Tubbed Supra

[Poodles]

Have no idea how much more clearance you'd get as I've never seen anyone do it.

I'm curious to see how much clearance you could get (I bet our suspension SME might have some insight...)

 

[suprabad]

Thanks Hommer, those diagrams answer my questions regarding the "lay down" shock set-up we were pm'ing about.

I see most of that type of set-up would have to be fabbed, but I wonder if the pieces that link the coilovers to the actuator arms (or whatever you'd call them) are somethinig that could be easily bought? I don't recall seeing suspension hardware like that, but I've never looked for them, so I don't know. Might be cost prohibitive but I love the F1 idea.

Also, I'm checking into the idea you suggested of springing the IRS like a corvette with a single leaf spring to hopefully gain some "inside" wheel space. I'm going to talk to some builders I know and see what their ideas are on the subject.

 

[suprabad]

Have no idea how much more clearance you'd get as I've never seen anyone do it.

I'm curious to see how much clearance you could get (I bet our suspension SME might have some insight...)

I'm going to get my car up on the lift this weekend and eyeball the rear upper strut tower and see how much room could be made, and what it would take to move the mount over.

I'm sure our SME (as well as unofficial) experts can add something to this and hopefully they'll pipe in when they get the time. If our SME's (official and otherwise) don't know what's up, than no-one does :icon_bigg

 

[IJ.]

From memory (been awhile since I've had stock fittment springs) the rears are reduced diameter near the lower mount for clearence so small diameter coilovers don't help a lot.

Any linkage design is going to be all custom and doesn't really apply to the Mk3 unless you're willing to totally butcher the car.

 

[suprabad]

Any linkage design is going to be all custom and doesn't really apply to the Mk3 unless you're willing to totally butcher the car.

It does defeat the main criteria which was to keep the cars integrity as a streetable driver.
I don't want to start cutting the car up with maybe the exception of inner fender wells, which I would ideally just make larger, rather than cutting out the rear floor entirely.

I don't want to get too far into the experimental insofar as it will cause this project to never happen. I have to keep reminding myself to keep it simple and remembering what the whole point of the mini tub is:

Getting bigger tires in the rear than would be possible with the stock suspension w/ low back spacing being the most important detail.
What I dont want is rolled fenders and tires sticking out.

 

[IJ.]

The tubs aren't the limiting factor though the strut position is.

 

[HommerSimpson]

I believe the design or the moving parts or what ever is called.. Pushrod rocker suspension.. i think its doable with out choping car up alot...but is not going to be something that will be easy..

What i would do.. if you have time... get the wheel tire combo you want to put on.. if you cant find a loner or something make one out of cardboard and gorilla glue.. :} just make it close to the size of tire you want under...

snatch the strut and front trailing arm off and stick it on there.. see were you are at...

maybe ditch the front trailing arm all together.. and add one to rear like the middle one.. at a angle.. / | \ < like that :} lol

figured easyer to post then to PM...

hope you decide to do something.. :}

 

[IJ.]

And totally destroy one of the best features of the Mk3.....

There is a HUGE amount of math involved in a rocker suspension it's not something you build in the backyard with cardboard and a mig.....

 

[HommerSimpson]

yea you pretty much will have to destroy the factory stuff...

He asked how it could be done.. Im only making sujestions..




but i think ill just shut up.. i see a ban coming..everytime i post someone has to make issues with it..

 

[IJ.]

I think SupraBad is smart enough to know how unrealistic it is so no harm done.

 

[suprabad]

It's a great system and I love the idea. If I were going to build a tube frame and just sit the car on it, then it would be worth doing. I fear getting the geometry right would be mind numbing.

Having now given it some thought I want to keep this as simple as possible.

What i would do.. if you have time... get the wheel tire combo you want to put on..
...snatch the strut and front trailing arm off and stick it on there.. see were you are at...

hope you decide to do something.. :}

That's the next logical step.

I should be able to get it done early in the week and measure/record everything so I know exactly how much room I need to create. I've got to find a street tire and a track tire size that will both look and work well. Definitly going 15" wheel for the strip w/ a M/T cheater, not sure what I'll use on the street, maybe a larger diameter wheel (17") with a 5o series tire. I'm not sure, I'll have to see. But, I am going to find a way to get more tire under there.

 

[HommerSimpson]

Ill make it real damn simple for you ...

http://cgi.ebay.com/ebaymotors/Heid...RS-Heidts_W0QQitemZ350097954301QQcmdZViewItem

 

[Wiisass]

Moving the top of the shock won't give you that much more room. You would need to look at moving the bottom mounting point if you really wanted to get more room back there.

And let me get this straight, you want to tub the rear and move suspension points and throw together something custom, but you don't want to roll the fenders? That makes absolutely no sense and that is really dumb. It would be a lot cheaper and easier to modify the fender to get a little more room than it would be to modify all of the suspension. And if you don't get the fender perfect, it won't make the car handle like crap, you can't say the same about not getting the suspension right.

And do you really need a 13.5" wide tire? Or do you just think that's the coolest tire you can think of? Or is this like a way down the road idea? I don't really follow many people's builds, so I don't know what you have or what you're building, just curious if a 13.5" tire would really be needed. There's no point in doing all this work if you don't need to.

So why don't you figure out how much you can fit under there without cutting everything apart first before going too far with it. Then you will know if you need 1/2" or 2" and where.

 

[suprabad]

Moving the top of the shock won't give you that much more room. You would need to look at moving the bottom mounting point if you really wanted to get more room back there.

I assume you mean move it inward...it occured to me too, but I'm concerned about finding a shock that would stand up to the increased leverage.

And let me get this straight, you want to tub the rear and move suspension points and throw together something custom, but you don't want to roll the fenders? That makes absolutely no sense and that is really dumb. It would be a lot cheaper and easier to modify the fender to get a little more room than it would be to modify all of the suspension. And if you don't get the fender perfect, it won't make the car handle like crap, you can't say the same about not getting the suspension right.

That's right, I dont want to roll the fenders, it defeats the look I'm trying to get, how's that dumb?

As I said, I'm looking for a mini tub effect and haven't decided how I'm going to approach it. The point of this thread is to get some different ideas on how to accomplish it. Moving suspension parts is just one possible way. Obviously, that's a complex task, one I wouldn't really look forward to.

As I also stated, I'd like to keep it as simple as possible. But wide body or even rolling the fenders is out...besides, everybody and their mother has rolled their fenders to get a little bigger tire in there.

And do you really need a 13.5" wide tire? Or do you just think that's the coolest tire you can think of? Or is this like a way down the road idea? I don't really follow many people's builds, so I don't know what you have or what you're building, just curious if a 13.5" tire would really be needed. There's no point in doing all this work if you don't need to.

Do I need a 13.5 inch tire? No.
Is it the coolest tire I can think of? Well...now that you mention it...it would be pretty cool if you could get it all inside the fenderwell, and not have to butcher the car.
Coolest? I'm not sure what you mean.

So why don't you figure out how much you can fit under there without cutting everything apart first before going too far with it. Then you will know if you need 1/2" or 2" and where.

Yeah, I agree, and said so in my last post. Did you read my last post?
How much I need is definitely the question...where I need it is easy, I need to make clearance inside, that's why I'm running into clearance problems.

Now be helpful...or I'll have to drive to your house and kick your scrawny ass.:icon_razz

 

[annoyingrob]

Finding shocks isn't that hard. A lot of companies can make you something custom.What I would be worried about is how you would manage to extend the lower shock mount further inside the wheel well, while keeping it strong.

 

[suprabad]

Finding shocks isn't that hard. A lot of companies can make you something custom.What I would be worried about is how you would manage to extend the lower shock mount further inside the wheel well, while keeping it strong.

I think I could beef-up the lower control arm to handle the additional stress and move the mount back some. How far? I'm not sure yet.


As far as shocks go...I think the simplest/best way to go would be to valve some bilsteins or koni's to provide more dampening (comensurate with the increased leverage on the control arm) and build an upper shock tower extension (if necessary) to compensate for any increase in height as a result of moving the lower mounts further back on the control arm.

If I can gain 4 or 5 inches of clearance on the inside I could probably meet or at least come close to my goal of wider rubber w/ no backspacing. It's going to look killer and certainly provide some more bite for when I go th350 w trans brake.

 

[Wiisass]

Yes, I meant move the lower point inward. And the increased leverage you mention, is nothing more than a different installation ratio. As long as the shock is mounted properly, that is easy to account for. If the shock is not mounted correctly and seeing other loads, then you did it wrong. But all of that needs to be accounted for in the shock/spring. If you do move the coilover like that, you will need different spring rates and different damping values.

Rolling the fenders just means to fold the inner lip in to gain a little more clearance. Why would you not want to do that? That's what doesn't make any sense.

And because other people have rolled their fenders to get a bigger wheel/tire in there, that's a reason that you don't want to do it. You know people have used aftermarket wheels so they could fit a bigger tire on there, actually a ton of people have, so maybe you should stick with sawblades.

All I was asking was if you really need that much tire. If all the extra work and chances that you're going to totally screw up the car are worth it if you only need a 10.5" tire? So I was asking if the choice was based on the need to put power down and smaller tires aren't enough or if 13.5 was the biggest you coudl find and therefore the coolest tire you could think of.

I did see the your last post, but I kind of stopped reading when Homer said to remove suspension arms and see what you could fit. You should leave that stuff on and see what you can fit. Also remember, that the wheel doesn't have to be sunken in there, you can go out closer to the fender as well. You said you were running into inside clearance problems, does that mean you're already hitting on the outside?

And I don't think moving the lower shock point is going to get you 4-5 inches, it will get you some, but most likely not that much. And what does "wider rubber w/ no backspacing" mean? Does that mean you don't want to run different backspacing than stock?

 

[suprabad]

I understand what rolling the fenders is. We used to do it with a baseball bat when I was a kid, I've also used the tool they make for it (the one that bolts to the hub). I think it weakens the fenderwells most times, as well as giving them a little different shape that I'm not in love with, which is irrelevent because:
I'm not looking to offset rubber on the outside, I want to offset it towards the center of the car. That's the whole point.

And maybe a 10.5 would do... and also satisfy my desire for the look I'm trying to describe. I don't know yet. I plan on sizing up some tires like I said and seeing what looks good/is do-able.

wiisass: I'm surprised you're not more positive about trying to do something like this.
I just want to have/build something a little different from what you normally see or what is normally done with MkIII. I don't think that is so bad or stupid. C'mon dude, get on board.

 

[Wiisass]

So you want to fit as much tire as possible, but you don't want to go any further outboard than the stock wheels? That's what I find as dumb. There's a lot of room on the outside that you can use without having to modify the fender or do anything else that you don't want to do, so why not use that?

And rolling the fenders, just take it to someone or do it yourself and take your time, it will give you more room, but if you aren't moving outboard at all, then I guess you really don't need to.

And if you aren't moving outboard at all, I doubt you'll be able to fit as big of a tire as you want.

It's not that I'm not positive, I think putting as much rubber back there as possible could be a good thing, but you're putting constraints on yourself, that in my opinion are not necessary. It sounds like you would rather modify the suspension than have the wheel/tire further outboard than stock, to me, that is dumb. So it's not that I'm not on board with putting a big tire back there, I just don't understand why you are limiting some of the things that would make this easier.

 

[frontierguy25]

I have talked with Bryan (Slow66) several times about tires, you can see my threads in the Drag Racing section. The biggest tire you can fit is a MT ET street 28x11.5x16. It has to be on a 16x9 wheel with a +40 backspace and a slight fender roll. The tire fits great and is really fat. It doesn't hit the spring or strut. With out having to change a bunch of stuff, this is a big tire that will fit. If you did the same tire on a 15" wheel it will not fit because it is too fat and will hit the spring/shock.

The main thing is your power goal, you can fit some 26x11.5x16 ET Streets in the back and have more than enough tire to handle 550rwhp.