Frame Notch/Tub/Cage-Complete build Start2Finish

[prostreetdrag]

One more thing I would like to add, There are alot of pics of this process all over the web. I would recomend doing a search with google on ( G-body Project Grandma) or any other search engine. I personally use google and know it comes right up. Anyway, It is about a build up on a Malibu and it is well documented with alot of great pics that would help you as well. You will want to look at the section of the 25.5 cage install as it explains the steps they took on the tubs and cage process.

 

[coach]

Still havent forgot. Just busy as heck. Im trying.

Thanks
Coach

 

[prostreetdrag]

Trust me I do understand, It's no problem at all I'm still working on the notch part of my build as you can see then im moveing to the Tubs so it will be week or two before starting trunk and fuel cell braceing...Also Coach, my fuel cell I'm fabricateing a drop fuel sump in it as well my fuel cell is 18 1/4 x 20 1/4 the sump will be around 15 inches long tappering to a 3 inch drop...So i just need to work that into my designs as well..But again man I apprciate all your sugestions and ideas.

 

[cruzn57]

wheel tubs

I am glad you posted your build as i was going to ask a question in regards to the tubbing process.

I have already notched my car but i would like to redo the entire trunk paneling in the car and the wheel tubs as well.

So here is my question, would cutting out the entire wheel well (front lip of the fender where the inner and outer portions are spot welded together) will weaken the outer body paneling too much and ultimately cause creasing like with improperly notched and reinforced cars?

Hopefully someone has some real life experience and photos maybe

I removed only a portion of the original wheel well, then used a summit tub kit to fit it in, using carboard to get a template to cut the metal.hope that helps

 

[prostreetdrag]

I think he was wandering about full tubs though rather than mini tub and if doing full tub would loose structure integrity. The only down side to the mini tub is it could still limit how low and how much tire you can fit up inside wheel well due to the curve on the inner tub. Looks good though nice work.. You can still get quite a bit more tire in there with the mini tub and would be alot less work for someone just needing a bit more room. The stance and look I'm going for though would be no way I could get by with doing mini tubs. Another thing for people to consider is Backseats???? mini tub may be the way to go if you would like to keep your backseat. I noticed what you did for trunk hinge clearence..The hinges in these cars sit so low and are bulky..I hate gm's design with them, I think they could have done better but then again who knows...I plan on doing somthing simalar to what you did because my tubs will be little more further in and i plan on getting them to sit little higher..I may just fab up some custom trunk hinges if the factory ones sit too low because I will be useing a 29-30 tall slick

 

[coach]

I think he was wandering about full tubs though rather than mini tub and if doing full tub would loose structure integrity. The only down side to the mini tub is it could still limit how low and how much tire you can fit up inside wheel well due to the curve on the inner tub. Looks good though nice work.. You can still get quite a bit more tire in there with the mini tub and would be alot less work for someone just needing a bit more room. The stance and look I'm going for though would be no way I could get by with doing mini tubs. Another thing for people to consider is Backseats???? mini tub may be the way to go if you would like to keep your backseat. I noticed what you did for trunk hinge clearence..The hinges in these cars sit so low and are bulky..I hate gm's design with them, I think they could have done better but then again who knows...I plan on doing somthing simalar to what you did because my tubs will be little more further in and i plan on getting them to sit little higher..I may just fab up some custom trunk hinges if the factory ones sit too low because I will be useing a 29-30 tall slick

Most tubs are 36inch diameter, regardless of tire used. A mini tub vs. full tub would only be on the width, not the dia. If you are not back-halfing the car, then you are mini tubbing it. In order to do a full tub, you would need to move the frame rails in about 8-10 inchs a side. For a notch, just build your tubs to sit right inside the back of your frame rails. I would eliminate the factory trunk hinges all together and use struts like on the hood. You dont need to work around something that you can easily alter quicker with struts. I will tell you from expierence, go to your local appliance shop and get a bunch of big boxes and use th cardboard for your patterns. You should be able to construct your entire floor and tubs in cardboard and tape, then once it fits, cut it apart, lay it onto some sheetmetal and cut. I bet I built or had a hand in building at least a dozen pro street cars during the 90's. This is a full proof way of wasting cardboard not steel. I think I would do your frame a little different since your car is not original anymore. I would have moved that entire section of frame in, not just notch it. Would have been very strong, and you do not have the GN's racing rules to worry about for a legal notch.
I will get a few sketched done up and take pics so you can see what I mean.

Thanks
Coach

 

[prostreetdrag]

Yes the average size for these cars used is 36 inch tubs which is the smallest aftermarket tub avalible. I have seen 38 inch used as well. The car will sit very very low which is all going to be taken into consideration..I have seen hinges be an issue and I have seen tubs installed low enough where they clear the hinges. I wont be sure of the placement until i actually make the templete from cardboard and take measurments there has to be enougn room in wheel well side to side and as well as above to get car lowered where i need it...Definatly have planed on useing the cardboard method, cardboard is easier to cut and trim and i only want to cut the sheet metal once....As far as the mini tub v's tub issue

 

[prostreetdrag]

as far as the tub mini tub issue i think that is something that is debateable and think you would recieve a diffrent opinion depending on who you speak with i have read and heard many diffrent times of people debateing the definition of tub v's mini tub. Some people say in order for it to be considered a tub you have to move the frame rails in...Other people say it is a full tub if your doing exactly that which is removeing entire factory tubs and replaceing with a new tub...and that a mini tub is adding a filler peice or cutting a full wheel tub in half and adding to the factory tub to make it slightly wider

 

[prostreetdrag]

So whether it is a tub or mini tub it doeasnt really matter to me what people want to call it as long as it looks good, rides good, and is fast... outside of that I do know theres no way i can get the look I want without removeing entire factory tub due to the rounded edges on the inner/outer wheel tub

 

[coach]

Yes the average size for these cars used is 36 inch tubs which is the smallest aftermarket tub avalible. I have seen 38 inch used as well. The car will sit very very low which is all going to be taken into consideration..I have seen hinges be an issue and I have seen tubs installed low enough where they clear the hinges. I wont be sure of the placement until i actually make the templete from cardboard and take measurments there has to be enougn room in wheel well side to side and as well as above to get car lowered where i need it...Definatly have planed on useing the cardboard method, cardboard is easier to cut and trim and i only want to cut the sheet metal once....As far as the mini tub v's tub issue

Dont forget one VERY important factor. You cannot lower your car like most racecars because you are using stock location trailing arms. You have not engineered your suspension to do so. You need to run your ride height so the trailing arms keep there geometry correct. If you had 4 linked it, that is different. You have 10 different locations to hook up on the housing alone. You do not have that luxury. You are sorta stuck. If you want your car to hook and go, it will have to sit about stock height, maybe a little lower.

Coach

 

[karolko]

Coach i correct. You cannot lower you vehicle and expect it to react and handle the same or better at the track, because it won't.

If you are willing to spend the money, go to TRZ and talk to Todd about getting a custom 9" housing built. These housings have adustable holes in both the upper and lower axle mounts. This will let you to lower your car AND MOST IMPORTANTLY tune your suspensions Instant Center, Anti Squat, and everything else.

The TRZ boys have put down 1.18 60" times with this housing, so you know it works.

Adrian

 

[prostreetdrag]

Yes your correct but will not be mounted in stock location points. However the 9 inch I'm using has CA relocation brackets installed. When I mocked up my 9 inch rear after i cut the stock wheel tubs out with a 30 inch slick, I was able to get the rear to sit about 2 3/4 inches lower than stock even with the taller tire (which was look I'm going for). the Lower control arms were sitting level with floor and the top of the tire had about 1 1/2 clearance from the bottom of the trunk hanger which will not provide me enough room with suspension travel. This is why I need to make sure the tubs are installed where there is enough up and down travel. I will have a better idea once the cardboard templates are installed in the wheel well. This is why I have earlier said I may need to do custom trunk hinges. There is still quite a bit of material I can trim from the bottom of the trunk hanger where I may be able to get it sit high enough for the right amount of wheel well room above but low enough to use stock hinges, we will see. I'm defiantly not going to let a minor problem like trunk hinges limit my ride height ability. It has been said many times depending on which g-body it is that the trunk hangers sit lower or higher than others. I do know for a fact that Malibu's trunk hangers sit much higher than my cutlass as I just sold my Malibu about a year ago to put a down payment on my Harley. Originally it was going to be my pro street project until little over a year ago when i started going a little more wild on my engine build for the cutlass. So we will wait and see I'm defiantly not against changing things as I go along to get the look and performance I want as this is solely a project thread about a car being built strictly for fun and performance as it is by no means a daily driver but instead a way for me to relieve stress and keep sanity

 

[prostreetdrag]

Just went out and took another look at my hinges and I can tell you That I'm defiantly doing away with them and going with the approach of a cleaner look with a much more simple design concept. I've also just done some quick web searches also on universal type hinges and I'm very confident that I can make something work pretty easy and cheap with minimal fabrication and a few welds..I think I am going to tig somthing from alluminum though for good looks and weight reduction. Depending on the weight of the trunk will most likely do as coach stated with some sort of a lightweight small struts though. I do have a 442 spoiler on the deck lid which makes the deck lid litttle heavier.. For those of you with the same problem there is several companys with universal hinges one company off hand I remeber seeing is autoloc They specialize in lambo kits,alarms and other custom asscessorys. If you dont want to fool with making your own...This should also give everyone another cool thread to follow regarding custom alum trunk hinges...

 

[prostreetdrag]

Here is another update, I still have to do some more trimming and cutting on the other side this should show so far...I still need to weld the steel plate on where the notch is but im wanting to weld some reinforcements inside the frame rail where it is notched also I'm going to weld in some plate on back side of the frame rail where the full frame and notch meet..I have a cross-member that runs in between right there as well but the plate that gets welded on the backside will have a notch cut out of it where it will fit snug around the crossmember where it ties to the frame rails.... I'm just about ready to make my cardboard template for the wheel tubs then i will trace patterns on the steel tubs and then cut and assemble them...Before i install the wheel tubs their final time I also need to drill out the spot welds for the factory trunk hinges since it will be easier to get to with the tubs removed..right now they are just trimmed and the trunk is removed so they do not interfere with mocking up the wheel tub templates

 

[prostreetdrag]

Here is a pic of the drop sump I made at work for my alum fuel cell. I would have prefered not to use diamond plate but it was the only extra(free) alum I had laying around I think should still look very nice when complete. I will post another pic when I have it welded to fuel cell. Sorry if image is smaller I took pic with my phone..

 

[prostreetdrag]

Should be able to get a pretty wide tire stuffed in there I have about 14 3/4 inches of width between the notch and wheel well lip. That is before rolling the fender lip. I should be able to gain another 1/2 rolling fender lip which will give me 15 1/4 space minus 3/16 for the plate over the notch. I took the notch 1/4 or so past seam so i will most likely weld plate in the outer edge v's inside notch to give little more strength and thickness. With both crossmembers the reienforcement inside the frame rail and the plate steel on the back side of notch it should be plenty strong from side to side and ofcourse up and down strength for the stress from leaving the starting line. My plans have been to use a 15x12" wheel. I will need to do some measureing though to figure out proper backspace for it though...My 9 inch ford rear has been shortened about and inch shorter on each side from the factory 7.5 axle housing that was in it before. Everybody elses fitment may be a little diffrent.....If anyone is running this size wheel if you dont mind letting me know what type backspacing your useing I prob wont need to go as deep on backspace since my rear is shorter but I'd like to get an idea what I will be looking at..I wont know for sure what i need till everything is installed again. I will most likely be going with a 12 inch wide slick as well..worst case 12 inch tire on a 10 inch wheel.. however i'd like to do 12inch wheel. i think i should have plenty of room..well see i guess....So again if anyone is running a 12 inch wheel/tire combo...pics and backspace???

 

[prostreetdrag]

I havent got too much more done this weekend due to the bad snow storm we just had. Their will be more progress pics of the tub/notch this week. Just wanted to post a couple pics of a crossmember/driveshaft loop I made this morning...This will actually be welded just in front of the lower control arm mounts in between the frame rails... I will weld braces off of this crossmember to brace the lower control arm brackets..The main hoop for rollcage will tie into this aswell....I have seen a crossmember simalar to this same one at jegs for over 240.00.. There was no way I would have ever paid that price...I had some 1 1/2 x 2 1/2 steel box laying around the garage and decided to use it instead of some round tube.. The reason I used this instead of round tube is in the future I may decide to change over to a 4 link set-up I can use it for the 4 link crossmember.

 

[prostreetdrag]

ok guys little more progress this morning, earlier in a prev post where I showed the frame notch there was a bad spot in the frame where a rust hole had started right where the notch ended and full frame started towards rear. Here is a pic of some 3/16 plate i welded on backside of frame notch where the full frame starts again. Prob didnt need to do it but was worth some cheap insurance...On the inside of the frame notch I cleaned all the rust to bare metal around the whole and i tacked welded the hole until the hole was full of weld. That hole will be grinded smooth on the inside of the notch. I will post a pic of that once im finished grinding the weld smooth where the rust hole used to be...it will look like turky s**t if not grinded smooth with the all the tack welds. Im pretty picky about my welds most of the time and I like for them to look nice. otherwise i would leave it since will remain un seen but the problem that always remains is i know its there. The plate thats welded on the back of frame gave it something for the weld to penentrate to once i filled the hole with tack welds.

 

[prostreetdrag]

Here is a pic of the cardboard templete being test fitted in the frame rail

 

[prostreetdrag]

I havent got much work done the last few days. Im on vaction next few weeks I plan on doing quite a bit of work and get the new plate welded in within the next few days.