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Re: Seized Protech dampers/shocks
Posted: Wed Jan 28, 2015 11:19 am
by josephmoore
Yep, they're the same as these:
Which seems incredibly crude as a way of adjusting ride height as it means the spring has to be kept loaded by the car. But I guess with so many using this setup it must not really matter in the real world.
I'm more used to this kind of thing - two locking rings for spring preload, adjustment into the bottom of the shock with a separate locking ring for ride height.
Re: Seized Protech dampers/shocks
Posted: Wed Jan 28, 2015 1:42 pm
by CMA
Crude maybe but they both do the same job
As usual it probably all comes down to cost. How many kit car owners would by suspension if it cost £3000 a corner compare to £100 a corner. (made up values as I'm assuming those in your second pic are higher value than the procomp)
A Robin Hood kit could be called crude compared to a Caterham kit, but they both serve the same purpose.
Also looks like a space limitation too, would all that fit in the available space on a kit car?
When fitting you need to adjust so that at full extension the spring doesn't sit loose enough to drop out. So you need slightly softer springs to ensure you have some load on them at full extension.
Re: Seized Protech dampers/shocks
Posted: Wed Jan 28, 2015 2:22 pm
by josephmoore
Mmm... I think you're right there regarding softer springs to maintain some preload on them, though I still don't see how the ride height can then be changed as it's surely governed by the max extension of the shock, minus the loading of the vehicle which ought to always be constant at rest regardless of the preload. If can surely only move further down with either more weight or negative preload (as in, a dislocated spring). I feel like I'm missing something fundamental here
Fancy ones like those are almost the same price as a Protech and spring set - about £130 a corner. Wrong for these cars, though of course.
Anyway, might try my 225lb springs on the front and get a softer set for the rear - either 200 or 180... maybe I'll try 180 for a bit more comfort and swap them out for 200 if it's too soft.
Re: Seized Protech dampers/shocks
Posted: Wed Jan 28, 2015 2:31 pm
by stylussprinter
Stop theorising and just fit them as post above --- preload is not required , otherwise the car cannot be set-up properly once fitted . Also the springs will not unseat but just let the car down nice and slowly so you can see they don't.
If you insist on having the shock totally extended with the spring adjusted to just touch (to prevent unseating) then you're going to have a lot of work to do in adjusting the ride height etc etc once the car's on the ground
Re: Seized Protech dampers/shocks
Posted: Wed Jan 28, 2015 3:07 pm
by CMA
stylussprinter wrote:Stop theorising and just fit them as post above --- preload is not required , otherwise the car cannot be set-up properly once fitted . Also the springs will not unseat but just let the car down nice and slowly so you can see they don't.
If you insist on having the shock totally extended with the spring adjusted to just touch (to prevent unseating) then you're going to have a lot of work to do in adjusting the ride height etc etc once the car's on the ground
Unlike you I have to drive mine on the roads, which as you know are not smooth and perfect like the tracks you drive on. With the potholes around there is a high chance of it coming unseated around here. On track you are highly unlikely to fully extend the available travel. On the road it's a different world.
If needed you can get spring helpers (can't remember the proper name) which add next to now resistance but just enough force to hold the spring in place and prevent a nasty unseat.
Re: Seized Protech dampers/shocks
Posted: Wed Jan 28, 2015 3:12 pm
by CMA
josephmoore wrote:Mmm... I think you're right there regarding softer springs to maintain some preload on them, though I still don't see how the ride height can then be changed as it's surely governed by the max extension of the shock, minus the loading of the vehicle which ought to always be constant at rest regardless of the preload. If can surely only move further down with either more weight or negative preload (as in, a dislocated spring). I feel like I'm missing something fundamental here
Fancy ones like those are almost the same price as a Protech and spring set - about £130 a corner. Wrong for these cars, though of course.
Anyway, might try my 225lb springs on the front and get a softer set for the rear - either 200 or 180... maybe I'll try 180 for a bit more comfort and swap them out for 200 if it's too soft.
Ride height is governed by the poundage of the spring. Softer will allow it to sit lower, harder will make it sit higher. You have a small amount of adjustment in the seat to get things level without putting too much preload on them.
If you don't get on with the 180s then give me a shout, I might be interested in a set. Procomp said 180 - 200max should be right for the stylus when I enquired.
Re: Seized Protech dampers/shocks
Posted: Wed Jan 28, 2015 3:18 pm
by josephmoore
CMA wrote:With the potholes around there is a high chance of it coming unseated around here.
This was my concern entirely. It's a slim chance, but a chance nonetheless.
As I took them off they had been nipped up so there was a little preload and the ride height was ok, if a little high at the back. I can live with that as there has to be some travel anyway. This was really just a speculative concern about how you'd adjust it short of fitting different length shocks.
Agreed that all things being equal it will ride a little lower at the back with 180s rather than 225s.
Re: Seized Protech dampers/shocks
Posted: Mon Mar 09, 2015 11:44 am
by josephmoore
Back on the road. The 225lb front, 180lb rear springs are much more tolerable than the 250lb front, 225lb rear before. They give a better looking ride height too (previously always being a little too high). I've yet to adjust the front dampers down to their correct rate, but it's all an improvement.
Just need to give the old girl a proper clean up and pop that missing centre cap back in!