Pablo

iTrader: (1)

Here are some pics of my minitub job in progress. I am fitting 17x12 ccw classics with 335 hoosier R6s. The wheels have an 8.75 back spacing and I am using a 2 inch spacer for a total backspacing of 6.75. I have the drivers side almost done. Here are some shots.

BTW this is not a show car so if you are expecting some chip foose "overhaulin" stuff, you will be disappointed. This car is driven hard. That said. Some rattle can over my crappy welds will go a long way to making it look halfway decent.

The tubs are courtesy of Jerrywho, a man with some amazing fab skills. I managed to beat them up, cut them, and make them look much crappier than what he handed me

now on with the picts



















oh, yeah, the drum brakes are to make the r i c e r competition look stupid at the local time attack sessions. Track time is not long enough to get the brakes too hot.

Questions, comments, complaints, suggestions... all welcome

Drew

iTrader: (58)

Didja get those spring perches yet? I'm envious of your crappy welds, wish I had the guts to go nuts. LOL Looks good!

Pablo

iTrader: (1)

Got em today says the wife. Ill see them when I get home.
Thanks. Going nuts on a car is a lot easier when you are working with a crappy car to start with
There's not much to lose on this thing.

ASE doc

That car will eat any ***** alive. Even with 17x9.5s and 275/40/17 BFGs, these cars do 1.1g on the skid pad, with the right chassis and suspension mods. Thats enough to makes Ferraris blush.

Drew

iTrader: (58)

I was just thinking about how mini tubs and a couple patches in the front floors would have solved all the rust issues on the 84 I crushed a couple years ago. Get welding, I want to see how it turns out!

Guest

I'd like to see the car you are refering too that has pulled 1.1 g's on street tires

JamesC

iTrader: (5)

As the thread is interesting as well as informative, locking it would be a shame. Please stay on topic.

JamesC

Pablo

iTrader: (1)

Well I've experienced a setback, I managed to break my shocks. I suppose I can have them repaired but I haven't looked into it. I ended up breaking off the threaded portion off the piston. I think I could somehow unscrew the sleeve that's still on the shaft and have a new one machined to put on there. That could become expensive. I doubt I could just order that one piece from koni. $*** happens.

I did finally put my springs and bump rubbers on order. I have 250 lb inch qa1 springs and koni bump rubbers coming. The 250s are to compensate for me lowering the rear roll center maybe 4 inches or so.

The other thing that I want to do is put a roll bar in the car with the rear bars welded to the upper shock mounts. I think by doing the mini tub job I have reduced the structural integrity of that area.

As far as the tub job is concerned. I am basically done with the driver's side. I welded in the upper spring mount yesterday after I spent half the day repairing my craftsman grinder and dewalt angle grinder. The harbor freight angle grinder is still running like a champ though, go figure. The harbor freight grinder reminds me of an AK47, super loose tolerances is probably what keeps it alive.

All I have to do now is lay down some seam sealer and rattle can the whole thing. Unfortunately I'll have to wait another week before I can get back on the project. I keep having things pop up eating away at my car time.

Pablo

iTrader: (1)

BTW if anyone has any tips on overhead mig welding I would be happy to hear them. I am having a heck of a time trying to do this. A lot of my welds look like they want to fall off the work.

Guest

I forget where exactly the shock attaches (been a while since i looked at a cutaway like yours) but if you can strap down from the mount to the middle of the car, and the back, it will help some. Then make a flat piece (marked in red) to close in that entire area. I'm assuming the spring is an issue with that, but anything you can do to close that in will help a lot. Maybe find a smaller OD spring to do the job.

Its hard to tell what exactly you're dealing with from the pictures, but I think you get the idea.

1MeanZ

iTrader: (9)

If your puddle is trying to fall off the car weld in shorter bursts. You want to bond the parent material together so you need some heat, but you need to not get thigns so hot the puddle wants to drip off. You may also try torch angle changes as well. Many times on projects like this there isn't room for optimum welding angle, but if you can angle the torch to push the wire directly into the weld joint, this can help fight the puddle dripping as well. Those things helped me on the couple welds I did on my rear suspension....

EvilCartman

iTrader: (1)

Try turning up the wire speed also.

superirocz

iTrader: (5)

what size are the fronts?

Looks good!

DeanJ

To add to what the other guys said, make sure the base metal is perfectly clean.

Pablo

iTrader: (1)

Thanks for the tips guys, I managed to get the driver's side painted and seam sealed. I also got my QA1 spring in the mail. Apparently they are sold individually . So now I need to order another one.


BTW the front wheels are 17x11s with 315s mounted on them (Hoosier R6)

Here are a couple of picts. I will be painting over everything. I just threw primer on there. Sorry for the bad quality, cell phone picts.

1MeanZ

iTrader: (9)

Love the drum brakes.....

I'm assuming you're going to have a roll bar in the car with back stays that mount on top of the shock mount? I'm concerned about the fact that your spring bucket is only 3 sided now, instead of having 4 sides like it did. The "outer" part of the spring pocket that you've removed is 3 layers thick if I remember correctly, and each layer is fairly heavy guage material. On my car I replaced that "outer" pocket wall with a piece of 1/8" plate. It is contoured different than stock so it does not protrude into the wheelwell. Is there any way you could fit something like that in your car? Is your new spring diameter small enough to allow that?

Pablo

iTrader: (1)

My new spring diameter is small enough to accommodate that. The only problem is that the adjuster is at the top. Now that you bring it up, I think a better way to do this is to have the adjuster on the bottom. On the top, I should have just welded in a solid mount and then boxed in the area like you are saying. Now I don't know where to go from here really, I was planning on doing the roll bar with the stays to the shock mount. I may need to look at tying more of the spring mount into it aswell.

And yes, drum brakes are making a comeback. I'm just on the cutting edge. Disks were just a fad.

1MeanZ

iTrader: (9)

the roll bar will help support the area greatly. We also need to remember that we don't know why the spring buckets are made the way they are. It could be for chassis rigidity, could be for rear impact stiffness, it could be for spring and shock support, we really don't know. I did the best I could to reincorporate the outer wall of the spring bucket because I didn't really know why it was there and I didnt feel good removing it in the absence of any information. You may be OK without it, and I don't want to say you did a bad job. I'm just asking the question. If you can invert the spring and get the adjuster on top of the axle so you can box the spring bucket back in I'd certainly do it.

Pablo

iTrader: (1)

I'm not taking you to mean I'm doing a bad job. You bring up some good points. As I look at the area I get the sense that there may be some cantelever action going on. I'm guessing the upper fwd corner (just fwd of the shock) is where bending stress will concentrate. Maybe if I tie the rear area just above the panhard support mount to the front "frame rail" that would take care of that. Any thoughts?

1MeanZ

iTrader: (9)

What I am poorly describing is what is pictured below. Obviously some differences are present such as my diff mounts and bump stop pads (which are where they are to interface with the knuckle). But you can see that I've attempted to tie the "frame rail" behind the bucket to the "frame rail" in front of the bucket. I think this is a version of what you mention in you last post.

Something else you mentioned in your post triggered a thought that I was missing, but may be what you mean when you are talking about the cantilever action. Your panhard bar is mounted behind the spring buckets, and it is the only thing keeping the axle centered in the car around corners, and not so obviously, over sharp bumps. If your car can pull over 1G with slicks on it, that panhard bar will see nearly all of that force, which at the rear of the car could be in excess of 1500lbs. Over a sharp bump you could see a very brief spike of that force or more.

In other words, the body structure behind the spring buckets can see a substantial side force from the panhard bar. This is not a direction of force that even a roll bar can support. With the outer spring buckets gone, I'm not sure there is enough material in the rest of the body to properly absorb a 1500lb side load without deflection. Make sense?

Primetime91

iTrader: (15)

I'm late to the party here. But I've found that when doing vertical and overhead MIG welding, that welding in shorter durations helps reduce "dripping" (Beat me to it 1MeanZ), and I've also found that "weaving" helps. I always weave, makes them a lot purdier than just running a bead and helps me pace it better. On horizontal welds I usually use the "C" pattern, but overhead and vertical, a "zigzag" helps.

Spend more time on the points, and less on the distances between them. I've found it to help greatly reduce dripping in my experiece, and if you space and time it right (Read: practice) you can make a pretty good vertical or overhead bead that way

Looks like it's coming along nicely by the way Love the drum brakes, lol

Pablo

iTrader: (1)

Update:

I sat the car down on the QA1 spring on the drivers side and it looks great. It tucks a little better than the front.
I did run into a problem though, as it turns out, the stock upper spring mount is actually forward of the axle mount. This isn't noticeable with a stock diameter spring. With the 2.5" diameter spring it is a problem. There is a pretty nasty angle on it. I'd say the mount on the top is about an inch or so forward of the bottom



This pissed me off when I realized it (as I was putting the spring in). My first thought was that I was going to have to cut the mount out and reinstall it. I then came to the conclusion that this could work out in my favor. After looking under the car at the driveshaft, the yoke has enough stick out from the trans. to give me about 1 inch of play to move the rear axle forward. Moving the axle forward is something I wanted to do anyway. I need to pick up some adjustable control arms.
The only concern I have with this is the sway bar. I hope i have enough room to play with on the end links to allow this move.

The next pic is where I am at now. Cutting out the wheel well:



This is really brutal work. I spent all day cutting, grinding, more cutting, more grinding. The amount of dust and crud everywhere is unreal. I've been wearing a respirator, ear muffs, goggles, etc. With everything on my endurance for cutting/ grinding is not that long Tomorrow I'll only have a couple of hours (if that) to work on it so I'll probably wire wheel the area to have it ready to weld.

Once I removed the bump stop area I discovered this:



If you look closely, you'll see that there are two significant cracks. One is in the direct center and the other is toward the bottom right. There is no question that this area sees significant stress. I will be bracing both sides from the front to the rear of the spring area. Unfortunately I do not believe that this is enough to compensate for the removal of so much material. Especially for a car that will be seeing hard cornering.

I can visibly flex the car by putting my body weight on the back of the rear quarter panel. I see the c pillar area flexing. I also realize now that there is really no "frame rail" fwd of the spring. The box section there is tiny. Probably less than an inch tall and not much wider than that.

This has changed my view on the roll cage from "soon" to definitely required. This opens up a whole can of worms though. I'm not really sure what I want to do cage wise. I live near Autopower and was considering just going down there and buying one of their full cages. Unfortunately their website just has a generic picture of said cage:



I'll have to talk to them about it. I want a main hoop that comes very close to the roof (I don't care about headliner) and rear stays that mount on the spring/shock area. I also am not sure if I want the full cage. I think a 6 point will do what I need for now. Doesn't seem like they sell something like that but I guess I will talk to them.

and thanks for the tips guys, keep em coming

1MeanZ

iTrader: (9)

Hit up blainefab on frrax. (also a great place to check out other cage designs) He can bend you a hoop you need and send you tubing for the other stuff as well. Depending on how much street use you plan on, and what seats you plan to run, I'd recommend a 6 point like I did in my car. It is shockingly stiff now compared to my 91 TA t-top car without subframe connectors. The door bars get mixed reviews but I can climb over them so thats all I care LOL.

Pablo

iTrader: (1)

I spoke to autopower today. I believe they might have a drug problem. The guy wants 800+ dollars for a 6 point cage and 400 something for a 4 point roll bar. I asked him about just selling me a hoop and he said he would sell me one for 100 bucks. 100 bucks is more than double what a comp engineering hoop is from summit racing.

I'll have to hit up blainefab and see what he wants for a 6 point.

I have a 5 point (previous owner put it in, didn't put in the passenger side door bar) in my Buick. I daily drove that for 4 years and it never bothered me.

Pablo

iTrader: (1)

Update:




Do I have enough tire?




I'm almost there, need a roll bar to hold it all together.

//<86TA>\\

iTrader: (14)

nah, never have enough tire

looking pretty sweet though

1MeanZ

iTrader: (9)

looks good. Got any pix of what you did with the spring buckets? I'd also like to see pix with the car on the ground too.

Guest

I had to wipe my computer screen off after looking at this.

Pablo

iTrader: (1)

Hahaha, thanks guys. I will get pics of it on the ground soon enough. I could set it down just to take pics but I have to weld in some more material around the spring buckets still. I also need some adjustable LCAs.

Anyone know how much shorter than stock an adjustable LCA (experience with any brands welcome) can be adjusted to? I could use about an inch shorter.

I was looking at the spohn adjustable lcas with offset spacers/sleeves. I'm just not into paying 200+ dollars for a pair of control arms.
The other thing I am wondering about is what this will do to my sway bar mounting. I'm concerned that if I move the rear an inch forward that the sway bar will have some funky preload going on. Anyone have any experience with this?

Guest

Just grind the positioning tabs off the rear axle tubes and rotate the swaybar clamps backwards. They will stay in place. I did this to mine.

Pablo

iTrader: (1)

Well it looks like I've made a pretty dumb mistake. In my haste to get this thing on the road I just ordered up a jegster 8 point roll bar kit. It got here today and actually looks pretty good. The problem is that instead of looking at a rulebook beforehand (or listening to some advice on this thread ), I looked after the fact.
So I was pretty bummed to find that only DOM tubing is allowed in NASA and SCCA and the kit that came in the mail is ERW even though it is of the proper diameter and thicker than the minimum spec. After researching this nonsense I've come to the conclusion that I think its a pretty dumb rule to ban it outright. Anyway I feel like I have to use it now, the logistics of returning it and the added time is just not something I want to deal with. The other thing is if this is really a moot point anyway. The only thing I'm really concerned about at this point is being able to do time attack sessions or HPDE.
Bah, I hate when I screw up like this. Sometimes I feel like I over think things and then I go against that instinct trying to just get things done and this happens.

Guest

Guest

Just sand, prime and paint the ERW real well and hide it. Drill a few little inspection holes for thickness inspection in a few obvious places in the main loop and call it a day.

Romours have it that there are alot of ERW cages out there being used.

1MeanZ

iTrader: (9)

I haven't researched this so I'm asking in complete ignorance, but why is ERW banned? What is it metalurgically that makes it inferior to DOM?

Primetime91

iTrader: (15)

To simplify it at it's most basic, DOM tubing (You probably know this, but drawn over mandrel) is seamless. ERW tubing (Electric resistance welded), as the name implies is not seamless.

Compared to DOM, ERW is more "stressed" and has lesser yield and tensile strength properties. With a well built cage however, the difference is insignificant, IMO. The cage construction, quality of welds and thicknesss of tubing are much more important

DOM only really poses a greater advantage IMO when a smooth inner diameter is required. Stupid rule

Primetime91

iTrader: (15)

By the way Pablo, since you're using 1.75" tubing... A couple tips to make installing it easier, especially the tube notching.

Cut the end of the tube to a point with a chopsaw set to a base angle of 28*, it'll fit up nearly perfectly for the "T" joints and you can touch up with a grinder if needed. WAY faster and easier than using a hole cutter, you can make a good fitting joint in a minute.

For those other joints that aren't at a 90* "T", take the cardboard center from a roll of paper towels and mock the joint up on that with scissors until you get it. Then slit lengthwise, slip over the end of tubing and copy it


---Sorry if you already knew those things, but it's also good to get that info out there for anyone who doesn't

//<86TA>\\

iTrader: (14)

i could be wrong here, but i though DOM tubing still started life as ERW tubing, then, when cold, was drawn over a mandrel to smooth out the inside and bring the tubing to the proper tolerances. Am i insane and misinformed?

Primetime91

iTrader: (15)

You're right actually...

There are different "levels" of DOM tubing. I guess I should clarify, the DOM tubing used in automotive/4x4 applications like roll bars is created through the process you describe, where ERW tubing is annealed and cold worked. Through these processes, the initial seam is all but unnoticeable.

"True" seamless tubing (CDS) is much more expensive, I guess I wasn't clear on that, sorry. But you have it right Phil, you're not insane lol

//<86TA>\\

iTrader: (14)

you can't prove that

Pablo

iTrader: (1)

That's exactly the information I found. It definitely seems like a stupid rule.

Vetruck... I just went out to the garage and looked at the tubing and it seems to have turned into DOM overnight

quickkris2006

iTrader: (2)

Do I have enough tire?




I'm almost there, need a roll bar to hold it all together.[/quote]


now thats a car i would not wanna f*ck with comming up behind at a light lol..can we get a burn out picture please please please!!!! nothing to hurt the tires but u know what i mean.. nice job.. wish i had ur jack i need a new one mine almost killed me the other day..

Pablo

iTrader: (1)

We'll you'd be disappointed because under the hood is a bone stock LB9. Drag racing is not the purpose for what I'm doing to this car. I have a turbo buick drag car for that.

I gotta say it's a whole lot more fun putting euro snobs and the pink wheel crowd in their place on what they believe is their home turf. I will post some time attack video when it's all done so you can see what I am talking about.

By the way, you really can be killed by a car falling on you. You should never get under a car without jackstands securely supporting it. I always set the car down on the stands and try and jerk it around a little to be sure its absolutely stable before I start working on it. I had a neighbor who's hand was almost removed because of a vehicle falling on it, and a member of Turbobuick.com was killed not too long ago when his truck fell on him. It really is serious business.

Guest

I love when a company makes a mistake in your favor and sends you DOM instead of ERW... I run the same thing in "vetruck". I bought mine from S&W racecars and installed it myself.

Primetime91- What a great tip on the use of old paper towel rolls for templates. Sometimes ideas seem so simple AFTER you hear them.

Guest

Ok,,,its late I know, but I just am not seeing what that license plate means...

EBT8N ???

Ebaten like as in ebatement, or maybe "evaden"

Nice home welding cart Pablo, I have mine resting on a low Eddie Murphy push cart (aka: trading places movie)

Pablo

iTrader: (1)

hahaha EVERYONE asks me about the plate. Would you believe that is just the random numbers and letters I got from the DMV? I keep trying to make sense of it myself hoping I can translate it into something cool but I still can't. Just luck of the draw after I paid a little extra for the "Share The Road" vanity plate. Yeah I ride bikes too.

DeanJ

Here's my guys. ERW or "welded" tubing has no place in race car construction. I have personally saw this type of tubing that the weld was offset from the seam. Not the whole length, but enough that it would not be safe if used in a roll cage. The stuff is basically nothing more than thick exhaust tubing. I wouldn't use it in anything but a cosmetic roll bar in a street car, but then again I wouldn't install a roll bar or cage in a street car anyway, but thats another story. Get you some "cold drawn seamless"and some ERW, and bend a loop out of each. Then try to stretch the loop out. Then decide which to use. Pablo, the car looks great.

Primetime91

iTrader: (15)

That's not really a fair argument... There's a big difference between typical DOM tubing you find in roll bars and true seamless CDS. CDS is very exensive

EDIT-- I'm just saying that you need to compare ERW and DOM tubing, not ERW and CDS.

If you have data from testing ERW cages versus DOM cages, I'd be interested in seeing that. But I still feel that the cage geometry/construction/mounting points, thickness of tubing used & quality of the welds are more important. Of course, none of that matters if your safety harness isn't properly installed, but that's getting off tangent

DeanJ

Only data I have is 27 years of experience building drag cars. With that said, all of the tubing types listed in this thread is not even legal in the type of cars we build at work.We are only allowed 4130, talk about expensive! DOM should be fine for this application, given satisfactory construction and welds, as you pointed out. Given my choice and I was riding in the car, it would be CDS. That is some tuff stuff. I'm going to say it again, ERW has no place in rollcage construction.

Guest

In a street car that is DOT safety rated without a cage- an ERW cage is excellent as long as you have it padded for occupant safety. It is only adding to the integrity of an already DOT rated cockpit. DeanJ, you are not thiniing in the correct application we are discussing. We are not building a chassis entirely out of ERW that can hit a wall at over 200mph. We are taslking added strength to a self supportive chassis. ERW is perfectly fine.

DeanJ

I guess your right about it being installed in a already somewhat rigid structure. But the title said a road race car. You touched on a subject that I'm very passionate about, and that is roll bars in street cars. Most people do not properly pad. Roll bars require good padding where the body may come in contact. Also helment should always be worn in any car with a roll bar IMHO. A little head bump, sometimes is all it takes.We all know that it is the secondary crash,(your body parts hitting car parts) that does the damage, even when the structure is still intact. I simply don't like roll bars in street cars. Please think about this guys!! Sorry for the hijack. Back on subject. Pablo' the mini tubs look good. Fun installing them, isn't it.