jdiddyws6

iTrader: (5)

Just out of curiosity, what is your experience with SFC'S? Bolt in vs welded. Triangulated vs standard. I have the typical type that weld in the front and bolt in the back. Have to say they stiffened the car quite a bit.

Major_Lee_Slow

iTrader: (1)

They are not usually utilized on cars which are used for Autocross. It is a debated if there is an actual performance gain from them or not vs. the additional weight.

jdiddyws6

iTrader: (5)

Sorry, I guess I should have been more specific. I was talking about in reference to drag racing. Wrong section?

Major_Lee_Slow

iTrader: (1)

Nope, it's the right forum, but 9 times out of 10 most people in here are road race/autocross or street handling orientated. You might have better luck in the Drag Race Forum.

For High Power'd Drag race applications there may be a benefit. But then again, most cars running that much power usually are required to have a cage to run down the track.

The forth gens are much more ridged than the 3rds, 2nd and 1st gens.

bongva

iTrader: (7)

yes what about at the track? will they help at all? for cars like bolt-ons, or cam only cars.

Major_Lee_Slow

iTrader: (1)

Which track? Road Race or Drag Strip?

As far as help, there is a low probability that they will net lower times at either venue, and actually may result in higher times due to the weight. However, if the car is a T-top or vert, then there may be some benefit in terms of reducing squeaks and rattles.

My coupe has been autocrossed for 7 seasons without subframe connectors and I don't have any squeaks or rattles, except for the rear axle clunk but that's a whole different story. The car is as square now as it was when it was delivered from the factory, and let me tell you it's seen some pretty good cornering loads.

JamRWS6

I don't think you'll see a performance improvement.

However, I can say they will stiffen the car up. For instance when jacking the car w/o them i can jack the passenger side and the driver tire never comes off the ground. After the SFCs the driver side will definitely lift off the ground.

They stiffen the car up which is nice but I doubt they help performance.

No difference between bolt in and weld-in. They are both equally as strong when installed properly. I have 3pt SLP bolt-ins.

They also provide a nice jacking point which makes jacking a lot easier especially now that my car is lowered and getting a jack under the car is a PITA.

BMR Tech

iTrader: (9)

I would think most Autocross guys don't run them do to rule restrictions for each class they are participating in especially the lower entry level classes ?

Major_Lee_Slow

iTrader: (1)

Street Prepared which is the class that 75% or more of the 4th gens participate in, allows the use of SFC's. Street Prepared is one step above stock, and all the classes above Street Prepared allow the use of subframe connectors.

Sam Strano

iTrader: (41)

Hanging 30-50 pounds off the bottom of the car isn't exactly an easy way to go faster. And for the last few years, SFC's have been legal in every class you'd compete in with an f-body except for stock (which is very limiting).

You want them to make the car stiffer, that's fine. They really don't make the car faster. And that's fine too--I sell a lot of connectors just because folks want to put their mind at ease the car chassis isn't a noodle. And with age and pounding they do loosen up.

Ironhead

Incorrect. Most of us don't run them because, after we get better shocks on the car, most of us realize we don't need them.

Years ago, I had a good beefy set welded on when I still had crappy shocks on the car. "Wow, what a huge difference" was the impression at the time.

Much later with good shocks on the car, I cut them off. No noticeable difference before or after. Hmmm. Realize also that this was now after ~100 1/4 mile passes and several hundred autocross runs. >100K miles on the clock. Sammy will vouch for the quality of PA roads where the car had spent most of its life to that point.

It appears at least to me that much of the NVH we experience comes from the stupidly valved shocks transmitting a lot of impact harshness directly to the body of the car. The car actually rattles less now at nearly 14 years of age, after years of competition and on 600 / 150 springs than it did bone stock 10 years ago never having turned a wheel in anger.

Do SFC's make a car stiffer? Sure. Are they needed for anything resembling a street car? IMO, no.

Want a quieter car? Spend some money on shocks... err... *dampers*.

JamRWS6

I'll agree w/ the part about the shocks. However, I took mine off while still on stock shocks and I felt the SFCs didn't do crap. After Konis I put them back on and the car does feel stiffer. They do stiffen the car up...but like has been said 30-50 lbs hanging on the bottom of the car doesn't help performance.

BassProCamaro97

iTrader: (10)

In my opinion they can't hurt when it comes to drag racing. Drag racing is hard on cars, it's the nature of the beast. How hard depends on how much you are putting to the wheels.

From an engineering stand point the faster you can transfer energy to the rear of the car the faster you will be. Energy is lost in body roll/twist. SFC help you limit that. Now weather or not that is energy transfer is worth the 30-50lbs is beyond me. I've never researched or measured that difference.

After doing some work on the chasiss I can tell you that I feel alot better about putting my power down with the SFC then I would have with out. It was mentioned that most drag racers use a cage to help stiffen the car. While this is true, the cage is a saftey device. I would assume that a cage doesn't fully tie the chassis like SFC would.

I still think SFC will help. Must high end builds 25.5 or 25.2 have under car bars as part of the cert.

Thats my 2 cents. I hope it made some sense.

EDIT: After typing that I realized I really didn't answer your original question. I went weld in because its stronger. I don't see the need for triangulated I used the straight pieces.


~Jim~

wtomlinson

iTrader: (6)

ok so what advantages do the 3-points have over the regular SFCs?

JamRWS6

Doubtful. A proper weld is stronger than a bolted connection but it is a lot more difficult to get a proper weld especially w/ all of the paint, dirt, grease, and crap under a car. Not to mention the weld has to be done properly and most welders aren't near as good as they think. A pretty weld isn't a strong weld.

Mostly the obvious. Connecting in 3 points is going to be stronger than two and will tie the chasis together better.

RevGTO

iTrader: (12)

I put mine in (2pt., welded) because I got a wrinkle in my right rear quarter from launching at the strip. Hasn't come back. But I was suprised at how much harshness they added to the ride.

I hated them for a long time, but now, as the miles have racked up on my car, it still feels very tight and the SFC's have probably helped in that regard. So I'm no longer thinking about cutting them off.

BassProCamaro97

iTrader: (10)

A weld is almost always if not always stronger then a bolt. When you compare within application. (for example a 10 inch diameter bolt will be stronger then 1/4" weld on two 1/8" pieces of metal. Plus you don't have to worry about bolts coming loose or falling off.

Now if the welder is lazy or unqualified then that is a different story. Like anything else you should be researching folks who do work on your cars/possesions.

I figured prepping the area for a weld was a given. If you're not welding properly (this includes prep), then of course the weld will be weak.

As said above three points adds another point for extra rigidity.

~Jim~

DoubleTapDrew

iTrader: (1)

That's a big friggin bolt!

Maybe I'll hold off on SFCs until after the rest of the suspension is done.

02TransAm/Batmobile

iTrader: (32)

That's why I went with UMI's 2-point tubular bolt-in subframe connectors. It weighs a mere 24 lbs.

Sam Strano

iTrader: (41)

See, I'm of the opinion that if you feel the car needs to be stiffened, then do it right and do 3-points. Yes they weigh a little more, but that weight serves a purpose. If you are about compromise, then by all means--2 points will also stiffen the car, but not to the same degree as they are not triangulated.