Removed SFC's with Dremel - easy
07-22-2007, 09:40 AM
#41
TECH Junkie
iTrader: (7)
Join Date: Jul 2005
Location: MA
Posts: 3,934
Likes: 0
Received 0 Likes
on
0 Posts
Question. Does this chassis flex thing where the window is an inch away from the ttop happen launching only on slicks and or 400+ rwtq? If so then SFCs sound like they have a place for drag racing but wouldn't be that important on a road race car.
Does anyone have a link to any pics of this extreme twisting happening? I'm not saying it's not happening ( I wouldn't know ) but if its so common, there must be some pics of it somewhere. There's a ton of those drag launch shots. Whether its the front swaybar or the sfcs, everyone seems to say what they feel but I never see anything that proves something is happening. Only a few people here explain what and why it happens.
Does anyone have a link to any pics of this extreme twisting happening? I'm not saying it's not happening ( I wouldn't know ) but if its so common, there must be some pics of it somewhere. There's a ton of those drag launch shots. Whether its the front swaybar or the sfcs, everyone seems to say what they feel but I never see anything that proves something is happening. Only a few people here explain what and why it happens.
07-22-2007, 01:58 PM
#43
Originally Posted by Specialized
I dont think I have ever seen a car which is intending to lift its tires WITHOUT SFCs. SO I cant say for sure, but I think everyone does it because its expected.
07-23-2007, 08:37 PM
#44
Originally Posted by OldeSkool
Trust me, no one can relate to your concerns about driving around in a sloppy chassis more than me. What do you think drove me to welding these things to my car in the first place?
But you gotta realize that ALL cars flex a little. Even a nicely designed tubular spaceframe. The question is how much do they flex? And the next question is how much of a difference will welding those 2 bars in actually make? If a car is made out of metal and if its going to be at all within a reasonable weight limit, there's going to be flex. Thats why carbon fiber chassis like some of the mega-bucks exotics have are so nice, VERY rigid yet still light.
If you really believe that these cars are so sloppy that welding 2 bars underneath will make a significant difference, fine, do it. But I firmly believe that they dont do anything except transmit noise from the back of the car up to the passenger compartment.
And for the record, removing the T-Tops shouldn't have any kind of an effect on the ol Butt-O-Meter because they dont have make any sort of structural contribution to the car being that they're held on by 2 sliding pins. If you feel a difference, its probably imagined, just like the flex you imagine yourself feeling. Just like the improvement I imagined myself feeling when I installed my SFC's years ago
But you gotta realize that ALL cars flex a little. Even a nicely designed tubular spaceframe. The question is how much do they flex? And the next question is how much of a difference will welding those 2 bars in actually make? If a car is made out of metal and if its going to be at all within a reasonable weight limit, there's going to be flex. Thats why carbon fiber chassis like some of the mega-bucks exotics have are so nice, VERY rigid yet still light.
If you really believe that these cars are so sloppy that welding 2 bars underneath will make a significant difference, fine, do it. But I firmly believe that they dont do anything except transmit noise from the back of the car up to the passenger compartment.
And for the record, removing the T-Tops shouldn't have any kind of an effect on the ol Butt-O-Meter because they dont have make any sort of structural contribution to the car being that they're held on by 2 sliding pins. If you feel a difference, its probably imagined, just like the flex you imagine yourself feeling. Just like the improvement I imagined myself feeling when I installed my SFC's years ago
think about it in this way. The T top has a solid leading edge over the window on both sides (in effect similar to a SFC located under the car). When you remove the t tops those bars are no longer connecting the roof at the outer edges. I could feel a difference between the T tops installed and removed. That is the reason I installed SFC's. I felt that the car was sloppy with the T tops off.
07-24-2007, 12:09 AM
#45
TECH Fanatic
Thread Starter
Join Date: Nov 2004
Location: TX
Posts: 1,118
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by wannafbody
think about it in this way. The T top has a solid leading edge over the window on both sides (in effect similar to a SFC located under the car). When you remove the t tops those bars are no longer connecting the roof at the outer edges. I could feel a difference between the T tops installed and removed. That is the reason I installed SFC's. I felt that the car was sloppy with the T tops off.
Sorry, but they just don't do anything but keep the rain off your head. Thats why there's a T-bar down the middle to add structural integrity that the T-tops don't provide. If they were meant to be structural, there'd be bolts holding them on like the targa tops on Corvettes. But its a pain in the butt to have to dig the wrench out of your glove box and undo the 4 bolts and lift the heavy roof panel by yourself and put it in the back. Why I just left the top on my Corvette most of the time and why the Corvette catalogues have a half dozen kinds of lightweight alternative, fabric and temporary targa tops so you don't have to go through the trouble. And thats part of why t-tops are nice. You have the same structural integrity whether the tops are on or off. you dont have to unbolt them, just turn a handle. They're much lighter and more convenient to stow.
Last edited by OldeSkool; 07-24-2007 at 12:25 AM.
07-24-2007, 08:14 AM
#46
TECH Junkie
iTrader: (7)
Join Date: Jul 2005
Location: MA
Posts: 3,934
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by wannafbody
think about it in this way. The T top has a solid leading edge over the window on both sides (in effect similar to a SFC located under the car). When you remove the t tops those bars are no longer connecting the roof at the outer edges. I could feel a difference between the T tops installed and removed. That is the reason I installed SFC's. I felt that the car was sloppy with the T tops off.
07-24-2007, 06:03 PM
#47
take a look at this picture i have added.. notice the front part of the subframe connector bends over and attached to the front frame ... you said you have "never seen a subframe connector do this"... the only subframe connectors I I have ever, seen do this..
this particular subframe is made by UMI performance.. a sponsor on here.. they also make 2 other types as well.
and this one is the basic tubular ones they offer.. note they also go to the bottom of the front subframe..
what company or brand of subframe connector did you have?
this particular subframe is made by UMI performance.. a sponsor on here.. they also make 2 other types as well.
and this one is the basic tubular ones they offer.. note they also go to the bottom of the front subframe..
what company or brand of subframe connector did you have?
07-24-2007, 08:34 PM
#48
Originally Posted by GR33N GoblinM6
take a look at this picture i have added.. notice the front part of the subframe connector bends over and attached to the front frame ... you said you have "never seen a subframe connector do this"... the only subframe connectors I I have ever, seen do this..
and this one is the basic tubular ones they offer.. note they also go to the bottom of the front subframe..
what company or brand of subframe connector did you have?
and this one is the basic tubular ones they offer.. note they also go to the bottom of the front subframe..
what company or brand of subframe connector did you have?
Personally I love my subframe. There was a definite seat of the pants difference. The first thing I noticed was how the weight transfered so much better to the rear and the car left straighter. It felt like a totally different car the first time a launched it. Is the car stiffer yes it absolutly is but I like the car to be stiff but I have also replaced everything else except the sway bars. In my opinion subframes are not neccesary on a DD or someone looking to leave there car close to stock all it will do is make the ride stiffer which usually is't desirable on a DD. My car is a DD but i like it the way it is.
07-24-2007, 08:47 PM
#50
TECH Fanatic
Thread Starter
Join Date: Nov 2004
Location: TX
Posts: 1,118
Likes: 0
Received 0 Likes
on
0 Posts
Mine were BMR boxed
And if you'll look where they weld, its hollow, full of holes and 1 thin layer of sheet metal. You can see inside it even from the picture. If the SFC's are subjected to a load that metal there is just going to twist under it. As anyone who has ever placed a jack stand in that exact spot can tell you, thats no substantial part of the car. Also, many folks who have installed bolt on subframe connecters have experienced slotting, elongation of the holes there because thats such a weak place. If the SFC mounting tab ran up along that a little further it might benefit enough from the cross sectional size of that part of the car to actually do some good, but they dont, they just tack on to the tail end of that thing, just enough to keep them from falling off the car while you're driving. Which is all a SFC is good for, a jacking rail that you carry around with you wherever you go
And if you'll look where they weld, its hollow, full of holes and 1 thin layer of sheet metal. You can see inside it even from the picture. If the SFC's are subjected to a load that metal there is just going to twist under it. As anyone who has ever placed a jack stand in that exact spot can tell you, thats no substantial part of the car. Also, many folks who have installed bolt on subframe connecters have experienced slotting, elongation of the holes there because thats such a weak place. If the SFC mounting tab ran up along that a little further it might benefit enough from the cross sectional size of that part of the car to actually do some good, but they dont, they just tack on to the tail end of that thing, just enough to keep them from falling off the car while you're driving. Which is all a SFC is good for, a jacking rail that you carry around with you wherever you go
Last edited by OldeSkool; 07-24-2007 at 08:57 PM.
07-24-2007, 09:01 PM
#51
TECH Fanatic
iTrader: (15)
Join Date: Jun 2006
Location: Janesville WI
Posts: 1,155
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by OldeSkool
Mine were BMR boxed
And if you'll look where they weld, its hollow, full of holes and 1 thin layer of sheet metal. You can see inside it even from the picture. Its a good thing SFC's don't actually do anything or else they would just deform that sheet metal whenever they were subjected to a load. As anyone who has ever placed a jack stand there can tell you, thats no substantial part of the car. If the SFC mounting tab ran up along that a little further it might benefit enough from the cross sectional size of that part of the car to actually do some good, but they dont, they just tack on to the tail end of that thing, just enough to keep them from falling off the car while you're driving.
And if you'll look where they weld, its hollow, full of holes and 1 thin layer of sheet metal. You can see inside it even from the picture. Its a good thing SFC's don't actually do anything or else they would just deform that sheet metal whenever they were subjected to a load. As anyone who has ever placed a jack stand there can tell you, thats no substantial part of the car. If the SFC mounting tab ran up along that a little further it might benefit enough from the cross sectional size of that part of the car to actually do some good, but they dont, they just tack on to the tail end of that thing, just enough to keep them from falling off the car while you're driving.
The prob I have w SFCs is this attatching to this sheet metal up front. I like how they frab the LCA pocket out back. But up front they don't get a substantial enough part of the car IMHO. On 1st and 2nd gens for example they have "real frames" up front. Heavy guage frame stubs, that the SFc welds to. This makes sense.
I realize this isn't practical, but if the SFCs could say...connect the rear LCA mounting point to the front LCA mouning points a more realistic gain would be achieved.
I can see the body twist upon launch at the drag strip issue. But the real way to combat this would be a well designed cage tying more than just the floor sheetmetal together.
Its not that I don't beleive SFCs do anything....just not as much as some people hope/believe. They aren't evil, or (completely) worthless...just not a need by any strech of the imagination (especially on a street car).
07-24-2007, 09:41 PM
#52
TECH Fanatic
Thread Starter
Join Date: Nov 2004
Location: TX
Posts: 1,118
Likes: 0
Received 0 Likes
on
0 Posts
The other thing thats been nagging me about this is that so many people say "yes SFC's make the ride harsher, but at least the chassis is stiffer" and this is a contradiction in itself. In every other instance I've ever heard of or experienced, a stiffer chassis is a more comfortable chassis.
For instance, when Porsche turned the Boxter into a coupe and called it the Cayman, the chassis stiffness increased dramatically so they were able to install even stiffer springs and yet the ride is even more comfortable.
I've experienced the same thing going from a C4 to C5 corvette and going from a cageless to a caged first-gen f-body. In all other instances, a truely stiffened chassis is more comfortable. So, why then does adding SFC's to 4th gen f-bodies decrease ride quality? I wonder if its because they don't actually stiffen the car, just spread the noises and vibrations around.
Im with you on the cage. If you're a drag racer, if you have a real reason to be concerned about chassis flex, get a cage and forget about the SFCs.
For instance, when Porsche turned the Boxter into a coupe and called it the Cayman, the chassis stiffness increased dramatically so they were able to install even stiffer springs and yet the ride is even more comfortable.
I've experienced the same thing going from a C4 to C5 corvette and going from a cageless to a caged first-gen f-body. In all other instances, a truely stiffened chassis is more comfortable. So, why then does adding SFC's to 4th gen f-bodies decrease ride quality? I wonder if its because they don't actually stiffen the car, just spread the noises and vibrations around.
Im with you on the cage. If you're a drag racer, if you have a real reason to be concerned about chassis flex, get a cage and forget about the SFCs.
07-24-2007, 09:57 PM
#53
TECH Fanatic
iTrader: (15)
Join Date: Jun 2006
Location: Janesville WI
Posts: 1,155
Likes: 0
Received 0 Likes
on
0 Posts
Yeah, I think you are on the $ w/ the noise and vibration transfer idea.
And I am also under the idea a stiffer chassis "allows the suspension to better do its job".
And I am also under the idea a stiffer chassis "allows the suspension to better do its job".
07-25-2007, 01:33 PM
#54
Originally Posted by SMOKY
All i have to say is the design of the f-body hasnt changed much from 3rd to 4th gens. Now go outside find a nice hardtop 3rd gen that has a "stiff" factory chassis and look at the rear corner of the drivers window on the roof. If the car has normal milage the small bumps turn into a tear in the sheet metal. Now go look at a 3rd gen with subframe connectors if they did it at an earlier stage thiers no rip. Hmm I wonder if that means the chassis is flexing over those little bumps. The world may never know in the eyes of the ignorant to facts.
Ps I'm done talking to the uninformed.
Ps I'm done talking to the uninformed.
The 4th gen is a much stiffer car than a 3rd gen ever was. When you say "it's not that different" is shows how uninformed you are. The 4th gen was designed from the get-go to be a convertible and as such it's a much stiffer platform. I think you're looking at the floorpan and making an assumption. You can't see inside the rocker sills and such. I've owned both generations and raced both generations (multiple cars of each), the 4th gen is much stiffer than a 3rd gen is.
The smooth ride they feel is not chassis flex, it's proper suspension calibration. You can see that clearly with anyone who notes the much improved ride/impact harshess quality when they change to good shocks and nothing else. They haven't suddenly make the car flex more and improved the ride that way. No, they now have things that keep the impact harshness from getting into the uni-body.
Clearly there is no convincing you. You probably equate a stock f-body with a piece of wet bread. Meanwhile while I don't think SFC's are bad, I don't think they are the end-all and necessary in all cases. I don't run them on my car, which I drive often and kind of gets run hard on the 315 Hoosier tires, suspension work and multiple national championships.... And it's been wrapped around a light pole after jumping a curb. Still not falling apart, doesn't rattle and is faster than ever.
__________________
www.stranoparts.com --814-849-3450
Results matter. Talk is cheap. We are miles beyond the success anyone else has had with the 4th gens, and C5, C6, C7 Corvettes,
10 SCCA Solo National Championships, 2008 Driver of they Year, 2012 Driver of Eminence
13 SCCA Pro Solo Nationals Championships
2023 UMI King of the Mountain Champion
www.stranoparts.com --814-849-3450
Results matter. Talk is cheap. We are miles beyond the success anyone else has had with the 4th gens, and C5, C6, C7 Corvettes,
10 SCCA Solo National Championships, 2008 Driver of they Year, 2012 Driver of Eminence
13 SCCA Pro Solo Nationals Championships
2023 UMI King of the Mountain Champion
07-25-2007, 01:45 PM
#55
TECH Junkie
iTrader: (7)
Join Date: Jul 2005
Location: MA
Posts: 3,934
Likes: 0
Received 0 Likes
on
0 Posts
I'm thinking maybe I should try this, but I don't want to loose those awesome jackpoints. I got the huge *** boxed hotchkis ones on my car. Those things were pretty heavy
07-25-2007, 02:04 PM
#56
There are only three reasons I'd recommend you remove them.
1. You compete in the car and they are screwing you class wise. Dump 'em because they don't make the car faster.
or
2. You want to save the weight
or
3. You are really just that curious about the change once you have good dampers. The folks this works for started with junk and then improved (either to Revalves or Koni's). The shocks are the key.
1. You compete in the car and they are screwing you class wise. Dump 'em because they don't make the car faster.
or
2. You want to save the weight
or
3. You are really just that curious about the change once you have good dampers. The folks this works for started with junk and then improved (either to Revalves or Koni's). The shocks are the key.
__________________
www.stranoparts.com --814-849-3450
Results matter. Talk is cheap. We are miles beyond the success anyone else has had with the 4th gens, and C5, C6, C7 Corvettes,
10 SCCA Solo National Championships, 2008 Driver of they Year, 2012 Driver of Eminence
13 SCCA Pro Solo Nationals Championships
2023 UMI King of the Mountain Champion
www.stranoparts.com --814-849-3450
Results matter. Talk is cheap. We are miles beyond the success anyone else has had with the 4th gens, and C5, C6, C7 Corvettes,
10 SCCA Solo National Championships, 2008 Driver of they Year, 2012 Driver of Eminence
13 SCCA Pro Solo Nationals Championships
2023 UMI King of the Mountain Champion
07-25-2007, 02:11 PM
#57
TECH Junkie
iTrader: (7)
Join Date: Jul 2005
Location: MA
Posts: 3,934
Likes: 0
Received 0 Likes
on
0 Posts
Well the ones that apply to me there are 1, 2, and 3 haha. Though removing them still won't bump me down from Street Mod due to my other modifications. My camaro won't be my autox car soon anyway. My primary goal with it is to win local spectator drag events.
07-26-2007, 10:41 AM
#59
Yes, I have...... and you it's funny... most of them are bone stock including the shocks. Didn't your car's dashboard quiver less when you change away from DeCarbon's?
__________________
www.stranoparts.com --814-849-3450
Results matter. Talk is cheap. We are miles beyond the success anyone else has had with the 4th gens, and C5, C6, C7 Corvettes,
10 SCCA Solo National Championships, 2008 Driver of they Year, 2012 Driver of Eminence
13 SCCA Pro Solo Nationals Championships
2023 UMI King of the Mountain Champion
www.stranoparts.com --814-849-3450
Results matter. Talk is cheap. We are miles beyond the success anyone else has had with the 4th gens, and C5, C6, C7 Corvettes,
10 SCCA Solo National Championships, 2008 Driver of they Year, 2012 Driver of Eminence
13 SCCA Pro Solo Nationals Championships
2023 UMI King of the Mountain Champion
07-26-2007, 06:31 PM
#60
Originally Posted by Sam Strano
Yes, I have...... and you it's funny... most of them are bone stock including the shocks. Didn't your car's dashboard quiver less when you change away from DeCarbon's?