If you Drag Race, PLEASE weld your axle tubes.

[skwerl]

^ I have those same subframe connectors. Many say we don't need them but I noticed a difference in frame stiffness with them, especially when jacking up the car. They make a handy place to put the jack stands.

 

[fdjizm]

Wasn't there a thread around here where someone squeezed the CHE brace with BMR relocation brackets?
You know since BMR is all anti-tube brace *looking at you, Kelly*

 

[Sharad]

Nope. The panhard bar and brace are UPR pieces.

That looks great. Fitment is close, but there's room!

^ I have those same subframe connectors. Many say we don't need them but I noticed a difference in frame stiffness with them, especially when jacking up the car. They make a handy place to put the jack stands.

I'm finally coming around on this one. I always heard the S197 is 1000x stiffer torsionally than the Fox chassis so I never worried about SFCs. Then we took our 2010 Convertible to the track a couple weeks ago, and when we went out to dinner afterward, we noticed that the hood was sitting a little crooked. Oops.

 

[wbt]

I'm finally coming around on this one. I always heard the S197 is 1000x stiffer torsionally than the Fox chassis so I never worried about SFCs. Then we took our 2010 Convertible to the track a couple weeks ago, and when we went out to dinner afterward, we noticed that the hood was sitting a little crooked. Oops.

Well a 'vert is going to be structurally challenged regardless of platform. As you know they brace the underside more than a hardtop.

I am not sold on the subframe stuff for the non-convertible s197's. There may be something to it on the convertibles.

If you put an ARB on that 'vert I think that would help more than the subframe connectors for drag racing.

 

[Norm Peterson]

Well a 'vert is going to be structurally challenged regardless of platform. As you know they brace the underside more than a hardtop.

I am not sold on the subframe stuff for the non-convertible s197's. There may be something to it on the convertibles.

Absolutely. Torsional stiffness is kind of a 3-D problem, and it's that third dimension that the roof structure in the coupes gives you in spades.

If you put an ARB on that 'vert I think that would help more than the subframe connectors for drag racing.

That's debatable, and will come down to how much torsional stiffness the SFCs add vs how much stiffer the ARB is than whatever sta-bar may already be there. IOW, you'd have to run the numbers, and just how much ARB you're adding will matter (at some point it won't make any difference at all how much stiffer you make it - further gains will become too small to notice).

The convertible's lower torsional stiffness means that no matter how far you skew the car's roll stiffness toward the rear, you're going to lose more of its effect to chassis torsional distortion.

If I was going to drag race a convertible and had got to the point where I needed to play with roll stiffnesses to get the RR re-planted and my launch straightened I wouldn't think of doing an ARB without SFCs or some other sort of chassis torsional stiffening . . . or vice versa. Those are complementary mods, not competing mods where choosing one means you should ignore the other. Whether that creates competition for the contents of your wallet/checkbook/CC is a separate matter


Norm

 

[Sharad]

Well a 'vert is going to be structurally challenged regardless of platform. As you know they brace the underside more than a hardtop.

I am not sold on the subframe stuff for the non-convertible s197's. There may be something to it on the convertibles.

If you put an ARB on that 'vert I think that would help more than the subframe connectors for drag racing.

My boss Mark is adamant about keeping his convertible a cageless street car with our STREET suspension, so it won't get a cage and probably won't even get our ARB. That's a shame because this thing might run low 9s with a more street/strip oriented setup. But I'll give him credit. It's a nice cruiser.

 

[dream07]

I know I'm re-entering this arena and bringing another fighter into the ring, but why hasn't anyone here even mentioned the Swarr Bar?

http://www.americanmuscle.com/swarr-bar-88-rear-2005.html


I like the fact that it wraps around the axle tubes (the bolt-on model could be "de-bolt-on'd" and welded to prevent tube rotation). I also like the fact that welding it would bring metal of similar type and thickness together, thus increasing the likelihood of a sufficiently executed weld (compared to axle tube to 8.8" center housing) even by a novice with a MIG welder. Negative would be the minimal front-to-back flex support (appears to favor up-down support, although the tube does run behind the cover flange).

I have welded a few 8.8" rears and I was previously a weldor, certified to weld on nuclear reactor plants. I am NEVER happy with any of my welds as a condition of my OCD (although having OCD is a good thing in the case of a weldor). I really hate my 8.8" welds. I spend a lot of time pre-heating and post-heating and it really just makes me anxious.

Due to the amps and different metals, the chance to get undercut on the axle tube edge of the weld is very high and that is where all the Jeep/off-road axle tube breaks happen. When these tubes are installed, Ford leaves a lot of flex (they have silicone-like seals to prevent lube leakage). That's why they don't want you to jack under the center pumpkin, because it just is not intended to carry that load. Just throwing metal at the joint will only work for so long. The tube will still prefer to flex in the housing and if that weld is not perfect, it will crack/break the weakest spot.

Keeping the outside (brake) ends of the axle tubes from flexing (in relation to the axle centerline) in the first place is mandatory. The tubes' factory pins/rosette efforts would resist axle tube rotation if the tube was firmly held square, in line with the housing (what you are trying to do with the welds and braces). The CHE brace, UPR braces (and maybe the Swarr bar) likely provide enough support to the outside (brake) ends of the tubes that they would prevent flexed outside ends.

Also, the new GT500 rear housing with the extra rosettes is about $300 at the dealer. That's what I'm running. I just ordered another one for my 2005 drag-only project and plan on a homemade combination of the CHE, UPR, and the Swarr design elements - BMR/Kelly, nothing yet?

 

[Sharad]

I've been kicking this dilemma back and forth for a while now. I'm torn between a heavily reinforced 8.8 or a 9" for my 2011.

 

[BMR Tech]

I've been kicking this dilemma back and forth for a while now. I'm torn between a heavily reinforced 8.8 or a 9" for my 2011.

Aren't you going to be shredding corners in it?

Not sure why you would want a 9" set-up in a corner carving machine?

 

[drive_55_not]

I know I'm re-entering this arena and bringing another fighter into the ring, but why hasn't anyone here even mentioned the Swarr Bar?

http://www.americanmuscle.com/swarr-bar-88-rear-2005.html


I like the fact that it wraps around the axle tubes (the bolt-on model could be "de-bolt-on'd" and welded to prevent tube rotation). I also like the fact that welding it would bring metal of similar type and thickness together, thus increasing the likelihood of a sufficiently executed weld (compared to axle tube to 8.8" center housing) even by a novice with a MIG welder. Negative would be the minimal front-to-back flex support (appears to favor up-down support, although the tube does run behind the cover flange).

I have welded a few 8.8" rears and I was previously a weldor, certified to weld on nuclear reactor plants. I am NEVER happy with any of my welds as a condition of my OCD (although having OCD is a good thing in the case of a weldor). I really hate my 8.8" welds. I spend a lot of time pre-heating and post-heating and it really just makes me anxious.

Due to the amps and different metals, the chance to get undercut on the axle tube edge of the weld is very high and that is where all the Jeep/off-road axle tube breaks happen. When these tubes are installed, Ford leaves a lot of flex (they have silicone-like seals to prevent lube leakage). That's why they don't want you to jack under the center pumpkin, because it just is not intended to carry that load. Just throwing metal at the joint will only work for so long. The tube will still prefer to flex in the housing and if that weld is not perfect, it will crack/break the weakest spot.

Keeping the outside (brake) ends of the axle tubes from flexing (in relation to the axle centerline) in the first place is mandatory. The tubes' factory pins/rosette efforts would resist axle tube rotation if the tube was firmly held square, in line with the housing (what you are trying to do with the welds and braces). The CHE brace, UPR braces (and maybe the Swarr bar) likely provide enough support to the outside (brake) ends of the tubes that they would prevent flexed outside ends.

Also, the new GT500 rear housing with the extra rosettes is about $300 at the dealer. That's what I'm running. I just ordered another one for my 2005 drag-only project and plan on a homemade combination of the CHE, UPR, and the Swarr design elements - BMR/Kelly, nothing yet?

I've looked at the Swarr bar, looks like the biggest knock on it is as it bolts around the tube, if they don't get good bite the tubes can still spin.

I've got some 4" angle iron I'm going to weld to my tube and the pumpkin sometime this spring.

Got the idea from some Sn bracing. I haven't had any issues with my axles but I'm adding a 100 shot thru my blower. Dyno on Monday ....

 

[dream07]

Yes, at what point does bracing the crap out of an 8.8" become impractical?

I guess it depends on the weight of the car, the HP/Torque and how you intend to drive it. I guess it is also a matter of money and abilities. For my 8.8", I am making my own bracing and adding 9" ends; labor= $0, metal cost using stuff laying around from other projects= $0. My car will be stripped down to nothing, have 600hp, and is no way anything but a racecar. Not many here are building racecars and they carry around 500-800 pounds of "street" items (sound system, upholstery, EFI, crash/impact items, A/C, power accessories, etc). Get down to Fox-body weight and the 8.8" is fine. If you have a loaded 4000 pound GT500 with 800hp and drag radials, why do you think the 8.8" will handle that?

For the street, if you had to buy a rear girdle cover (T/A, FRPP, etc), CHE brace and c-clip eliminators w/ good axles for your 8.8", you just paid for a new s197-spec bare 9" housing and axles. Now add a Detroit Locker, alum. 3rd, street gears and you built a rear you won't break for the cost of a gear swap, TruTrac and install. If you stick with the stock suspension setup, you won't need a back-brace and all that other stuff shown on that pro 9" rear. The KISS principal says the 9" is the answer.

After all is said and done, for racing, the 9" with the Yukon aluminum thru-bolt 3rd, a spool, pro gears, 35+ spline bullet-proof axles, etc, is going to be way stronger and lighter (you have to weigh all that bracing, etc too).

 

[dream07]

Kelly, you want a 9"" in corner carving because it doesn't have c-clips and people in high horsepower road racing have used 9" rears for decades.

 

[BMR Tech]

I understand that, I promise, but I am not so sure I see the need for them on a 500-700 HP S197 Road coursing application.

I have some customers, with some extremely fast course cars, that have been running the 8.8 for years, with no issues.

Personally, I would not even consider doing the upgrade if I set my car up for road racing.

 

[dream07]

You must really trust your axles! lol! Or you can put 9" ends on it.

Some classes don't allow c-clipped axles because they are an accident waiting to happen.

 

[JEWC_Motorsports]

C clip eliminators, duh!!!!!! lol

 

[kdanner]

After all is said and done, for racing, the 9" with the Yukon aluminum thru-bolt 3rd, a spool, pro gears, 35+ spline bullet-proof axles, etc, is going to be way stronger and lighter (you have to weigh all that bracing, etc too).

Hope to have final numbers making this comparison soon. My 8.8 with stock brakes, 9" ends, 31 spline non c clip Mosers, and a detroit locker was 239lbs dry. I think the 9" may end up 50lbs less even with 35 spline axles. A lot of that is the brakes though.

 

[Sharad]

Aren't you going to be shredding corners in it?

Not sure why you would want a 9" set-up in a corner carving machine?

It's a win-win situation. Better dragstrip powerhandling with a 33-spline 9-inch, and like dream07 pointed out, safer on the open track because no c-clips.

 

[thundr306]

Jeff...when are you going to weld my axle tubes??

 

[Falkinman]

Got the idea from some Sn bracing.

I don't see how the angle brace in the picture you posted would help with axle tube deflection at all.

 

[JEWC_Motorsports]

Falkinman ask upr, they sell one similar.