Concave Driveway Fixed By Speed Hump?

[GTR-N1]

The new car with 105mm clearance at the front lip, won't get down to the garage without wrecking the front lip via the smooth, steep but concave section of driveway. (R34 GT-R)

The previous car cleared it by about 5mm whether or not it was coming down the driveway or going up. (R33 GT-R). It would get real close at one spot only.

We've sourced a speed hump firm which seems to have an ideal solution unless someone here kaiboshes it.

The rubber hump is 900mm across and 50mm at its highest point. It comes with dynabolts. I would need at least 2x because each one is 1m long.

We've worked out that to measure and mark a chalk line on the concrete at the point of the front axles, the front lip will have to clear the speed hump before it dips lower.

Q. Has anyone done this before using a speed hump as your solution?

Q. Any tips?

Q. Is the speed hump going to work in its fixed position regardless of the car coming down the drive or going the other direction?

Thanks in advance - and I'm going to ask the firm if they can test-position before we buy.

[alr33x]

couldnt u just buy a peace of steel or something as a cover for the ditch? got a pic of the problem

[raZ1911]

Take a pic

[HEKT1K]

Yeah i'm trying to imagine what you're on about Terry.. not happening sorry bud

post pics! Also what's this about a new car?

[gtr fan]

He Terry,

I am sure I have the same problem as what your talking about. I just back the car into the garage so I still get a bit of a scrape. Although its not desireable its not to bad.

I put down a piece of carpet whilst getting in and out of garage so it drags accross that surface and not the concrete (most of the time).

Short of putting down steel ramps I don't think I could solve my problem. I thought of the speed humps (I remember you could buy pieces) but I didn't think this would work.

Put up Pics.

And what is the new car??

[SKITTLES]

You know those annoying angled gutters in Queensland? The ones that kinda look like this...

I've seen a lot of people putting big thick ropes along it where they drive so they don't scrape their cars getting into their drive ways.

The same theory could probably help you

If that doesn't work, I saw a lot of people doing the metal trick.

If you've got a really nice house and you're looking to keep it looking awesome, just pour some concrete into the gutter and make it flatter ;]

Also, the commodore drivers have some interesting fixes on their forums... tips for driving a lowered car

Edit: http://www.carguygarage.com/singlecardrivew.html

Again, rope does the same thing.

Edit: something a guy on ozmps posted...

You can get an approval from the council, just say because your car is lowered and you would like to keep your bumper intact.

*You can't disrupt the flow in the gutter* (like the ones in the link)

*You can't have them on any external corner*

*You can't have a narrow street either* (like most suburban streets are now)

Edited January 10, 2011 by SKITTLES

[Daleo]

I think I understand what you're talking about Terry, and you might have hit on a fairly simple solution That is; it raises the nose just enough to get you past that low point, then once off the hump you no longer need the clearance.

The proof will really be in a first hand trial, as the positioning will be critical. The other thing to watch, will be avoiding clouting the nose as you step down off the hump as the suspension compresses. Still, that's just a matter of going slowly.

Using a steel plate works quite well, as long as the material is thick enough, (think chequerplate at least 1/2" thick) and braced underneath.

The problem occurs if you have to extend the plate into the area where your garage door closes, which i'm assuming is why you're not looking at that?

[GTR-N1]

I think I understand what you're talking about Terry, and you might have hit on a fairly simple solution That is; it raises the nose just enough to get you past that low point, then once off the hump you no longer need the clearance.

The proof will really be in a first hand trial, as the positioning will be critical. The other thing to watch, will be avoiding clouting the nose as you step down off the hump as the suspension compresses. Still, that's just a matter of going slowly.

Using a steel plate works quite well, as long as the material is thick enough, (think chequerplate at least 1/2" thick) and braced underneath.

The problem occurs if you have to extend the plate into the area where your garage door closes, which i'm assuming is why you're not looking at that?

Yes thanks Dale! You've got the picture.

And thanks "team" for trying to understand some of my gobbledygook.

My next Q is whether or not the car needs to get that clearance each time by going over the thick plate or speed hump in the same direction? Or can the car go both ways?

If so, it'll be better to back down the driveway (rather than reverse up the driveway - feeling sorry for the clutch).

Sorry I can't do pics - I'm so sh!tty with photobucket despite my "Japan 1976 Thread" resuming once more!

- so I'll let Matt do it perhaps.

Car? Matt (my son) bought the black R34 GT-R and that's where it'll sleep in future. I'm a meanie. I wouldn't let him have it for free.

Me? My b/blue R34 GT-R VS2 arrived in port on Fri thanks to Iron Chef and Jap Link.

Again, thanks for responding so soon. You're a bunch of friends here on SAU. I seem to know most of you - even tho' I've only chatted with one.

[Messiah]

place the bump at the apex/centre of the concave section.

What you have here really is a hole on a slope, by placeing the speed bump in it your effectively filling in the middle of the whole.

Assuming that there isnt too much space infront/behind the bump it will work fine.

and it should be useful for both directions as it should add a nice pre hill lift to the front bar.

[GTR-N1]

That'd be the best starting point eh Simon?

If it has to be placed either side of that apex, I can only assume the car will have to drive over it rearwards in one direction, and frontwards in the other direction.

* Update, it looks as though the boss of speed-humps.polite.com.au will allow me a 'try-before-you-buy' !

Now that's good service!

[Tangles]

get a concrete mob to fill/patch the irregular surface area?

[GTR-N1]

I think that would be a good plan B (-and thanks for that).

I'm thinking Brendan, that whilst that'll work, there'll be a fair bit of labour because it needs to be about 50mm maximum height as a 'patch'.

The driveway is 4m across at that point.

And then using 4:2:1 concrete, for it to hold onto the existing slab, we'd need to jackhammer down at least 25mm > formwork.

Comparatively, the 2x speed humps cost $400 all up. If I can get them into the right position, then I can drill > dynabolt it myself.

[gtr fan]

Matt scored a nice car! Even though his 33 was pretty nice as well!

[GTR-N1]

Matt scored a nice car! Even though his 33 was pretty nice as well!

Many thanks "R" > in future, the pearl black R34 will either have bronze LMGT4s or titanium RE30s.

It looks totally different now.

[GTR-N1]

Well, the 'Speed Humps' were laid down yesterday.

Pics to come up on a later post.

The black R34 is in the garage now.

Some fine tuning adjustments still have to be made, but...

* when reversing down the slope, the car's splitter doesn't touch the concrete driveway.

* when moving forward off the flat > up over the 'Hump' > it can touch about half the time > there's only 1-2mm in it now

* we'll try to maneouvre the humps just a wee bit more > then dynabolt them down with 26x bolts

And I used to swear at speed humps on the road > terry swallows humble pie

[23 GTR]

Any photos yet Terry?