Foxxtron

iTrader: (1)

Hmm...

Now to get back to the point for the forum community, if you must weld them one go ahead. I don't think that they're useless, just not being used for the appropriate purpose(s). Not all monocoques, and certainly not all 4th Gen F-bodies need SFC's.

Again this link to the other thread will get more to the point.

https://ls1tech.com/forums/suspension-brakes/398983-subframe-connectors-2pt-vs-3pt.html

(Disclaimer: As a reminder, I'm only supplying very hard scientific findings, otherwise what end user will purchase and what vendor will sell is outside of my business. Therefore, the end users and businesses bear the sole responsiblity for their actions/decisions. Keywords: scientific findings, not commands. And yes, I and others at many SAE clubs do "real world" testing. They do because many will eventually be responsible for engineering from the original manufacturer and/or the aftermarket).

BJM

iTrader: (1)

I will constrain the problem further then.

Two cars, as identically shaped as possible given the two constrction methods.
Both have the same stiffness - torsion and bending modes are the same.
One is body-on-frame, ladder frame with bushings isolating the body (Crown Victoria, GM Caprice, etc.)
The other car is uni-body.
Built with the same materials - let's pick steel

The uni-body car will have less mass.

I have no URL to give you, I would refer you to a dynamics text book ideally.

Foxxtron

iTrader: (1)

Now that's what I can agree with. Just had to contstrain the facts, because I still have that "dynamics text book."

You are aware also that was a me correcting myself earlier?

BJM

iTrader: (1)

Actually, I didn't figure out what TSB meant.

Foxxtron

iTrader: (1)

No problem. As you know (and pretty much stated), tubular space frames are great for optimal performance needs, so senior project students like to use them quite a bit. My friend wanted to use a unit body for his MSME Master's thesis, so that's where I got involved (although my Material Science interests lie mostly with phototransparency through lattice structures).

BJM

iTrader: (1)

I have designed many structure types including some "TSBs" just never knew it by that name.

Foxxtron

iTrader: (1)

Whoops! TSF (edited Earlier posts)

jst

Please post pics of the mounting locations from under the car.When welding in the sfc do you need to remove the carpet because of heat melting it or am I way off?thanks

Bo White

iTrader: (59)

No, I have never had to remove the carpet. I know its kinda wierd welding on the bottom of the car but the parts were the welds are to be is multilayer construction that is well isolated.

Foxxtron

iTrader: (1)

The real area of worry with carpet fires would be the central floor pan area, which only 3-points are supposed to deal with.

GR33N GoblinM6

iTrader: (14)

i think its funny that Foxxton and his B.S. degree, doesnt think a STB is needed but the PHd's and Masters of the GM engineers put a STB on GTO's..

if you look at other auto manufacturers .. they do this also.. so im going to trust the acutal manufacturers of vehicles, people that are highly funded, years of experience, and do this on a daily basis..

BULLET99Z28

iTrader: (9)

Get welded in if u can. I have Boxed BMR's, and I could tell a difference as soon as I left the shop. The car planted better under power, handled better,handled larger bumps better(car stayed more rigid)I could tell the ar wasn't flexing as much. Chassis rigidity is very important so the suspension can do its job. I can feel the difference in how much tighter the car is.Also, I can put a jack just in front of the left rear tire, and the right rear will come off the ground also, the car is more rigid period, I would recoment SFC's to anyone. And Foxxton- the car only had 30k,older 1owner,mint condition, and it had new bilsteins- So even on a nice,not abused,w/ good shocks, the SFC's did make a differnce in how stiffer the car felt. One more point mr Foxxton- I raced sprint cars for 9 years, I know a little bit about how a car "feels" , I know what chassis flex feels like, and I could feel the extra rigidity in my car after SFC's

Foxxtron

iTrader: (1)

well, got some news for you,

F-body 4th Gen front suspension: short long arm
Pontiac GTO/Holden Monaro/Vauxhall Monaro front suspension: Macpherson strut.
Also, F-body 3rd Gen front suspension: Macpherson strut

Do you understand why the STB on the 4th gen isn't needed?

and here's a link:
https://ls1tech.com/forums/suspension-brakes/412893-shock-tower-brace.html

And please read the whole thread. Doesn't surprise me that the STB argument goes on this long, especially when it has been quoted what the GM engineers have done. Even though Holden is owned by GM, the chassis was engineered by Holden in Australia (good company nevertheless). Once again, comparing apples to oranges.

Just to let you know, this board and FRRAX have many experienced RR and AXer's that are aware just like GM that a STB isn't needed for the 4th Gen Camaro. Also if you really trust the GM engineers, then you might want to be consistent with the fact that the 1LE packages for the 4th Gen never once included a STB, and that package is also meant for RR and AX.

Not telling anybody what to do, just straightening the facts once again.

jst

What the hell is STB?

BadAzz96Z28

iTrader: (8)

Strut Tower Brace

BJM

iTrader: (1)

Let's keep our eye on the real ball. There are two camps, the "STB and SFCs are needed club" and the "STB and SFCs are useless club". Both are right for different reasons and I have not seen anyone really distinguish between the following points.

It would take a great deal of flexibility in a car for a brace to much increase a car's handling. If an autocrosser added a brace and suddenly improved their standings then that car really needed help. So I agree the "useless" club is right, from that particular pespective.

However, again, people are just not adding them for that reason. They add them to improve NVH. Just a look at the comments in the 20 or more SFC threads. people say things like, "I noticed as soon as I got the car back", or "The car feels more solid", " Most of my squeaks and rattles are gone". The situations described are just normal street driving. The added stiffness in the car's most flexible areas helps this out and its quite apparent why. So the "needed" camp is right as well. To my G-body Buick GN I added rear seat bracing, engine cross member braces, fender to rad support braces, each subtley improved the car's feel, but overall on a road race track I used to drive it on I noticed no overall performance improvement other than a more solid feel.

Can't we agree to at least disagree?

Foxxtron

iTrader: (1)

Only partially my fellow LS1Techer. Those squeaks and rattles must come from the chassis itself if those items are going to correct them. Squeaks from worn and/or weak bushings, other suspension parts, loose interior trim, loose door hinges, loose windows, and other loose items in the interior won't be corrected with either of STBs or SFC's, as you must replace and/or rid those worn items themselves. Those G-bodies have a much different design than the F-body, and so do 3rd vs. 4th gens F-bodies themselves. I know you know better, it's just that there are too many generalisations for where the SFC's and STB's efficacy is about, and that's what I am getting to the bottom of.

Fortunately for the 4th gen, there really hasn't been a need for STB's for most daily driving. I AX and RR still (though not with any SCCA sanctioned events) and like Sam Strano mentioned, adding the STB is like adding a passive front stabiliser bar to the vehicle, when it is more effective to upgrade the stabiliser bar size, along with it's included newer bushings. If you perform a search, you'll see where the comments like mine are present, and who they're coming from.

Now back to SFC's. If you must get them, why not weld them on, and why not get some that are the strongest around? Another question would be, if you're not changing from a trans mounted torque arm to a floorpan mounted torque arm, do you need a 3-point? FWIW, I had never bolted in my SFC's when I had any of them installed, so if you must, it's better to find someone that welds properly to get the job done right the first time. Also, make sure your monocoque is straight before putting it on, because if its geometry is out of whack, then you're just bracing the monocoque in its out of whack state. Even though many here would say it doesn't matter if the suspension is loading the chassis, if you're going to install them, why not get the vehicle in a similar physical state by letting the chassis load the suspension, then weld them on for better assurance?

Again, for the NVH? Check all shocks, springs, bushings, mounts, door hinges, and/or interior trim. Depending on age and/or use, you might surprise yourself.

Foxxtron

iTrader: (1)

And bear in mind that that's the same testimony that many have said here with their SOTP. That's that exact same effect that I had too, so I after much of the debate from what I see on this forum, I decided to approach my alma matter's SAE club, which is how this got started.

If you perform a search, you'll see how old my vehicle is, and how many times I've installed/removed SFC's.

And mr bullet, I've raced for nearly 22 years (open wheel karting, then sports car racing), 14 of those years in F-bodies (6 in a 3rd Gen, 9 in a 4th Gen). Be careful, there are other's who've AXed and RRed much longer in F-bodies, especially in that other forum I mentioned. Just look at some of those other members who've competed, such as Cal and Sam Strano.

Oh and btw, if anybody thinks that SAE club isn't s***, they have many resources that also contribute to many professional sanctions. Also bear in mind again that I'm not saying that chassis stiffness is unimportant, it very much is. How stiff (or weak) is the 4th gen and to what point the chassis stiffness is no longer stiff enough. This is what the debate is about.

BULLET99Z28

iTrader: (9)

I read the whoel thread, no disrespect, but I could tell that sfc's tightened the car up, it was worth my money.

shoemike

iTrader: (25)

bolt ons are just fine if your going to weld weld
in a cage while your at it so as to get the most out of
your prep work