I heard T-TOP camaro body is easy twist. How to prevent the body from twist ?

 

Start with SFCs or sub frame connectors

 

btw how do I know if the body already twist ? what sign do I look for ?

 

Stress cracks in the paint near the t-tops for starters...

 

I just look, and dint see any crack at T-Top, so i guest im good for now . how easy its for these body to twist ?

 

Just listen to the body creak when pulling into a steep uneven driveway...basically anytime you drive over uneven ground. Going over a speed bump with just one tire will let you hear it too. But if you are just keeping the car a simple daily driver, nothing fancy (other than looking good), I'd say sfc are not really needed. Someone correct me if that is wrong. What is important and you should stay on top of is making sure your door hinges are in good condition- no sagging. The doors are structural and tie the front and rear of the car together when closed. If the hinges wear, this connection is weakened. I did not a slight improvement in squeaks and feel after having a new hinges kit installed.

 

SFC's are a must for any third gen camaro, even hardtops, let alone t-tops. They structurally re-inforce the frame which should have been re-inforced from the factory. Now after years of wear and stress (and sometimes rust), the body is weakened and needs SFC's. Either inner or outer frame connectors are sufficient for daily driver, I have both installed on the car and it makes handling, the feel, comfort, squeeks, rattles, comfort, etc. all a million times better! I have a t-top car as well and after the first set I welded on I couldn't beleive the difference, I have no doubt that you will NOT regret installing them. They are not that expensive for what they're worth... And if you do install them get them installed by a professional welder and pay the extra bucks instead of getting a buddy in his driveway to do it, you don't wanna mess this install up. The better the weld job, the better the re-inforcement.

Hope this helps! I will say.. DO it!

Later,
-Marc

 

Hi, I think imma do it, do you guy have link where to buy SFC for good price. thanks

 

I have the SFCs that Lon over at TDS (board sponsor) sells. They are "bolt in" but I had them welded in. And yeah, get them professionally installed, the car has to be proper and level when installing. The suspension has to be loaded when installing. UMI, BMR, and Spohn also make SFCs.

 

Ok, I stand corrected. What is the difference between inner and outer sfc? I've seen the Spohn and UMI designs, don't they both tuck up near the rocker panels and get welded in?

Also Marc- nice to know of someone else with a thirdgen in Montreal. I went to school in Montreal before moving south, and had my car up there for one summer. What performance shops do you use up there?

 

Hey man,

Inner and outer SFC's do the same trick, really... The only difference visually is that the UMI/SPOHN version tucks along the rocker (outer) and the MAC/TDS/HOTCHKIS etc. are welded directly from the tranny xmember mount subframe to the rear LCA mounting point part of the frame. One could argue that since it's a direct weld it's 'stronger', but who knows really, i have both so there's no real way to tell, just that damn it makes a ton of a difference! I started with the MAC sfc's and it made a huge diff... Then after two years of having that, i put another set on, the SPOHN sfc's, and it stiffened things up a bit more but not near as noticeable as the MAC ones... It's definitely necessary to have one set, but to have two sets it is a bit overkill it seems but it does help a bit more.. It's just more re-inforcement at the end of the day.

Yeah there's not many people from Quebec on here, and i haven't seen anyone from Montreal. My dad's got a garage so I do some stuff over there but for the big things i'll go to this place called "Zekes" in Lachine. They're really good, they actually used to build the Firehawks for GM when they were building F-Body's over here from 93 to 2002.. They charge a pretty penny though but the work is top notch and they've got a great rep.

Which school did you go to?

 

Its not the same thing between the SFC's that mount to the 'frame' and those that mount near the rockers. I've tried to explain this in various ways, I just thought of another that maybe some can relate to. Imagine the force required to turn your steering wheel when the car is parked. If any of you have driven an older car with a huge wheel or swapped out your wheel for one that is smaller, you would know the extra effort required to turn the smaller wheel. This works in reverse as well, if the wheels try to turn from hitting a bump or something like that, it is easier to resist the movement of the wheels at the steering wheel if the steering wheel is larger rather than smaller. Its a simple fact of leverage. Another thing I brought up before that is similar is a breaker bar, if you use a 6" ratchet vs a 24" breaker bar, its going to be a lot easier to apply the same amount of torque with the longer bar (force being applied further away from the axis you are trying to twist) much like the smaller and larger steering wheel.

What this means on the car is that, ideally, connectors farthest away from the axis the car is trying to twist on (somewhere in the center of the body of the car) are better. However there are always limitations and exceptions due to what you're working with. The Alstons do mount to the 'frame' of the car, but the 'frame' is not exactly substansial to begin with. That is because the car is a unibody. The side rockers are part of the frame as well, although somewhat poorly connected/attached to the front and rear 'frame' rails. If you can improve the connection of the front and rear to the side rockers, then the SFC's that mount to the rockers are absolutely going to be better to resist torsion and they should be equal in resisting bending. Another possible benefit of the rocker mounted SFC's is if you can weld or attach them to the rockers at multiple locations. The strength of any member is determined by its unsupported length, so if you have the Alston connectors attached at the 'frame' in the front and back and nothing else vs being attached to the floor at multiple locations, the second will be much stronger than the first because it will be using portions of the floor to resist movement.

 

All third gens can easily twist and need SFC. After that, there's little you can do to "stiffen it up" short of putting a simple 6 point roll bar into it.

My car has T-tops. After the first year of racing, I installed a roll bar. I never had stress cracks in the roof but I was wrinkling the floor because the LCA were pushing so hard. I now have a back halved car with a full cage and still have T-tops.

 

I am all about SFC's but I was just driving (without SFC's) and turned right on to a steep incline at low speed and my whole car teeder toddered for a second then my forward momentum got the wheels back to the pavement. All this and my floor boards near the rockers are hemmed up on both sides from the previous owner. I am still going to make my own SFC's this summer but I think they are more usefull on some cars than others. Maby ill see a difference maby not, at least ill be able to jack her up easier.
ps. most of us dont have enough torque to mangle our floor boards. ALKYIROC with your low 9's

 

I was wrinkling floorboards running low 12's. I've only been in the 9's for the last 3-4 years. I've raced the car since 1999.

 

I was at McGill from '04-'08 studying chemistry (brutal). I am from NJ but my dad insisted I check out McGill & Montreal, which I did and I loved it.

Cool to know that shop Zekes built the Firehawks! My friend out on the West Island had a neighbor with a Firehawk, said driving in it was crazy. My landlord downtown, while watching me fix the headlights in the street also said the GM factory for the fbodies was in Quebec.

Being in Quebec I know you must have a winter beater?

 

ofcourse! My winter / work car when the iroc is resting is a 2001 cavalier... Pretty standard, 4 door, beat up thing... Still in great shape and runs good... I would drive it anywhere I maintain it very well, but after driving that it's such a rush going from a cavvy to the iroc! Handling, speed, looks, CD player, it's all in there.. One of my friends is from NJ and studied at concordia in engineering i believe. He said it was way less expensive to study in Quebec or somethin. Anyways sorry to hijack the thread guys! SFC's all the way lol..

 

I read somewhere that the hardtop was only 5% more rigid than the T-top cars. so it can't be that bad. The roof of pretty much any hardtop is paper thin and can't be relied on for structure of an entire vehicle. that includes the fbody.
also, I've noticed many other cars have sub frames that stretch the length of the floorboards, it's just a smarter design. that would make the addition of SFCs on such cars pretty much pointless, because there's nothing to really connect to.

 

SFC join the front and rear subframes. Third gens don't really have much for subframes but the metal is heavier and has more layers where the subframes are. Between the subframes is nothing more than sheetmetal. Joining the subframes prevents the body from flexing through the thin sheetmetal.

All unibody cars need SFC to stiffen up the body for performance use. It's not just a third gen or any generation F-body problem. At least the first and second gens had beefier subframes.

 

what i'm talking about is that there are some cars that have sub frames the full length of the floorboards. for example my 90 eagle talon has this. the "frame rails" run on both sides of the transmission tunnel. an SFC would do practically nothing to a car with this design. would you like a picture?

 

I own 4 of those car, 3 sti and 1 gsx 4g63 all awd, fun little car to drive, after I crash my last 1, I never go back to import, that how I move to american car .

 

i built 10 point sub frame connectors. . . i don't have any worries about flexing.

 

or, you could try and adhere a cored (nomex, foam, balsa, etc) carbon fiber laminate adhered to the interior of the car to include the roof. I'd probably make an X in a box on the interior roof (on a hard top) you'd have to figure something out for the t top- tied into the a pillars and down the c pillars and just some ribs along load paths in the floor. Use a good adhesive with bond line control and maybe wet lay it up (epoxy resin of course) and co-cure it in place after you prep the metal properly (probably don't even have to worry about it too much)
You could probably be fine with some 3k plain weave. If you want to get crazy throw in some unidirectional along the load path of highly stressed areas. Vacuum bag it and get the car as hot as you can. Might not be a bad idea to fill interior metal cavities with an expanding foam, various densities are available.

You'd have a ridiculously stiff chassis with hardly any weight penalty

 

Got some scrap laying around that needs some use? Could probably even get away with doing that within scca rules

 

here's a picture of what I'm talking about. it's too bad f-body cars weren't deigned a little bit like this.

 

Heh, those would be some big chunks of "scrap".

The CF alone isn't really that expensive. Its all the other supplies that start to add up. Plus the time involved. I'll have to look at the scca rules more closely. Not that I would ever cheat but that kind of stiffening would probably be rather easy to conceal.

That said, I've got some stuff in the works. Stay tuned

 

this is how i strengthen my t-top.

 

you need more bars, i can still see through that jungle gym

 

that too much more then I expect lol.

 

What is the point of all that?

 

damn..... that is WAY too much....