Put on my SFCs tonight...
09-20-2007, 08:46 PM
#1
Put on my SFCs tonight... ... and not too thrilled 
I just drove around the block, but initial impression is just less sqweaks, rattles, and clanks. Notice I said LESS, not GONE. I remember hearing nothing but "must do mod" "best and first mod" etc... Maybe if it was the first thing I did I'd be a little more pleased. Oh well they are bolt in so if I ever wanna get rid of them it's not a serious issue. I drive the car to work tomorrow so we'll see if my attitude changes by the time I get home. UMI SFC/LCA/DA-PHB so far, next up are Konis and maybe the strano springs, enough fooling around I will say that with the addition of these parts (mostly the first two), the car feels MUCH better than when I first got it (felt like a land yacht).
BTW, those with bolt-in SFCs, what did you torque the front bolts to? I threw some Loctite red on there and tightened them as best I could without feeling as though I was gonna snap them.
-J
I just drove around the block, but initial impression is just less sqweaks, rattles, and clanks. Notice I said LESS, not GONE. I remember hearing nothing but "must do mod" "best and first mod" etc... Maybe if it was the first thing I did I'd be a little more pleased. Oh well they are bolt in so if I ever wanna get rid of them it's not a serious issue. I drive the car to work tomorrow so we'll see if my attitude changes by the time I get home. UMI SFC/LCA/DA-PHB so far, next up are Konis and maybe the strano springs, enough fooling around I will say that with the addition of these parts (mostly the first two), the car feels MUCH better than when I first got it (felt like a land yacht).BTW, those with bolt-in SFCs, what did you torque the front bolts to? I threw some Loctite red on there and tightened them as best I could without feeling as though I was gonna snap them.
-J
09-20-2007, 10:03 PM
#2
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i put my weld on sfc's tonight and they made the car feel firmer but i still have a few minor rattles but they did get better. my car has 124k and the doors seemed to drag a little but i could jack the car up and put jack stands under the the front frame behind the front tires and the doors shut perfect so even though eveybody including the instrucions said the suspension needed to be loaded when welding the sfc's on i left it on stands with the front end hanging and now my doors shut perfect. im thinking my car had a good bit of sag and this just fixeed it. i also found a bad bushing on a lca so i guess ill have to get some new adjustable ones
09-20-2007, 11:10 PM
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sfc's are gonna be my first mod where did you guys get yours at and how much??? If you put them in would they have to be removed to do under body work such as putting in full exhaust later??? Thanks!!! 
09-21-2007, 12:23 AM
#6
Originally Posted by z28bryan
Trying to get rid of squeaks and rattles in our car is a lost cause 
Yeah, I didnt notice a difference. I noticed a difference with new springs, also shocks, swaybars, and even an airlid. But I noticed nothing with the SFC's.
09-21-2007, 01:36 AM
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This is just a situation where you are not likely to recieve immediate satisfaction.
Vehicle chassis stiffness is measured in pounds per twist angle degree, lb/deg. As the vehicle is loaded on one corner, the vehicle front end twists relative to the rear. Or they can be measured for bending, pounds per inch, about a central position. This is where loadings are placed at the center of the chassis and the deflection relative to the front and rear, causing bending, is measured.
If we look at the old second order differential homogeneous equations that govern the reactions given an input, we see that there is an extremely high stiffness value spring with very little shock dampening that has an extremely high resonant frequency (tire), a low stiffness value spring with a high amount of dampening (suspension usually has resonance of around 1 cycle/sec), and another high stiffness value spring with virtually no dampening value (chassis usually has a resonant frequency of around 10 Hz). Taking the first (tire) and last (chassis) out of the equation by increasing the values until they are irrelevant is the way to gain control and customize the overall properties with shock and spring adjustment. This is the key.
Increasing the values of tire and chassis helps engineers eliminate these variables so that, again, they can customize ride properties more directly by tuning the shock and spring. We all remember the 1982/83 corvette and camaro, the stiffness of the suspension was used to compensate for a chassis made out of licorice (sp?)
what you have improved with your chassis stiffening efforts is: higher chassis resonant frequency which means you are less likely to stumble upon that frequency that makes the car shudder, higher twisting and bending stiffness which means less distortion under loading, and a higher chassis spring constant, again further removing this uncontrollable property from the equation.
Incedentally, the new Camaro chassis has a resonant frequency of around 27 Hz. Mercedes with the bank vault construction have upwards of 50 Hz. THere was a 22% stiffness increase in the '92 vs. '93 F-body chassis when tweaked by GM engineers.
if you ever do decide to increase handling or engine performance, then the effects of the SFC's will be more drastic, but, again, you will never notice.
Vehicle chassis stiffness is measured in pounds per twist angle degree, lb/deg. As the vehicle is loaded on one corner, the vehicle front end twists relative to the rear. Or they can be measured for bending, pounds per inch, about a central position. This is where loadings are placed at the center of the chassis and the deflection relative to the front and rear, causing bending, is measured.
If we look at the old second order differential homogeneous equations that govern the reactions given an input, we see that there is an extremely high stiffness value spring with very little shock dampening that has an extremely high resonant frequency (tire), a low stiffness value spring with a high amount of dampening (suspension usually has resonance of around 1 cycle/sec), and another high stiffness value spring with virtually no dampening value (chassis usually has a resonant frequency of around 10 Hz). Taking the first (tire) and last (chassis) out of the equation by increasing the values until they are irrelevant is the way to gain control and customize the overall properties with shock and spring adjustment. This is the key.
Increasing the values of tire and chassis helps engineers eliminate these variables so that, again, they can customize ride properties more directly by tuning the shock and spring. We all remember the 1982/83 corvette and camaro, the stiffness of the suspension was used to compensate for a chassis made out of licorice (sp?)
what you have improved with your chassis stiffening efforts is: higher chassis resonant frequency which means you are less likely to stumble upon that frequency that makes the car shudder, higher twisting and bending stiffness which means less distortion under loading, and a higher chassis spring constant, again further removing this uncontrollable property from the equation.
Incedentally, the new Camaro chassis has a resonant frequency of around 27 Hz. Mercedes with the bank vault construction have upwards of 50 Hz. THere was a 22% stiffness increase in the '92 vs. '93 F-body chassis when tweaked by GM engineers.
if you ever do decide to increase handling or engine performance, then the effects of the SFC's will be more drastic, but, again, you will never notice.
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09-21-2007, 02:02 AM
#8
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Originally Posted by THE_PROFESSOR
Increasing the values of tire and chassis helps engineers eliminate these variables so that, again, they can customize ride properties more directly by tuning the shock and spring. We all remember the 1982/83 corvette and camaro, the stiffness of the suspension was used to compensate for a chassis made out of licorice (sp?)
09-21-2007, 10:58 AM
#12
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SFC's are a must if you make real power.
I cracked a windshield and tore/cracked the sail panel on my 3rd gen before they were installed. The 4th gen has them also.
I cracked a windshield and tore/cracked the sail panel on my 3rd gen before they were installed. The 4th gen has them also.
09-21-2007, 11:17 AM
#13
You'll be happy to have them when you don't develope any ripples in your quarters after racing. I could really care less about the rattles being solved by a set of SFC's. I bought mine for what they are designed for. To stiffen the chassis & help prevent ripples in the quarters from hard launching.
If you mainly bought them for eliminating the rattles you bought them for the wrong reasons. But I see alot of people on here doin that.
If you plan on racing, I suggest keeping them. If not then it won't really matter if you keep them installed or not.
If you mainly bought them for eliminating the rattles you bought them for the wrong reasons. But I see alot of people on here doin that.
If you plan on racing, I suggest keeping them. If not then it won't really matter if you keep them installed or not.
09-21-2007, 12:45 PM
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Originally Posted by CAMARO_THUNDER
SFC's are a must if you make real power.
I cracked a windshield and tore/cracked the sail panel on my 3rd gen before they were installed. The 4th gen has them also.
I cracked a windshield and tore/cracked the sail panel on my 3rd gen before they were installed. The 4th gen has them also.
I have never heard of any evidence that the 4th gen twists that badly. There's a ton of those drag launch photo shots out there. How come I haven't seen any showing the car's chassis twisting? Maybe it's minimal and you can't see it, but significant enough to matter? I'm not convinced that the SFCs make that much of a difference unless you are on slicks where you can put real sudden shock between the rear axle and engine.
I think the biggest drawback to SFCs is for the SCCA drivers, since they bump you up to SM class on an often first modification for a lot of fbody owners (it was my first modification when I was an fbody noob)
SFC's make great jack points though. Lifting the entire side of the car up in 10 seconds is pretty nice.
09-21-2007, 04:48 PM
#15
Originally Posted by BIG_MIKE2005
You'll be happy to have them when you don't develope any ripples in your quarters after racing. I could really care less about the rattles being solved by a set of SFC's. I bought mine for what they are designed for. To stiffen the chassis & help prevent ripples in the quarters from hard launching.
If you mainly bought them for eliminating the rattles you bought them for the wrong reasons. But I see alot of people on here doin that.
If you plan on racing, I suggest keeping them. If not then it won't really matter if you keep them installed or not.
If you mainly bought them for eliminating the rattles you bought them for the wrong reasons. But I see alot of people on here doin that.
If you plan on racing, I suggest keeping them. If not then it won't really matter if you keep them installed or not.
-J
09-21-2007, 08:00 PM
#17
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Originally Posted by lastcall190
... and not too thrilled I just drove around the block, but initial impression is just less sqweaks, rattles, and clanks. Notice I said LESS, not GONE. I remember hearing nothing but "must do mod" "best and first mod" etc... Maybe if it was the first thing I did I'd be a little more pleased. Oh well they are bolt in so if I ever wanna get rid of them it's not a serious issue. I drive the car to work tomorrow so we'll see if my attitude changes by the time I get home. UMI SFC/LCA/DA-PHB so far, next up are Konis and maybe the strano springs, enough fooling around I will say that with the addition of these parts (mostly the first two), the car feels MUCH better than when I first got it (felt like a land yacht).
BTW, those with bolt-in SFCs, what did you torque the front bolts to? I threw some Loctite red on there and tightened them as best I could without feeling as though I was gonna snap them.
-J
I just drove around the block, but initial impression is just less sqweaks, rattles, and clanks. Notice I said LESS, not GONE. I remember hearing nothing but "must do mod" "best and first mod" etc... Maybe if it was the first thing I did I'd be a little more pleased. Oh well they are bolt in so if I ever wanna get rid of them it's not a serious issue. I drive the car to work tomorrow so we'll see if my attitude changes by the time I get home. UMI SFC/LCA/DA-PHB so far, next up are Konis and maybe the strano springs, enough fooling around I will say that with the addition of these parts (mostly the first two), the car feels MUCH better than when I first got it (felt like a land yacht).BTW, those with bolt-in SFCs, what did you torque the front bolts to? I threw some Loctite red on there and tightened them as best I could without feeling as though I was gonna snap them.
-J
09-22-2007, 01:06 AM
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My old 1991 camaro was a wonderful little car. I knew and could tell that the car was slithering down the road. The chassis was very unstiff but the shock/spring combo just tuned out the wrong frequencies and it was a vicious handler and a fun ride! Moreso even than my current WS6!! Just shows what ten years of learning curve can do to improvements!
Again, the new F-body chassis (93-) has been advertised as 22% more stiff. This might possibly be enough to cancel out all the odd effects found in the previous model. For the average driver, I bet it is.
In my research in the field, the torsion created by seizing that big power motor directly to the rearend under clutch dump is the main contributor to a high performance drag car twist. However, for a road racer, loading up that outside front tire under a heavy combo of braking to shift the weight transfer, and then cornering to take advantage of it, is the point of largest load. Higher chassis stiffness is not only desireable, it is necessary. This is perfectly illustrated by the outright damage created with Big_Mike and Thunder. My guess is that Mr. Strano uses them as well. We took a certain pro stock champion's chassis and added 75% to the stiffness, filtering out resonance from the engine and providing for a better launcher. He qualified first, time after time (pat on the back)
Rattles and creaks aren't necessarily caused by just torsional stiffness or lack thereof. Take an angle at a entrance approach and see if the inside creaks as much. I would probably advise welding the SFCs to get the best result.
Apolgies for the condescension, sometimes we just don't feel appreciated.....
Again, the new F-body chassis (93-) has been advertised as 22% more stiff. This might possibly be enough to cancel out all the odd effects found in the previous model. For the average driver, I bet it is.
In my research in the field, the torsion created by seizing that big power motor directly to the rearend under clutch dump is the main contributor to a high performance drag car twist. However, for a road racer, loading up that outside front tire under a heavy combo of braking to shift the weight transfer, and then cornering to take advantage of it, is the point of largest load. Higher chassis stiffness is not only desireable, it is necessary. This is perfectly illustrated by the outright damage created with Big_Mike and Thunder. My guess is that Mr. Strano uses them as well. We took a certain pro stock champion's chassis and added 75% to the stiffness, filtering out resonance from the engine and providing for a better launcher. He qualified first, time after time (pat on the back)
Rattles and creaks aren't necessarily caused by just torsional stiffness or lack thereof. Take an angle at a entrance approach and see if the inside creaks as much. I would probably advise welding the SFCs to get the best result.
Apolgies for the condescension, sometimes we just don't feel appreciated.....
09-22-2007, 01:56 AM
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Originally Posted by Sharpe
Not surprised. Waste of money and adds weight to your car. 
Sorry if I start another one of 1,000 threads of SFC Lovers vs. SFC Haters war...
Sorry if I start another one of 1,000 threads of SFC Lovers vs. SFC Haters war...
09-22-2007, 02:10 AM
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Well I made my own subframe connectors and I welded them to the front and back points like most, but also stitch welded them the entire length of the rocker panel. I noticed a big difference immediately. Also noticed a big difference when jacking the car up, you can no longer see the chassis flex.
I think bolt in subframes are waste. Weld them in or leave them out.
I think bolt in subframes are waste. Weld them in or leave them out.