Mini tub and spring relocation kit

[whitsend]

Hi Guys,

So i was looking at a spring relocation to fit a fat tire but if i do that can i still use a rear sway bar? It would change the width between swat bar brackets wouldn't it?  Also if one installs mini tubs, do you have to modify/ shorten width of the rear seat? Thanks in advance. 

[anlauto]

The factory sway bar won't work unless you find some sort of off-set sway bar links because the spring perches will be moved in three inches at least..and your fat tires would likely rub the bar....I'm sure someone likely makes a sway bar to fit under the rear axle 

I think the lower rear seat needs to be modified but when I do mine I'm going to try and notch the tub to make the stock seat fit. That area of the tub is not needed for tire clearance 

[Dmod1974]

The bigger issue is that the rear sway bar already protrudes into the factory wheel well as it is, making mini tubbing pointless.  Assuming you're referring to the USCT kit with frame notching, the notching is done near the shock crossmember mounting area where the frame rail splays outward - nowhere near the sway bar bracket.  And yes, you will need to narrow the rear seat.

[rikkitik]

 I have the Dr Diff relocation kit, ('71 Challenger) with a factory rear sway bar. 295/50×15 T/A's (ice skates) fit on my car, 15x10's with 6.5 backspace, nothing rubs. There's a fair bit of variation on these cars, so not necessarily a "one size fits all" answer. I'm (currently) running a std. E width S60 rear. For the sway bar links, I bought some good quality steel 5/16" rod, z'ed them 3/4", and threaded the ends. Everything works fine with no rubbing.
If you want a more "correct" setup, IIRC, Firm Feel will make you a custom ($$) rear sway bar to fit.
From what I've measured, the stock inner lip to inner fender well is usually in the 12.5" - 12.75" range, and the rear axle is rarely centered in relation to the wheel wells. Not necessarily a problem, but I thought I'd mention it.

(I realized most of what I posted here doesn't apply to the OP's question, mini tubs. Rather than delete it, I'm just going to leave it, someone perusing the thread might find something useful in it.)

[Dmod1974]

When you mini tub anything you're adding depth in the wheel well toward the inner side for the purpose of running a wider tire.  The bend of the factory over the axle bar sticks past the factory inner wheelhouse as it is, so adding more depth for a wider tire isn't going to accomplish anything if you're running that style of bar.  The bar will be in the way before the frame rail taper or wheelhouse is.  He asked about mini tubbing; all I'm saying is it's a waste of time if you are going to run the factory sway bar.

[anlauto]

A 295/50 would barely need a mini-tub, I'm going with a 345/50 so they would for sure hit the factory bar

[MoparCarGuy]

Passenger side factory sway bar area at framerail/tub for reference.

[Brads70]

Hotchkiss  sway bar will give you more room? FYI....

[Dmod1974]

Man, I wish they made something like that for the RMS Street Lynx suspension with inboard mounts.  That style would work perfect if they made a narrower bar and offset dog bone end links to clear the lower links (or 3" inboard leaf springs too I suppose).

I know I've seen an article a few years back about them starting to offer a rear sway bar option on some of the B-bodies, but I haven't seen anything since and their website doesn't reflect it either.  I'd also have to cut out and weld in a new cross bar which is more surgery than I want to do on a fresh build.  Oh well.

[HP2]

How large a tire  do you want?

I've seen several people fit 335 tires in the stock wells, so they can swallow a fairly wide tire. However, the backspace on the rims has to be spot on and the overall diameter could be a factor as well. If you wanted to go with a wide and tall sidewall tire like a drag tire, then you may have issues at the top of the well.

Another  thing to keep in mind is that on E bodies, frame rails are splayed wider in the rear. That means adding extra wheel tubs will gain you 3" in the front of the well, but only gains 1" in the rear. If you want more room than that, then you will be getting in to frame rail surgery to move it in.

Regarding the sway bar, again, that depends on how large you want to go and how you backspace the wheel. It is possible to bend in the ends of the stock sway bar to gain and inch  per side, but you will still have the original 90* transition turn to deal with.  Rim diameter and tire height are factors here. Same with using an offset link.  If you are going 3" or more, than the stock bar can't really be used.

There are a number of aftermarket, under axle bars that are significantly more narrow and do not have any interference issues because of where the are located.

There are always the option of making a custom bar. There are companies out there that offer splined solid or tubular bars that could be matched with bolt on, custom ends to attach wherever needed. Of  course you also need to fabricate the mounting brackets and attaching brackets. A couple of places with parts for this would be Speedway Motors or Speedway Engineering (two separate companies, btw).

[Brads70]

Man, I wish they made something like that for the RMS Street Lynx suspension with inboard mounts.  That style would work perfect if they made a narrower bar and offset dog bone end links to clear the lower links (or 3" inboard leaf springs too I suppose).

I know I've seen an article a few years back about them starting to offer a rear sway bar option on some of the B-bodies, but I haven't seen anything since and their website doesn't reflect it either.  I'd also have to cut out and weld in a new cross bar which is more surgery than I want to do on a fresh build.  Oh well.

Do they offer a rear sway bar? If not you could add a splined sway bar up above in the frame rails and have the links coming down to the rear end. Pretty easy/common set up. 

[Dmod1974]

Man, I wish they made something like that for the RMS Street Lynx suspension with inboard mounts.  That style would work perfect if they made a narrower bar and offset dog bone end links to clear the lower links (or 3" inboard leaf springs too I suppose).

I know I've seen an article a few years back about them starting to offer a rear sway bar option on some of the B-bodies, but I haven't seen anything since and their website doesn't reflect it either.  I'd also have to cut out and weld in a new cross bar which is more surgery than I want to do on a fresh build.  Oh well.

Do they offer a rear sway bar? If not you could add a splined sway bar up above in the frame rails and have the links coming down to the rear end. Pretty easy/common set up.

I'm not sure if they do or not; there are articles but nothing on their website.  I'll call them about it when I order a 9" or Dana 60 with inboard mounts welded on after I scatter my 8 3/4".  At that point I'll be switching to 18x12's and running the biggest street legal drag radial I can.  I have 18x10's with 305/35/18 Nitto drag radials and that ain't enough.

[anlauto]

Man, I wish they made something like that for the RMS Street Lynx suspension with inboard mounts.  That style would work perfect if they made a narrower bar and offset dog bone end links to clear the lower links (or 3" inboard leaf springs too I suppose).

I know I've seen an article a few years back about them starting to offer a rear sway bar option on some of the B-bodies, but I haven't seen anything since and their website doesn't reflect it either.  I'd also have to cut out and weld in a new cross bar which is more surgery than I want to do on a fresh build.  Oh well.

Do they offer a rear sway bar? If not you could add a splined sway bar up above in the frame rails and have the links coming down to the rear end. Pretty easy/common set up.

I'm not sure if they do or not; there are articles but nothing on their website.  I'll call them about it when I order a 9" or Dana 60 with inboard mounts welded on after I scatter my 8 3/4".  At that point I'll be switching to 18x12's and running the biggest street legal drag radial I can.  I have 18x10's with 305/35/18 Nitto drag radials and that ain't enough.

I have 17 X12's with a 345 going on my next resto-mod...but we're going to build the car (tubs) around the wheels....I have the RMS inboard kit with a Moser Dana 60 going in..

[Dmod1974]

Man, I wish they made something like that for the RMS Street Lynx suspension with inboard mounts.  That style would work perfect if they made a narrower bar and offset dog bone end links to clear the lower links (or 3" inboard leaf springs too I suppose).

I know I've seen an article a few years back about them starting to offer a rear sway bar option on some of the B-bodies, but I haven't seen anything since and their website doesn't reflect it either.  I'd also have to cut out and weld in a new cross bar which is more surgery than I want to do on a fresh build.  Oh well.

I have 17 X12's with a 345 going on my next resto-mod...but we're going to build the car (tubs) around the wheels....I have the RMS inboard kit with a Moser Dana 60 going in..

Do they offer a rear sway bar? If not you could add a splined sway bar up above in the frame rails and have the links coming down to the rear end. Pretty easy/common set up.

I'm not sure if they do or not; there are articles but nothing on their website.  I'll call them about it when I order a 9" or Dana 60 with inboard mounts welded on after I scatter my 8 3/4".  At that point I'll be switching to 18x12's and running the biggest street legal drag radial I can.  I have 18x10's with 305/35/18 Nitto drag radials and that ain't enough.

Yup, I'm already mini tubbed, frame notched, and have inboard spring boxes from USCT installed as well so I'm good to go.  I have room for 15" wide tires if need be.  If RMS doesn't have anything off the shelf I'll probably fab up a splined bar like Brad suggested.  The RMS lower link brackets already have mounting holes for the sway bar saddle brackets, so all I'd need to do is fab up the end link brackets on the chassis where they won't interfere with anything.

[whitsend]

Thanks for all the replies guys. This is a great group of vast knowledge.