View Poll Results: Which SFC's are you using?
Voters: 205. You may not vote on this poll
SFC's Bolt-on vs Weld
#21
TECH Fanatic
iTrader: (1)
Join Date: Sep 2002
Location: Brisbane, QLD, AUS
Posts: 1,747
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by chrs1313
just an fyi my BMR SFC are 16lbs together not 30 like mentioned above. and they are mild steel not Chromemoly
Nevertheless they made no detectible improvement for my application, and my application sees some serious cornering along with some serious HP, not to mention I have a lot of heim joints and spherical bearings in my suspension parts.
#22
TECH Veteran
iTrader: (1)
If you really feel you must have SFC's, may I suggest square tube rather than round. Makes them work better as jacking rails. Then you can lift the whole side of your car up NASCAR style for some quick tire swaps down at the track.
I could show you guys pictures of some very serious fbody race cars that don't have SFC's. Even more serious cars than Foxxtron's! (or mine for that matter, he he) Kinda makes ya say hmmm . . .
I could show you guys pictures of some very serious fbody race cars that don't have SFC's. Even more serious cars than Foxxtron's! (or mine for that matter, he he) Kinda makes ya say hmmm . . .
#23
TECH Fanatic
iTrader: (1)
Join Date: Sep 2002
Location: Brisbane, QLD, AUS
Posts: 1,747
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by Cal
If you really feel you must have SFC's, may I suggest square tube rather than round. Makes them work better as jacking rails. Then you can lift the whole side of your car up NASCAR style for some quick tire swaps down at the track.
Originally Posted by Cal
I could show you guys pictures of some very serious fbody race cars that don't have SFC's. Even more serious cars than Foxxtron's! (or mine for that matter, he he) Kinda makes ya say hmmm . . .
Cal is pretty serious about his car and way more than I am about mine. What I have done with mine isn't direct competition, but rather R&T in a manner that the Automobile (OEM and aftermarket) industry does, but nevertheless I make it a point to abuse mine in an objective and constructive manner, along with my wallet too. I try to experiment on as many closed circuit road courses and AX "lots" I can. That's why I mention what I have been through and who I researched and tested with, including but not limited to my alma matter's SAE club.
You could also perform a search for my posts, and you'll notice that I had KBDD's installed at one point here, but I guess I haven't mentioned the SLP DD's. I continue to do this in order to seperate marketing schemes (sometimes scams) from the factual bases.
#24
TECH Addict
Originally Posted by Cal
That's true, Foxxtron does sound off!
But I'm afraind he is right inspite of that. One thing not everyone is aware of is SFC's were developed for the older fbodys, and the 3rd gens and Mustangs really need them. The 4th gen chassis was designed to be a convertible to start with, so if you don't have a 'vert, the car is already overbuilt. It's cheaper for GM to build all cars one way than to have a different floorpan for 'verts. Note that you still have a space for the cat under the passenger seat like the LT1 cars had.
As I think Foxxtron was hinting at, a six point roll bar or better yet a full cage will stiffen the chassis far better than SFC's, and will tend to save your sorry azz when you go rubber side up. I say put the steel inside the car,not below it. But hey, it's your money and your azz.
But I'm afraind he is right inspite of that. One thing not everyone is aware of is SFC's were developed for the older fbodys, and the 3rd gens and Mustangs really need them. The 4th gen chassis was designed to be a convertible to start with, so if you don't have a 'vert, the car is already overbuilt. It's cheaper for GM to build all cars one way than to have a different floorpan for 'verts. Note that you still have a space for the cat under the passenger seat like the LT1 cars had.
As I think Foxxtron was hinting at, a six point roll bar or better yet a full cage will stiffen the chassis far better than SFC's, and will tend to save your sorry azz when you go rubber side up. I say put the steel inside the car,not below it. But hey, it's your money and your azz.
If you want regidity you'll be looking at some maojor work as an integral roll cage is pretty involved to fit, and you might as well seem weld the chassis at the same time.
Foxxtron - I assume you have a roll cage? If so that may be why you didn't see any gains with SFC's.
Example:
If you assume the chassis has a rating of 10 (made up number system).
The SFC's will add 2
But a roll cage has already added 6.
so you would be 4 points higher with the cage than what the SFC's offer, hence no difference. However, if you don't have a roll cage they may still be of benefit.
#25
TECH Fanatic
iTrader: (1)
Join Date: Sep 2002
Location: Brisbane, QLD, AUS
Posts: 1,747
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by 300bhp/ton
Foxxtron - I assume you have a roll cage? If so that may be why you didn't see any gains with SFC's.
Also bear in mind that this chassis isn't a "virgin chassis" when I got it. It was obtained from an auto auction as a repo @28K on the odometer (1999 VIN obtained in early 2001 with all features matching with VIN door jamb sticker, so there could be odom turnback, however it's unlikely since it was in pristine condition for the appearance alone), however when I removed the fascia, it did have a poorly repaired collision on the left front. Took it right to the body shop, all measurements okay, except where the collision took place. They used a Cheetah 360 just to straighten that part out which took only about less than 45 minutes to perform on the front left, but about 10 labour hours for prep and reassembly. Repaired @ 30K, all chassis measurements within factory spec since, even with all of the rough driving and switching all sorts of suspension parts (from bone stock to 1LE enhancements, to tubular and poly stuff, back to a modified 2001-2002 1LE spec, and now upgrading with other parts made specifically for the track while operating as a daily driver when needed).
I guess you could say I'm mad, however this is an experiment in pushing the limit of what a successful sleeper can be, safely that is. This is for my benefit, however it's also serving as a basis for my friend's MSME thesis.
Originally Posted by 300bhp/ton
Example:
If you assume the chassis has a rating of 10 (made up number system).
The SFC's will add 2
But a roll cage has already added 6.
so you would be 4 points higher with the cage than what the SFC's offer, hence no difference. However, if you don't have a roll cage they may still be of benefit.
If you assume the chassis has a rating of 10 (made up number system).
The SFC's will add 2
But a roll cage has already added 6.
so you would be 4 points higher with the cage than what the SFC's offer, hence no difference. However, if you don't have a roll cage they may still be of benefit.
Also to note, doors still line up correctly, t-tops only give slighty, but no change in behaviour while any of the SFC's were installed, and no dimpling. Once again, I'm pushing this vehicle at probably only slightly lower than most of the highly experienced AX and RR's here are. I'm only doing this gradually as to exceed the current limits of the vehicle, the powertrain, the suspension and chassis and mostly myself and the other two drivers (won't disclose their identity yet). In our case, it's important to push the factors gradually (suspension and power mods) in order to detect and/or prevent any fallacies.
I hope this thread can remain like it is now, because it can use more input from a variety of drivers (daily driver, drag racing, AX, RR, and/or combination thereof). I would to see more "positive" and "constructive debate." I welcome naysayers as well, however I'd like to request to please reinforce your position with some solid info.
I know this is a super thread hijack, however I feel it's getting interesing. Moderators, please PM if you need me to divert this to another thread.
#26
Hmm, Foxxton, are you saying that STBs don't have any effect on the rigidity of the car???
If so, then on a t-top car you are SADLY mistaken, as with a STB the chassis is much more rigid and 'solid' feeling going over uneven surfaces, and even tho it may be 'subjective' I have ZERO doubt ANYONE will notice the difference...
And if you feel that there is not enough movement to warrant one, then why were there so many problems with the three-point units that not only mount to the strut towers but also the cowl? There were people cracking windshields from all the movement of the chassis, thus a lot of places stopped making those all together.
What it comes down to is personal preference. End of subject. As in you prefer a loose chassis that compliments your driving style and your use of your vehicle. For *ME* I want, and desire, to keep my car basically as long as I am living, and for that I feel MUCH better with as solid and rigid a chassis I can get, which includes the best subframes I can find as well as a STB... At the moment, with the aftercooler on my setup, I am running without a STB, but I can tell you it is a major difference in chassis rigidity 'feel' than with it. Thus I will be going to Alston Chassis this next spring to see if they can custom fab one to fit with the aftercooler.
I do feel a cage is the best way of making the chassis as rigid as possible, but I also feel that in doing such it somewhat limits the 'functionality' and asthetics of the car as a whole, and should only be done if you feel you need it for safety as well as rigidity reasons.
Also, one thing you are greatly forgetting is there is this wonderful reality called build-quality, and I HIGHLY doubt all 4th gen floorpans are all exactly as rigid as one another. I have known of a couple of fairly 'stock' 4th gens that have had ripping near the center console on the floorpans and they have only been to a handful of autocrossing and maybe 1 or 2 road racing events and about 2-3 dozen drag racing outings, and these cars have been owned since new by these same owners, so previous owner collisions aren't a factor...
Besides all of that, another factor is how heavy the car really is, as in my case my car tips the scales at near, if not above, 4000lbs because of all the extra equipment I have on my setup (supercharger, aftercooler, large fuel system, brakes, cooling systems, dual disc clutch, ignitions, suspension, stereo, etc)... So I am sure I am over the 'specification' that GM designed into the floorpan of the car by weight alone... In your case, by the way you describe your desire to reduce weight, I would imagine your car may actually be under the original weight of the car as new?
Again, point being, YOU may find you have no need for subframes, but by far, and large, the largest majority of people prefer to have the car 'feel' solid regardless of it having an overall 'effect' on 'performance data'... Hell there is so much that people do to these cars that is FAR from 'necessary' it isn't even funny, but that is the key, people do what they want because of personal taste. Just like I probably couldn't stand it if your car is as 'stiff' as a truely competetive suspension needs to be, you probably couldn't stand how 'soft' I have my suspension tuned, yet while utilizing far from stock parts that *I* feel are best for thier purpose (rod ended PHR, LCA with rod ends on one end and a howe rubber end on the other, 32mm/21mm sway bars that work well with my weight balance, bump steer kit, eibach pro-kit springs and custom shock setup, larger Z06 brakes to handle the extra power/weight, which is needed with roughly 750+rwhp), and when combined pretty much I have my car tuned quite well for my tastes... And my car is designed around being a well-balanced all-around 'car', not a dragstrip monster, or a AX champion, but something I can enjoy to it's fullest in ALL cases, so a ton of factors come in vs the 'normal' buildup where you make compromises based upon the 'main' use, be it drag-racing or road-racing/ax, I want mine to be well balanced throughout... And for me, a solid chassis is paramount, thus I may end up going with a cage at some point, but for now the amount of work required to 'bury' a cage to where it has minimal impact on asthetics and useability, for me, is far too costly to justify... But who knows, maybe another year or two down the road I may just take the plunge...
If so, then on a t-top car you are SADLY mistaken, as with a STB the chassis is much more rigid and 'solid' feeling going over uneven surfaces, and even tho it may be 'subjective' I have ZERO doubt ANYONE will notice the difference...
And if you feel that there is not enough movement to warrant one, then why were there so many problems with the three-point units that not only mount to the strut towers but also the cowl? There were people cracking windshields from all the movement of the chassis, thus a lot of places stopped making those all together.
What it comes down to is personal preference. End of subject. As in you prefer a loose chassis that compliments your driving style and your use of your vehicle. For *ME* I want, and desire, to keep my car basically as long as I am living, and for that I feel MUCH better with as solid and rigid a chassis I can get, which includes the best subframes I can find as well as a STB... At the moment, with the aftercooler on my setup, I am running without a STB, but I can tell you it is a major difference in chassis rigidity 'feel' than with it. Thus I will be going to Alston Chassis this next spring to see if they can custom fab one to fit with the aftercooler.
I do feel a cage is the best way of making the chassis as rigid as possible, but I also feel that in doing such it somewhat limits the 'functionality' and asthetics of the car as a whole, and should only be done if you feel you need it for safety as well as rigidity reasons.
Also, one thing you are greatly forgetting is there is this wonderful reality called build-quality, and I HIGHLY doubt all 4th gen floorpans are all exactly as rigid as one another. I have known of a couple of fairly 'stock' 4th gens that have had ripping near the center console on the floorpans and they have only been to a handful of autocrossing and maybe 1 or 2 road racing events and about 2-3 dozen drag racing outings, and these cars have been owned since new by these same owners, so previous owner collisions aren't a factor...
Besides all of that, another factor is how heavy the car really is, as in my case my car tips the scales at near, if not above, 4000lbs because of all the extra equipment I have on my setup (supercharger, aftercooler, large fuel system, brakes, cooling systems, dual disc clutch, ignitions, suspension, stereo, etc)... So I am sure I am over the 'specification' that GM designed into the floorpan of the car by weight alone... In your case, by the way you describe your desire to reduce weight, I would imagine your car may actually be under the original weight of the car as new?
Again, point being, YOU may find you have no need for subframes, but by far, and large, the largest majority of people prefer to have the car 'feel' solid regardless of it having an overall 'effect' on 'performance data'... Hell there is so much that people do to these cars that is FAR from 'necessary' it isn't even funny, but that is the key, people do what they want because of personal taste. Just like I probably couldn't stand it if your car is as 'stiff' as a truely competetive suspension needs to be, you probably couldn't stand how 'soft' I have my suspension tuned, yet while utilizing far from stock parts that *I* feel are best for thier purpose (rod ended PHR, LCA with rod ends on one end and a howe rubber end on the other, 32mm/21mm sway bars that work well with my weight balance, bump steer kit, eibach pro-kit springs and custom shock setup, larger Z06 brakes to handle the extra power/weight, which is needed with roughly 750+rwhp), and when combined pretty much I have my car tuned quite well for my tastes... And my car is designed around being a well-balanced all-around 'car', not a dragstrip monster, or a AX champion, but something I can enjoy to it's fullest in ALL cases, so a ton of factors come in vs the 'normal' buildup where you make compromises based upon the 'main' use, be it drag-racing or road-racing/ax, I want mine to be well balanced throughout... And for me, a solid chassis is paramount, thus I may end up going with a cage at some point, but for now the amount of work required to 'bury' a cage to where it has minimal impact on asthetics and useability, for me, is far too costly to justify... But who knows, maybe another year or two down the road I may just take the plunge...
#27
TECH Addict
Originally Posted by Foxxton
Due to the fact that I am trying to still find the limits of where the chassis can fail, I will leave all bracings off until I can find really where it is weak, how much it takes to break,
Originally Posted by Foxxton
Tried two different makes of tubular ones and still both failed in two different manners.
Originally Posted by Foxxton
Chassis geometry tests still didn't yield any differences, and the tests are extremely accurate up to 1x10^(-6)metres (by use of laser measurement of course).
Also there are many differnt ways a chassis can twist:
-Bow, in the middle either up or down, or with the noise of the car becoming higher/lower than the rear. SFC's would help here.
-Lateral, crabing so that the rear wheels appear offset from the front. SFC's probably wouldn't help much here, especially if only welded at the ends.
-Rotational, where the horizontal line intersects on a cross section, the front and rear can simply twist in opportist directions. SFC's again probably wouldn't help here as transverse bracing is needed.
I have no idea where the Fbody platform is strong and where it is weak. But I'm sure it isn't brilliant in every aspect.
Take the new Aston Martin DB9, it has one of the strongest chassis out there, as it uses technology similar to the Lotus Elsie. It is a bonded chassis. The coupe has a rotational force of 27,000 newton meters, the convertable is still incredable strong, but only has rotational force of 15,000 newton meters. (Or something like that, need to find the article about it). But uses the latest technology and CAD/CAM the convertable is severly limited compared to the coupe.
Therefore it is logical to assume a T-Top Fbody is not as good as a coupe. and the coupe is undoutably not brilliant either.
I still stand by my previous claim, that I see no reason NOT to get SFC's.
They are cheap and easy to install and are likely to show a benefit for many people. Plus they really arn't all that heavy, they mount in the middle of the car so won't affect the balance and are mounted below the centre of gravity so in many ways could be considered an advantage in this respect alone.
Originally Posted by Foxxton
I guess you could say I'm mad,
Originally Posted by Foxxton
Also to note, doors still line up correctly, t-tops only give slighty, but no change in behaviour while any of the SFC's were installed, and no dimpling.
And to see dimpling would mean slightly more than just abuse. I think if you are cornering hard enough to do this you probably have a major structural problem, I can't beleive a healthy car would suffer this, even with slicks.
Not sure if this will work on a Fbody (never tried). But it does on my TR7. Use a trolly jack an jack the car up under the front jacking point (think it's near the door hinges/front wheel). Get the car a good distance in the air, so that the front wheel is off the ground and the rear suspension is almost fully dropped. Now open the door on that side of the car. Gently try an close the door and see if it hads dropped at all. Or actually jack the car up with the door open if not.
I know if I do this on my TR7 the door will drop maybe 1/4 inch. Enough so that you have to be careful when closing it. However take it off the jack and it's all back to normal and you would never have know. This is chassis flex in slow motion.
Originally Posted by Foxxton
I hope this thread can remain like it is now, because it can use more input from a variety of drivers (daily driver, drag racing, AX, RR, and/or combination thereof). I would to see more "positive" and "constructive debate." I welcome naysayers as well, however I'd like to request to please reinforce your position with some solid info.
#28
TECH Enthusiast
iTrader: (1)
Join Date: Nov 2004
Location: Ontario, Canada
Posts: 698
Likes: 0
Received 0 Likes
on
0 Posts
I have never seen anyone make a credible claim that frame stiffening (SFC, STB) would make a car handle "better". Far and away the most common claim is that rigidity, and NVH are improved. For me that is worth the price of entry. As a second benefit, reducing fatigue wear on the chassis is worthwhile so that aggressive driving over many years will not result in a failure (or at least last longer before failure). This is a different goal than for an auto-crossed car that is constantly being modified or improved. I want endurance in the worst possible long term test there is, street driving.
#29
was going to get on the poll but i got bolt in then welded them in for more clearnce becouse i have a lt1 car and the bolt in ran up inside of the drip rail as far as gain could tale other than lot stiffer
#30
TECH Fanatic
iTrader: (1)
Join Date: Sep 2002
Location: Brisbane, QLD, AUS
Posts: 1,747
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by 95 TA - The Beast
If so, then on a t-top car you are SADLY mistaken, as with a STB the chassis is much more rigid and 'solid' feeling going over uneven surfaces, and even tho it may be 'subjective' I have ZERO doubt ANYONE will notice the difference...
Originally Posted by 95 TA - The Beast
And if you feel that there is not enough movement to warrant one, then why were there so many problems with the three-point units that not only mount to the strut towers but also the cowl? There were people cracking windshields from all the movement of the chassis, thus a lot of places stopped making those all together.
Originally Posted by 95 TA - The Beast
What it comes down to is personal preference. End of subject. As in you prefer a loose chassis that compliments your driving style and your use of your vehicle. For *ME* I want, and desire, to keep my car basically as long as I am living, and for that I feel MUCH better with as solid and rigid a chassis I can get, which includes the best subframes I can find as well as a STB... At the moment, with the aftercooler on my setup, I am running without a STB, but I can tell you it is a major difference in chassis rigidity 'feel' than with it. Thus I will be going to Alston Chassis this next spring to see if they can custom fab one to fit with the aftercooler.
#31
TECH Fanatic
iTrader: (1)
Join Date: Sep 2002
Location: Brisbane, QLD, AUS
Posts: 1,747
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by 95 TA - The Beast
I do feel a cage is the best way of making the chassis as rigid as possible, but I also feel that in doing such it somewhat limits the 'functionality' and asthetics of the car as a whole, and should only be done if you feel you need it for safety as well as rigidity reasons.
Originally Posted by 95 TA - The Beast
Also, one thing you are greatly forgetting is there is this wonderful reality called build-quality, and I HIGHLY doubt all 4th gen floorpans are all exactly as rigid as one another. I have known of a couple of fairly 'stock' 4th gens that have had ripping near the center console on the floorpans and they have only been to a handful of autocrossing and maybe 1 or 2 road racing events and about 2-3 dozen drag racing outings, and these cars have been owned since new by these same owners, so previous owner collisions aren't a factor...
#32
TECH Fanatic
iTrader: (1)
Join Date: Sep 2002
Location: Brisbane, QLD, AUS
Posts: 1,747
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by 95 TA - The Beast
Besides all of that, another factor is how heavy the car really is, as in my case my car tips the scales at near, if not above, 4000lbs because of all the extra equipment I have on my setup (supercharger, aftercooler, large fuel system, brakes, cooling systems, dual disc clutch, ignitions, suspension, stereo, etc)... So I am sure I am over the 'specification' that GM designed into the floorpan of the car by weight alone... In your case, by the way you describe your desire to reduce weight, I would imagine your car may actually be under the original weight of the car as new?
Originally Posted by 95 TA - The Beast
Again, point being, YOU may find you have no need for subframes, but by far, and large, the largest majority of people prefer to have the car 'feel' solid regardless of it having an overall 'effect' on 'performance data'... Hell there is so much that people do to these cars that is FAR from 'necessary' it isn't even funny, but that is the key, people do what they want because of personal taste. Just like I probably couldn't stand it if your car is as 'stiff' as a truely competetive suspension needs to be, you probably couldn't stand how 'soft' I have my suspension tuned, yet while utilizing far from stock parts that *I* feel are best for thier purpose (rod ended PHR, LCA with rod ends on one end and a howe rubber end on the other, 32mm/21mm sway bars that work well with my weight balance, bump steer kit, eibach pro-kit springs and custom shock setup, larger Z06 brakes to handle the extra power/weight, which is needed with roughly 750+rwhp), and when combined pretty much I have my car tuned quite well for my tastes... And my car is designed around being a well-balanced all-around 'car', not a dragstrip monster, or a AX champion, but something I can enjoy to it's fullest in ALL cases, so a ton of factors come in vs the 'normal' buildup where you make compromises based upon the 'main' use, be it drag-racing or road-racing/ax, I want mine to be well balanced throughout... And for me, a solid chassis is paramount, thus I may end up going with a cage at some point, but for now the amount of work required to 'bury' a cage to where it has minimal impact on asthetics and useability, for me, is far too costly to justify... But who knows, maybe another year or two down the road I may just take the plunge...
Sorry, but once again some here would like to see more evidence than testimonies saying, “I like this, so everybody needs to listen to me.” A lot of people here have heard personal taste, I want to give them the meat of the facts, not just the fats and sugars on the tongue their taste buds desire (no pun intended).
Are you aware of the suspension mods we have? Did you read what we have? We have tried much of those “placebo pills” and have deduced to what works so far, which our setup is now similar to what many FRRAX users have, provided their sanctioning bodies will allow, so this is far from a normal “build-up.” I’m not going to reveal all what we have now, however I can mention that we’re running around 400rwhp/378rwtq SAE(not revealing cam profile and other exhaust and engine mods yet). Wanna hear something that’ll make you s*** in your pants? We’re still running the stock 10 bolt with a T2R. Our shocks have spherical bearings with 650front/225rear spring rates. We are using the Sam Strano 35/22 stabiliser bar combo. Yes, we are also using Aluminium LCA’s and PHB’s with Aurora Heim joints (quiet, strong, and durable). Here’s the kicker, the car is still street friendly and still whips many other cars on the street, that is tested safely through an AX course. We’re experimenting with different types of tires as well.
#33
Foxxton, your WHOLE argument is based SOLELY on YOUR measuring a body at rest for 'change' from a previous set of measurements... That does NOTHING, NADA, INFINITO, NOT A GOD DAMN THING for measuring the amount of flex the car has... PERIOD... Just because YOUR CAR doesn't have a static change only means that the ELASTICITY factor of the chassis is well built-in, so good that it seems to 'come back to norm'...
That does NOT MEAN the chassis doesn't flex... End of subject...
you have even mentioned that you udnerstand the windshield can crack with a 3-point STB... What is causing the cracking, CHASSIS FLEX!!!
Gods, you are an arrogant pup, that is for sure...
Until YOU put stress gauging IN the car and the only way to do that properly is to gut the damn thing and put all the proper measurement collecting sensors in and aroudn teh body you FOR FACT cannot claim to mention ANYTHING as to the AMOUNT of flex the car has... Measuring a body at rest DOES NOTHING to indicate how much flex it went through, jsut in case you missed that point above...
And if you think the floorpan on a f-body isn't part of the stress bearing components, then you are showing how TRUELY IGNORANT and foolish you really are based on the simple fact that the construction of the F-Body is a UNIBODY, and as ALL UNIBODIES, the entire BODY OF THE CAR, thus the UNIBODY moniker, is part of the stress bearing structure... That is one point I don't have to go into detail for as any FEA analysis engineer would be happy to explain that to you... I just laugh at times at your lack of engineering understanding, and your 'thumping your chest' on hollow, this and very short-sighted data elements... Your 'facts' are FAR FAR FAR from the imperical data auto-makers actually generate to properly produce a vehicle... It is all based upon 'trial and error' and 'measureing to the best of YOUR ability', which again is far from what the automakers and professional engineers do... Just trying to 'qualify' your ASSumptions about 'your' readings...
You just come off that everyone else is 'ignorant' because of thier choices... Fact is ANYONE that has a clue can feel outright a chassis' rigidity over uneven surfaces, and if stiffening them up with SFC and STB is something THEY want to do, then it is thier choice, again REGARDLESS of ANY performance increase or decrease... That is all...
Such arguments are even futile for you to attempt to make based upon such thin 'evidence' you claim to have...
That does NOT MEAN the chassis doesn't flex... End of subject...
you have even mentioned that you udnerstand the windshield can crack with a 3-point STB... What is causing the cracking, CHASSIS FLEX!!!
Gods, you are an arrogant pup, that is for sure...
Until YOU put stress gauging IN the car and the only way to do that properly is to gut the damn thing and put all the proper measurement collecting sensors in and aroudn teh body you FOR FACT cannot claim to mention ANYTHING as to the AMOUNT of flex the car has... Measuring a body at rest DOES NOTHING to indicate how much flex it went through, jsut in case you missed that point above...
And if you think the floorpan on a f-body isn't part of the stress bearing components, then you are showing how TRUELY IGNORANT and foolish you really are based on the simple fact that the construction of the F-Body is a UNIBODY, and as ALL UNIBODIES, the entire BODY OF THE CAR, thus the UNIBODY moniker, is part of the stress bearing structure... That is one point I don't have to go into detail for as any FEA analysis engineer would be happy to explain that to you... I just laugh at times at your lack of engineering understanding, and your 'thumping your chest' on hollow, this and very short-sighted data elements... Your 'facts' are FAR FAR FAR from the imperical data auto-makers actually generate to properly produce a vehicle... It is all based upon 'trial and error' and 'measureing to the best of YOUR ability', which again is far from what the automakers and professional engineers do... Just trying to 'qualify' your ASSumptions about 'your' readings...
You just come off that everyone else is 'ignorant' because of thier choices... Fact is ANYONE that has a clue can feel outright a chassis' rigidity over uneven surfaces, and if stiffening them up with SFC and STB is something THEY want to do, then it is thier choice, again REGARDLESS of ANY performance increase or decrease... That is all...
Such arguments are even futile for you to attempt to make based upon such thin 'evidence' you claim to have...
#35
TECH Fanatic
iTrader: (1)
Join Date: Sep 2002
Location: Brisbane, QLD, AUS
Posts: 1,747
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by 95 TA - The Beast
Foxxton, your WHOLE argument is based SOLELY on YOUR measuring a body at rest for 'change' from a previous set of measurements... That does NOTHING, NADA, INFINITO, NOT A GOD DAMN THING for measuring the amount of flex the car has... PERIOD... Just because YOUR CAR doesn't have a static change only means that the ELASTICITY factor of the chassis is well built-in, so good that it seems to 'come back to norm'...
That does NOT MEAN the chassis doesn't flex... End of subject...
you have even mentioned that you udnerstand the windshield can crack with a 3-point STB... What is causing the cracking, CHASSIS FLEX!!!
Gods, you are an arrogant pup, that is for sure...
Until YOU put stress gauging IN the car and the only way to do that properly is to gut the damn thing and put all the proper measurement collecting sensors in and aroudn teh body you FOR FACT cannot claim to mention ANYTHING as to the AMOUNT of flex the car has... Measuring a body at rest DOES NOTHING to indicate how much flex it went through, jsut in case you missed that point above...
And if you think the floorpan on a f-body isn't part of the stress bearing components, then you are showing how TRUELY IGNORANT and foolish you really are based on the simple fact that the construction of the F-Body is a UNIBODY, and as ALL UNIBODIES, the entire BODY OF THE CAR, thus the UNIBODY moniker, is part of the stress bearing structure... That is one point I don't have to go into detail for as any FEA analysis engineer would be happy to explain that to you... I just laugh at times at your lack of engineering understanding, and your 'thumping your chest' on hollow, this and very short-sighted data elements... Your 'facts' are FAR FAR FAR from the imperical data auto-makers actually generate to properly produce a vehicle... It is all based upon 'trial and error' and 'measureing to the best of YOUR ability', which again is far from what the automakers and professional engineers do... Just trying to 'qualify' your ASSumptions about 'your' readings...
You just come off that everyone else is 'ignorant' because of thier choices... Fact is ANYONE that has a clue can feel outright a chassis' rigidity over uneven surfaces, and if stiffening them up with SFC and STB is something THEY want to do, then it is thier choice, again REGARDLESS of ANY performance increase or decrease... That is all...
Such arguments are even futile for you to attempt to make based upon such thin 'evidence' you claim to have...
That does NOT MEAN the chassis doesn't flex... End of subject...
you have even mentioned that you udnerstand the windshield can crack with a 3-point STB... What is causing the cracking, CHASSIS FLEX!!!
Gods, you are an arrogant pup, that is for sure...
Until YOU put stress gauging IN the car and the only way to do that properly is to gut the damn thing and put all the proper measurement collecting sensors in and aroudn teh body you FOR FACT cannot claim to mention ANYTHING as to the AMOUNT of flex the car has... Measuring a body at rest DOES NOTHING to indicate how much flex it went through, jsut in case you missed that point above...
And if you think the floorpan on a f-body isn't part of the stress bearing components, then you are showing how TRUELY IGNORANT and foolish you really are based on the simple fact that the construction of the F-Body is a UNIBODY, and as ALL UNIBODIES, the entire BODY OF THE CAR, thus the UNIBODY moniker, is part of the stress bearing structure... That is one point I don't have to go into detail for as any FEA analysis engineer would be happy to explain that to you... I just laugh at times at your lack of engineering understanding, and your 'thumping your chest' on hollow, this and very short-sighted data elements... Your 'facts' are FAR FAR FAR from the imperical data auto-makers actually generate to properly produce a vehicle... It is all based upon 'trial and error' and 'measureing to the best of YOUR ability', which again is far from what the automakers and professional engineers do... Just trying to 'qualify' your ASSumptions about 'your' readings...
You just come off that everyone else is 'ignorant' because of thier choices... Fact is ANYONE that has a clue can feel outright a chassis' rigidity over uneven surfaces, and if stiffening them up with SFC and STB is something THEY want to do, then it is thier choice, again REGARDLESS of ANY performance increase or decrease... That is all...
Such arguments are even futile for you to attempt to make based upon such thin 'evidence' you claim to have...
Again your presumptions don't answer the point. Your name calling makes you look much more ignorant tham I supposedly am. Again, are you aware that I have a Baccalaureate Degree in Material Sciences? Your not going to shut me down, nope sorry. If you don't like a scientific approach, no problem, but you need to chill, plain and simple. I'm not perfect, however I and 300/bhp are being much more objective to determine whether the efficacy of SFC's for the 4th gen f-body.
Personal choice has been beat to death. I'd like to offer much more evidence, but again time must permit. And again, not going to reveal all what there is to have, but once again, we are using several techniques, and finite element analysis isn't always going to reveal all that is or isn't present as far as stiffness would be, however that is another method we are using at the SAE club. We do have several Mechanical Engineers that specialise with FEA that are participating as well.
Monocoques are designed with only certain parts have a better job at stress bearing than other parts of the unit-body. Basically, If the firewall and the floorpan was designed on a full frame chassis, why are they too still weaker points? Easy, they aren't designed to be responsible for that purpose. The monocoque is designed to offer an easier method of mass manufcturing, and even though it has a poor rigidity-to-weight ratio due to most of its pressed sheet metal, it can be strong and highly rigid overall, plus there are parts to this chassis and other monocoques that cam be spot welded to it, which often includes the floorpan and firewall areas.
Sorry, but you can't just go by SOTP alone. Some people that have installed STB's and SFC's have kept the much maligned DeCarbons installed, which many AX and RR participants can agree is the wrong thing to do, espcially since they are essentially the connecting point between tires and body, hence suspension. I had many rattles myself and did install several types as mentioned, however the problems weren't solved, until I went right to the problems themselves. Shocks are extremely important to handling and maintaining a vehicle's handling characteristics. Yes chassis need to be rigid, however the chassis is extremely rigid from the factory, but the suspension is mostly garbage at it's bushings, sway bars, and shocks.
300/bhp is challenging me in a much more objective manner, so I'll just ignore your bs and will deal with his challenges, and those who choose to do so in a civil manner. Oh yes, you shouldn't read into more than what I am saying. If you do read and offer direct challenge, that's okay, but since you're spouting off and not really answering directly, I'll deal with those who do, and will ignore you as well. By the way, we do have not ONE, but TWO 4th gen F-bodies. One is kept stock, while another is practically bare, however the testing controls are very consist. Sorry, instead of you assuming things with spouts of namecalling, just ask and you'll find out.
How I come off I could care less as I keep it straight to the point, and the point of what we in the SAE clud are doing with this is to test the efficacy of SFC's and STB's on different platforms. We're not just limited here to an F-bosy, but those that have been deemed "weak", so we'd like to test their limits. If you can't handle the discussion, then you have a choice like everybody here to put up or shut up, and you have offered little input other than your simplistic opinions.
Just to inform you we have some AXer's and RRer's that have information consistent with my findings so I'll let them chime in.
#36
TECH Fanatic
iTrader: (1)
Join Date: Sep 2002
Location: Brisbane, QLD, AUS
Posts: 1,747
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by 95 TA - The Beast
you have even mentioned that you udnerstand the windshield can crack with a 3-point STB... What is causing the cracking, CHASSIS FLEX!!!
http://www.bmrfabrication.com/faqs.htm
Don't like most of their stuff, however this is a much more accurate explanation that is consistent with my findings, and other RRer's and AXer's as well.
Chassis flex per se isn't responsible for the windshield cracking under that circumstance, but rather the transfer of the stresses from the shock towers.
#37
TECH Fanatic
iTrader: (1)
Join Date: Sep 2002
Location: Brisbane, QLD, AUS
Posts: 1,747
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by 300bhp/ton
Are yousaying you actually want it to brake?? Becuase you can have excessive twist and it will be fine, doors will open and close and body work will be fine. But that doesn't mean there isn't a lot of twist.
Yes, the door will open and close fine, however we still must perform all measures we are capable of to rule out any errors as what you are too with these replies. We are operating the vehicles on road courses and AX courses in order to detect where the twisting could occur. Nevertheless, we must perform all checks, including the cheetah machine.
Originally Posted by 300bhp/ton
When you say failed, what do you mean. You failed to notice any difference, or the actual part broke? Sorry if I'm being dumb, just not sure what you meant
#38
TECH Fanatic
iTrader: (1)
Join Date: Sep 2002
Location: Brisbane, QLD, AUS
Posts: 1,747
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by 300bhp/ton
That I don't doubt, but as I said above, you can have twist and it will be fine. Just like a leaf suspension spring you can compress and decompress it (a form of loading, i.e. twisting) but it will still meausre the same shpe, angle and dimensions because it will return to its previous state.
Also there are many differnt ways a chassis can twist:
-Bow, in the middle either up or down, or with the noise of the car becoming higher/lower than the rear. SFC's would help here.
-Lateral, crabing so that the rear wheels appear offset from the front. SFC's probably wouldn't help much here, especially if only welded at the ends.
-Rotational, where the horizontal line intersects on a cross section, the front and rear can simply twist in opportist directions. SFC's again probably wouldn't help here as transverse bracing is needed.
I have no idea where the Fbody platform is strong and where it is weak. But I'm sure it isn't brilliant in every aspect.
Also there are many differnt ways a chassis can twist:
-Bow, in the middle either up or down, or with the noise of the car becoming higher/lower than the rear. SFC's would help here.
-Lateral, crabing so that the rear wheels appear offset from the front. SFC's probably wouldn't help much here, especially if only welded at the ends.
-Rotational, where the horizontal line intersects on a cross section, the front and rear can simply twist in opportist directions. SFC's again probably wouldn't help here as transverse bracing is needed.
I have no idea where the Fbody platform is strong and where it is weak. But I'm sure it isn't brilliant in every aspect.
#39
TECH Fanatic
iTrader: (1)
Join Date: Sep 2002
Location: Brisbane, QLD, AUS
Posts: 1,747
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by 300bhp/ton
Take the new Aston Martin DB9, it has one of the strongest chassis out there, as it uses technology similar to the Lotus Elsie. It is a bonded chassis. The coupe has a rotational force of 27,000 newton meters, the convertable is still incredable strong, but only has rotational force of 15,000 newton meters. (Or something like that, need to find the article about it). But uses the latest technology and CAD/CAM the convertable is severly limited compared to the coupe.
Therefore it is logical to assume a T-Top Fbody is not as good as a coupe. and the coupe is undoutably not brilliant either.
Therefore it is logical to assume a T-Top Fbody is not as good as a coupe. and the coupe is undoutably not brilliant either.
I cannot remember offhand what its complete torsional rigidity was, so I’ll ask the engineer for that.
Originally Posted by 300bhp/ton
I still stand by my previous claim, that I see no reason NOT to get SFC's.
They are cheap and easy to install and are likely to show a benefit for many people. Plus they really arn't all that heavy, they mount in the middle of the car so won't affect the balance and are mounted below the centre of gravity so in many ways could be considered an advantage in this respect alone.
They are cheap and easy to install and are likely to show a benefit for many people. Plus they really arn't all that heavy, they mount in the middle of the car so won't affect the balance and are mounted below the centre of gravity so in many ways could be considered an advantage in this respect alone.
#40
TECH Fanatic
iTrader: (1)
Join Date: Sep 2002
Location: Brisbane, QLD, AUS
Posts: 1,747
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by 300bhp/ton
Well, as Isaid the flex you have may not be permenant anyhow. As for the T-Tops, well if the chassis had flexed before the SFC's that may account why you saw no difference. (I know thes to statements are contridictory, but you could get both things occuring at the same time).
Originally Posted by 300bhp/ton
And to see dimpling would mean slightly more than just abuse. I think if you are cornering hard enough to do this you probably have a major structural problem, I can't beleive a healthy car would suffer this, even with slicks.