Tubbed Supra

[suprabad]

I know tubbie has done it with a 9" ford or 12 bolt chevy or something but:

Has any one ever done a mini-tub and retained the IRS Toyota rear-end?

I realize it would be a major... since you'd probably have to notch/narrow the subframe as well as shorten the drive axles, not to mention fabricate control arms or possibly move the suspension pivot points inward. And that isn't counting any sheet metal work needed to make room for suspension and tires.

I mention mini-tub in particular because I was thinking of this for a street driven car and obviously a fully tubbed car isn't terribly practical on the street.

Just curious what some of our craftier dragracer/fabricators thoughts on this are.

 

[Slow66]

IMHO, you can fit enough tire in the stock wheelwell/axle setup to handle a ton of power, so, to me, the only reason to start cutting stuff up would be to go to a solid axle setup. You could still do an unnarrowed solid rear with some 28x10.5's or similar, modified wheelwells, modified floor and a streetable torquearm/control arm suspension like found in 4th gen f-bodies. I just think that if youre going to do all that work, (for drag racing) the IRS ends up still being like tits on a bull. Anything can be built...its just a matter of what you can think up.

What do you think your ideal combo would be?

 

[IJ.]

IRS Axles get very expensive when you go custom

[thumb]http://ij.supramania.com/reassembly15.jpg[/thumb]

 

[suprabad]

IMHO, you can fit enough tire in the stock wheelwell/axle setup to handle a ton of power, so, to me, the only reason to start cutting stuff up would be to go to a solid axle setup. You could still do an unnarrowed solid rear with some 28x10.5's or similar, modified wheelwells, modified floor and a streetable torquearm/control arm suspension like found in 4th gen f-bodies. I just think that if youre going to do all that work, (for drag racing) the IRS ends up still being like tits on a bull. Anything can be built...its just a matter of what you can think up.

What do you think your ideal combo would be?

What I'm thinking is...I'd like to be able to get a set of M/T 28 X 13.50R15 drag radials inside the fenderwells. While it's not a huge tire, I think it's quite a bit more tire than I could stuff inside the Supras fenderwells.

I'll have to take a hard look at it with the wheels off and a M/T28 X 13.50R15 mounted on a rim and see what it would take. I'll measure it tomorrow for clearance, but my "guess o' meter" (admitedly flawed at times) is saying "no way".

Any of you guys ever size up similar dimension tire?

 

[IJ.]

285/35/18's here and they're about as big as I can squeeze in without them rubbing on either the struts or the fender lips.

 

[Slow66]

I think even with a "dead nuts perfect" offset, that tire has about as much of a chance fitting as I do at being the next president. Even with a rolled/cut lip...

So lets mini-tub it what do you got in mind for an ideal setup for your goals?

 

[drbowser3]

305/35/18 fit with a 10" wheel and the right offset.

PM 2JZMK3 He attempted to fit 28x10.50 and they rub the coilover, and I believe he tried everything under the sun....

 

[Boost Lee]

I've seen 315's with appropriately matched rims fit beautifully with slightly rolled fenderwells.

But as mentioned, the offset could be a big determining factor as to just how wide is "too wide".

I'm with Bryan. I'm very interested in hearing about this mini-tub idea.

Do it.

Jeff

 

[Poodles]

The strut is the issue, and the Group-A cars ran offset top mounts for that reason... (and I've been waiting for someone to notice this besides me and come out with replicas)

If you're cutting the rear apart you could lean them in a lot more, but the leverage and the loads they'd be under would make tuning them a bit of a hassle I would think...

 

[suprabad]

So lets mini-tub it what do you got in mind for an ideal setup for your goals?

Help me figure it out.

Other than keeping the Toyota IRS...I'm in the head-scratching stage.

Since this appears to be uncharted water I'm not really sure how I'm going to go about it yet. It would be neat to have something a little unique and I love the way it looks in my minds eye. I'm sure it would be awesome looking.

Insight, facts, thoughts and speculations appreciated.:icon_bigg

 

[supraguru05]

The strut is the issue, and the Group-A cars ran offset top mounts for that reason... (and I've been waiting for someone to notice this besides me and come out with replicas)

If you're cutting the rear apart you could lean them in a lot more, but the leverage and the loads they'd be under would make tuning them a bit of a hassle I would think...

got some pictures of the top mount. iirc they ran a solid metal top mount with a spherical bearings for the shock to bolt to so when the bottom of the shock travels it doesnt bind but i would like to see a picture since its been so long.

this might buy you a little bit of clearance. also switching to a coil over might buy you some if the spring OD is smaller than factory

 

[Poodles]

Here's pics:

 

[suprabad]

Here's pics:
[THUMB]http://www.turbosupras.com/images/Group%20A/Group%20A%20Interior%207.jpg[/THUMB]

Am I supposed to looking at the rear shock towers? Are they moved inward? It's hard to tell with the cage and all the other stuff going on...

Can you sort me out on this?:icon_conf

 

[Poodles]

Look at the top strut mounts. Stock top mounts are centered, on the the race car it's offset and angled inward.

It's not a LOT of clearance, but when you as much rubber as possible on the track...

 

[Slow66]

Help me figure it out.

Ok.

Lets start with this. Whats the intended use of this vehicle ( i.e. 75/25 street/strip etc.) ? How much power you plan on making? What exact tire/wheel combo do you want to use that will suit the purpose and be as you say "different and asthetically pleasing"?

this.(mild size and high backspacing)

this. (mild size and low backspacing)

or this. (lots of everything )

#1 you can do with the IRS, but youre basically limited to a 9" slick unless you start rearranging suspension.

#2 you could do with an unnarrowed (or slightly narrowed, depending on what it ecactly came out of)solid axle out of a mustang/camaro, and then just build a suspension around it. It would involve making some differently contoured wheel tubs, making new suspension points and clearancing of the floor (among other things)

#3 is obvioulsy a radical approach and one that I dont reccommend from personal experience...

I personally like the #2 approach if youre going for drag reliability, while still streetable, and it looks nasty too

 

[Kristian_Wraae]

Someone in Denmark did this:

Still running 7M.

 

[Janz99]

More pics of that car please

Ryan

 

[Kristian_Wraae]

Don't have any more.

Some vids though, don't know if you need to be a member to watch.

http://www.bilgalleri.dk/html/vid_vis.asp?VideoID=15791


http://www.bilgalleri.dk/html/vid_vis.asp?VideoID=15790


It didn't run that well when I saw it last. Only running 9.65 s.

Owner claims it has more than 1000 hp but haven't been able to measure it since the dyno couldn't.

 

[suprabad]

[THUMB]http://www.japanerfusk.dk/427757_l.jpg[/THUMB]

THAT IS AWESOME!!!

However, it's too much tub for what I am trying to do, but still awesome.

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[THUMB]http://www.turbosupras.com/images/Group%20A/Group%20A%20Interior%207.jpg[/THUMB]

Look at the top strut mounts. Stock top mounts are centered, on the the race car it's offset and angled inward.

Ahhhh...I see. How much "inside" clearance would you guess that would buy me?
Might be the most practical way to do it, if it's enough.

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Ok.

Lets start with this. Whats the intended use of this vehicle ( i.e. 75/25 street/strip etc.) ? How much power you plan on making? What exact tire/wheel combo do you want to use that will suit the purpose and be as you say "different and asthetically pleasing"?

It won't be a daily driver but... I would like it to retain all the aspects of a capable dd.
In other words, I want it to be as streetable as possible so I could drive it just about anywhere. Also I'm hoping that I can mini-tub it, and with the right street tires not adversly affect the handling and still fit in a good size slick or a cheater like the M/T in pic #3

#3 Is almost exactly what I'm looking for

 

[HommerSimpson]

Anything is posible with the right frame of mind and attitude...

Hope these help you...