Minimum air jack stroke length for Type-65?

[kd0wda]

Hello all,

Would 9" of lift be enough stoke length to lift the Type-65 off the ground completely? I ordered A/P Racing air jacks last fall, but the lead time for the 310mm stoke length has been ridiculous and keeps getting pushed out. I can get the 230mm version today (well, 3 of them anyway...have to wait for the 4th). Would they work? If I'd known last fall that it would be this hard to source the parts I would have gone with Allstar's, but I've already committed to the rest of AP's running gear (lance, inlet, etc). I'm trying to get the mounts fabricated and welded in place while I wait for the remainder of my kit.

Also, is a 3-point / tripod setup feasible with this frame? If so, where would you recommend placing the rear jack mount?

Thanks!

-Rob

[Logan]

Rob - It depends on what you intend to use the jacks for. If you just need tires off the pavement to change wheels or whatever then yes the 9” stroke length is fine. If you have a big aero package up front and you need clearance to raise the hood, you’ll want the 310mm/12” jacks for that.

Also, remember the chassis and suspension can be setup in Street or Race heights. So basically the belly of the car can range from less than 3” from the ground, to over 5” from the ground. This distance needs to be taken up by the air jack before any lifting actually occurs. The lower the car, the less stroke length you’ll need.

As for the tripod setup, I wouldn’t recommend it. The capacity rating for the Allstar jacks are 750lbs per cylinder, which means that 4 are required for a 2,800 - 3,000 pound car. I think the AP Racing cylinders are actually higher rated, but I still would use 4 of them if not for the capacity then for the stability.

[Logan]

Forgot to mention, but if you do decide to do a tripod setup, you may want to put the single jack at the front of the car instead of the rear. The Coupes end up being rear heavy, even more so than the Roadster which is also slightly rear heavy I believe. There is a great point just ahead of the engine that has 4 diagonal tubes joining the large main lateral square tube in an X-shape. This is probably the strongest possible point forward of the engine, and a lower mount would be easy here, and figuring out the top mount shouldn’t be too hard either with the frame design directly above it.

I just finished the mounts for my Allstar jacks after Christmas. Well, I have one more support left to fabricate but it doesn’t need to be welded to the chassis so it’s a lower priority detail. I follow virtually every Coupe build on both forums, plus FaceBook and YouTube. I’ve only ever seen air jacks done on 4 Gen 3 Coupes:

1. SurfDog57 Coupe-R on the “other” forum
2. Wake Productions Coupe-S on YouTube
3. FFR themselves, Snap On/Joey Logano Coupe-R
4. Mine...! Build thread coming soon

[Jim Schenck]

I will add from using ours I wish we had gone with the shorter ones, they don't always go down evenly or consistently so you never know what end or side is going to drop. If they were shorter it would be a lot less of an issue, plus they are really a little higher than I would like when changing wheels/tires.

[kd0wda]

Thanks Logan,

If you have a chance would you be able to post some photos of the mounts as they are welded to the frame? I'll go with the 4-jack setup and stick with the 230mm ones (three showed up today, the 4th due in sometime in March). Did you use the weld-on mounting rings that come with the Allstar's or did you fabricate something else?

-Rob

[Logan]

kd0wda - I have a few pictures, sure. Just posted about 5 pics of the brackets in my new build thread, see post #9 at the link in my signature. I don't know if AP Racing says the same thing, but the Allstar jacks are load bearing on the bottom mount, and the top is just positional indexing. I didn't find this out until after mine were done, or I might have lightened up their construction, but as it is they're seriously overkill. Haven't pressurized the system yet, it'll be a while before I get tanks on hand. If you need any other pictures or info just let me know.