Coil over adjustment

[RogerB]

Advice required as to where to buy C spanners for adjusting Bilstein coil overs.

[Jonathan Kay]

Demon Tweeks or DIY or borrow:

https://duckduckgo.com/?q=site:caterhamlotus7.club+bilstein+spanner

Jonathan

[SM25T]

Car spares shop. eBay. etc ... measure the diameter of the collar and see if slots or holes around the edge. Buy as required

[RogerB]

 

 

Okay so I've borrowed some alignment kit off a friend and fellow 7 owner. Now I'm on the learning curve as to how to use it and taken some basic measurements before making any adjustments. The main reasons for doing this are that my front tyres have scrubbed off on the inside and my dry sump pan is worn away significantly. My car is a K series SV and I'm 50/50 track and road. My tyres are 185/60 R13 front and 205/60 R13 rear.

Firstly checking  to see that my garage floor is reasonably level and  even.

My findings are:

Camber.                             Dry Sump clearance.     Condition.                                   Fuel

L. Deg.      R Deg.            

-1.5.            -2.5.                82.5 mm.                         No driver or Passenger.             1/4 Full

-1.5.            -1.5.                72 mm.                            85 kg driver.                                ,,      ,,

-2.0.           - 2.5.                65 mm.                            85 kg driver & passenger.          ,,      ,,

My questions are how do these figures look and what adjustments should I make if any. Should I be raising the ride height and where on the chassis should I be taking the height measurements from.

Tomorrow I'll try to figure out how to check the toe and would also appreciate recommendations as to what it should be.

[Jonathan Kay]

On clearance under the sump:

"A widely recommended minimum is the ability to roll a Coke can under the lowest point. That's 66 mm. But there are many experiences in the archives describing 75 mm as being needed to clear obstacles."

Jonathan

[Jonathan Kay]

There are some suspension settings suggested by the factory in the Assembly Guide. Please let me know if you'd like a copy.

And of course there are others suggested by others. : - )

Jonathan

[Drakman]

What spring rates are you using, the camber change looks a bit excessive, perhaps the spring rate is a bit soft.  What is the toe, too much toe, in or out will wear the inside tyre as will excessive camber.

[RogerB]

I have now checked with Trackace laser gauge and find the Toe out to be 30' (1/2 deg). The front springs are Caterham pt no 75517 which are listed as170 Lb/in. 

I think the ride height is acceptable and in fact there are only a couple of threads available to raise it. Possibly I need some form of sump protection if there is anything available.

Edited May 3 by RogerB

[SM25T]

I changed my front springs, initially to 250lb then up to 300lb. Smooths out the bumps and helps keep the sump off the ground. Check any ride heights with the equivalent of your weight in the car.

[7 wonders of the world]

Unless you have a level datum form which to measure you are guessing.

I suggest you mark the floor with the cars footprint then using a long bubble (or box section with a short bubble) with two identical rests to measure from (I use the tops from cans of brake cleaner measure front rear side to side and the corners you can then find the low corners and make some simply square floor shims from 6mm ply, mark them all once you have a level platform so you know what goes where next time.

Set the car on these with a plastic carrier bag with a little soap or silicone grease inside under each wheel to act as slip plates, ballast the car with driver, speed limiter and fuel as required for road or track and now you have a know level datum from which to measure.

[RogerB]

On 03/05/2024 at 17:23, SM25T said:

I changed my front springs, initially to 250lb then up to 300lb. Smooths out the bumps and helps keep the sump off the ground. Check any ride heights with the equivalent of your weight in the car.

Wouldnt this also require changing the rear springs to match also maintaining the same rake. 

[SM25T]

You can adjust the ride height at the rear. When I changed to 300lb front springs the rears were changed to 175lb linear springs. New one way adjustable dampers too.