Tube subframe should I build one ( not connectors)

[SHODWN]

Aslo not to mention the much thicker AL you would need to make this work, you cant use the same 3/16 thickness of steel if you wanted this out of AL. The AL would be much thicker and would more then likely weigh in at about the same, maybe a little less. But if you were to get it done would it be worth the 15-1800$$ that you would spend to have saved 10lbs or so? I think to that 1500-1800 is on the Low side for the first one.

Just use a Gen 3 if your looking to save a little bit of weight, there are a few things and I mean only a few to get it in the car. The Gen 3 subframe has the same exact dememtions(sp) only things that have to be retrofitted are the engine mounting points. Still to much work for most people.

Plus the addition of a subframe like that would be nice but it should also the last thing that you do to the car, and if you have that much tied up in a Taurus to add another 2k should make you think why did I build a race car for XXXXXX.XX when I could have gotten a real race car.

 

[v-tec killer]

UM...Last I checked Chrome moly was not aluminum. *** But what do I know? shrug I'm the *****.

 

[twr]

You are correct. However - the point is the same for any material used. It is basically a crap shoot - save a few pounds of weight in exchange for possible saftey issues.

 

[Todd TCE]

This is a messy one.

The weight savings of the Alum is minimal when you consider the additional material required to build it. You CANNOT make it out of alum without perhaps 3-4x the wall or 1.5x the diameter. And then, and ONLY then, you'd still need to heat treat it.

 

[twr]

Todd TCE:
This is a messy one.

The weight savings of the Alum is minimal when you consider the additional material required to build it. You CANNOT make it out of alum without perhaps 3-4x the wall or 1.5x the diameter. And then, and ONLY then, you'd still need to heat treat it.

Todd,

The original poster said he planned to make it from chrome moly tubing...

Terry

 

[gmorrell]

I don't care if you want to make a SHO subframe from reinforced concrete.

Can you answer these questions:

1. Do you possess the tools and requisite knowledge to perform a finite element analysis of the assembly in order to understand the high stress areas and bending moments of your subframe? Can you predict load paths, deflections, and reinforce highly stressed areas?

2. Do you have the crash simulation tools and supercomputer needed to evaluate your design and its effect on the crash-worthiness and occupant protection of the vehicle?

If the answer to either of these is no, I propose a third question:

3. Do you know a good attorney?

You may think, "Hey, the University of Wisconsin subframe was simulated to 1G, that's enough, right? Maybe for a street car that rarely sees over a third of a G, but for a track car pulling near 1 G on every corner of a 10-turn road course, the potential for fatigue failure builds up in a hurry.

If you want a light, nimble car, go buy a light, nimble car. Go test drive a Mazda RX-8, you'll never want to get back in your SHO again.

<small>[ March 02, 2004, 02:22 PM: Message edited by: Gary M. ]</small>

 

[twr]

Gary M.:
I don't care if you want to make a SHO subframe from reinforced concrete.

laugh_ti Thanks Gary... I need that this morning.

 

[SonicRiot]

A tubular subframe is a good idea, but not for a car that weighs 3500LBS + driver! What if we decided that we were going to lighten your bones? You'd still have all that body weight putting stress on your "lightened" bones.

I commend you on your efforts, but you will need an engineering degree and a place to crash test it. This is a HUGE step over AL SFB and even weld-in SFC. If you have either of these two requirnments (obviously I don't b/c I can't even spell!), please keep posting because it is rather interesting.

Want to lose 20LBS? How about a lot more by removing all of the "unneccessary" seats, donut spare, rugs, headliner, accessories, and dash? If risking everything for a loss of 20LBS. is worth it to any of you, good luck. But unless you are tracking the car, the world's best driver could not take advantage of a 20LBS weight loss on the street in a street car! And if you are tracking the car, putting a new tubular subframe in is very risky unless it has been crash, stress, and fatigue tested with lots of power, weight, and grueling tests. This is why NASCAR puts so much time into JUST the tube frames of the cars.

Want rigidity? Weld in a roll cage and get some suspension upgrades.

But good luck! thumb Seriously, keep thinking out of the box.

 

[drivinhard]

My interest in doing a tube subframe wasn't so much the weight savings, as it was to build something to accept gen3 LCA's and use of alum knuckles. Turns out the knuckles aren't much lighter, and they appear to not be able to fit a 4 piston fixed caliper. Sorta moot now!

 

[Hack]

So Mark, does that mean you have already done it?

 

[Lance Cheney]

drivinhard:
My interest in doing a tube subframe wasn't so much the weight savings, as it was to build something to accept gen3 LCA's and use of alum knuckles. Turns out the knuckles aren't much lighter, and they appear to not be able to fit a 4 piston fixed caliper. Sorta moot now!

Just curious, since I haven't seen one, what the advantages of the Gen III LCA are over the Gen 1/2 SHO pieces. Strength? Weight? Both?

I picked up a pair of McQuay-Norris LCAs a few weeks ago from Kragen for ~$60 each, and they're actually beefier than the stock SHO ones (which are already a lot stronger than the normal Taurus ones). Probably 15-20% more material in the critical sections (vs. the SHO one), or about double the standard Taurus one. thumb

I'm keeping these...

-Lance

<small>[ March 02, 2004, 11:48 AM: Message edited by: Lance Cheney ]</small>

 

[gmorrell]

Lance Cheney
Just curious, since I haven't seen one, what the advantages of the Gen III LCA are over the Gen 1/2 SHO pieces. Strength? Weight? Both?
-Lance

Weight to some small degree, but this comes mostly from the Aluminum knuckle.

The real advantage to the Gen 3 LCA is its anti-dive geometry. The Gen 3 cars get something like 15% less dive under braking and they accomplish this with softer front springs then the Gen 1/2 cars. The Gen 3 LCA looks more like a classic A-arm, and if you fiddle with the height of its pickup points on the subframe, you can build in more anti-dive then the Gen 1/2 LCA, which is really a POS, but we're dealing with a Taurus here, not a "real" sports car.

<small>[ March 02, 2004, 02:27 PM: Message edited by: Gary M. ]</small>

 

[SonicRiot]

Why not just build a multi-link front end and do away with the MacPhearson setup all together? That would SERIOUSLY eliminate brake dive because of stronger geometry.

Although...working around those CVs is hard. But it seems like a better option than a tubular subframe.

 

[Toolman]

Gary M.:
Go test drive a Mazda RX-8, you'll never want to get back in your SHO again.

Hehe, I have yet to be in a car that makes me not want to get in my SHO again. The turbo ownz me!!

 

[1slickRED89]

"The reason is I am building one for the new SHOGUN's and that stock one is damm heavy"

"So let me know if you guys think it is a good Idea"

yeah I think it's a good idea, especailly for a custom car, like a SHOGUN. I would use the opportunity to incorporate lots of cool ideas like:

-a good try at anti-dive. (edit: or in the case of a rear engine SHOGUN anti-squat)
-incorperating corvette (or any exotic/wild/heavy duty)LCA's
-a slider for the R&P, to ajust the ackerman angle.
- attachemnt points for undercar skid plates (for areodynamic reasons)

also, the day one needs a super-computer and fancy modeling programs to be an enthusiast is a bad day. i think of the altered-wheelbase funny cars of the '60, made in a neighborhood garage, that i have seen in HOTROD. however, if one sells parts like subframes to other people, over the internet, they had better be very well designed and tested.

-Corey
'90SHO

<small>[ March 11, 2004, 10:55 PM: Message edited by: 1slickRED89 ]</small>

 

[Hack]

Just curious, but why is there no concern over mounting subframe connectors? The way they are positioned upon installation, they do not lend themselves to the subframe assembly sliding under the car in a frontal collision. The difference is slight, but real.

 

[91taurisho]

As Terry(TWR) Has stated in a previous post, you should cut them off at an angle and cap them so there are no worries that the subframe will get lodged in a frontal collission(SP?)... See there is concern. He actually told me this tonight when he gave me my SFC's too.

 

[Hack]

Coincidentally, mine are done in just such a fashion. Not for those reasons, but to keep moisture out and having them rust away from the inside. Personally, I am not too terribly concerned about the issue. I just thought it was odd that everyone jumped all over the tubular subframe issue and I had not seen anything on SFCs. Now I have. wink

 

[twr]

I strong;y recommend that anyone with subframe connectors make sure that the ends are cut at an angle like this.

I also recommend that they be capped, unlike mine which aren't.

Just a note: I don't recommend capping both ends because it will promote condensation and the SFC will eventually rot from the insdie out.

<small>[ March 12, 2004, 08:29 AM: Message edited by: twr ]</small>

 

[91taurisho]

Told ya Terry said so...