Suspension and Chassis Questions about your suspension? Need chassis advice?

t-tops fly out due to chassis flex??

Thread Tools
 
Search this Thread
 
Old Aug 23, 2006 | 09:21 PM
  #1  
slickrock55's Avatar
Thread Starter
Member
 
Joined: Nov 2000
Posts: 323
Likes: 0
From: mayfield, OH
Car: 82 Trans am
Engine: Twin turbo 350
Transmission: T-56
t-tops fly out due to chassis flex??

So i had a little un-nerving experience a few days ago. Giving a friend a ride, accelerating down a straight on-ramp to the freeway, my passenger t-top suddenly popped out, flew maybe 20 feet spinning into the air and landed in the grass at the side of the freeway. Astonishingly, the glass was not broken and just the fiberglass was chipped. I'm thinking to myself, idiot, must not have been latched all the way.

However, when i retrieved it, it was fully latched! It somehow managed to flip out of its restraints regardless. This is an 82, so it has the L shaped clips to keep the tops in, not the later pin-style.

The car makes somewhere in the 450-500 hp range (based on a 12.4@118 pass). Is this enough to flex the chassis and make the top pop out? Is there another cause i'm overlooking? Clearly this is quite unacceptable and i REALLY dont want it to happen again.
Reply
Old Aug 23, 2006 | 09:57 PM
  #2  
johnnyboy's Avatar
Supreme Member
iTrader: (3)
 
Joined: Feb 2006
Posts: 1,093
Likes: 0
From: western ny
Car: '82 formula clone, 95 saab 900se
Engine: 350 vortec'd tbi, 2.0L turbo
Transmission: 700r4, 5 spd
Axle/Gears: 10 bolt 2.77 open
ABSOLUTELY that is definitely more than enough, i have a friend who had an 85 t-top car and the smae thing happened to him with a mildly modified 350 nothing near what you had, and another friend who had the same problem with a stock t-top car. do you have sfc's or anything to stiffen your chassis?
Reply
Old Aug 23, 2006 | 11:07 PM
  #3  
slickrock55's Avatar
Thread Starter
Member
 
Joined: Nov 2000
Posts: 323
Likes: 0
From: mayfield, OH
Car: 82 Trans am
Engine: Twin turbo 350
Transmission: T-56
Yep, forgot to add I do have spohn subframe connectors.

This all may be moot - as i think i'm installing a S&W racecars 8pt rollbar that i got a good deal on within the next week or two (Although not the one with the f-body door bars ) Hopefully THAT should be enough stiffness to keep those bad boys attached.

Ever heard of anyone changing to more robust latches (the kind on convertibles come to mind) or some kind of safety strap?
Reply
Old Aug 23, 2006 | 11:20 PM
  #4  
2kflhr's Avatar
Member
15 Year Member
iTrader: (1)
 
Joined: Jan 2006
Posts: 369
Likes: 0
From: Texas
Car: '68 396 SS/RS, '02 SS
Originally Posted by slickrock55
So i had a little un-nerving experience a few days ago. Giving a friend a ride, accelerating down a straight on-ramp to the freeway, my passenger t-top suddenly popped out, flew maybe 20 feet spinning into the air and landed in the grass at the side of the freeway. Astonishingly, the glass was not broken and just the fiberglass was chipped. I'm thinking to myself, idiot, must not have been latched all the way.

However, when i retrieved it, it was fully latched! It somehow managed to flip out of its restraints regardless. This is an 82, so it has the L shaped clips to keep the tops in, not the later pin-style.

The car makes somewhere in the 450-500 hp range (based on a 12.4@118 pass). Is this enough to flex the chassis and make the top pop out? Is there another cause i'm overlooking? Clearly this is quite unacceptable and i REALLY dont want it to happen again.
Seems to me if you had that much body flex you should also have some cracking going on with the body panels and seams breaking loose.

I could see some flex during a hard launch but not once the vehicle is rolling at 35 mph+.
Reply
Old Aug 24, 2006 | 07:42 AM
  #5  
AlkyIROC's Avatar
Moderator
25 Year Member
Liked
 
Joined: Jul 1999
Posts: 17,268
Likes: 169
From: 51°N 114°W, 3500'
Car: 87 IROC L98
Engine: 588 Alcohol BBC
Transmission: Powerglide
Axle/Gears: Ford 9"/31 spline spool/4.86
My car has never lost a T-top
Reply
Old Aug 24, 2006 | 12:02 PM
  #6  
2kflhr's Avatar
Member
15 Year Member
iTrader: (1)
 
Joined: Jan 2006
Posts: 369
Likes: 0
From: Texas
Car: '68 396 SS/RS, '02 SS
[QUOTE=Stephen 87 IROC;3034701]My car has never lost a T-top[/QUOTE

I think it is more a latching issue, if it came unlocked it could have hit right and knocked into the locked position.
Reply
Old Aug 24, 2006 | 02:18 PM
  #7  
slickrock55's Avatar
Thread Starter
Member
 
Joined: Nov 2000
Posts: 323
Likes: 0
From: mayfield, OH
Car: 82 Trans am
Engine: Twin turbo 350
Transmission: T-56
[QUOTE=2kflhr;3034937]
Originally Posted by Stephen 87 IROC
My car has never lost a T-top[/QUOTE

I think it is more a latching issue, if it came unlocked it could have hit right and knocked into the locked position.
Im starting to agree. I'll have to take a look at the latch mechanism and make sure its adjusted properly etc.

Guess i just wanted it to make too much power for the t-tops
Reply
Old Aug 24, 2006 | 06:54 PM
  #8  
Time2Fly's Avatar
Member
 
Joined: Jun 2006
Posts: 198
Likes: 1
Car: 1991 Z28
Engine: 400 ci LS3
Transmission: Jerico DR4
Giving a friend a ride, accelerating down a straight on-ramp to the freeway, my passenger t-top suddenly popped out,
That is an excellent example of Bournulli's principle.
Reply
Old Aug 24, 2006 | 07:20 PM
  #9  
2kflhr's Avatar
Member
15 Year Member
iTrader: (1)
 
Joined: Jan 2006
Posts: 369
Likes: 0
From: Texas
Car: '68 396 SS/RS, '02 SS
Originally Posted by Time2Fly
That is an excellent example of Bournulli's principle.

I needed it dumbed down:

"The decrease in pressure simultaneous with an increase in velocity, as predicted by the equation, is often called Bernoulli's principle"
Reply
Old Aug 25, 2006 | 11:41 AM
  #10  
V8Rumble's Avatar
Supreme Member
iTrader: (2)
 
Joined: Feb 2006
Posts: 1,547
Likes: 0
From: 39.84N 105.11W
Car: '89 Trans Am GTA
Engine: WAS 350 - now L92 (alum. 378/6.2L)
Transmission: WAS 700R4, now a built T56
Axle/Gears: 3.27 9-bolt
Originally Posted by Time2Fly
That is an excellent example of Bournulli's principle.
Reply
Old Aug 25, 2006 | 11:47 AM
  #11  
slickrock55's Avatar
Thread Starter
Member
 
Joined: Nov 2000
Posts: 323
Likes: 0
From: mayfield, OH
Car: 82 Trans am
Engine: Twin turbo 350
Transmission: T-56
Originally Posted by Time2Fly
That is an excellent example of Bournulli's principle.
Very well might be. Obviously theres fast moving air above the car, and its already an area of (however limited) flow detachment. But the windows were open, and unless that served to "ram" air in and increase the pressure, i dont see how such forces could build up.

Possible though
Reply
Old Aug 28, 2006 | 01:06 PM
  #12  
Gallileo60's Avatar
Supreme Member
 
Joined: Dec 2005
Posts: 1,244
Likes: 1
From: Texas City, Texas Area
Car: 89 RS, 92 Z28
Engine: 305 TBI, 350 TPI
Transmission: 700R4 Both Cars
Axle/Gears: 3.23 Posi.. 4 wheel disc both cars
My modded out 84 Berlinetaa did the same thing during a 1/4 mile race against a same color, same year Vette.. (I won)...Im just glad there was no one behind me....The car started wheel hopping really bad, and instead of letting off like a normal person would have...Well you know....Anyway mine driver side top went airborne, and broke into so many little peices.....I did not get laid when I got home. (Wife was pissed)...Mine was a combo of body flex, and poor back shocks....This car ran low 13's..mostly an Edelbrock 350.....I quickly replaced the shocks, and did not have the problem again, altho later I did tie the subframes...
Reply
Old Aug 28, 2006 | 02:39 PM
  #13  
slickrock55's Avatar
Thread Starter
Member
 
Joined: Nov 2000
Posts: 323
Likes: 0
From: mayfield, OH
Car: 82 Trans am
Engine: Twin turbo 350
Transmission: T-56
I wonder if maybe its an issue with the type of latching mechanism. I dug this up:

Fisher*
1982-1983
Factory Installed
LOF Gray 08 glass, plastic edge trim around 3 sides. Hook type latching system.

Fisher*
1984-Mid 1985
Factory Installed
LOF Gray 08 glass, plastic edge trim around 3 sides. Pin type latching system.

Fisher*
Late 1985-1988
Factory Installed
LOF Gray 08 glass, exposed glass edge on 3 sides. Door key also fits t-top locks.

Fisher*
1989-1992
Factory Installed
LOF Gray 08 glass or LEXAMAR acrylic. Door key also fits t-top locks.

Ive got the hook type latch, i wonder if the pin type latch help retain the tops better. Im going to take a look at it today after work, but does anyone know if the mounting parts on the roof can be swapped for a later year? I would like to get some lexan tops for weight saving purposes.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Veaceonee
Firebirds for Sale
11
Sep 29, 2016 08:15 PM
1Aauto
Sponsored Vendors
1
Jan 15, 2016 06:26 AM
IROCZDAVE (88-L98)
Exterior Parts for Sale
1
Sep 22, 2015 08:28 PM
1Aauto
Sponsored Vendors
0
Sep 10, 2015 02:02 PM
SG91camaro
Camaros for Sale
2
Sep 5, 2015 10:27 PM




All times are GMT -5. The time now is 01:54 PM.