Pro comp/ protech dampers

[Shooter63]

Today I phoned procomp about replacment dampers for the front of the car, boy do those guys have it in for rocker arm suspension but they are really nice guys with loads of time to chat, I came to the conclusion that I might be better making a set of brackets to move the lower suspension fixing points inwards and also knocking up a set of phosphor bronze bushes for the pivot mounts.
While I can make the lower mounts pretty easily, I need to know the dims of the bushes, so does anybody know what size they are?

Shooter

Ps I have a lathe and milling machine so knocking the parts up won't be to bad.

[pigeondave]

Today I phoned procomp about replacment dampers for the front of the car, boy do those guys have it in for rocker arm suspension but they are really nice guys with loads of time to chat,

There was a similar point made on the JPSC. Like I said over there they do know their stuff but you have to listen to a lot of hate for the inboard stuff.

If you're feeling brave you could ask if its so bad why has the caterham CSR have inboard shocks and Caterham list it as an improvement? (I didn't have the balls to ask )
https://en.wikipedia.org/wiki/Caterham_ ... provements

With Caterhams R&D im sure it was well considered.

[Shooter63]

Now I've got over the tirade of hate and uselessness of the design and had time to think, part of there gripe was total cobblers, a big moan was about the pivot itself hence me stating that I would make some bushes up, but hold on me thinks , minis seem to get on quite nicely with a roller bearing set up in the top arm. I don't think I really helped the situation when they were talking about the need to use 5w oil in the shock due to the heat flood from the rad ( use the thinnest oil then it can't get any thinner) and I said that you can get 2.5w
Anyway I've decided to be brave and make the second call and order up a pair of 11" dampers with 6" 250lb springs.

Shooter

[stylussprinter]

The 6 inch springs will allow you loads of lowering opportunities as you develop the car. Not sure how high off the ground at the front bottom chassis rail your car is. Mine is 75mm's and I run 7 inch front springs . You'll likely have to cut some of the wheel arch out to accomodate the wheel/tyre depending of course what diameter they are ie. 13 , 14 , 15 inch wheels etc.
11inch open front shocks is ideal for the front though.

[pigeondave]

minis seem to get on quite nicely with a roller bearing set up in the top arm.
Shooter

I did this side ways step (not an upgrade) and found that the roller bearings were pushing on the steel tube and ever so slightly dented it. (It was actually MikeB off here that spotted it.)

I think it comes about due to there not being enough spiny movement to the rollers to spread the load.

Tim Hoverd was talking of using Igus bearings these should spread the load more and not just have one corner of the car resting on two needle bearings.

EDIT

some thing like these
http://www.igus.co.uk/iPro/iPro_02_0001 ... &c=GB&l=en

[Shooter63]

The bush/ bearing thing is something I will have a look at over the winter, I will probably stick with the phospher bronze idea as I can machine an interference fit to the od then ream the bore to the correct diameter.
As to the damper/spring length that I arrived at, calculating that I want to drop the front 30mm from its present height at a minimum to get some decent rake, my front suspension is 12" damper 8" spring with the platform wound pretty much to the bottom, an 11" damper will obviously drop me 1" while the 6" spring should give me plenty of adjustment to play with. Just to make sure that my calcs were correct I phoned protech up today and they confirmed that a 6" spring should be used with that length damper time will tell.

Shooter

[pigeondave]

Interesting reading and a really good site

Damper lengths

http://www.everettmail.co.uk/mods/mods_ ... ampers.htm