GT40 vs Speed bumps

[TrevS]

Hi all

This is something that has been playing on my mind for quite a while but I have been trying not to think about it. We have 3 speed bumps down our road and I am a little concerned about getting the GT40 safely over them.

Can anyone tell me roughly what the ground clearance is on a GT40 and does anyone else have issues with getting the car over speed bumps?

Thanks

Trev

 

[Ian Anderson]

Bank on 4 inches clearance

Yes speed bumps are a problem and some more so than others

The "Pillows" I need to wait for a clear road and run each wheel over one of the pillows - sum in middle of the pillows

Plain hump - you may need to take it at an angle to stop the car scraping so for example Left front tyre climbs the hump first - can also scrape under the seats on these if they are higher than normal

The full width pavement side ones (12 foot long) need to crawl (5mph) over these - going up tends to be OK but coming off the nose can scrape

So yes you can get a GT40 over them but with care

Oh yes I also ran over a dead fox - in traffic - 3 lanes - nowhere to go and the "body" appeared between the wheels of the car in front - he cleared it but I made a horrible noise rolling the length of the underside of the GT - so avoid road kill!

Ian

 

[Tony Hunt]

They can be an issue, worst of all when you don't spot them!
The average ground clearance is around 4¾ inches, which should get you over most.
However, if the bump is steep, it could catch under the nose overhang, particularly if it coincides with a change of gradient.
I try and steer between them if they aren't continuous across the road, but the burghers of Beaconsfield don't like being slowed down by a GT40 cautiously negotiating a bump!
Alternatively, take them at an angle so the wheels on each axle meet the bump at different times. Bumps are also lowest near the edges of the road.

 

[TrevS]

Thanks guys, I'll pop out and measure the height of the bumps when I get a minute. The road is private so the speed bumps do have a gap at edge which 1 wheel will fit down. These were added for a few neighbours that needed access to the road for mobility scooters. So only 1 side of the car would have to get over the bump, would this help?

Also is there anything you can do to increase the ride height as I am most worried about my lower seating area? I am fitting the 15" knock on wheels so would fitting some chunky tyres help?

Something like this:
Red gt40 image by jeffy10028 on Photobucket

Trev

 

[Brett James-McCall]

Either that or contcat Fran and see if you can put his hydraulic lift system in.....

 

[Grant S]

Or you can go out there at night when no one is looking and pour Diesel fuel on them and they will melt away, not that I condon that type of behavior (wink) lol.

 

[Ian Anderson]

Or you can go out there at night when no one is looking and pour Diesel fuel on them and they will melt away, not that I condon that type of behavior (wink) lol.

Actually they are made out of the tarmac brand industructable!
All the roads around here are horribly pothioled after a pile of snow over the winter but every speed bump is in pristine condition!

Perhaps they got the tarmac mix the wrong way around

Ian

 

[TrevS]

Fran has emailed me some details of the hydraulic system which sounds good but I am checking with Tornado to see if the system will work with their suspension.

I am very close to turning my attention to the suspension on my build so I guess now is the time to be thinking about this

Trev

 

[Rich Roy]

Doing the angle attach seems best. Get one front up and over then at an angle try to get the other front up on the hump at the same time the oposite rear is climbing up as well, then yer up-n-over. Seems to maximize the clearence when you have it tittering from corner to corner. Happy motoring......................CAV#99:shocked:

 

[glen]

use 'em as jumps!!

 

[David in Durango]

We have (had?) a SEVERE gully at the head of our cul-de-scac . . . some ne'er do well spilled a couple of big globs of cement in the thing one night.

Hope you live in a nicer neighborhood!

 

[Kym Haines]

You can adjust the ride height when you set up/adjust your suspension (within limits). Here the legal minimum ride height is 100mm (4") but I went for 125mm (5") and I can get over most speed bumps without having to crawl but there are a few that require an angled approach.

For me, getting in and out of my driveway was more problematic. Initially I had some pieces of timber in the gutter. Fortunately by a lucky coincidence some concrete seemed to appear in the gutter one day and solved the problem.

Also don't even think about going into a multi-storey car park. Although I had taken this to heart, on a business trip to Brisbane in the GT40 I needed to park it in a hotel car park. There were two ways in: drive straight in from street level with no changes in height - simple (and why this hotel had been booked for me); or the other entrance at the other side of the block which I was parked next to. For convenience I thought I would try the latter option so first I walked the route to ensure there would be no problems: down a gentle ramp then flat which all looked fine. In I drove but soon realised that I had failed to take into account the spiral nature of the gentle ramp: its radius was slightly less than that of my turning circle but somehow I managed to keep the car off the walls!

 

[Cliff Beer]

Go sloooooow. The faster you go the more bounce and spring compression you get....which, of course, reduces the ground clearance.....

 

[Phil]

Trevor:
I have seen a couple of chassis with small urethane wheels mounted under the front frame horns. They protruded downward enough to prevent the nose from scraping on aprons, and some small strips of polyethelene (HDPE) were riveted to the chassis under the seating area to keep the undertray from the same, just a thought. Both were unnoticeable on the car unless in the case of the nose it was tilted up.
Cheers
Phil