homemade shocks

[locostkiwi]

hi guys been looking at different forums ( locost etc... ) and some people on them have suggested making their own coilover shocksw using "mini" shocks and springs.
does anyone on here have or know of details of these..
Do they work or are they a waste of time making.
If they are worth it who has plans for these?
cheers Tony

[AnguS]

robin hood used to do something similar
the eyes at the ends of the shocks are not designed to hold the car, just the forces of the damper... they fail

dont do it:eek:

on the other hand, if you want the bits to do it, i think there are some in my shed :D

[Bonzo]

Hi Tony

When I first started my build, I nearly S**T my pants when I found out how much my coil over shocks wer going to cost me :eek:

A few good ebay sales later, I decided to bite the bullet & buy them .... One of the first things I bought, glad I did because nearly 4 year's later & they have gone up by almost £100 !!

Anyhow to the point of this post.

I did toy with making my own coil overs with these

http://i274.photobucket.com/albums/jj266/Bonzoronnie/Triumphshocks.jpg

Triumph shocks .... As fitted to the front of Triumph Herald, Vitesse, GT6 & Spitfire ect .... They can be had for as little as £30 per pair.

I had a few kicing about when I was clearing all of my Vitesse parts & the measurements were not a million miles away from what was needed for the Roadster.

My Idea was Machine some top fittings to take a bush ( Not unlike a coil over ) then machine some spring retaining plates ( Again, not unlike a coil over )
Top of the shock is pre threaded so it would not be a problem fixing the top fittings.

I guess the hardest work would be finding the ideal size of spring to use ... Again custom springs can be found for about £40 a pair.
Never going to be adjustable ( Unless you are clever ) so ride height will be fixed & a fair bit of trial & error finding a suitable spring poundage :confused:

Right now for the disclaimer !!??

This post is purely the thoughts of this old fool on a Sunday morning :D
Deliberately posted to encourage the debate .... Are Lo-Cost shocks possible.

I For one think coil over shocks are grossly overpriced for what they are !!??

As said, for deabate .... Don't go & actually make them without propper research.

[Big Vern]

With alll due respect Angus, most dampers are used to limit both bump and rebound travel and are therefore subjected to considerable loads often shock loads!
Having been involved in designing and making prototype dampers in the past there is no real difference between a plain damper body and a coil over body such as the one in Ronnie's picture.
If the 'ends' are falling off that is more likely to be they way they have been mounted to the chassis and would likely fail if they were just being used as dampers.
The cost of converting stock mini dampers to coil overs would make a cheap option but it would be unlikely that the damper manufacturer would service (rebuild) them when they wore out so you'd have to make another set! Most coil over manufacturers will service their dampers.
Also mini damping would not match the haynes roadster as the effective spring rates would be different and as the dampers would be non-adjustable the handling could be interesting to say the least.
Adjustable mini dampers arn't much cheaper than the coil overs specified for the haynes roadster which are the most logical choice, - You'll end up getting them in the end anyway so why not start out right to begin with!
As for spring rates there are many spring lengths and sizes for coil overs so that wouldn't be a problem but matching the damping rates to the spring is. (something that is eliminated with adjustable and rebuildable coil over dampers such as AVO or GAZ.)
It also never ceases to amaze me how many people skimp on tyres and dampers, the two things that will make or break the cars roadholding while spending 1000's of bucks on tuned engines......
Colin Chapman designed the original Seven to light and nimble with good roadholding and modest power, using the superior roadholding to beat morepowerful cars of the day.
To my mind spending money on good suspension, brakes and tyres yealds greater rewards than a tuned engine and that tuned engine can always be added later when funds allow.
I would however agree with ronnie that coil overs are overpriced but that's generally because most coil overs are sold to race teams for single seaters so you have to pay race car prices - but then AFAICS you get what you pay for and I'd pay for good roadholding.....


BV.:)

[3GE Components]

Alternatively, if you have access to a lathe and a mill there's always these

http://www.locost7.info/mirror/dampers.php

Kind regards

John

[Big Vern]

Interesting john,
These drawings appera to have been 'ripped off' from some race team or other.
1) How will you 'gas' them up without a filling rig and how do you know the 'valving and shim stack' is what will work with the haynes roadster?
2) How will they be adjusted ie shims for the shimstack etc. These parts are beyond the abilities of the home mechanic and to buy in the parts (even if a damper manufacturer will sell them to you) will cost more than the coil over you're trying to avoild buying......
Yes Coil overs are annoyingly expensive :eek: but people are still prepared to spend loads on tuned engines and fancy wheels so I don't see what there is to complain about! It's just a matter of project priorities.:confused:
Perhaps it's just a reflection of the people here that style is more important than substance, but I'd rather get the basics right first.

BV.:)

[3GE Components]

H Vern,

They are "apparently" by Darren George, GTS's Darren George maybe?, he's always said he was an F1 suspension designer, wether these are his work or not who knows :rolleyes: There are people on this forum who could make these, and if you don't cost your time & have the material already could probably make a reasonable effort. But as you say, the tuning would not be perfect.

Agreed, quality suspension makes or breaks a car, and is something that you should buy the best you can afford, the nicest ones i've seen of late are these guys, http://www.blackartdesigns.com/ who have a good pedigree behind them.

Kind regards

John

[Talonmotorsport]

I don't think £360-440 for a set of springs and coilovers is too much to ask. I know people will say it's not 'locost' and it's alot of money to pay, but last time I looked a half reasonable set of wheels and rubber was £300+, full set of fibre glass body work was £600-700+, IVA £450. The book is called 'build a car on a budget' not 'build a car for free'. I know some grasstrack racers that would'nt even use the base coilovers from the factory without the manufacturer having the cars corner weights first. You pay your money you make your choices it's up to you, but if at least you buy the right thing for the job in the first place you won't have to spend more money to correct it.

[mr henderson]

Also it's worth bearing in mind that you can actually calculate the correct spring poundage and length if you take the trouble to weigh each corner of the car. It's possible to do this with reasonable accuracy with bathroom scales.

You might need 2 sets depending on the maximum reading of the scales. Just put the car on a reasonably flat surface, raise one wheel and rest it on a board that goes across both sets of scales, then raise the other 3 corners and rest them one blocks of wood or whatever the same height as the scales, and you can weigh that corner, then just a question of repeating it on the other 3 corners. Tedious but cheap and effective

[Bonzo]

Some good debate here :cool:

Usually when someone asks if home made is possible, all you hear is " Don't do it, you'll die " !!??

Not saying for one moment any of us would actually make home made coil overs to save a few quid but it is good to have a debate of this nature :)

Personally, I still think coil overs are expensive for what they are but as Phil said, in the grand scheme of things not the end of the world.

Thank's for some interesting reading folks :) :)

[mr henderson]

I still think coil overs are expensive for what they are



I agree, and it's entirely in keeping with this type of project that one should look for less expensive ways of achieving good results, after all, that's a lot of what building your own car is all about.

In general, for a road car, it's usual to have the shocks on their lowest stiffness setting, so shocks designed for a road car would be a perfectly satisfactory starting point (can always uprate later). So, if one used the Triumph shock absorbers shown above, all that one then needs is springs the correct length and poundage. That can be calculated once the weight and a few other factors are known, so that it isn't necessary to have adjustable seats (as said, this is a starting off position). For the build, the shocks/springs could be replaced with lengths of 1X1 drilled for suspension bolts, until the weights are known.

I have a spreadsheet written by suspension guru Mike Capon which I would be happy to upload, but looking at the 'upload' window there doesn't seem to be a way of uploading this excel (I think) file. If anyone else knows how to do it, let me know and I will pass it on, or pm me an email address and I'll send it direct.

[locostkiwi]

thanks for all the input, coilover shocks here in New Zealand are SO overpriced
im looking at NZ$600 per wheel, im not looking at racing it but the triumph option looks good and maybe update later?
now to price a set of triumph dampers???

[ozzy1]

You can get the Gaz shocks for around the $1200 for a set here incl springs.If you get stuck i can find out for you.I know a guy at my car club supplies Gaz shocks to most of the members although not sure what length they are.

[Bonzo]

thanks for all the input, coilover shocks here in New Zealand are SO overpriced
im looking at NZ$600 per wheel, im not looking at racing it but the triumph option looks good and maybe update later?
now to price a set of triumph dampers???

Holey moley LK, they are expensive in NZ that's for sure :eek:

I have been an avid fan of Triumph's over the years & this is why the front suspension sprang to mind.

The front suspension of the Triumph was quite revolutionary in it's day .... One of the first UK production cars to make use of a double wishbone suspension design.
It has to be said, the front suspension of the Vitesse, GT6, Spitfire ect, worked really well.
That is more than can be said about the rear set up with it's dreadfull, single transverse leafspring !!
Front of the car would handle well but the rear wheels had a tendency to fall over.

Here's a diagram of the Triumph front suspension for anyone interested.

http://i274.photobucket.com/albums/jj266/Bonzoronnie/vitessesuspension.jpg

It can be seen that the front shock is in effect, a coil over concept.
Also mounted at quite an accute angle ( Not unlike the Roadster ) .... One can only assume that it has been designed to withstand some latteral load !!??

Here are some UK resources for you LK. Rimmer Bros (http://www.rimmerbros.co.uk/Item--i-GRID005375)

Disclaimer time again :D

I have provided this information soley for the purposes of healthy debate.
Please do plenty of research into this subject.

Wish I still had some Triumph front shocks here, some accurate measurements may have been usefull.

As Mr H has said, Finding the correct springs to use will be the trick.

[AshG]

H Vern,

They are "apparently" by Darren George, GTS's Darren George maybe?, he's always said he was an F1 suspension designer, wether these are his work or not who knows :rolleyes: There are people on this forum who could make these, and if you don't cost your time & have the material already could probably make a reasonable effort. But as you say, the tuning would not be perfect.

Agreed, quality suspension makes or breaks a car, and is something that you should buy the best you can afford, the nicest ones i've seen of late are these guys, http://www.blackartdesigns.com/ who have a good pedigree behind them.

Kind regards

John

The last thing that i used designed by Darren George, catastrophically failed during normal use, it could have been any number of factors that caused it but thought i would share. Those drawings look ok but i would still get them stress modelled in a good cad package before feeling comfortable about using them in a road application.

[davidimurray]

Don't do it :p

A couple of years ago I was involved with building a set of prototype MR dampers for our race car. Wow what a job that was - you need to be extremely accurate with the machining and work to very fine fits/tolerances. All the seals need to be correctly specced (we had problems with the MR fluid eating seals) and you need to get the correctly ground piston rods. Add to that the fun of machining a very fine thread on the outside/inside of the shock/spring seat combined with getting all the tolerances right for hard anodising. We must have been a good week of 12 hour days, jigging, machining, programming etc. When you realise how much work goes into a set of dampers then £85 each is a bargain.

It's the dampers that keep the car firmly planted on the road so they are a worthwhile investment.

[Big Vern]

I'm with you on this one Ash, the only thing he was good at was talking, unless he owed you somethin', then he couldn't manage that:mad:
David, your right of course, it's not just a case of poppin' into the garage with a basic lathe and knocking out some dampers and considering whats involved then coil overs arn't that bad - unless you live in NZ:eek:
LocostKiwi, have you thought about using second hand coil overs from the monoshock rears of motorbikes? Might be a bit better damping than those of the triumph spit:)


HTH BV.:)

[Bonzo]

LocostKiwi, have you thought about using second hand coil overs from the monoshock rears of motorbikes? Might be a bit better damping than those of the triumph spit:)


HTH BV.:)

Now there's a thought Big Vern :)

I know a few folk on LB have used motorcycle shocks on inboard suspension set ups.

Just for the record, I only toyed with the idea of making my own coil over's

Very fortuantely for me, the parts from my abandoned Triumph Vitesse projects sold unbelievably well .... So much so, those sales have financed the majority of my build.

Buying the Gaz coilovers was heck of a lot easier not having to raid the bank for them :)

[chrisunwin]

Hi

Found these GAZ coilovers for £70.00 a corner ... http://www.corbymotorsport.com/1-34-bodies-12mm-rods-bonded-bushes-p-4298.html

Anyone considered using Citroens hydropneumatic units?? Or am I the only completely mad one on here!!!

Regards

Chris

[Bonzo]

Hi

Anyone considered using Citroens hydropneumatic units?? Or am I the only completely mad one on here!!!

Regards

Chris


Less of the swearing please :D :D

That could actually be quite a cool project if you could get it all to work .... I guess Mr IVA man would have something to say about type approval for the system though :eek:

My old Citroen BX estate was one of the best all round cars that I have ever owned ..... Hated working on it with a passion though :rolleyes:

[flyerncle]

Nothing wrong with Citroen hydraulic system and easily tunable if you get the old DS sphere's ( Sorry Ronnie )shoot me for this suggestion but what about seperate spring and shocker with some kind of rocker arm or dare I mention torsion bar and shock.

[Bonzo]

Nothing wrong with Citroen hydraulic system and easily tunable if you get the old DS sphere's ( Sorry Ronnie )shoot me for this suggestion but what about seperate spring and shocker with some kind of rocker arm or dare I mention torsion bar and shock.

I have to admit it Paul, the hydraulic suspension of those Citroens was quite awsome, when they wern't leaking .... But then, that's the hazzard of running an ederly car :o :o

Not being a driver, driver I do not know if any of those Citroens had the same sort of success on the WRC circuit as todays ones :confused: :)

[chrisunwin]

Ronnie

I believe the DS put up quite a good show rallying.

The GS units look very usable on the roadster, they have a 117mm travel, and the front and rear units are the same (different static pressures though).

Biggest problem with the DS suspension was taking a humpback bridge at speed. Fantastic suspension tried to compensate for the wheels being too low just after takeoff, so it raises them. Brilliant, no suspension just when you land. One sickening crash, feel like your spine has compressed, then all is serene and smooth as it pumps back up. (Just dont tell Dad, twas in his car).

Torsion bars? Whats wrong with them. The Marina used them to great effect. Didn't it!


Chris

[flyerncle]

Been down the Citroen road as I used to PDI new DS,BX,CX,GS and a couple of Light 15's and Panhard thrown in for good measure.
The problem is as stated when the leave they road.
I had a fair bit to do with Citroen rally cars as a youngster and the "D" was shortened by the length of the rear door,it tended to pitch quite badly under acelleration so the front tended to be set higher than the rear.

As for torsion bars the front is fairly do-able but the rear would be more of a challenge.