[project] The Ultimate Track 205

[Cameron 16]

I'll make you a deal - I'll give you the dimensions when you explain yourself properly. Let's not shy away from a good discussion when there's a chance that either you or me (as I've been wrong before!) could learn something.

 

Just for the benefit of anyone reading who may get lost by all this, I'll try and explain my reasoning as simply as I can. Imagine you have a lever: at one and you have your wheel and at the other you have your spring & damper. With the fulcrum in the centre, when you apply a force at one end you get an equal force at the other end. This is basically your 1:1 installation ratio - force applied at wheel = force applied at spring / damper, and spring rate = wheel rate. Now move the fulcrum 3/4 of the way down, towards the damper, and the force applied at the wheel will be multiplied by 3 at the damper. Now you need to select a spring that is 3 x as stiff to get the same wheel rate (actually more so, but we'll keep it simple) and the forces into your damper will be 3 x as high.

 

So, going back to this..

 

I'd disagree with your suggestion that a 1:3 ratio means everything works 3 times as hard (and that sticking with 1:1 is easier)..

 

As per all the above, when you have a 1:3 ratio the force into the damper is 3 x that applied at the wheel, which means your damper mounting bolts and brackets need to be 3 x as strong, so even if you only look at it from a design standpoint it's nasty. If you then go into damper rates, your piston moves 1/3rd of the distance that it would with 1:1, so you need to work the fluid much harder to get the same rate.

 

Unless I'm very much mistaken.

 

So yeah, please tell me why you'd disagree with all of the above.

Edited June 16, 2012 by Cameron

[GLPoomobile 958]

Has your Warn increased again? Any chance you might actually finish this build before you get banned?

Edited June 16, 2012 by GLPoomobile

[Cameron 16]

I don't think it has.. I'm still at the same level as you aren't I?

[Anthony 1,002]

or me (as I've been wrong before!) could learn something.

Own up, who's hijacked Cameron's account? Clearly such words would never come from the real Cameron

[GLPoomobile 958]

I don't think it has.. I'm still at the same level as you aren't I?

 

That's weird, it was showing half way across the bar this morning, but I was on another PC. You are now back to mini-warn, for us trivial rule breakers.

[Cameron 16]

The two brothers..

 

 

Nice.

 

Shame it came with the biggest torch known to man, how the guy managed to weld with it is beyond me, I bloody hate the massive torches! I've ordered myself a nice new water-cooled flexi torch that's much smaller and lighter, then once my bank balance has recovered a bit I'll get it a trolley with a built-in water cooler.

Edited June 17, 2012 by Cameron

[EdCherry 34 1 Cars]

You do indeed need to work the fluid harder, the force applied to the mountings is harder as well yes. Are you worried that much about the forces through mountings that you change the ratio?

 

My understanding and experience is that the ratio is not a bad compromise though. You end up with a shorter damper (packaging ) which also weighs less. You will have a larger range of second hand quality parts thanks to single seaters (if you base your damper mounts on a pretty stand length of 320mm).

 

At the end of the day you are trying to now build a 'race' version of a saloon car, silhouette almost I guess. If you have to change some internal shims and damper fluid every 5-6 meetings rather than every 12 meetings that the 1:1 ratio might have given you then so be it, its going to cost you like £100.

 

Personally, and once again this is YOUR project after all id be searching for dampers first or at least get an idea of what is pretty readily available second hand (Single seater stuff is easy to come by!) and then designing the ratio around that. After all this isn't going to be a production car, so you can do one off's easily, and source one off's for it.

 

Hope that made sense, long couple of days working and only just made it home.

[qwerty 9]

The two brothers..

 

 

Nice.

 

Shame it came with the biggest torch known to man, how the guy managed to weld with it is beyond me, I bloody hate the massive torches! I've ordered myself a nice new water-cooled flexi torch that's much smaller and lighter, then once my bank balance has recovered a bit I'll get it a trolley with a built-in water cooler.

 

I'm in real need of a new mig welder as the one I have now is just a Clarke hobby welder, yours seems to be a one to go for by the looks of your welding, is this a good one?

 

I saw this on ebay

http://www.ebay.co.uk/itm/MUREX-TRADESMIG-171-SINGLE-PHASE-MIG-WELDING-MACHINE?item=180562607715&cmd=ViewItem&_trksid=p5197.m7&_trkparms=algo%3DLVI%26itu%3DUCI%26otn%3D3%26po%3DLVI%26ps%3D63%26clkid%3D9206039286131372228#ht_932wt_1002

 

Is this a good price do you think?

[Cameron 16]

It's not that I'm worried about the forces, the safety factor in my M10 bolts is plenty - even with a 6g bump load; it's more that I don't believe the trade-off is worth it. It's no coincidence that if you read any literature on designing suspension they state 1:1 as being the ideal target ratio. If you're doing things on the cheap (which hopefully you realise I'm not) then sure, design a suspension system around the parts available; but if you have a clean sheet of paper and a proper budget, why cut corners?

 

This build doesn't require one-off dampers, I can use any quality off the shelf part and have the valving done to suit. I've based the dimensions on Nitron's standard lengths, but it's flexible to a degree as I'm using a sensible amount of suspension travel.

 

Qwerty - I bought mine from SPA Welding and it was significantly cheaper than that - £575+VAT! Visit this link and give them a call for prices: http://www.spaweldin...mig-welder.html

Edited June 18, 2012 by Cameron

[shalmaneser 26]

There are lots of other advantages to 1:1 ratio other than the frequency of rebuilds - you're less likely to get cavitation of the fluid on big hits, they are much less easy to overheat, and you'll have lower static friction. Obviously there are packaging compromises but that's just part of the game.

[Cameron 16]

So here we go.. work platform 2.0:

 

[EdCherry 34 1 Cars]

Either way, like was said before its your project if you want to go 1:1 ratio go for it.

 

Looking good on the platform, can't wait to see you get on with adding some bars.

[calvinhorse 870]

Erm what's that at the back of the garage???

[Rippthrough 98]

It's not that it's ideal as such, just makes tuning a bit easier, if you really weren't bothered about weight and size of the damper package and wanted more control you'd go for 2:1 or 3:1, etc...

[Cameron 16]

So after an incredibly frustrating afternoon I've come to the conclusion that I won't be bolting this new platform to the floor, and will just let it stand free instead. Drilling into the floor is an absolute bloody nightmare!

[Rippthrough 98]

Pfft, bigger hammer and some nails.

 

Or stick it down with some poly.

[qwerty 9]

Why? Is it too tough or it is breaking up, have you got SDS drill?

 

 

[pugdamo 111 2 Cars]

I'm loving this thread,just a bit sad at the mo because i keep seeing updates and when i come to check there's no pictures of progress on the car

 

You are doing an amazing job,i don't really understand what your all going on about half the time,especially with this 1.1, 2.1, 3.1 ratio but its such an enjoying read,keep up the good work

 

Erm what's that at the back of the garage???

 

I'm going for a mini pickup

Edited June 19, 2012 by pugdamo

[Cameron 16]

Haha sorry! Don't worry, as soon as I get to building the thing I won't have enough time to talk about ratios and all that bollocks.

 

I don't have an SDS drill but I was using a good carbide-tipped bit in a decent hammer drill. The top inch of the slab is pretty soft then it goes to granite infused with diamond-hard pebbles that just make the drill bounce or overheat. Meh, it doesn't need to be bolted down that badly anyway.. my one in the garage wasn't and that coped just fine.

Edited June 19, 2012 by Cameron

[Cameron 16]

Well, I was reminded today that it's been a while, so it's update o'clock! Firstly an apology that it still doesn't involve pictures of the car!

 

I've had a huge list of jobs to whittle through since moving to the unit, and they're pretty much all ticked off now. I have a work frame built, levelled and awaiting some wooden boards to fill in with; and a work bench installed that just needs the 3mm steel worktop fitting. I just need to finish up these 2 little jobs then it's all systems go.

 

I bought a very very nice new TIG torch from the USA, complete with a large gas saver lens..

 

 

Which, frustratingly DOESN'T BLOODY WORK!

 

The gas passage hasn't been drilled properly so no gas comes out at all.. great! I phoned them up and they agreed to give me a flexi-head model (this one is fixed) in exchange at no extra cost, so I'll be happy with that!

 

Anyway.. everything is just about ready to go, which is great. Next week is pay day, so I'll be placing a fairly substantial tube order, then the following weekend I'll get cracking. 14th July - watch this space!

[unariciflocos 49 1 Cars]

Can't believe you're actually starting work after only 32 pages .

[brumster 135 1 Cars]

The gas passage hasn't been drilled properly

 

Am I the only one who went all Finbar Saunders at that line?

[Cameron 16]

I haven't started yet!

[Cameron 16]

This looks familiar..

 

http://smotra.ru/use...ff/blog/143795/

 

If anyone is still struggling to see what I'm doing here, take a look at that link. It's a very similar concept, though my suspension will be a little more sophisticated.

Edited June 30, 2012 by Cameron

[GeorgeXS 32]

That BMW is awesome! Not that there's a lot of BMW left mind.