car seems unstable - Toyota Nation Forum : Toyota Car and Truck Forums

kid_quik · 07-09-2003, 12:54 PM

when i remove the top of my 1990 supra, it seems if i loose some of the rigidity of the car, ie it doesn;t seem as stable as with it.
is there anything i can do about this???
any help is appreciated

high c · 07-10-2003, 07:59 AM

hey do you live in ME? any how back to your Q, I am no supra guy but I think that takeing off the roof made the car less rigged. the car....(how do I say this) isent hole any more. do you get it?

kid_quik · 07-10-2003, 08:02 AM

thanks or your help
where do you live???

***Chris Corolla S*** · 07-10-2003, 01:29 PM

Hey Hi-C I'm from Maine originally but kid_quick I'm sure is from the scarborough in Canada

And yes I assume you are talking about T-Tops and it does make sense that you would lose some ridgidity when they are removed. Just don't do any road-racing with the tops off.

Otherwise the only way to address the problem would be to get a roll cage

kid_quik · 07-10-2003, 01:31 PM

would i have any luck putting in a strut bar in the front????

***Chris Corolla S*** · 07-10-2003, 02:09 PM

Well that's not exactly going to curb your chassis flex, but it will prevent flex between the strut towers. I guess front and rear sways and a strut bar should help over-all rigidity, but it is mostly stiffening the suspension, not the chassis.
Some stiff lowering springs and High performance gas shocks would be the best thing to stabalize the car. The only way to stiffen the actual chassis as I said is a roll cage...

jm_2thow · 07-10-2003, 07:09 PM

actuallllllllllllyyyyyyyyy u can stiffin the chassis with out putting a role cage in it talk to your local speed shop or whatever but on alot of cars to get rid of flex they weld bars underneath the chassis under the outsides, i am not really sure of the details but i have heard of alot of guys with 5.0 mustangs doing this, i think this would best address your problem and would be cheaper then doing a complete suspension stiffening

kid_quik · 07-10-2003, 08:03 PM

cool thanks for the help guys

Deep · 07-10-2003, 08:06 PM

Quote:

Originally posted by jm_2thow
actuallllllllllllyyyyyyyyy u can stiffin the chassis with out putting a role cage in it talk to your local speed shop or whatever but on alot of cars to get rid of flex they weld bars underneath the chassis under the outsides, i am not really sure of the details but i have heard of alot of guys with 5.0 mustangs doing this, i think this would best address your problem and would be cheaper then doing a complete suspension stiffening

Subframe connectors.

***Chris Corolla S*** · 07-11-2003, 10:48 AM

I thought of sub-frame connectors, but I have never heard of this being used on anything but a 5.0 stang. I figured a 90 Supra had a unibody construction and not a frame and therefore couldn't use sub-frame connectors...

I'm just guessing at this point. I'm sure some MkIII guy will stop by eventually.

high c · 07-12-2003, 09:25 AM

Bowdoinham, ME

jm_2thow · 07-13-2003, 03:45 PM

5.0 stang has a unibody constructino too, the only thing that doestn have unibody construction is trucks, or pretty much so for the last like 10-20 years

cdnsupra · 07-14-2003, 08:47 PM

if you think about it, you take the top off, then open the two doors. your whole car is being held together by whatever is on the bottom. the leverage alone is going to give you flexing. in future designs, toyota stiffened up the frame, the windsheild and rear window supports so the mk4 with the tops off is as tight as a mk3 with the top on. the mk4 still has targa shimmy. it is physics, and you can't beat science!

we have these various options.

add the front and/or rear strut tower bars. these provide a fair amount of stiffness as it creates a box around the suspension.

aftermarket sway bars also help to tie the sides of the car together, but do help a little.

stiffening up the suspension will not help stop the targa sway, as stated earlier, and will make it worse as the suspension passes the bumps off on the rest of the car.

Reg in calgary and a couple of fellows have fabricated targa-bars which connect up to the 4 bolt holes for the targa, but still allow that open air feeling. think of it as the biggest sun roof you have ever seen on a supra. these get you as close to having tha targa on as you can get, as long as you get them from reputable people. i heard of a few guys who made bad ones which didn't connect all that well, or provide the required stiffness.

thats my 2 cents. i don't often look in this section. if you have any other supra specific questions, feel free to PM me or post it in the supra section. I frequent the supra section, and the meets, and occasionally the off-topic. okay, okay, off-topic is where i heard to first every night looking for asian pron!!!!