rayar

iTrader: (1)

One of my friends just got a new set of scales so he gave me his ruggles scales(the ones that use bathroom scales) so I decided to weigh the car today. First off I will say that they are homemade and he owns a sub 2000 lb car and they where accurate on that car. He was also able to have it set to read 1/2 the actual weight. I knew my car wouldn't work with the 2:1 setting so I marked it out for 4:1 and it was accurate with my body weight on it. Not sure how accurate they are at 4-5 times that weight.

First I weighed it without putting my weight in the drivers seat and came out to 3552 LBS. That surprised me because even though it is all steel it is fully gutted and the doors are nothing but the outer shell pinned to the roll cage. Then I started figuring out what I removed and what I added and I came up with removing approximatly 400lbs but I added back in 450 lbs including 200lbs of ballast towards the rear of the car because I thought my car would come in under the 3150 limit in my class if I ever got protested. I guess I really shouldn't be suprised.

I then added 200lbs to the drivers seat so I could set corner weights. Got the corner weights pretty well squared away and here are the readings
LF: 1016lbs
RF: 1016lbs
LR: 884lbs
RR: 884lbs

Pretty good huh? Corner weights wheren't even close to that when I first started.

About 53% weight is on the front but the strange thing is I added it all up at 3800lbs and that is 248lbs heavier after only putting 200lbs in. I guess it is possable that I missread the scales as the difference in the reading on the scales would only be 12lbs total(4 lbs per scale) and I did look at the before weights pretty quick, but the car is still a pig.

If I would remove all of my ballast and start replacing parts with lexan and Fiberglass I might be able to get the weight down to 3000-3050 lbs without the driver. I am thinking a fiberglass hood might be 75lbs less. since my doors are so gutted I might only lose 25 lbs there. Not sure how much a stock windshield weighs.30lbs? So I could lose 25lbs. The rear hatch is heavy so could I loose 90-100lbs with a lexan hatch? The front and rear urethane bumpers seem very light so maybe another 20lbs lose with fiberglass. the stock front fenders are allready very light so I am guessing I could only loose 10 lbs with both. Maybe cut away 30lbs of unneeded sheetmetal like the radiator support and start cutting out some of the interior sheetmetel but not sure that I could get more then 20 lbs there and of course the 200 lbs of ballast so that is getting me close to 3000-3050lbs but then I would need to add ballast to get back to legal weight. I don't believe that these changes would change my F/R weight bias for the better in fact they might get a little worse. I would really like to get it down to at least 51% on the front. Any ideas? it allready has aluminum heads.

racing geek

iTrader: (5)

That can't be right... My car with full interior, no fiberglass, no aluminum, power everything, and with me in it weighs very close to 3550 (I'm 207#). I don't think your scales are right, that or you were weighing them goofy like you weighed the front with the bathroom scales with the back wheels on the ground. But I would think that would make it seem lighter...

What about an aluminum water pump, an aluminum plate for the gauges to serve as the dash, aluminum radiator...

You could go extreme and move the engine back an inch or two.

rayar

iTrader: (1)

You have to realize that I put back in a lot of weight with things like some beefy subframe connectors and a rollcage, bracing for the upper link on the rear 3 link. The wheel/tires I have I am sure are heavier then stock(Steel 16X12's and big slicks) and the 200 lbs of ballast I put in. without the ballast the car is closer to 3350lbs, I think it is reasonable for the car to weigh that much. All of the interior was fairly light even the AC components really arent all that heavy. The only place I went wild with the lightening was on the doors but they are probably still 20-25 lbs each. Like I said when it was all said and done I probably added at least 50 lbs more then I removed.

I have been seeing a lot of radiators located to the rear of the car in this class and an aluminun water pump would also help. I can't set the engine back as it needs to be in the stock location.

racing geek

iTrader: (5)

Some people take out the back hatch completely and just leave it open with a radiator mounted back there. Personally, I would mount the radiator low enough that a lexan hatch can still be put on for storage purposes if nothing else.

Actually, you can move the engine back... it would just bump you into XP or some other crazy class where the cars are pretty much all carbon fiber and are purpose built. Just food for thought.

Post pics of your car or a link to a photobucket account or something so we can get an idea of wat is still on the car and what can come off/out.

rayar

iTrader: (1)

Just a quick question. I am pretty sure I measured for a 4:1 ratio but it just might be 3:1 but I don't think so. The beam is 18 inches long. I put the pad that the wheel goes on 4.5 inches from the floor pivot or 1/4 of the total distance between the floor pivot and scale pivot. This might help Floor { I ! ! } Scale My wheel pads are where the I is in my little picture. It is accurate at 4:1 with my body weight, tried it again today.

In CP I would still need to keep a rear hatch. I would want the radiator low anyway just to keep the weight low. I cannot have it open. I have thought about cutting off the top and go convertable but technically it wouldn't be legal(unless I find some OEM convertable parts) I doubt it would be protested. Sure I could go XP but considering my car is overweight for CP I don't think I could even get close to minimum in XP.

Anyway, I think just getting the corner weights better will help the car out. Weighed the car again today and it came out to 3540 lbs without driver.


As far as pictures, I really don't have any of the build other then a couple of the roll cage and third link mount.

AlkyIROC

Assuming you now have the corner weights close enough to balance it out, find a drive on scale to recheck the front and rear weight.

Drive onto the scale and stop with the front wheels near the center. Record the weight. Drive the entire car on, record the weight. Drive off the scale and stop when the rear wheels are near the center, record the weight.

The front and rear weights should match the total or be very close. The front and rear weights should also equal what you got for front and rear weight using the 4 corner scales.

My race weight is just under 3100 pounds but it's a drag race only vehicle. Although much of the car has been gutted, adding in a full roll cage put a lot of weight back into the car.

According to your 4 corner weights, your car is very nose heavy compared to mine. 2032 pounds compared to my 1800 and I have a BBC under the hood. All the weight you have on the rear compensates for that extra weight on the front for a good weight ratio. Although the front of my car is lighter, I have 58% of the weight on the nose because the back is so light. Still doesn't stop me from pulling the wheels.

rayar

iTrader: (1)

Stephen, What parts are fiberglass on your car? I think I could get my car into the 3000-3050lb range by removing all of the ballast, changeing the fenders, doors, and hood to fiberglass and also doing lexan for the windshield and rear hatch. I know there are people running thirdgens in CP that are in the 2800lb range

I will probably borrow my friends real scales before racing season starts next year just to cure my need to know but for corner weighing and adjusting I think these ruggles scales will do just fine. The more I think about it I feel 3350 lbs without driver or any ballast isen't to bad for an all steel car with factory glass.

rayar

iTrader: (1)

I just read the info on your car, pretty impressive for an all steel car. I see you have lexan and that is probably the difference in weight.

AlkyIROC

Currently just the hood is fiberglass and it's a factory hood so it's still heavy. The Lexan windows do help a bit. The Lexan windshield only cuts off 20 pounds. Side windows I'm not sure as so much has also been gutted from the doors. I do know that when I removed the original doors from my car, power windows, mirror, locks, inner panels etc was 105 pounds each. My current doors are probably 40-50 pounds now and when I get around to installing the fiberglass doors this winter, they should be 25 pounds maximum each.

The rear window is very heavy. I still have the rear window and deck lid sitting in my back yard. That probably weighs close to 100 pounds. I never did weigh it and it's too heavy to move around. Try lifting a rear hatch with blown lift shocks.

rayar

iTrader: (1)

That all sounds about right. The only thing lighter on my car is the doors. Mine are just the outer skin but I did leave just a lip of the inner door so they arent flimsy. My doors probably weigh 25 to 30 lbs each. If I made fiberglass doors it would also just be the outer skin and probably weigh between 5-10lbs each. I know the stock steel hood is very heavy(probably as much as the rear hatch) but not sure how much more it weighs then the factory glass hood.

racing geek

iTrader: (5)

Been there done that. I had a rear shock go out on me when I was putting my back pack in there after school a year or so ago. The whole thing just slammed down. Luckily a freind drove up and called me over so I didn't have my arm or something get crushed. Now I'm not weak by any stretch of the imagination, but I had a hell of a time trying to open it with one arm and lifting up the back pack in the other. I would believe it weighs around 100#'s.

cprepared125

You know whats funny is that it's not the glass thats the heavy part. it's the decklid. I was very suprised when i swapped out my rear hatch for lexan how much that thing weighs

cprepared125

I have cut nothing off my car, had the rear glass still in, and even didn't have a fiberglasss hood at the time i weighed it. with driver 3300. even with iron heads and a 10pt cage.

AlkyIROC

My rear window is 1/8" Lexan. It doesn't open and it's riveted to the body with supports in the center to hold it up. My deck lid is simply a piece of aluminum with the factory spoiler bolted on. The deck lid is held on with some Dzus fasteners. The only time I need to remove it is if I need to access the battery which isn't very often because I have boost posts mounted at the rear of the car.

rayar

iTrader: (1)

Hmmm, I wonder where the difference is between the weight of my car and your car. I pulled a lot of weight out of the doors. My 80 lb estimate removed is probably very conservative if the factory doors are 100 lbs each. I haven't weighed the doors but a guess would be mine weigh between 25-30 lbs each now. Your starting to burst my bubble because I was starting to thing that 3350 lbs for an all steel car with factory glass was pretty good. I can probably find allmost 200 lbs just in the hood and decklid alone but would like to find more so I can ballast back up to 3150 and get a little rear weight bias. I even still have the small 7.5 inch reaend and that is much lighter then a 9 inch or D44.


Another question. I have seen sheets of Lexan at the Home Depot that look big enough for a windshield or even the decklid and it is priced very reasonably. I am pretty sure it's flexable enough for the windshield but could I use a heat gun and make it flexable enough for the bends in the rear glass of the deck lid without ruining it? I would also replace or severly gut the steel portion of the decklid. Might try the windshield first and see how well I do.

AlkyIROC

Lexan at Home Depot isn't the correct dimensions and Plexiglass will easily crack. You should be able to find a plastics supplier who can provide you with proper sized Lexan a whole lot cheaper than what you can get it for from Home Depot.

The windshield should be 3/16" thick. The arc is small enough that it's very close to flat and can easily sit in place.

The side windows can be 3/16" or 1/8" thick but both sizes will need some sort of tubular frame support around the Lexan to hold it in place. Third gen doors have no window frame to hold the window.

The rear window can be 1/8" thick and a piece that thin can easily be bent to the shape of the opening without heat. My rear window installation is not a pretty show car job. I cut the window seal lip right out then slid the Lexan under the body. It's riveted to the body and sits in an aluminum channel at the rear. The deck lid covers the channel. With the Lexan under the body, there's no chance of wind getting under the Lexan.

None of these Lexan windows are water tight. The windshield sits on some 1/2" wide house door weatherstripping and is bolted into place. There's always a gap somewhere at the top of the door windows. The rear window under the body skin isn't 100% sealed and there's no seal under the deck lid.

My car isn't designed to be driven in wet weather so window sealing isn't an issue.

racing geek

iTrader: (5)

That is basically my car without my ~200# in it. But my car also has power everything. To me, 3350# is a pretty good wet street weight. If all goes according to plans, I should have my car down to >3200# with full interior even after the SFC go back on the car. I would love to gut the thing and go with a very simple interior and what not, but my car is still my daily commuter.

rayar

iTrader: (1)

I went back to Home depot to check the sizes of lexan they have. .220 thick X 36" X 72" for allmost $76.00. Should be big enough for the windshield. I know Home depot can special order a lot of items so maybe they can get a larger 1/8" thick piece for the rear hatch. Finding a plastic supplier in Bozeman I have a feeling will be tough so that looks like my best bet. They have smaller sizes that would work for side windows but I don't have side windows.

My car is a fully gutted race car so maybe it should be lighter. I just know that I did add a lot of weight back in so the car really should be back to stock weight. while 3350(without ballast and driver) isnt as light as I would like it to be I guess I really shouldn't be surprised.

BTW, I did find the extra 48lbs between weighing the car with the driver weight and without. I thought SBC iron heads would be around 50 lbs each so I used 4 in the drivers seat. They are approximatly 60lbs each so that would be the difference within 8 lbs and that 8 lbs could have easily been missread. I also found that I can put a bind on the scales and that really shots the weight very high(30 lbs per scale), Before I do my final adjustments I need to lift each corner off the scales and set it back down and the measurment go back into line. I think these scales are pretty accurate but will take the car over to my friends house and use his scales to get the actual weight. These will work fine for checking corner weights though.

rayar

iTrader: (1)

Just want to let you know I was wrong on the thickness of the Lexan at Home Depot. It is only .097. I was going to buy a sheet but noticed the thickness after getting down on the floor to read the price tag better. I also noticed that it is pretty heavy, can't imagine more then a 20lb savings on the front windshield so I might stay with glass.

BTW, the 36X72 is allmost big enough for the rear glass. needs to be 4-6 inches wider. I might try it for the rear with the steel portion of the deck lid fabbed out of fiberglass only 6 inches bigger so it mates with the lexan. The thickness isen't a big concern as I have no rules that really govern that and my car is strictly an autocross car. Legally I could even use .097 for the front.

GMan 3MT

iTrader: (4)

Help me out with something... why do you have 200lbs of ballast? That should be the first thing to go. Less weight is more important than a nicer f/r bias.

I would really try to find someone with real scales to get a baseline and compare that to your readings. I'm thinking there's something incorrect with your numbers.

My car comes off track at 3220 with me in it and a little less than 1/2 tank fuel. 8 point cage, sfcs, interior removed. Nothing crazy done to remove weight. Steel hood, steel front bumber, stock front/rear glass, steel driveshaft, stock iron 305 TPI, Toyo's on GTA wheels. I'm 175lbs. Figure 6lbs for ~6 gallons = 36lbs. I figure my car is ~3000lbs dry w/o driver.

Did I read you still have a/c? The compressor is a GOOD few pounds. If you're going to the extents of lexan why not get rid of the a/c and heater?

Got a race seat installed? Hopefully you're sitting on the stocker still.

How overkill is your cage? Wall thickness? I seen people here suggest .134 wall for stuff (I guess drag racing). WAAAAAY overkill. Shouldn't need more than .095 for an AX car.

Look into lighter wheels?

Big tires don't necessarily mean heavier tires. A 315 Hoosier is lighter than a 275 Kumho. It's all in the brand.

When I gutted my doors, I removed only 12.5 lbs of metal per side. Glass and interior was already removed. As far as the decklid being the heavy part??? what?!? The glass is a ton. I have one hatch glass without the decklid and one wik in my storage unit, and I can tell you they are both equally a b**** to move.

If you really want to go the lexan route, I really suggest browsing the CP boards or even FRRAX.

I don't think it should be necessary to goto all the trouble of those fibreglass components (like the doors and fenders) you want. Well, take that back. A fibreglass hood sould be an easy fix. But the rest? Seen a few steel bodies CP 3rd gen cars doing just fine. (Todd Farris firebird,the Beairds (sp?) firebird, Tommy Reagan's old Camaro etc)

*edit* what are the min weight rules for CP now? I know it varies depending of tire width and motor size, but say for your combo. It's without driver correct?

cprepared125

I believe it's 3000lbs if under 310 cid 3200lbs if over 310 cid and if you run a wheel any wider than 10" or taller than 16 I think it's like 100lb penalty but don't quote me on that

robertfrank

iTrader: (27)

Dude I've gotten my car down to 2860 (according to flying j's truck scales) and I still have the stock heads, rear glass , ground effects and suspension. then again my car is GUTTED.

rayar

iTrader: (1)

My car is gutted, no AC, no dash, no side glass, no nothing. The cage I believe is .095 1 1/2 tubing but I might have went with .120 wall, been a whille since I built it. It is an 8 + point cage. Not legal for anything but autocross, can't even do hill climbs with this car, It was built to help stiffen the car as the primary goal. The rear bar of the cage has extra support for the upper link(3 link) on the rear suspension. I also put in weight jacks and shock mounts in the rear that I tied that into the cage. I used 3 20 foot sticks when I built the cage and probably another 10-20 feet of scrape I had laying around. Not sure what 1 1/2 .095 tubing weighs but thought the weight on the invoice was around 3 lbs per foot. Subframe connectors where made of 1 1/2" .120 wall square tubing and go from the front K member all the way back to the rear LCA arm mount, and fully welded to the Rocker panels, probably 20 lbs each. I know I put back in just as much weight as I removed probably more. Really, everything I removed(Interior, carpet, seats, AC/heater) ended up going to the local landfill and with a lot of household trash I was charged for just over 500lbs of trash. BTW, I advertised everything here with no one interested in it before it went to the landfill.

I have decided the first thing that will be removed is the 200 lbs ballast. It was just a thought to get better forward bite on the super slick glass like sealed asphalt we run on and the car wasen't weighed before hand so I was thinking that I might be a little under weight. I was wrong. Without the ballast it should be 3350 on my scales. I believe the traction problem has been resolved so no need for the weight anymore.

CP weight for a V6 less then 4.5 liter is 2400 lbs, V8 under 310CI is 2700lbs and over 310 CI is 3000 lbs. Add another 150 lbs for larger then 10 inch wide wheels and my minimum is 3150 lbs. I think there is a 200 lbs weight penalty for larger then a 16 inch diameter wheel(that might have changed). All without driver. Considering the weight, I am Seriously thinking I should go with some 17 or 18 inch wheels with some 315 or 335 Hoosier A6's. Should be faster on the surfaces we run on.

Gutting the doors was huge. They are only the outer skin, the beam and most of the inner structure was removed. Just left a little inner structure so it wouldn't flop around. I use pins to hold them on the car and need to climb thru the Window opening NASCAR style. I would say they weigh 25-30 lbs each.

I have a pair of Summit poly seats to sit on. Hate them, no lateral support but they are pretty light. Plans are to get a good Kirkey Aluminum unit for the driver.

Lighter wheels would be nice. The 16X12 steel wheels are very heavy. I could probably lose a good amount of weight right there. Your right, the slicks are pretty light but when you figure the weight of stock 14X7 inch aluminum rims and rather small tires that where on it I am sure the weight difference is more then 20 lbs total.

Considering I have seen factory weight advertised anywhere from 3400 lbs or more I think 3350 isen't to bad with what I added back in. BTW, the scales where accurate withen 5 lbs per scale with a sub 2000 lb car on them, with them set on the 2:1 ratio. I imagine the margin for error is greater at the 4:1 setting but still pretty accurate. The only way I will know for sure is borrow my friends scales.

robertfrank

iTrader: (27)

Have you taken out the stock bumper bars? I replaced mine with some 1/4 inch boxed aluminum tubing. That pulled almost 70lbs off the car alone. My new ones weigh less than 10lbs TOGETHER. I think whats weighing you down is all the strengthening weight but you need that for what you're doing I guess.

Here's everything I have done that might help you.

Everything as far as interior has been removed save my 15lbs Mastercraft racing seat I got for free from a buddy of mine. I made my dash out of cheap grey walmart carpet and home depot styrofoam.

Replaced my stock HEAVY A$$ bumper supports with boxed aluminum.

Stock SMC hood with weight pulled out of it. I swiss cheesed the bottom skeleton and removed the heavy steel supports and replaced them with homemade aluminum. The hood only weighs 22lbs and is just as strong as stock.

Stock 16x8 GTA wheels with Nitto NT555R drag radials with old kuhmo's up front. 41lbs a piece

Gutted my stock wiring harness, I was able to pull about 5 lbs of unneeded wire out of it. I still need to do my dash harness though.

Aluminum LS1 driveshaft. 10lbs versus 18lbs

Everything under the hood that wasn't needed is gone. the only thing that running on the front of my engine is my Alt. I'll take pics tomorrow to show you.

rayar

iTrader: (1)

Bumper bars are gone but they where rather lightweight. The rear was Aluminum and I think the front was also but also had that plastic honey comb support behind the bumper cover that I also removed. Maybe 30 lbs removed total.

No dash and Summit poly seats.

I don't think my cage work is overly built. In fact it only has a full height main hoop. The front hoop that would usually goes up the A pillers, stops at the cowl height in an effort to save a little weight up top. Like I said, it is an autocross cage that is not legal for anything else. I even thought about making the main hoop only high enough to properly mount the racing harness but then decided that if I cut off the roof I would need the full height main hoop to remain legal and I also wanted the bars to come down at an angle to the rear weight jacks instead of straight back. Allthough recomended, A cage is not required in any autocross car with a full roof. I got the cage idea from a Boss 302 replica C-prepared car that I saw a web page about the buildup. I call it a semi-cage. Still took between 70-80 feet of tubing to build the cage so maybe it is overkill. I think it could be stiffer.

Pulled all the wiring out and wired from scratch only what was needed. Alternator, Ignition, starter, fuel pump and electric fan. Not much but I am amazed how much wire that actually took, I also have the battery in back so I have two 00 gauge battery cables running from the front to the back. Those cables are fairly heavy but I didn't want any starting problems.

Under the hood there is an alternator and PS pump. Even the Brake booster has been thrown away becase It has 180 degree crossover headers that hit the booster. The headers where a major mistake, they are heavier then the Hooker 2055's I used to have, where a pain to install but, IMHO they sure sound awsome.

I am looking for a Fiberglass(or SMC) hood cheap, it can even be damaged.

robertfrank

iTrader: (27)

I'd like to build an autocross/driftcar one day, I already have it planned out for the most part. A built up/bored out 4.3 v6, 4.10 gears and a built T-5. I think it would be a fun little car. Hell I already have the engine and tranny but it's all going in a 1980 chevette, not a Camaro. If I find me a rolling chassis I might just ditch the Chevette idea and go this route with it.