Sub-frame connectoros

[JAM]

Are there any bolt on sub-frame connectors for an 02 model other than SLP?

[Dominic]

Not that I'm aware of - besides if you really stress your car the bolt holes will lengthen and become ovals, eventually making the SFC's worthless unless welded.

[JAM]

Thanks Dom! I had never thought of that. (the loosening and all) I will be just driving normal on the street. I'm not planning on racing or anything.

I was looking to add strenght because my firebird has T-tops and I know that weakens the structure a bit.

Are weld in's better? What if the weld in's rust? How would you get them off?

If I use weld in's here is the package of stuff I was thinking of using:

Full length, bolt-in adjustable torque arm, tubular subframe connectors, non-adjustable panhard rod, shocktower brace, and tubular control arms.

Any advise is appreciated!

[JAM]

Anyone?

[zlightning]

weld in's are better you cut them if they rust. and the other things you listed will help your car.

[Dominic]

<blockquote>quote:</font><hr> Full length, bolt-in adjustable torque arm, tubular subframe connectors, non-adjustable panhard rod, shocktower brace, and tubular control arms. <hr></blockquote>

The Torque arm probably won't do you much good - many people have problems with aftermarket arms too. The stock arm is good for 12 second passes if you're curious [img]smile.gif[/img] .

The 2-point weldon subframe connectors are all you need, but if you want the best many argue the boxed Kenny Brown Double Diamonds are the best you can buy.

Shocktower brace wise, I've found the BMR to be sufficient and helpful. For its low price it cannot be beat - plus it looks snazzy under the hood [img]smile.gif[/img] .

If you're going with tubular control arms you need to decide how serious you are with drag racing vs autoX/Roadracing and know why exactly you want these. If you think you would like to focus at all on handling/cornering performance I would advise against going with stiff polyurethane bushing aftermarket arms and would suggest something like the 1LE rubber bushing arms (they're not pretty but they work) or the LGMotorsports G2 race arms with rod-ends.

If you need any help please let me know. [img]graemlins/burnout.gif[/img]

[cb1101]

what does the sfc's actually do for your car? pretty much hugs the road better? my car isnt that great at staying around turns.. i feel myself sliding out a lil' at higher speeds. will this help me stick?

[JAM]

Dominic I think I do need some help on deciding what to get. My main goal was to eliminate body flex. It sounds like the sub-frame connectors do just that.

I thought about the torque arm, and other parts just because I thought it would be better than weak stamped steel, and possibly lighter.

However, will the other parts make my car have any problems or be un-streetable? If so I definatly do not want them.

What is the advatage of the LE stuff with rubber bushings that you mentioned over stock? Isn't that what our cars have?

Please fill me in as soon as you can.

[Dominic]

The subframe connectors, especially the double diamonds, and the strut tower brace will turn the car into a solid object and give it nearly the strength of a true frame - you can't eliminate more body flex than this without installing a 6pt rollcage [img]smile.gif[/img] (Another option)

The concept behind "weak stamped steel" is a poor marketing gimmick which I believe we've all believed to be true at one point in time. It turns out our current control arms don't really "flex" fore/aft under acceleration, the bushings deform. The U-shaped stamped steel is VERY strong fore/aft compression wise and can probably handle 600hp with 0.00% flex. The bushings are rubber, which have a spring constant, and thus oscillate when put under force. As each gear tooth meshes and unmeshes the force varies slightly on these bushings, and they compress/release a little - this oscillation can add and create "wheel hop." If you desire to rid yourself of wheel hop, you simply need stiffer bushings.

The 1LE Control arms are not stock, they're a part of the 1LE suspension package GM created for Fbodies (Factory upgraded parts for performance in handling). You can read up on 1LE if you like by doing a few quick searches. The 1LE control arms, and even the panhard rod, are identical to the stock units however they have FAR denser/stiffer rubber bushings which do not flex nearly like the stock bushings. It is nearly impossible to replace the stock control arm bushings with 1LE ones, so most people just spend the $70-80 on a pair of 1LE control arms and swap them - it doesn't take long and its effective.

The nice thing about 1LE componentry is it won't affect your ride quality adversely and will give you a squeak free ride since it doesn't use polyeurethane bushings [img]smile.gif[/img] (everyone hates squeeks!). As FirebirdGT has said about a million times also, the 1LE arms allow for the axle to rotate slightly left and slightly right so it can stick to the road when the body rolls (and it will roll, even with bigger swaybars and superduty springs etc, roll is a good thing to some extent).

The problem with these SOLID ALUMINUM and SUPER STIFF CHROMEMOLY control arms that appear so beefy only applies to how the car handles around a curve. These units are 100% stiff, they do not allow the rear to stay attached to the road when the body rotates on the suspension, and so they bind and can really adversely affect the handling of our cars. However, if you need your rearend BOLT/WELDED to the car practically to prevent wheel hop using supersticky dragradials you might want to consider these - they do an excellent job of that!

The third option is to go with Rod-Ended units which don't use a bushing but instead use a "rod end" which is a steel round piece that is allowed to rotate inside the tube/pipe of the LCA. These allow for the full stiffness of a poly/poly superstiff control arm and they don't bind because they're allowed to rotate! The sad part is most companies install very cheap rod-ends in their units and so within 10,000 miles they wear out, and for those 10,000 miles they're extremely noisy. I have found through many readings though if you're going to go this route the LGMotorsports G2 Race LCAs are the best way to go and use high quality noise-free rod-ends, and most people agree they don't wear out like the cheapies... Although nobody has told me yet how long they last.

Now, as far as the panhard rod goes - you're probably fine going with a BMR solid piece or adjustable one if you need it. Some people claim bind can occur in the PHR but that's just plain silly if you see that the PHR doesn't need to twist [img]smile.gif[/img] . Pick your favorite color I guess I should say :D

The 1LE stuff is very good, you can't go wrong with it, and its often cheaper than aftermarket things. If you're just looking for improved streetability with very little risk and very few disadvantages 1LE is the way to go IMO. I'm currently running 1LE swaybars successfully, they helped the body roll tremendously, and I'm quite satisfied. Since I'm poor right now I am probably also going to opt for 1LE LCAs and the 1LE PHR simply because -for a V6 at least- they're strong enough to do the duty and won't kill my handling :D

The most dramatic way aside from all of that you can change your suspension is in the spring/shock area - plenty of good options there too :D

Did that help?

[V6Bob]

JAM - If you're mostly trying to control body flex -

Welded subframe connectors are a must. Big difference. All of the standard ones are decent. To help control rust be sure to coat the welds after with spray undercoating. The premium quality Kenny Brown's are plated to help control rust. 3M "weld-thru" coating before the welds may help with rust also.

A strut tower brace will also help stiffness. Again, all of the standard ones are good. These are the two highest priority things.

If you can deal with the cost/space, a roll bar will add much strength.

If you're concerned about streetability - do not use rod ends anywhere. Be careful about where you use poly bushings; swaybar links and Panhard are generally OK, anywhere else can cause noise/bind issues. A virtue of the 1LE stuff is that the bushings are still rubber, just harder rubber. Rubber is the most streetable stuff.

The stock steel stampings aren't that bad, except maybe for the Panhard, and people differ about that.

[Edit} Dominic was posting while I was writing :D . But we pretty much agree. I'm not sure the double diamonds are that much stronger than other sfcs. They all seem to work well. I got them because I have a convert and wanted every bit I could get. For you, the rust issue (coating) may be more important.

[ September 18, 2002: Message edited by: V6Bob ]</p>

[JAM]

Yes, that does help alot!! It sounds to me that I basically need a sub-frame connector and a shock tower brace to eliminate some body flex. (I wanted to eliminate body flex since I have T-tops and I know that slightly weakens the car)

I definatly do not want binding, and all the associated problems. I am only driving on the street with my car. I won't be taking this to the track. With that in mind, and with what I have just learned. I will probably leave all the controll arms, panhard rods, and bushing stock.

Now with getting to the subframe connectors. You mentioned Kenny Brown. I looked those up real quick, it seems the only difference is that they connect where the tunnel brace connects. SLP makes a weld on that does this also. What would you recomend for this item, and why?

Also I thought about replacing the tunnel brace with a BMR tunnel brace. Any advise on that?

[JAM]

Will the BMR tunnel brace work the Kenny Brown sub-frame connectors?

[Wicked 3800 V6]

Spectacle Solutions also make a set of diamond subframe connectors. No, I don't have them, or any for that matter (i've got a 6-point welded roll bar), but don't count out the company that sells bolt-on diamond subframes for only like $160.

Torque arm: Just get a poly bushing, and forget about it. I got mine for $12 new shipped from a different board.

LCAs: If you have a drag only car (never drive it on the street), get poly. Otherwise, go with 1LE. Unless you've got a road circuit only car, when you should get rod-ends.

PHR: Get the strongest you can find ... or just the 1LE. DOminic was right -- most LCAs are marketing gimmicks, and the 1LE's are killer.

STB: Don't even question yourself, get one, put it on, and forget about it. Good mod, looks good too. Cheap stiffness.

Edit: Tunnel brace: I still want some feedback on these things. I could have Eric at Kent Island Speed make one up for me ... but would it do anything?

[ September 18, 2002: Message edited by: Wicked 3800 V6 ]</p>

[strobhen]

I disagree about not using rod ends in a street application.

I could cite about 50+ opinions from guys at ls1.com's autocrossing forum that run G2 rod/poly lca's. Eliminates almost all the bind (85%) and no noise thanks to the poly. G2 does use very high quality rod ends, and you will likely get little, if any, noise from them.

I honestly believe that unless if you are under a budget restraint, G2 lca's are the way to go.

I am waiting on my finances to get straightened out over at UCF, soon as that happens and I know where I stand, G2 lca's are on the top of my list. In fact, I will probably get rod ends on both -- I don't mind a little noise (and again, there isn't much w/ good rod ends) -- as long as I know where it is coming from.

Rod ends do require maintenance though. The good ends are about 25 a piece (I think) and will need to be replaced about once a year, give or take a few months depending on how much you drive & how hard you drive.

Please, don't take my word for it, go over to ls1.com's autocrossing section. There is a LOT of good information there about suspension setup.

[Dominic]

I agree but it is very hard to dispute maintenance free if it does the job you need it to (i.e. rubber 1LE LCAs).