Will the honda pu not alter the total weight and it's distribution ?? and thus also the end result

Yes it will.

By how much is impossible to say without having the figures to work with. That's why I qualified it by saying 'according to the data supplied by Bob'.

If somebody is prepared to give me the correct figures I can easily do the sums for them.

This is what I need.


Total weight including driver.
Front / Rear weight distribution including driver.
To calculate total weight at each corner.

Un-sprung weight at each corner.
To calculate sprung weight at each corner.

Front Lever Ratio. (Wheel movement/Spring movement).
Rear Lever Ratio. (Wheel movement/Spring movement).

Front fitted spring length with the car at the correct ride height.
Rear fitted spring length with the car at the correct ride height.

Chosen front wheel frequency.
Chosen rear wheel frequency.

The natural wheel frequency (cycles /min) is your choice and determines the overall 'feel' of the suspension. As a guide it should be around 60 – 80 for a comfortable road car, 80 – 100 for a sportier car and 100 – 125 for a circuit racer on smooth tracks. (Alan Staniforth). The front and rear wheel frequencies cannot be the same or the car will oscillate in pitch (backwards and forwards). It is normal to set the front wheel frequency 10 -20 c.p.m lower than the rear.

Interesting reading, shame I just got the protechs with their standard 250 front 300 rear as it doesn't feel right at all. Rear sags a lot more than front it seems and front feels light. Especially with more weight at the back as its Honda engined.

Thinking of trying 225 / 350

Any suggestions?

Or maybe just go stiffer at the back for now so at least the front and rear are sagging more equal

https://kitnet.uk/community/threads/suspension-topics-springs.319/

There is some interesting info in this link from suspension guru Dave Gallop. Not sure I fully understand it though...

I've just changed my 300lb rear springs for 400lb springs. It feels much much better
Its firmer but not uncomfortably so. Nowhere near as saggy & not bottoming out - as it used to with the 300lb springs!
So i've now got 225lb front & 400lb rears. It feels the best i've had since owning the car.
My personal suggestion now is: 225-250lb fronts & 375-425 rears. This is for road use, not track!