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View Full Version : Jacking Pads for the GTM



The Stig
07-17-2012, 02:23 PM
Has anyone incorporated jacking pads on the bottom side of the GTM Chassis?

I'm thinking that it would be a good idea to at least place 3/8" plate steel (4"x4") at each corner:(behind the front wheels, and ahead of the rear wheels). My question is whether or not it matters if they are welded, or if they can be attached by counter-sunk screws.

There really isn't any "good" place to jack the car without using a 3x3x2 block on the hydraulic jack.

I don't think that I've seen anyone do anything with this yet.

Also: I noticed that Hugo uses a set of Drive-on ramps to lift the from of his car, and I wondered which ones are shallow enough for the nose to clear, yet still give enough lift to get the jack under the car comfortably? I have a scissor jack, but it's more of a PITA to use than it's worth.

I guess I could bite the bullet and get one of the ultra low profile jacks, but I really don't want to spend another $500.00.

crash
07-17-2012, 03:25 PM
I'm pretty sure the cross tube on the FFR PDG GTM is the same as on "regular" GTMs. We use the open ends of the cross bar under the main hoop attaching points to put in "jacking posts". These allow the use of regular jacks. It also makes jacking able to be done when there is a flat tire. If you get a flat...and you happened to have a spare...you would have a tough time finding a way to jack up the car. The removable jacking post in the side of the rocker panel allows you to jack the entire side up as the crossbar also happens to be the balance point between front and rear.

The Stig
07-17-2012, 03:32 PM
Would you happen to have pictures of your "jacking posts"? How accessible are these bars with the body on? I hate to say it, but It has never really occurred to me to look for them.

crash
07-17-2012, 04:24 PM
This is how many race cars that do not have air jacks and are not NASCAR type stock cars get the cars jacked up. Some Porsches come with the system from the factory. Basically you just cut about a 1" diameter hole in the rocker panel where the frame rail is on the inside of the car. Then you stick a "jacking post" into the frame, through the hole, and you end up with a post that sticks out the side of the car. This allows you to put a jack under the post and jack the car up. When done, you pull the post out. I knew you would be asking for pictures, but I don't currently have any. Sorry. Maybe Richard can take one for us?

In this picture you can see the hole for the jack post on the lower rear of the rocker panel...

10745

Porsche has a little body color cover on this location on their street cars.

RumRunner
07-17-2012, 04:28 PM
Mike,

I know GLENNL put aluminum jack pads on his build at those same locations. I'm doing the same. Just screwing them in. Only normal force on them, no shear.

And I purchased this jack from Amazon about two years ago. As far as I'm concerned it's great.

http://www.amazon.com/Advanced-Design-Model-ATD-7325-Profile/dp/B000OUZVK0/ref=sr_1_1?ie=UTF8&qid=1342560371&sr=8-1&keywords=ATD-7325

-Michael

Kempo
07-17-2012, 07:57 PM
Mike the ramps I have are the ones on this link.

http://www.ebay.com/itm/NEW-COMPOSITE-PLASTIC-CAR-AUTOMOTIVE-RAMPS-STANDS-LIFT-6009-/390441200270?pt=Motors_Automotive_Tools&hash=item5ae81bea8e&vxp=mtr

The Stig
07-17-2012, 09:48 PM
Mike the ramps I have are the ones on this link.

http://www.ebay.com/itm/NEW-COMPOSITE-PLASTIC-CAR-AUTOMOTIVE-RAMPS-STANDS-LIFT-6009-/390441200270?pt=Motors_Automotive_Tools&hash=item5ae81bea8e&vxp=mtr

Thanks Hugo. I appreciate the link. Just placed a bid. We'll see what happens.

Mike

sk7500
07-18-2012, 12:14 AM
We cut a couple 3 in circles from 1/2" thick uhmw (plastic) and bolted them on the bottom of the frame. Then I clearenced the body to fit around them. You can see them in the bottom right corner of the picture. Like Crash said, it lifts the entire side of the car. I can lift it with one of those low profile aluminum jacks from Harbor Freight. The jacks are very light weight and less than a $100 I think. I'll try and get a picture with the body on from underneath.

10755

The Stig
07-18-2012, 08:24 AM
Thanks Steve. I appreciate it.

I'm getting ready to start doing a bit of suspension work, and will be lifting the car up and setting back down a few times before it's all said and done. My wife keeps asking me to buy a lift, to make life a little easier, and I suppose I should. But I still need to make sure that the lift points of the car are sturdy and safe.

By the way, the interior design of your doors, dash, and console are amazing. I wish I had the skills and the time to pursue that sub-project for my car. As it is, I'll be paying yet another shop a large fortune to do it for me... but at least then, IT WILL BE FINISHED!

Keep up the awesome work.

docglock
07-18-2012, 10:23 PM
Stig,

A couple of things. I use the extended race ramps. I am pretty sure a GTM would be able to go up these without a problem. My Boxster has a custom front end with a lower ride height than the GTM, and it clears these without any issues.

The other thing is your wife is right - buy a lift. It makes everything so much easier. I realize I just started my build, but I raise and lower the car all the time. I see things from top and bottom without having to scrunch along on my back. I purchased a four post lift and added an inline jack with extended arms to the package. This way I can move a hydraulic jack to any point on a car.

Doc

sk7500
07-19-2012, 07:52 AM
Thanks Steve. I appreciate it.

I'm getting ready to start doing a bit of suspension work, and will be lifting the car up and setting back down a few times before it's all said and done. My wife keeps asking me to buy a lift, to make life a little easier, and I suppose I should. But I still need to make sure that the lift points of the car are sturdy and safe.

By the way, the interior design of your doors, dash, and console are amazing. I wish I had the skills and the time to pursue that sub-project for my car. As it is, I'll be paying yet another shop a large fortune to do it for me... but at least then, IT WILL BE FINISHED!

Keep up the awesome work.

Mike,
You told us you have one of those one in a million wives? So if you can swing it, listen to her and GET A HOIST!!! It makes working on cars soooo much more fun. I always tell my partner Frank, he extended my car working days by at least 10 years when we put one in at his house. We went wih one of the old gas station center post lifts. Not so great for working on the center tunnel stuff but it's out of the way for everything else.
Thanks for the comments on the interior. We'll see if I still have the skills to pull it off. I really don't have the time either, but since the goal for me is not "finished" but the "enjoyment of the journey", it doesn't really matter. One small step at a time.

The Stig
07-19-2012, 09:23 AM
Mike,
You told us you have one of those one in a million wives? So if you can swing it, listen to her and GET A HOIST!!! It makes working on cars soooo much more fun. I always tell my partner Frank, he extended my car working days by at least 10 years when we put one in at his house.

Steve, You're Right! That's probably some of the best advice I've received in a while. Thank you!


I also went ahead and ordered some Aluminum Flat Stock. 4x4x1/2" I think I'll paint them black and mount them with recessed hex bolts, and call it done. I think I'll feel much better about jacking the car up on them than the flat underside of the car.

FFRSpec72
07-19-2012, 10:42 AM
So I have been after some ideas for jack pads/posts on the challenge car, the side pipes give us another challenge, just jacking under teh 4" tube does not give us much room, as when at the track there are uneven surfaces and oten the jack does not roll and thus the chance of the jack slipping off the tube. We do have a simular spot as the GTMin the rear where teh tubes come together and this is where a body mount plate is put on, I don't use the body mount plate so that may a place to start, if anyone elese has looked at this, I'm open to ideas