CrystalRedTed

Due to space obstacle constraints I'll need to back onto my Race Ramps. Before I attempt this has anyone tried backing onto Race Ramps and used the roll-ups in the front? My car is fairly low in front (<26" from wheel well to ground) and I'm not sure if the spoiler is going to drag if I attempt this. The spoiler barely clears with a slight rub on the 87-2 ramps when using them in front.

BadAV

I have backed up onto my Rhino Ramps quite a few times and never dragged the front of my GS, and it is pretty low. I have then used jack stands for the front a couple of times.

saplumr

I use the 7-1/2' Raceramps for my enclosed trailer. All I can say is I would never attempt to back on to them.

0Fred@ReverseLogic

Here's a formula you can use to estimate the clearance below the spoiler with the rear tires on the ramp platforms.

LGC - ((OH/WB) x RH) = AGC

Legend:
LGC = Ground clearance below spoiler when car is on level ground
OH = Overhang distance from front axle to spoiler edge that might scrape
WB = Wheelbase
RH = Ramp platform height
AGC = Ground clearance below spoiler after rear tires are on ramp platform

Assumptions for examples:
LGC = 4"
OH = 35"
WB = 105"
RH = 10" for RLL-87-2, 6" for Rhino Ramps

RLL-87-2 example:

4" - ((35"/105") x 10") = 0.7"

Rhino Ramp example:

4" - ((35"/105") x 6") = 2.0"

YMMV if the pavement is not perfectly level. For example if your garage floor is pitched towards a drain the final ground clearance could be reduced if the front tires are rolling towards the drain.

Tip for using Roll-ups: Position the Roll-ups so that the tires on the Roll-ups cannot overshoot the Roll-ups platform area. If the tires are allowed to descend the front incline section of the Roll-ups, the front and rear tires will be "wedged" between the stops on the primary ramp platform and the front incline on the Roll-ups.

Use this formula to estimate the distance to leave between the trailing edge of the primary ramps and the leading edge of the Roll-ups.

Wheelbase - Primary Ramp length - 2" = Distance between Primary Ramp and Roll-ups.

RLL-87-2 example assuming 105" wheelbase:

105" - 87" - 2" = 16"

RR-56-2 example assuming 105" wheelbase:

105" - 56" -2" = 47"

CrystalRedTed

Thanks. I assume this formula works both forward and backwards (backing onto the ramp)

0Fred@ReverseLogic

The Roll-ups formula works for both directions. The ground clearance formula could be used to calculate clearance below whatever is the lowest thing on the rear of the car (i.e. diffuser, exhaust tips).

Don't forget to use the actual measurements for your car and ramps.

CrystalRedTed

I see what you're saying. I'm actually looking for input on clearance between the ground and front of the car while backing onto the ramps. The 87-2 has a two stage incline and when it hits the steeper section I'm not sure what happens up front while backing up the ramps. However I may be climbing the roll-ups with the front wheels at that point and may be fine.

0Fred@ReverseLogic

If you have sufficient spoiler-to-ground clearance when the rear tires are on the 10" high platforms, you will also have enough clearance when the rear tires are on the second stage incline section. The height of the RLL-87-2 ramps where the incline section meets the platform section is 8.5".

mcandrew67

I have backed up onto mine with no issue. I had a very minor scrape of the air dam. Mine is also low. I have done it to replace mufflers, add a tunnel plate etc.

saplumr

I can kick one or both of mine out when loading in trailer, not completely but they can move. That's the reason I wouldn't attempt to ever back up on anything steep.

mcandrew67

I have the 67" with the extensions as well, never kicked out on me.

saplumr

Big blower cam isn’t easy to regulate at minor movement and high rpm’s