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Chassis Height Above Ground
John - 6/12/02 at 11:30 PM

Due to reports of incorrect measurements I am about to start drawing out the chassis (Avon) using CAD. To check the suspension I need to know the usual ride height above ground to the underside of the chassis. The car is road going only not to be used for racing.

Thanks for any help.

John.

interestedparty - 7/12/02 at 07:53 AM

Here's a good way to sort out that particular problem-

Ideally the lower wishbones should be level. That's your fixed starting point. The relationship between the chassis rails and the wishbone is fixed by the brackets and their mounting angle/position - So the question can be written, how high should the wishbones be? The answer to that will depend on the wheel/tyre combination you are using, as the relationship between the wishbone and the hub will also be fixed by the position and type of balljoint and the type of hub you are using.
The best way to get this information would be to set up a side i.e wishbone fixed to hub via balljoint and wheel bolted on. Set the wishbone level and measure the gap to the ground. As shown above, you can then calculate the chassis height.

John

bsilly - 7/12/02 at 04:15 PM

i would reckon on 6 1/2" to 7 1/2" from floor to bottom of chassis..that would give yer about 4" under yer sump..assuming pinto:

interestedparty - 7/12/02 at 05:09 PM

quote:
Originally posted by bsilly
i would reckon on 6 1/2" to 7 1/2" from floor to bottom of chassis..that would give yer about 4" under yer sump..assuming pinto:


I would say that was a touch on the high side, and would mean having to set the wishbones sloping down towards the wheel. As I said above, though, it depends on the wheel/tyre combination and the balljoint etc

John

stephen_gusterson - 7/12/02 at 11:29 PM

i would say 7 ins from floor to ground is really high. my non book car is 8 and a bit ins from the floor and it looks a fair height more than standard sevens I have seen.

As said, keeping wishbones level is a guide, but not essential - its the overall travel you have left if they are not level thats the important bit.

I have read that below 4 ins ground isnt good.

Dont you guy's tend to chop the sump and stuff to allow the car to run lower?


atb

steve

gjn200 - 8/12/02 at 12:32 AM

Er, whats wrong with tigers recommendation? Page 139

Graham

interestedparty - 8/12/02 at 09:36 AM

quote:
Originally posted by gjn200
Er, whats wrong with tigers recommendation? Page 139

Graham


For the benefit of those of us that don't have Avon's book, perhaps you would tell us what Avon's recommendation is? Then perhaps we could say what was wrong with it (if anything)

John

bsilly - 8/12/02 at 06:38 PM

well i must be wrong.......

chrisg - 8/12/02 at 06:43 PM

It says:-

Between 114-127mm (4.5-5 inches) from underside of chassis to ground.

Mines 120mm.

Cheers

Chris

stephen_gusterson - 8/12/02 at 07:33 PM

quote:
Originally posted by chrisg

Mines 120mm.

Cheers

Chris




We always suspected as much Chris.

Must be all that Northern pollution.

Glad I'm not from 'tup narf' now




atb


steve

Peteff - 8/12/02 at 07:51 PM

It's the cold weather that does it mate.
But on the chassis height, mine is 5" high at the front and 6" at the rear although you don't really notice the difference just by looking.

yours, Pete

chrisg - 8/12/02 at 08:25 PM

quote:

Glad I'm not from 'tup narf' now


How glad do you think we are!!

Yep, 120mm is an average(ride height, you divvy) it's slightly higher at the back

Cheers

Chris

cymtriks - 9/12/02 at 12:01 PM

I just thought I'd point this out. I've always assumed that statement along the lines of "about 4-1/2 inches ground clearance" refers to laden ride height which means that unladen will be a bit more. I would guess it'll only be about half an inch more though depending on the chosen spring rates and the weights of the driver, passenger, petrol, etc.

John - 11/12/02 at 12:01 AM

Thanks all for help.

John.