Help Needed Planning A Ramp For My Gti

[omri617 18]

Hi friends

Been planing to do this for a long time, and no I got the time!

I got my parking space , where I'd like to build a ramp to go down to the other parking.

the height differences is 1 Meter .

What is the ramp length I need , to make the GTi go down and up without touching

the ground / get stuck on the ramp??

Need to mention , i got 40 mm Eiebach springs. the car is pretty low!

16 c"m from the front bumper .

26 c"m from the back bumper.

12 c"m from the most middle point.

 

Thanks ..

[danboo89 1]

Hi. If you had room I'd say about 8ft should be Ok

[omri617 18]

It's less than than 3 meters .

Why you think it's enough?

[chipstick 382 1 Cars]

I am sure there is some fairly simple maths here regarding the available height underneath where it would catch if the angle was too steep, but I wouldn't have a clue where to start I'm afraid

[dch1950 37 1 Cars]

Hi Omri,

In addition I would also check the geometry for the rear end as well. It would be embarrassing to clear at the front and then rip the rear skirt off if you backed up the ramp

regards

Dave

[ORB 227 1 Cars]

Can you take a picture of what you are trying to achieve?

[dcc 855]

I'm not 100% on this, but I feel this would change the use of your garage, potential impact upon planning regulation of your country.

 

Eitherway, this is a car forum, full of pornstars. Try using a telephone and ringing some builders or even car workshops.

[Tom Fenton 1,562]

Using some very quick and rough calcs, I think the limiting factor is the clearance in the middle of the car, this dictates a ramp of 5 degrees max otherwise the centre of the car will ground out. 5 degree angle of ramp for 1 metre fall means the base length of such a ramp would need to be c.11 metres.

 

As for an 8ft ramp - that gives an angle of 22 degrees which is off roader territory.

[danboo89 1]

Was just basing my reply on the ramp into my unit is about 2 ft drop with about a 4 ft ramp and I've gone down it with 205s lowered 50mm

[GLPoomobile 958]

Was just basing my reply on the ramp into my unit is about 2 ft drop with about a 4 ft ramp and I've gone down it with 205s lowered 50mm

 

That just does not sound at all right to me Can you check and verify the measurements? Does your ramp have any gradient change at the top and bottom, or just sharp angles? Knowing from experience how easy it is so ground the middle exhaust box on fairly insignificant speed bumps on a 205 lowered 40mm at the most, I just can't see how you could possibly traverse such a ramp with out grounding out on the exhaust or sills. Just using an online calculator, it gives the angle at the entry of the ramp at 26.57 degrees, which is massive.

 

According to that calculator, Tom is spot on with a length of 11m required for a 1m height, if the entry angle is 5 degrees.

Edited February 7, 2013 by GLPoomobile

[allanallen 528 2 Cars]

f***s sake, I just read the topic title and thought you were making a ramp to jump a 205! I'm slightly disappointed now

[GLPoomobile 958]

Omri, I've done some basic armchair calculations for you. There's 2 caveats to this though

1 - Maths isn't my strong point

2 - Without knowing the maximum clearance between ground level and the lowest point of the floor in the mid-point between the 2 wheels, the calculation can't be accurate.

 

I know that the wheelbase measurement is 2420 mm (data taken from the blueprint available on this site). That mean the mid point between the 2 wheels is 1210mm.

I have assumed that the lowest point of the floor around the mid-point is 200mm. This is a pure guess though, I just pulled out a 30cm ruler, held it on the floor and guessed at 200mm going by my memory of how low I think a 205 GTI tends to sit.

 

Based on those measurements, I get an angle of 176.2 degress required to provide clearance at the peak of the ramp without the car grounding out. This means an entry angle of 3.8 degrees. Which means your ramp needs to be 15m long.

 

I don't expect many people to be able to make sense of my calculations without a visual aid. Happy to do that tonight if you want.

Edited February 7, 2013 by GLPoomobile

[GLPoomobile 958]

@Danboo89, using the same method I've used for Omri, I've calculated that your car must have a ground clearance of 51cm to clear your ramp. You might want to take a look at your ride height

[danboo89 1]

I will take a look tonight I think I've got my estimates wrong lol

[omri617 18]

Thanks guys.

If Tom & Barnaby are right , and the ramp should be more than 4/4.5 meters , I would have to pass ! Don't have that area down.

By my side , ( not based on any calculations ) 11 meters ramp in order to take a small car like the 205 down , is STRANGEEEE!!!

[Vili 18]

I did my calculations and I would say the should be roughly 5,1 meters long measured at ground level. So the actual ramp would be ~5,3 meters. You could make it shorter by doing the ramp arc shaped.

[GLPoomobile 958]

Hey Omri, remember that caveat I put on my earlier post? Turns out my calculations were a bag of wank

 

So let's try again. Would be good if someone smarter than me could check my calculations for correctness. And remember, I'm assuming 200mm ground clearance on the car, so that variable is going to change everything else.

 

I've used this site to calculate angles

http://easycalculation.com/trigonometry/triangle-angles.php

 

Here's the 205 blue print annotated

 

Now here's one half of the triangle from the above annotation. Angle A is 80.61 degrees, angle B is 9.39 degrees, and angle C (the inside of the "peak" if you like) is 161.22 degrees.

 

 

Now we need to take this peak and rotate it so that one side becomes the ramp, and the other is the horizontal plane at the top of the ramp.

Now we can put some figures in.

Angle D is going to be C - 90 (161.22 - 90 = 71.22 degrees)

Angle E is going to be 90 - D (90 - 71.22 = 18.78 degrees)

 

So with all the above, using the site linked earlier we can calculate that with an opposite side measuring 1000mm, and an entry angle of 18.78 degrees that the adjacent side (the horizontal, your ramp length) actually only needs to be 2940mm

 

 

[Anton green 12 1 Cars]

I was going to do a 'full' style reply to this involving the use of measurements and a flat section where the 'pointy corner bits' of the ramp are, which would catch the underside, but unfortunately I cannot really think straight due to the painkillers I am taking, as evidenced by my use of the phrase 'pointy corner bits'

 

An arc shaped ramp might be best, but a pain to construct properly unless you resort to the use of blocks firmly and permanently attached to a straight ramp to simulate the arc shape -having much the same effect as when people put planks under the wheels of a lowered car whilst it is being loaded on to a car transporter. It should shorten the ramp overall length considerably and be a good working solution, if done right.

Edited February 8, 2013 by Anton green

[Vili 18]

GLPoomobile you´re right except the car ground clearance was 120 mm at the middle. So the ramp length becomes circa 5,1 meters.

I'll give you 4/6 points and a happy face

[chipstick 382 1 Cars]

How do others with spaces below get to those spaces?

 

I'd drive around personally.

[m_attt 31 1 Cars]

bit more to fabricate, but can you not have the ramp hinged, so you drive on it then change the angle with a bottle jack. probably over complicating though.

[buchanan84 1]

Had a quick go at this in CAD, using the clearance of 12cm in the first post it gives you a flat ramp of over 10m!!!

as has been suggested you could add a curve or blocks of wood to help the car over the point of the ramp...

or you could use some kind of hinged ramp or 4 post lift to get it down...

Edited February 8, 2013 by buchanan84

[TT205 42]

How about creating a 'see saw' instead if it is a confined space, surely this gets rid of the central clearance problem but adds a 'height of garage' issue

 

 

Edited February 8, 2013 by TT205

[omri617 18]

I think i would build it from clay eventually so i can adjust the top and the bottom of the ramp.

[chipstick 382 1 Cars]

How about creating a 'see saw' instead if it is a confined space, surely this gets rid of the central clearance problem but adds a 'height of garage' issue

 

 

That's all well and good to drive the car on to it when it's in it's level position - but then when the ramp is tipped down, the 205's valance would smash the floor before the wheels have come to the bottom.

 

The angle needs to be small. And the smaller it is, the longer the ramp will be obviously.