I know the Supra body flexes a respectable amount with the targa removed, what I'm curious about is if that flex is concentrated in a specific area/zone of the body or is just a full body-length flex. I figure some of you engineering types and long-time targa owners might know as I'm still learning about the quirks with this ride. Thanks.
Targa-less body flex
- Thread starter mirage83
- Start date
It feels to be concentrated right in the middle, where, without the targa you've lost all its support. The front and rear sections seem to "wiggle" right in the middle from each other.
Aah, I remember my first experience of targa "wobble." Hell, I actually thought something was wrong when I sped out of my apartment complex with the roof out. The most noticeable thing to me is that the windshield/a-pillars "wobbles" left and right across the horizontal axis of the car.
After the springs/struts/sway bar upgrade it seemed to be even more noticeable than before. After the Do-Luck RXB it seemed to be decreased. Not sure how available these are anymore, I remember importing mine from Japan when the US Dollar was worth a bit more and the Yen was down and with the help of a fellow supra buddy that was 'in the biz.' There's also some "targa bars" out there that I've been told do a decent job, but I've never had my hands on them. I believe I remember seeing two models available. One was two bars that were parallel to the car length wise, and the other was a cross brace that made an X over the open hole in the roof. I'd imagine the X would be more effective, but as I said, I've never had my hands on them. Perhaps someone who has had them will chime in.
After the springs/struts/sway bar upgrade it seemed to be even more noticeable than before. After the Do-Luck RXB it seemed to be decreased. Not sure how available these are anymore, I remember importing mine from Japan when the US Dollar was worth a bit more and the Yen was down and with the help of a fellow supra buddy that was 'in the biz.' There's also some "targa bars" out there that I've been told do a decent job, but I've never had my hands on them. I believe I remember seeing two models available. One was two bars that were parallel to the car length wise, and the other was a cross brace that made an X over the open hole in the roof. I'd imagine the X would be more effective, but as I said, I've never had my hands on them. Perhaps someone who has had them will chime in.
Targa cars have supports added to the doors that fit into the body of the car when the door is closed. They are listed as "stabilizers" in the OEM parts catalog. The function of these has been debated, but they seem to try to use the doors to brace/leverage the front and rear of the car when the targa is out. For this to work properly, they would have to fit with very tight clearance, and the door hinges would have to have little or no play (brand new would be ideal). I'd bet just putting new door hinges on a targa car might really reduce targa wobble, assuming this is their intended purpose.
I went as far as to fill the framerails of my car with high-density foam, hoping to solve my targa wobble. I did not know about the door braces on targa cars, and ended up installing a rust-free set of non-targa car doors on my car. I still notice a fair bit of targa wobble, and plan to try to reinstall the braces. I really wish I had installed new door hinges, but this didn't occur to me until later.
Once I get around to it, I will at least have: front & rear strut, and floor braces, OEM stabilizers reinstalled. It's been a personal challenge for me to solve the dreaded wobble without using overhead bracing.
I went as far as to fill the framerails of my car with high-density foam, hoping to solve my targa wobble. I did not know about the door braces on targa cars, and ended up installing a rust-free set of non-targa car doors on my car. I still notice a fair bit of targa wobble, and plan to try to reinstall the braces. I really wish I had installed new door hinges, but this didn't occur to me until later.
Once I get around to it, I will at least have: front & rear strut, and floor braces, OEM stabilizers reinstalled. It's been a personal challenge for me to solve the dreaded wobble without using overhead bracing.
This is eactly why I took the opportunity to carefully drill through the top layer of sheetmetal inbetween every spot weld in my car last winter when I had it totally stripp bare.
Then I carefully and never near the same place twice welded basically almost double the number of spot welds on my car. Jumping from one area to the next for every single weld.
It took literally about a month and a half just for this upgrade to the stiffness of my ride. The difference is absolutely night and day though.
Even when I am hoisting myself outa the seat by pulling on the windshield pillars there is soooooooo much more strength and it feels so much more solid.
Massive undertaking, I had actually forgotten I did it, so long ago it was just a bared stripped unpainted frame. Wow, I've come so far it makes me realize.
Anyways, I have also seen a frame sorta dealymabobber the goes into the space when roof is out. Seemed like also a slick idea to me.
Then I carefully and never near the same place twice welded basically almost double the number of spot welds on my car. Jumping from one area to the next for every single weld.
It took literally about a month and a half just for this upgrade to the stiffness of my ride. The difference is absolutely night and day though.
Even when I am hoisting myself outa the seat by pulling on the windshield pillars there is soooooooo much more strength and it feels so much more solid.
Massive undertaking, I had actually forgotten I did it, so long ago it was just a bared stripped unpainted frame. Wow, I've come so far it makes me realize.
Anyways, I have also seen a frame sorta dealymabobber the goes into the space when roof is out. Seemed like also a slick idea to me.
Somewhat related question on the door/stabilizer point, the S2 CF Doors wouldn't be a good idea on a targa? I believe the same issue was brought up when someone was getting the CF targa piece, and there was a discussion since the targa itself is part of the structure.
Floor bracing was one of the things I had been considering to try and reduce the amount of flex and twist, and I figured that one or more people on here had already tried with some greater or lesser degree of success. The door hinges I hadn't thought about, might go ahead and plan on a new set of them just for giggles. The spot-welding marathon does make a lot of sense, though I shudder at the amount of time and effort you put into it.
Basically, I'm trying to map out the various options to reduce the flex as much as possible without massive reinforcements or modifications and without any overt, visible bracing. So all thoughts on the subject would be appreciated, as well as any attempts at this by others and what results they had. All of us Targa owners might benefit if we can get this worked out.
Basically, I'm trying to map out the various options to reduce the flex as much as possible without massive reinforcements or modifications and without any overt, visible bracing. So all thoughts on the subject would be appreciated, as well as any attempts at this by others and what results they had. All of us Targa owners might benefit if we can get this worked out.
replacing old sub frame bushing and torqueing the bolts will help some. and the best thing would be a an x brace underneath the car possibly from sub frame to sub frame and to the body if possible
As will a proper subframe connector setup. Working on that after my 2 piston 13" front brakes are finished 
mirage83;1152162 said:
This is exactly what got me started on my entire spot welding marathon in the first place.
The formost front brace that run side to side in front of the egine rad and justbehind your intercooler on my car had popped it's spot welds on on side of the car, can't remember if it were right or left. Anyways, I noticed this when I had the rad out and was in the process of taking the motor out for what originally was going to be a fairly in depth paint refresh for the first time in it's life, yes I am the original owner of my red 1990 supra!
Well I leaned in and had to pull myself up and then put my knee on that crossmember when I thought to myself, "Why the hell does this feel so wobbly", After some very detailed and very close inspection of the entire car I came to the conclusion that many spot welds throughout the car had released and they would only lead to the flex situation getting worse and worse of course.
My car has never seen a snow flake in it's life, as a matter of fact it rarely has ever seen rain. There isn't even the slightest spot of surface rust top or bottom on the entire beast and the only reason I was repainting is the trim (plastic pieces) had started to fade. So this was a fair weather car only and the body itself probasbly only has about 130,000Km on it or so. HOWEVER, pretty much all of that mileage was with a 600ish RWHP with the roof off pretty much all the time.
And an uncountable amount of 1/4 mile runs (pretty much weekly, my brother an I are very competitive and he's a nissan 300zx guy, no he only ever beat me once and that was only by a 10th of a second but to be fair I was only running on 4 cylinders at the time BHG, irradium plug in 6 dropped electrode into cylinder and 5 plug cracked in half from I assume the thermal shock of water in it's hot cylinder during a full boost run just previously)
I believe the torque of the motor and "spirited" driving around the mountains and town here (always within local speed limits and laws of course though :sarcasm
to be the cause of my spot weld failure over time.If you do decide to go through all the welds and double them up in your road sled you must be VERY CAREFUL not to weld more than 1 weld in one area at a time, and even then keep your air hose close with the blower and cool that puppy the second you finish the weld. I've heard horror stories (and fully believe them) and people welding to many in one side or area or even worse doing seam welds and ending up with badly twisted cars. Or cars that litterally break themselves up from the heat stresses of the welds during any kind of bump or slight stress to the body.
However, without any type of strut braces at all I honestly believe I have a stuiffer and better handling ride because of the welding, it's hard to descibe, but the crispness is substantal even over when the car was new. It's like driving with the roof on even when you have it off.
Maybe I should write up a howto from my experience of diagnosing and resolving/improving this problem. I'm betting more people have a bigger problem than they realize simply due to the fact it's easy to forget how crisp the ride why so long ago when they first got their car. The welds go so slowly and naturally you justy get used to it without realizing how good it used to be. I really did notice body flex but had forgotten how good it used to be before.
My sled in the red supras thread. I'll post some spot weld pics if there is interest.
http://www.supramania.com/forums/showthread.php?t=33184&highlight=supras+thread&page=22
even with the top on there is a considerable amount of flex in the car vs a hardtop. With all my targas you could feel it as you went up a steep driveway (going sidways so the front would be on a slope and the rear would be flat on the ground.). With my Hardtop I never felt anything. So another solid connection from the front to year would probably be the only way to clear it up.
wat about those weezel wings thingys? i seen em when i 1st signed up to SM but i believe they're not available anymore. i'd like to make one for my car.
I have a set of old targa bars (Dean Marcum?), which do reduce the flex significantly. I also have the 1st and 2nd gen of WeezL Wings. Hated driving with the wobble, even on Florida's fairly straight roads. Texas? This shit will make your eyes go "Cookie Monster."
Rajunz has the badest of all... He can actually place his targa on, while his crossbrace is on!!! From what Rajunz said, the person who made it said "never again."
Rajunz has the badest of all... He can actually place his targa on, while his crossbrace is on!!! From what Rajunz said, the person who made it said "never again."
I swear, I see one of these threads a week...
I have to say it everytime as well...
RETORQUE YOUR SUBFRAMES
It really does many a HUGE difference and make the car feel completely different, even with the top on.
I have to say it everytime as well...
RETORQUE YOUR SUBFRAMES
It really does many a HUGE difference and make the car feel completely different, even with the top on.
Poodles;1154502 said:
FWIW, I checked through all subframe bolts and all were tight. The targas have a lot of flex in good working, stock form. I can't imagine how bad it'd be with loose sub-frame bolts too...