages...i've seen a link here on RPR once that have them.

[dmotoguy]

Lets get real here.. If the car is <2000lbs, its freakin light. Why would anyone want to cut more off of the car if it could potentially weaken the structure of it? I yanked everything non-structural and it was around 140lbs of stuff but going for even more major weight reduction would be somewhat of a waste

BTW pocketrocket  good point about balancing the car and evening weight out, I think thats something that can be overlooked pretty often

its drag racing, the lighter the better. you want the weight low and as far forward as possible. i took another 10 or so lbs of metal out this weekend, i'll try to get some pics.

[b16_destroyer]

Weld the rear sway bar or the front torsion bars? I don't get what you are talking about. If I welded the front torsion bars they wouldn't move and would probably bend something or break something if driven on the street.

I don't want to evenly distribute weight, I want all of the weight to be as far in front of the tires as possible. Can I remove the rear sway bar and just have an empty tube in the rear?

[mayhem019]

Lighter and better, thats true to a point. At first you can yank 50lbs here, 50 there.. But eventually you get to a point where its like ok one pound here.. one there.. few ounces here.

Once you start talking bigger numbers in terms of power, weight starts to not really matter so much

You think my neighbor with a 500HP Galaxy 500 cares that his car weighs twice as much as mine? LOL

[RexKrazy]

yes, it will leave you w/ a hollow bar in the rear. no, don't weld the front bars..lol.

[jsgprod]

Get rear axle from an HF model or a CRX/Civic that came with the 1.3L motor. They don’t have a rear anti-roll bar in them and the axle is made from a smaller diameter tube. (lighter weight)

Better yet, you could remove the anti-roll bar from your current rear axle (don’t really need it for drag racing anyway) then have the main tube replaced with some lighter thinner wall chrome-moly tubing.

[Greg Gauper]

Here's a list of other places to loose weight (if you haven't already done it, or if you will not be driving this thing on the street):

Outside mirrors (the stock ones weigh a ton and have a lot of aero drag). Make blank plates to cover the holes.

Headlights, front turn signals, horn.

The stock dash weighs about 25lbs. You can make a very simple, lightweight dash out of thin aluminum stock and some angled aluminum that weighs less than 1 lb (guess what I worked on this weekend )

The stock wiring harness weighs a ton. It takes a lot of time but there is a lot of stuff that can be removed that's not needed (headlights, wipers, turn signals, interior lights etc.) Take your time and use the shop manual wiring diagram)

Heater core, blower.

For drag racing, you could probably get by with solid front rotors instead of vented fronts to save weight. If you can find them, run the HF aluminum drums.

[mordantly]

If you really want to save as much weight AS POSSIBLE then dont where a helmet or if you do then make sure its a nice lightwight one like a styrofoam cycling helmet.

besides all of this a nicely built cage can look very cool and get the ladies and hey lets face it, thats what racing is really all about.

Later, Jay.

i can't agree more man! also, ive removed most of the shizane listed for this guy. yet my '87 si "allegedly" weighs 2050 with me a gal of gas, a tool box and nothing else. of cource just how accurate is the county dump scale?? probably paddin their grimy pockets!! my 16x7 enkeies and 215/40s must weigh a good 50 per corner..... dumb but i sacrifice that wieght for SAFETY. a 215/40's contact patch is 7" by almost 4". at least 30% more per corner than those 165/85/14 stockies.

so i say i have a ~1900 pound crx. how the hell does one remove another 300 pounds??

Edited by mordantly, 03 January 2007 - 08:19 PM.

[Greg Gauper]

Mordantly,

Both Jay and myself both have to weigh 1848 lbs (weighed with the driver). Jay has done a great job of getting his car as light as possible and actually has to add lead ballast to bring his car back up to weight, but he has the option of putting the weight exactly where he needs it. So figure my Civic is about 1700 (empty w/o driver) and Jay's is probably around 1650 (also w/o driver) with his ballast removed (I still have a lot to do to shed weight over the winter). Keep in mind that those empty weights are with a full rollcage, fuel cell, and fire system.

The above posts outline everything you need to do to get rid of weight. It all depends on what you are trying to do i.e. keep it street legal, or strip it down for drag racing, or road racing (both forms of racing will have their own safety requirements per their respective sanctioning body i.e. NHRA, SCCA, NASA, etc.)

BTW - those 16x7 wheels are killing your performance. That's a hell of a lot of rotating unsprung mass (the worst kind of weight). Think of the wheels as big ass flywheels on each corner. Smaller diameter wheels and tires = smaller, lighter flywheels. Ideally, you want a wheel that is just large enough to give you brake clearence and nothing more. Your safety argument is bogus. A good quality tire with a 'V' rating has more than enough safety margin and a 205 to 215 aspect ratio will give you more than enough performance. Typically, a 215 or a 225 is the widest tire you will see in road racing. Before I converted to Production class and slicks, I used to run 185/60's Hoosier tires with no safety related issues.

While I'm not a drag racer, I would think that a set of 13" wheels on the rears with the absolute skinniest tall profile tire pumped up to about 50psi would give you the least amout of rolling resistance possible. Unlike solo or road racing, the rears tires on a FWD drag racer do absolutely nothing but keep the bumper from dragging on the ground. Get a set of alignment shims from NAPA and set the rear toe to 0.0 to further reduce the rolling resistance.

[Jack ffr1846]

I already gutted everything out but plan on gutting the metal webbing thats around the rear windows and around the bottom of the hatch. Will the car deform after I do that? I don't want to go roll cage and this is a drag car with occasional street racing.

I also want to gut the rear floor from the where the doors end all the way to the back. Is this possible without a rollcage?

Ane another roadracer WEIGHS in. (hahaha)

My 87 CRX-SI with an 8 point SCCA legal cage weighs under 1600 pounds without me in it. The others have lectured you on the need for a rollbar/cage, so I won't.

If you're not down to my weight, you aren't ready to go after cutting out the structure of the car. Lights, wiring harness, etc are the first things to go. Did you say that this still has to be registered or not? If not, remove anything that doesn't make the car go.

One warning....the rear unibody that holds the pan hard bar (that cross thingy from the axle to the frame) isn't real strong and with side forces seen in road racing will rip out just like E36 M3's. Mine has been re-enforced after a minor incident during an SCCA enduro.

If you must remove more weight, first be sure that the rear suspension structure is in tact and well supported. Work with things like the rear panel (holding the tail lights).

Have you scraped off the sound deading and undercoating from the body? It's way heavier than you'd ever think.

The door bars are the heaviest part of the door, after the glass, fyi. If you have a cage, you can go to a fiberglas skin with a fixed lexan window and save 50 pounds per door (guess).

Also, for drag, you'll want all of the weight over the front wheels. So move everything possible up front.

Good luck. Weight reduction is fun for the first couple hundred pounds because its so easy...after that, it's a lot of work for little gain. I spent at least 10 hours reducing wiring harness unused circuit wires. Saved maybe 10 pounds.

jack

[squareback]

I'll chime in too. I have an 85 CRX HF that is prepared to SCCA CSP rules. That means the car has a full interior. With the full interior and about 2 gallons of fuel, the car weighs 1580. There really aren't any weight-saving things that had to be done to the car to get it where it is; most of that work was done by Honda from the factory on the HF model.

I guess there's an answer to how to get a CRX from 1900 to 1600 pounds: start with an 84-85 base car. The 86-87 cars were all heavier, and the Si is even more so. My car still runs a 1.5 EW motor, which is going to be lighter than a B-series or whatever you're running in a drag car, so total weight will be lower on mine. On the other hand, all of that extra weight goes right over the front wheels, which is what you need.

It seems that rather than focusing on eliminating weight, a person with the power discussed here should concentrate more on getting it to the ground. Once you can put down all the power you're making, then consider losing weight.

Mike

[mordantly]

BTW - those 16x7 wheels are killing your performance. That's a hell of a lot of rotating unsprung mass (the worst kind of weight). Think of the wheels as big ass flywheels on each corner. Smaller diameter wheels and tires = smaller, lighter flywheels. Ideally, you want a wheel that is just large enough to give you brake clearence and nothing more. Your safety argument is bogus. A good quality tire with a 'V' rating has more than enough safety margin and a 205 to 215 aspect ratio will give you more than enough performance. Typically, a 215 or a 225 is the widest tire you will see in road racing. Before I converted to Production class and slicks, I used to run 185/60's Hoosier tires with no safety related issues.

While I'm not a drag racer, I would think that a set of 13" wheels on the rears with the absolute skinniest tall profile tire pumped up to about 50psi would give you the least amout of rolling resistance possible. Unlike solo or road racing, the rears tires on a FWD drag racer do absolutely nothing but keep the bumper from dragging on the ground. Get a set of alignment shims from NAPA and set the rear toe to 0.0 to further reduce the rolling resistance.

i wasn't trying to cop this guys post. i merely observed peoples responses of sane items to remove, and was curious how these crazy low weights really were attainable. many have said a lot of work to lose 5 pounds. i see that as a true statement. its a fine line to balance CA emissions/drunks/etc requirements and hopefully soon weekend soloII events. as to the wheel/tire i run, i meant safety for tire sidewall not wanting to roll off the wheel and the contact patch being larger.. making it handle a corner nearly twice as fast on the highways as the steely 14s i stupididly (Bush Coined) threw away. ive noticed no competition honda that runs a street tire in sub 185s only slicks. when i finally get to compete, you can bet your webers i wont have all the aluminum dragging me down.

Edited by mordantly, 05 January 2007 - 06:30 PM.

[kakabox]

its a fine line to balance CA emissions/drunks/etc requirements and hopefully soon weekend soloII events. as to the wheel/tire i run, i meant safety for tire sidewall not wanting to roll off the wheel and the contact patch being larger.. making it handle a corner nearly twice as fast on the highways as the steely 14s i stupididly (Bush Coined) threw away. ive noticed no competition honda that runs a street tire in sub 185s only slicks. when i finally get to compete, you can bet your webers i wont have all the aluminum dragging me down.

...huh, come again?

"drunks" ...huh?

[mordantly]

...huh, come again?

"drunks" ...huh?

well what i was tryin to convey is in this great state of callyfornia, we have readily availabe the following and many millions more motorist hazards:

senile i mean senior citizens
illegal immigrants
"barbi" the teenaged female in daddy's vw
drunk drivers
john q eatin a egg mcmuffin, yelling at his wife on the phone, and late to work speeding in the rain
police
dumb shit kids street racing there "half dismantled" vehicles (to qoute a local pig last week that pulled me over for my borla muffler. i don't condone street racing in the least)

all vehicles one can see on the roads are a potential killer. i don't trust any of them... not anymore. these are the times i wish my poor crx was 16,000 pounds with a blown 496 and awd.

so back on topic: we know a lot of people tend to REMOVE unnecisary bs thereby weight. i wonder how many people ADD unnecisary bs to there hondas?? come on guys don't lie.. examples would be spinner wheels, or those heavy .005 gram window Type R sticker's 'n shit.

[lil buddy]

u don't need to be super light to run 10s 9s. concentrate on your suspension and driving skill. yes guys beleive it or not running 10s and 9s does require alot of seat time and skill! its not just about making 600whp and bolting on a set of 24.5 M/Ts. my car was 2400lbs with driver (NHRA SFWD limit) cars in that class are as fast as 9.40 @ 160mph with full interior and street worthy. don't cut up the car! if u are making 800whp like u claim u will be there is no need. and a 10 point cage is a must if u plan to run 10.99 or better. @ 2000lbs with 500 whp u can reach your goals. suspension and seat time is what u should be concerned with...

dave

Edited by lil buddy, 05 January 2007 - 09:05 PM.