Shandingo

How close was the hood on the GT4 to the bottom of the tires or lowest point on the rack? Did you have enough bouncing that the hood made contact or came close to doing so?

ShakeNBake

It was close enough that I was uncomfortable. Never any indication of touching using jack point tie downs. I would not use wheel tie down methods on the front. i think there is enough adjustability that you could position the tire rack to mitigate the issue if you didn't have tongue weight limits to worry about.

Shandingo

How far back did you position the wheel stops and the tire rack with the GT4? Did you measure your tongue weight?

ShakeNBake

I don't recall the exact position, but with tires I had tongue set at 700, and without it was around 640. The tire rack is in same location in both pics. BTW when we were discussing heights before, the 911 pic is without rear auto leveling, and the GT4 was just after I stopped, so it was at the correct ride height. The F85 works out to be very similar in ball height as you see here.

tdjohn

Another option - we use an overwheel type strapping system for all the cars and have been really impressed. The only contact with the car is on the top of the tyre which means there's no concern of damage. It grips the tyre with a sliding sleeve - I can photograph today if you are interested.

Nice thing is the strapping worked equally well with all the cars which are remarkably different - Caterham, Elise, Exige V6 and 911 Cup.

Shandingo

Yes, please post the photos if you have time. I did buy axle straps already, and my plan was to just use those since so many others use them, but I am still open to taking a different approach. I do have some concerns about the tire rack clearance issue raised by ShakeNBake, but I don't think there is any way to address that without strapping tie downs to anchor points on the body of the car as ShakeNBake did. Not sure why Trailex does just make the bottom of the tire rack a bit higher. I understand that would raise the center of gravity but I would not expect a few inches to make any notable difference in the way the trailer handles.

GeoJoe

Here's how I'm rolling... I really like the Rennline attachment points that can be added to the underside of the car.

These for the front


These for the rear


Just towed it almost 500 miles.. no bouncing-on-trailer issues, no alignment issues.

aryork

Have you measured the tongue weight in that config?

tdjohn

4 of these. The black sleeve is like Velcro and grips the top of the tyre.
Loop over the top. A hook either side keeps it close to the wheel.
Usual ratchet one end to tighten.
Same set works on all our cars.
Nothing can make contact with body work. We've used for a couple of years on open and closed trailers. The GT4 will be transported the same where necessary.

GeoJoe

Not yet... google says bathroom scale or weigh station... which is more accurate?

That pic is a shot with track wheels inside the Q7, jack, etc... loaded... and no air suspension.

ExMB

Use the 2x4 bathroom scale method at your house. That way if you need to move the car you have everything readily available. You never know if someone is in line behind you at the weigh station and/or if they charge you for each measurement. I don't think that 50 lbs TW either way will make a big difference.

aryork

Okay, that makes sense because it looks like the rear end is sagging some. Looking at your car and trailer, I think it should be okay. I have a short trailer and a barely viable tow car, so it took me a long time to figure out a good configuration. I found the CG of the trailer by measuring weight of each wheel and the tongue using a bathroom scale that goes up to 400 lb (if you can find one that goes higher get it). I read some technical papers about optimal configurations having the vehicle’s CG close to the trailer’s CG. For my trailer the CG is pretty close to the front axle – probably same for yours. The CG of the GT4 is easily found using the front/rear weight specs. It is a bit more toward the rear axle. In your photo, I would guess the CG of the car is close to that of the trailer – good! If needed, you can affect the tongue weight by adjusting the height of the ball slightly, but I would guess yours is at least 500 lb by looking at it. If the tongue weight gets too low, the trailer may sway at higher speeds.

I did the scales thing one time...it was a bit intimidating because I didn't know what I was doing and the person controlling the scales was somewhere else and I had to talk to them through a speaker...

zedcat

Test loading today. Caveat- I'm no expert and this is my first trailer. Just trying to research and test things. No toolbox or fuel jugs on trailer. Tow vehicle is F150.

Need boards or helper ramps as front drags. With 2in thick boards it barely scrapes and splitter is already scratched up so went ahead. Still need to try something thicker.

With the tire rack empty I had to move the tire stops well forward to get 500lb tongue weight (Weighsafe hitch). Much further forward than the Cayman R which surprised me. need to recheck the R. Also not sure of accuracy of the scale. This far forward is the worst case for clearance of tires in the rack. About 8cm clearance hood to tire. Fender to tire is about 7 cm.

Next moved the car back to tongue weight of 400lb. Put 4 18in wheel/tires on the rack and got back to 500lb tongue wt. At this position there is about 14cm clearance hood to tires.

Tied down with the MACs straps/ ratchets. No problem in the rear with the 6 ft straps, although an extra foot would be a good idea if crossing the straps. 40in axle straps work fine. In the front there is slight interference with the soft plastic ducts although not bad. Tried both straight to the D rings and crossed in front. Ratchet strap length of 6 ft was fine either way.

I may go ahead and get the rennline front tiedowns. Although eyeballing the path the strap might rub on the tirestop so would need to check that.

ShakeNBake

Is that an 8045 or the shorter one? I think the GT4 has about 3-4" more wheelbase than the R. How much fuel in each when you measured (full/empty is almost 100lbs on the front axle)?

BTW for ramps I made a puzzle-ike series of three wood assemblies for each ramp that fit in the trailex tool box, and lifted 5". It worked for my RS with a cup lip and the GT4. People made fun of me, but it did exactly what it needed to do.

zedcat

It's an 8045 EB per the paper work. (The platform excluding the front taper/hitch is 176in). Good point on the fuel- the R was full and this morning when I did the test load the GT4 only had 1/4 tank.

Yeah I was already thinking about nailing/gluing boards to make a custom helper ramp.