Ride Height / Rake

[Bricol]

I know this has been done before, but . ..

 

what is the generally recommended rake frt to rear of a de-dion suspended K-series car? I'm assuming I start with front wishbones parallel to flat floor and adjust the rear to suit - but where do I measure?

 

Just want to get the baiscs right before I add in a guessimate for effect of full load of luggage and the spare wheel for the up-coming Euro 2003 - roll on saturday!!

 

 

Bri

 

[c21vhpd]

Bricol,

 

I recently asked Caterham this for my 21. The nature of the reply was such that I think they gave the standard ones for a 7...

 

75mm under the sump and 10-15mm rake between the front to back axle.

 

That last bit has me stumped as I certainly don't have a front axle and I don't think you can call a de Dion an axle either as nothing is spinning on it. If I did have axles, then as my wheels are at the same size I could only achieve a 15mm rake by strapping 15mm blocks of wood to the rear tyres

 

If I take my out of my 🙆🏻 for a few seconds though, I'm going to measure the bottom chassis rail height just behind the front wheel and in front of the rear wheel and set that to be ~12mm different.

 

Honda Passion Orange, 640kg , and proud of it

[Allen Payne]

They are normally measured on the side chassis rail just behind the front wishbone rear mounting point and at the end of the side chassis rail in front of the rear wheel.

[scooby dooby doo]

the rake isn't the critical thing.

 

you want the angle of the radius arms to be 'correct' at the rear to set the rear steer as required. and you want the corner weights to be 'correct', ie same weight on each of the fronts with the driver in (or same weight across the digaonals is I think the other school of thought).

 

 

obviously if you set based on the gap under the car then bigger or smaller tyres are going to give a different angle. I think the oft quoted figures are reasonable given a normal size of tyre. I don't know what a normal tyre is though ❗

 

Drive it, see if it over or understeers. get very confused, play with rear ride height, arbs, dampers, spring rates, tyre pressures. when you understand it all please come and explain it to me ❗

 

HOOPY

R706KGU Hoopylight R

[Bricol]

thanks one and all -

 

I'll give the 15mm idea a go sometime this wek on a nice flat works floor.

 

I don't drive hard enough on the road to get oversteer - occasionaly feel it push as the front hits the stops but thats about it. Until it rains - and then the last time it nearly bit me as it stepped so far out of line and I think only luck got it back.

 

Spent 15mins wrecking a Westfield setup and 7 years getting it perfect - don't want to tread the same path again - so this time it stays as near to standard and simple as possible!

 

 

Bri

 

(clean and shiny for Euro . .. .cars not too bad either . ..)

[scooby dooby doo]

"front hits the stops"

 

what do you mean by this 🤔 if you're hitting the bumpstops in gentle cornering then something is VERY wrong...

 

HOOPY

R706KGU Hoopylight R

[7SE]

The rather snappily titled "How to build & modify sportscar & kitcar suspension & brakes for road & track" might point you in the right direction. Its available from veloce publishing www.veloce.co.uk. Lots of diagrams of 7s and suspension settings

 

It all seemed very sensible and easy to read to me, whether I actually understood it is another matter 😬

 

7SE - Back to basix