soarestransam

Hey everyone I just a wonder bar off a 89 iroc idk why but my 89 Gta does not have one hmmmm weird but is there anything else that I could get to tighten the frame up an drivetrain I'm gonna be getting sbfc really soon since I got a t top car an gone be Putting all new bushing for the suspension

BlackenedBird

iTrader: (5)

What is a SBFC? Sub Frame Connectors? They are always just referred to as SFCs.

You can run 2 sets of SFC. One inner set that ties the sub frames together & an outer set that runs along the pinch welds under the doors.

A Wonder Bar is a good option for tightening the steering. A Strut Tower Brace (STB) will also provide a little extra chassis stiffening & tighten up the steering too.

Beyond that, the only option is an interior roll bar or cage, but then your adding weight & the car can be slower because of the added weight.

JamesC

iTrader: (5)

Not weird at all since only IROC's were equipped the the Wonderbar.

JamesC

sofakingdom

iTrader: (1)

Right: SFCs are a HUGE improvement to these cars. The "wonder bar" is really just a kind of minor tweeeeek; Id' classify it as a "just barely noticeable" difference, as far as driving the car. The STB will probably have a more noticeable effect.

You could add a "lower bay brace" that connects the 2 sides of the subframe together about under the flywheel; and I've seen somebody also make a brace to go across the back seat at the top rear corner of the doors which is another seriously weak spot in these cars.

A stiffer torque arm and rear LCAs make a noticeable difference under acceleration.

soarestransam

Yea sub fame connectors was what I meant to put do they make a stb for carb cars I'm only seeing them for the tbi, an tpi cars 85-92 for the torque arm what is a good brand I see alot that are adjustable an non adjustable I have no idea what the difference it makes an for rear lower control arms what is a good brand for that too I've seen a edelbrock set but don't know how well they will work wanna get peoples opinion before I order parts

BlackenedBird

iTrader: (5)

Wow. Let's see if I can figure out what you said, since you used zero punctuation. Hard to tell where one sentence stops & the next starts.

The TBI STB fits Carb cars as well.

As for Brand, they are all about the same, just some cheaper than other, yet no real difference in quality. I've been partial to UMI, but the Founders Performance parts are equal quality & less expensive.

For the PHB (Panhard Bar), go with an Adjustable unit. I've seen stock cars with the rear axle not centered that could use one & if you lower a 3rd gen, you WILL need one to recenter the rear end.

Drkhrse89

iTrader: (1)

Could you expand on this more? Maybe with some pictures? Are you talking about welding/bolting on a bar that runs under the flywheel connecting the subframe? Also the brace above the back seat, did the weld it to the pillars? Just trying to picture it, sounds like an interesting concept.

JamesC

iTrader: (5)

Kenny Brown used to make a Lower Chassis Brace (pics/discussion below) and a search will find some info on the B-pillar reinforcement.

https://www.thirdgen.org/forums/susp...r-chassis.html

https://www.thirdgen.org/forums/atta...-kblowchas.jpg

Homemade verison: https://www.thirdgen.org/forums/atta...race-acpta.jpg

JamesC

Drkhrse89

iTrader: (1)

Thanks for the links. I tried to search, but I had no idea what to look for. Do you know if the chassis support is still available? I have looked around and could not find one. I might have to look into making my own based off of the pictures.

Guest

I remember the ads, but it never made any sense to me until just now, seeing this pic of one installed. Now I want one for each of my 'maros.

Guest

And what stresses are even imposed on this area, since none of the suspension links are anywhere close, or pointed towards this area?

sofakingdom

iTrader: (1)

The whole car is weak.

At that particular place, if you hit the brakes let's say, the control arm tries to bend the K-member and the "frame": it will try to bend outward at the front of the CA, and inward at the rear of the CA; a brace at that point keeps the "frame" square.



The "wonder bar" keeps the front-most part of the "frame" rails square; the K-member comes next; the trans x-member is at the rearmost part of the "frame"; the brace in question stiffens the center part of the "frame", in that 3' long stretch where the only thing holding it in place from spreading or compressing together, is the trans tunnel.

Same for the B-pillar brace. Create yourself a mental picture of the car without the top (i.e. imagine a convertible). Now imagine, say, a shoebox, filled with sand; and you pick it up by the very ends, under the bottom. What does the shoebox do? The bottom sags, and the sides spread out, right? That's what a car does when it goes over a bump. Now imagine doing the same thing to the shoebox except with half of the sides cut out and replaced with a piece that swings out (let's call that a "door"). That's what the B-pillar brace would stiffen against.

BlackenedBird

iTrader: (5)

In your pic, I'm looking at that style SFCs & here is my question about those which relates to this no-longer-offered trans tunnel brace...

How can the trans tunnel brace be a :much needed item" when those style SFCs don't even tie into the stock rear subframe? Shouldn't the SFC tie into the rear subframe, not just into the rear LCA mount?

Shouldn't we be adding additional rear chassis bracing where is very little before we start adding additional front bracing which already has some?

I'm not saying that the additional front bracing, like the tranny cross brace, isn't as needed as rear bracing is. I'm just thinking the rear needs more bracing than the front does, with those style SFCs.

sofakingdom

iTrader: (1)

The SFCs in the pic are sort of irrelevant to the issue at hand; this particular pic just happens to include them. Not my choice really. I didn't take it, I just ganked it. (fine distinction between "take" and "gank"?) I wish I had one like this of a car that hadn't been sodomized the way this one has where the exhaust exits the engine bay, and also didn't have those on it.

However:

Where are the stresses ALWAYS greatest on ANYTHING?

Answer: where the thing that puts the stress on it in the first place, attaches. Especially when that ENTIRE force is applied via ONE BOLT on each side that just pokes through a hole in some sheet metal.

In this case, that would be, the rear LCA mount. So surely that point needs to be reinforced, if any point does.

But yes, I agree, those SFCs are less than perfect in other ways; while they attach to the point where the front-to-rear forces accelerating the car are physically applied, and reinforce that one specific axis, they don't reinforce the connection between that point and either the springs (where the vertical force on the car is applied) or the brace that the Panhard bar goes to (where the side-to-side force is applied). They only stiffen the floor pan a little bit against bending up and down in the middle, and ALOT in the acceleration direction; but NONE AT ALL in those other critical axes.

The Alston design does even less overall stiffening: ALL IT DOES is keep the floor pan from "accordion"ing when accelerating.

92RS_Ttop

iTrader: (3)

Like this one? Car belongs to another member on here, can't remember off the top of my head which thread I pulled it from though.

I've been using it to lay out the attachment points of the SFC's I want to build.

Confuzed1

iTrader: (4)

The SFC's in the pic look just like the ones I have - the old style Spohn ones. They do "tie in" to the LCA's, the SFC's have holes in the rear and kinda sandwich over the existing frame LCA bolt holes and provide additional support there - hard to see in that pic though.

I agree, they do nothing in the panhard bar area. Stiffening up the floor alone does wonders for these cars though. I'm no expert at any of this, but I'd think if someone added a cage and STB (and wonderbar) - there's nothing else I know of on the market to further stiffen anything up. Of course, things can be made if you're good at metal work. You just don't have a lot of these issues on full-frame cars....which they haven't made for years.

88fastgta

iTrader: (9)

best thing you can do to the car.... this is what i did... the first two suspension mods ive done and the best imo (these pics dont show my other suspension mods being these were my first two at the time)... id say do the following to dramitically improve chassis flex

bmr outer frame connectors
alstons inner frame connectors
strut tower brace
steering brace
bmr torque arm(improved nose dives when breaking and made the car alot more rigid imo)
2frame6.jpg?t=1254510733

2frame2.jpg?t=1280852007

11ellswray

iTrader: (1)

correct me if im wrong but, doesnt it look like those outer braces add at leat 100 pounds to the car? i was on the spohn site and they are selling tubular pieces but they look a little dinky right? 1" 3/4 doesnt seem it would do much. Has anyone installed these?

BlackenedBird

iTrader: (5)

Outer diameter has little to do with strength. It is the wall thickness that determines strength more than overall diameter.

//<86TA>\\

iTrader: (15)

you have that a bit backwards. OD has a lot to do with rigidity as well. a larger OD, thinner wall tube can be stronger than a slightly smaller, thicker tube.

And 1 3/4 is quite beefy. plenty strong for SFC's

11ellswray

iTrader: (1)

hmmm well cool, then it would look like a guy should buy the sphn tubular set and back those up with the Mac or alston set right? becasue if the 1" 3'4 is strong enough who needs the weight of the rectangular? i would venture to say that the rectangular may help some wat in the event of side impact with a fixed object tho.

89_RS

IIRC, the shipping weights listed for either BMR or UMI SFC's is right around 30-40 lbs.

If weight is an issue for you, break out the TIG welder and weld every inch of every seam on the car together. You'll have stiffness like no other and you'll have added about 30lbs to the weight of the car.

-srs-

FYI...

I emailed Founders the other day about whether they had any plans to manufacture SFCs. Their answer was "Yes but not for a few months."

Project 3.4 Camaro

SFCs are a must, when you get a strut tower brace make sure to get a 3 pt that ties into the firewall, not just a two point, as others have said you can run the 2 different types of SFCs together, using inners, and outers, I honestly don't get why GM didn't just run a full frame in the first place, would've made these cars so much more rigid. I get that unibody is lighter, but they shouldn't combined the best of both, with frame being an integral welded on part of the body, not as heavy or cumbersome as a frame off car, but still full length.
Other than that, I would say convert to a x-member mounted TA, mounting the TA to the trans tailshaft was just silly for so many reasons....the bar on the b pillars isn't a bad idea, rly for strength you need to integrate a roll cage, or full frame, I'm curious since someone suggested it, how stiff would welding all the seams make the car as opposed to building a full frame like the one guy on the fabrication section, or integrating a roll cage? Cause my interior is gutted, and that would definitely be a cheaper and lighter solution, I just wonder how much that could really do...

BlackenedBird

iTrader: (5)

I switched from an Edelbrock 3-pt (the only 3-pt I even know of) to a UMI 2-pt. I noticed zero difference in the way the car felt or handled. The UMI STB is definitely a stronger piece than the Edelbrock one was. And I liked the fact that it required no holes to be drilled to mount it. There was an option to drill 2 holes for additional mounting bolts, but I never have put then in nor do I feel any need to.

Project 3.4 Camaro

3 pt is better, even if it isn't a feel-able difference.

JamesC

iTrader: (5)

I recommend using an after market strut mount, which eliminates the OE rubber, along with the STB for full benefit.

JamesC

87CIZ

iTrader: (8)

I've got UMI and Alston on my car. I wish the UMI's wire closer to the pinch weld of the car so that the sfc's could be welded to it. Here's a picture right before they were welded on.

ErikWS6

Was wondering what those pieces would do to the "crushability" of the car in a nasty accident. But other than a strut tower brace, looks like they are far enough back from the ends that if you started deforming seriously in those areas, you would be in a world of trouble anyway....

White'89

iTrader: (8)

If you look at newer bicycle frames they make the tubes freakishly large for a reason. And if you saw a cutout of how thin the walls of the tubing are you would crap your pants. They are stronger, stiffer and lighter.

I have a set of Spohn SFC's sitting on the floor next to my car right now, and they are much beefier than I was expecting. No doubt in my mind they will get the job done.

InfernalVortex

iTrader: (4)

I've had my car on jackstands enough with my Spohn sfc's to have absolutely no doubt those things hold that car straight. I've jacked on the sfc's, put jackstands on them, I've even made a few judgment errors and had the car rock back and forth over the jackstands... no bend in that thing at all.

Now are the rectangular ones better? I personally think they look a little better, but Im not losing any sleep over it. Are larger tubes better? Probably... but I'm not losing any sleep over it. What I've got is more than adequate. The car is STIFF.

Edit: whoops... didnt notice this was a 5 month old thread... Sorry.

hellz_wings

iTrader: (2)

Still good info on this thread though! I have MAC inner and SPOHN outer SFC's. Both tubular. Both strengthened the chassis in different ways. I can put the car on a lift and open the doors perfectly (that was after SPOHN SFC's), I can jack the car with the SPOHN SFC's, the car flexes hardly anymore except only SLIGHTLY when I'm going diagonally up or down a steep driveway I can hear it above the b-pillars creaking SLIGHTLY (I have t-tops, nothing much to do with this lol).

Aside from that, poly bushings (and in some cases rod ended), wonderbar if you don't have one, STB (I have 2 pt and it improved handling), tubular steel components are less flexy as well although some may argue that tubular k-members and a-arms are overkill for most people, and in some cases weaker than stock.

That magical kenny brown brace would probably help as well but they don't make it anymore so unless somebody makes one, that's one area we can't re-inforce.

Then there's the "rear STB" which tie the rear shock mounts together laterally. Nobody sells this and I don't think there's a way to do this without sacrificing parts of the interior. An odd by possibly beneficial piece..

Then there's roll cages.. I've had this idea for awhile now where the roll cage stays UNDER all the panels/headliner. I'm still trying to figure out how to make this work. But I know for a fact you could weld a thin-ish tubular bar from the floor panel pinch weld (from inside the car) all the way up the b-pillars and across the roof (underneath the headliner) and then attach it to the rear-shock towers. This way you are tying in the lower pinch welds (which is tied to outer SFC's like SPOHNs) to the b-pillars, across the roof and then to the rear shock towers. This would be an awesome custom job for somebody who is a skilled welder and wants to keep the interior but have close to the structural rigidity of a roll cage.

I haven't thought of how to tie that in to the front frame while maintaining the "hidden" factor.

hellz_wings

iTrader: (2)

Here is a pic example of what I mean (but would probably require smaller diameter bar and have it welded to the roof and b-pillars):

soarestransam

Wow so many people are talking on this thread I made this thread when I had my 89 Gta carb car lol. Well to inform everyone I got a 88 Gta hardtop car now an this one is in terrific shape body wise atleast. So far I got founders lca's an phb, poly front sway bar bushings, a arm bushing, rear sway bar bushings, poly torque arm bushing, camaro iroc z wonder bar, moog 5662 front coil springs, moog ball joints an inner an outer tie rods, moog idler arm, an center link. I actually wanted to ask about the Alston Sfc's an also looking into getting a strut tower bar since I have the stock tpi 350 but don't know who makes them

NiG

dumb question is: for stock GTA for common usage for common people, are SFCs needed??

JamesC

iTrader: (5)

Since the car is a unibody, you really can't go wrong with SFC's regardless of how you wish to use the car.

JamesC

-srs-

You wan't find many around here that will disagree with James' statement.

hellz_wings

iTrader: (2)

I bought my car back in 2006, and it creaked and rattled just driving out of the driveway.. I hated those annoying sounds and it made me cringe lol. After installing the first set, the car, for the most part, was stiff enough.. Ofcourse if you plan on upgrading your suspension and steering etc. even more, you could always do like me and a few other and go overkill and get a 2nd set LOL!