Printable Version of Topic

Click here to view this topic in its original format

914World.com _ 914World Garage _ How flexy is your frame?

Posted by: mbseto Sep 20 2014, 09:09 AM

Did a quick and dirty check to see how flexy my frame is. Just stuck a laser pointer on the rear fender with a magnet and aimed it at a notecard taped to the front fender. Marked the position of the dot, then jacked the wheels off the ground and marked the position of the dot again.

Have nothing to compare it to, but will check this in the future after some restoration work. If anyone is game to try this, it would be interesting to compare.Attached Image

Attached Image

Attached Image

Posted by: malcolm2 Sep 20 2014, 10:24 AM

It's been awhile since I read it, but I think there is a quick and dirty method in the Buying A 914 post. It had to do with the passenger side, where the hell hole gets lots of attention. But IIRC, you take the roof off, but a FAT man in the car and see if the door will open or close.... maybe measure the door gaps, that kinda thing.

If the door won't operate then there are issues. I like your test, but I don't follow it. What do the dots mean? Try the dots with the FAT man in the car. lol-2.gif

Posted by: Cuda911 Sep 20 2014, 10:37 AM

I like your system! Nice and simple and provides useful data.

What jack point did you use? To compare to other cars, everyone would need to use the same location.

If I had a laser pointer I'd try it just for fun. The cover fell of of my laser pointer last year so it doesn't work. I used to see the cheap ones for sale all the time, but now can't seem to find one.

Posted by: boxsterfan Sep 20 2014, 10:45 AM

I think that unless you have stripped your 914 down, got all the rust out, and added some chassis stiffening then it is going to be a bit flexy.

Probably some guys who track their cars can talk about how flexy the car can be unmodified. For street cars, probably doesn't matter as much...

Posted by: Elliot Cannon Sep 20 2014, 12:29 PM

An inner, outer or both long stiffening kit will bring all the dots closer together.

Posted by: mbseto Sep 20 2014, 08:14 PM

So the first dot is where the laser hits the card with the car sitting on the ground. Then I jack the car up- the jack point is the built-in jack point. This causes the laser dot to move to a new location because of frame flex and then I mark the new location.

I will repair the rusted longs and repeat the test. I intend to install some frame stiffening kit (Engmann kit and maybe more). Then I will repeat the test again and see if stiffness is improved. As I said, it is quick and dirty.

I have no FAT man. :-(

I used to drive a Supra with a targa top and there was a huge difference with the top off. It would be awesome to have a targa with a nice stiff frame even with the top off.

Posted by: rgalla9146 Sep 20 2014, 08:29 PM

QUOTE(mbseto @ Sep 20 2014, 10:14 PM) *

So the first dot is where the laser hits the card with the car sitting on the ground. Then I jack the car up- the jack point is the built-in jack point. This causes the laser dot to move to a new location because of frame flex and then I mark the new location.

I will repair the rusted longs and repeat the test. I intend to install some frame stiffening kit (Engmann kit and maybe more). Then I will repeat the test again and see if stiffness is improved. As I said, it is quick and dirty.

I have no FAT man. :-(

I used to drive a Supra with a targa top and there was a huge difference with the top off. It would be awesome to have a targa with a nice stiff frame even with the top off.


Great idea.
Use a piece of graph paper at the indicator end.
The graph paper has 1/4" increments on both the vertical and horizontal planes.
You could have real numbers.
Did your drivers side move both up and over ?
I'd expect to see the passenger more flexible.

Posted by: Highland Sep 20 2014, 10:43 PM

Could the suspension not being fully settled cause some change.

Maybe more accurate if the laser and paper were placed between the wheels. confused24.gif

Posted by: mbseto Sep 21 2014, 10:30 AM

"I'd expect to see the passenger more flexible."

I expected that too, but really the hell hole area is not bad, but the bottom of the car is uniformly bad on both sides. I think it was in pretty good shape and then stored in a barn and rusted from below.

I like the graph paper idea...

Powered by Invision Power Board (http://www.invisionboard.com)
© Invision Power Services (http://www.invisionpower.com)