Scaffolding poles + old VW bits + Rotary engine....
Discussion
Well, they should stop the scoops stalling so possibly more drag...but then the air spilling over the side of the scoops won't seperate cleanly either so maybe not.....basicaly, god knows, but at least the engine bay will be cool 
Hopefully if we can get enough expansion into the airbox and enough outlet area we might be able to slim the side scoops down a bit, they're deliberately oversized at the moment for low speed cooling.
Hopefully if we can get enough expansion into the airbox and enough outlet area we might be able to slim the side scoops down a bit, they're deliberately oversized at the moment for low speed cooling.
No, ideally the side scoops will have an edge around them which is a little better in terms of flow/drag and looks better to boot, but at the minute we need to be oversized rather than under, so it'll be lots of testing and some gaffa tape for a while.
Cooling and reliability is everything first. Rest we can refine later.
Been going through some old photo's the past day or two and realised I left a few bits out on here along the way:
Front discs/calipers, etc, fitted. Also shows the unfortunate kink needed in the front reinforcing cross - ideally it would be straight for maximum stiffness, there's a bolt in aluminium tie bar that goes in there to link it down to the floor and keep the front of the chassis stiff.
And on the recent louver theme....it wasn't just the uppers that look like a set of blinds....
Skidpan's - 6mm thick aluminium plate for the transmission - goes forward under the beam tube/seats and is overlapped by the main floor for a while so it's even thicker there. The transmission plate also overlaps the engine plate when that is fitted so there's no leading edges anywhere to dig in - making the underbody armour half an inch thick in some sections - it still takes a beating mind.
The front beam and front section of the floor gets it's own piece of 6mm plate too which wraps up around the front beam and up a few inches to prevent the beam digging in on a nose-hard landing/drainage ditch crossing.
Unfortunately it doesn't look this shiny for long!
You'll have to excuse the rear of the floor, one of the helpers thought a hammer was a good substitute* for a sheet metal folder....
*It is, but not how he uses it!
Couldn't afford a CAT scan to check the discs for flaws, so went for the cheaper alternative:
He said they were a bit Ruff.
Rerouting some piping before Christmas, along with some other changes the eagle eyed might notice - basically the hoses were a little close to hot spots for comfort, even with heat shielding, mainly because they'd been made few mm long by the supplier but with such short, wide hoses getting rid of the extra length meant routing at quite an angle into some of the fittings, and it also meant the dry sump belt was difficult to access - not something you want in the field!
Anyway, chances are the hoses would have been fine but after this amount of time an oil fire is not the way you wish to discover that they weren't...
Anyway, that knocked on to shifting a few bits and pieces (exhaust relocated by removing the right rear frame support tube, and shuffling of the oil filter mainly - although then I decided I didn't like it anyway, so then it got moved again to completely under the engine now there's room due to the exhaust shift) and then it meant remaking panels that were already done:
Welded up awaiting the top rolling over the tube:
This was probably posted after finding some decent whisky in the back of a cupboard:
I make no apologies for that terrible joke, you've already read it now so it's tough anyway
Anyway, if you were wondering how the exhaust had magically jumped 2 inches to the right for no apparent reason in the previous posts, now you know
Front discs/calipers, etc, fitted. Also shows the unfortunate kink needed in the front reinforcing cross - ideally it would be straight for maximum stiffness, there's a bolt in aluminium tie bar that goes in there to link it down to the floor and keep the front of the chassis stiff.
And on the recent louver theme....it wasn't just the uppers that look like a set of blinds....
Skidpan's - 6mm thick aluminium plate for the transmission - goes forward under the beam tube/seats and is overlapped by the main floor for a while so it's even thicker there. The transmission plate also overlaps the engine plate when that is fitted so there's no leading edges anywhere to dig in - making the underbody armour half an inch thick in some sections - it still takes a beating mind.
The front beam and front section of the floor gets it's own piece of 6mm plate too which wraps up around the front beam and up a few inches to prevent the beam digging in on a nose-hard landing/drainage ditch crossing.
Unfortunately it doesn't look this shiny for long!
You'll have to excuse the rear of the floor, one of the helpers thought a hammer was a good substitute* for a sheet metal folder....
*It is, but not how he uses it!
Couldn't afford a CAT scan to check the discs for flaws, so went for the cheaper alternative:
He said they were a bit Ruff.
Rerouting some piping before Christmas, along with some other changes the eagle eyed might notice - basically the hoses were a little close to hot spots for comfort, even with heat shielding, mainly because they'd been made few mm long by the supplier but with such short, wide hoses getting rid of the extra length meant routing at quite an angle into some of the fittings, and it also meant the dry sump belt was difficult to access - not something you want in the field!
Anyway, chances are the hoses would have been fine but after this amount of time an oil fire is not the way you wish to discover that they weren't...
Anyway, that knocked on to shifting a few bits and pieces (exhaust relocated by removing the right rear frame support tube, and shuffling of the oil filter mainly - although then I decided I didn't like it anyway, so then it got moved again to completely under the engine now there's room due to the exhaust shift) and then it meant remaking panels that were already done:
Welded up awaiting the top rolling over the tube:
This was probably posted after finding some decent whisky in the back of a cupboard:
PhillipM said:
Today we see the lesser spotted Hermit Filter in it's natural location. Generally shy and lacking in mobility, this little fella finds a nearby engine and ducks underneath, using the sump for protection. Upon finding this safe location, he quickly hooks into the oil lines and then filter feeds on debris and dirt in the oil, providing a beautiful symbiotic relationship that helps the engine live longer.
That cute blue exterior hides some defences though - attempting to remove a Hermit Filter - even one that has only lightly screwed itself to it's new perch - often requires the services of Popeye (or alternatively the Left Hand of God, if he's around at the time) and unfortunately the trouble doesn't stop there.
After freeing the grip of the tenacious Hermit Filter, it borrows a trick from the aquatic world and aims a stream of hot, black oil at your hands, eyes, the floor, the walls and, for some inexplicable reason, the cream living room carpet.
Even if you've removed it in the garage, 10 miles away from home.
It's an incredible defence mechanism really.
And some louverly new vents.That cute blue exterior hides some defences though - attempting to remove a Hermit Filter - even one that has only lightly screwed itself to it's new perch - often requires the services of Popeye (or alternatively the Left Hand of God, if he's around at the time) and unfortunately the trouble doesn't stop there.
After freeing the grip of the tenacious Hermit Filter, it borrows a trick from the aquatic world and aims a stream of hot, black oil at your hands, eyes, the floor, the walls and, for some inexplicable reason, the cream living room carpet.
Even if you've removed it in the garage, 10 miles away from home.
It's an incredible defence mechanism really.
I make no apologies for that terrible joke, you've already read it now so it's tough anyway
Anyway, if you were wondering how the exhaust had magically jumped 2 inches to the right for no apparent reason in the previous posts, now you know
Edited by PhillipM on Tuesday 12th April 12:12
Managed to nip up yesterday for an hour or so.
1.) It's rudely healthy, as in - might have to turn the boost down when it's properly mapped healthy - but I've still got a fair bit of mapping to do, safe enough to bed in for the minute though.
2.) It's lighter than we expected, even fuelled and running. Going to need lighter rear springs even with the lower rates from the extended rear arms.
2.b) Not sure if that's a good thing. On one hand it's lighter, yay!
2.c) On the other, need to open wallet for new springs, boo.
1.) It's rudely healthy, as in - might have to turn the boost down when it's properly mapped healthy - but I've still got a fair bit of mapping to do, safe enough to bed in for the minute though.
2.) It's lighter than we expected, even fuelled and running. Going to need lighter rear springs even with the lower rates from the extended rear arms.
2.b) Not sure if that's a good thing. On one hand it's lighter, yay!
2.c) On the other, need to open wallet for new springs, boo.
Loving following this, thanks for persisting 
"On one hand it's lighter, yay!
On the other, need to open wallet for new springs, boo."
Since you seem to like cutting-up working things for fun - is there any mileage in shifting one of the mount points (adding a variant mount) for the coil overs you have to a more inclined angle to effectively soften a tad & gain travel (as if you need it...). Just a thought.
"On one hand it's lighter, yay!
On the other, need to open wallet for new springs, boo."
Since you seem to like cutting-up working things for fun - is there any mileage in shifting one of the mount points (adding a variant mount) for the coil overs you have to a more inclined angle to effectively soften a tad & gain travel (as if you need it...). Just a thought.
PhillipM said:
I'd have to make quite a large change to get the amount it requires, so much so the damper ratio would be terrible - the rear is about 3 inches higher ride height than required, even at the minimum setting.
Where did you learn all this stuff? Have seen your bits and bobs on here and GTi-6 and you certainly give the impression you know how things go boing (but only by just the right amount). I need to know how, too.Assume my understanding is that of a 2nd yr mech eng undergrad (because it is). How do I start understanding vehicle suspension proper?
1) Make sure up and downy bits go up and down. Friction makes far more difference than most people give it credit for. For reference see anyone fitting cheap polybushes and having to shove the suspension arm up and down by hand thinking that's okay...
Even for a car that has 18" of suspension travel and spends it time whalloping off rocks, I can tell when a bush is binding up, it affects the balance of a car massively, makes them unpredictable on turn in. That goes for dampers too. They have mechanical as well as fluid forces at work.
2) Cut some old shocks up and have a look how the internals work, have a look at how the seats and faces are designed as well as the stacks, most internet and book stuff will focus on the latter only in explaining how things work and onto equations, the former is just as important, as is all the variances introduced by actually making a physical damper rather than assuming it can do what you ask for perfectly.
3) I get way too bored some nights. I sit tweaking valving simulations for fun. Yes, I am that sad. Sorry.
4) Read, read everything. Even if it's bad it shows you what's bad in the stuff you may have taken for gospel before. And talking of gospel, never believe anything at face value. This is the internet, 98% of stuff on dampers is repeated chinese whispers built on pub b
ks. 50% of the stuff printed in books is still outright wrong or just assumes you're using theoretically perfect vehicle dampers - nobody built one yet - but you stand more chance with the old favorites on chassis dynamics.
5) Look at what OEM's are using and why, there's a lot of shiny graphs out there by people who want to sell dampers claiming they're better than OE because of X,Y,Z - that OE manufacturer put £X million into development, dynamics and NVH for a reason, learn from it. I've taken 30 year old Peugeot dampers apart that'd I'd rather stick some fresh oil in and use over some well known brand new aftermarket upgrades after comparing the two!
6) It's all well and good having the theory, a supercomputer to run circuit sims on and a set of Ohlins donated to your Formula Student team, but once you get out of Uni, you'll find you have £20 and half a mars bar to spend on some 10-year old non-adjustable shocks, you've got a laptop that can barely manage solotaire and that sim software turns out to be 5 grand a seat per year. And for some reason nobody seems to have mapped out a random forest in Wales. And the bloody course changes every time you go around.
I.E - be realistic with how much you can do, you have to make shortcuts and rules of thumb. And to do that you have to have enough knowledge to rule out what is wrong, and enough common sense to there might be more than one solution to the same result, but the one your gut says is right often isn't. Stick to the facts. That might mean a complete design direction change on your settings, simply because one day you've got an extra £20 spare and buy a new part. You're going to need your assumptions and rules of thumb to get you a quick, cheap baseline to work from.
On number 6 I can assure you that happens because I'll be heading in a completely different direction with settings once I get time to make some new parts up front, but for now, that way would hurt the car more than help it without the matching bits, so I need to keep refining the previous direction. Neither is right or wrong, just one is more right with the other parts and this one is more right without them.
7) Body control is more important that will be emphasised, sometimes you have to take damping well over critical to control the body at the expense of handling the tyres and contact patches, which seems terrible for a non-aero car. But rally cars have similar needs to heavy aero racecars, as strange as it sounds, and I've seen a perfectly working car taken to a single seater specialist, have some very trick terrain sensitive 3 way dampers fitted and setup over several test sessions, then promptly punched the whole lot clean through the bonnet because it kicked the rear up and came down hard on the front on the next bump the first time it went over something they hadn't simulated.
8) Realise you'll never know everything and will often be wrong, even if it's a 'right, but not quite perfect' situation. Then work out why you were.
You don't have to be right all the time, you just need to be right more times than the guy you're racing.
Even for a car that has 18" of suspension travel and spends it time whalloping off rocks, I can tell when a bush is binding up, it affects the balance of a car massively, makes them unpredictable on turn in. That goes for dampers too. They have mechanical as well as fluid forces at work.
2) Cut some old shocks up and have a look how the internals work, have a look at how the seats and faces are designed as well as the stacks, most internet and book stuff will focus on the latter only in explaining how things work and onto equations, the former is just as important, as is all the variances introduced by actually making a physical damper rather than assuming it can do what you ask for perfectly.
3) I get way too bored some nights. I sit tweaking valving simulations for fun. Yes, I am that sad. Sorry.
4) Read, read everything. Even if it's bad it shows you what's bad in the stuff you may have taken for gospel before. And talking of gospel, never believe anything at face value. This is the internet, 98% of stuff on dampers is repeated chinese whispers built on pub b
ks. 50% of the stuff printed in books is still outright wrong or just assumes you're using theoretically perfect vehicle dampers - nobody built one yet - but you stand more chance with the old favorites on chassis dynamics.5) Look at what OEM's are using and why, there's a lot of shiny graphs out there by people who want to sell dampers claiming they're better than OE because of X,Y,Z - that OE manufacturer put £X million into development, dynamics and NVH for a reason, learn from it. I've taken 30 year old Peugeot dampers apart that'd I'd rather stick some fresh oil in and use over some well known brand new aftermarket upgrades after comparing the two!
6) It's all well and good having the theory, a supercomputer to run circuit sims on and a set of Ohlins donated to your Formula Student team, but once you get out of Uni, you'll find you have £20 and half a mars bar to spend on some 10-year old non-adjustable shocks, you've got a laptop that can barely manage solotaire and that sim software turns out to be 5 grand a seat per year. And for some reason nobody seems to have mapped out a random forest in Wales. And the bloody course changes every time you go around.
I.E - be realistic with how much you can do, you have to make shortcuts and rules of thumb. And to do that you have to have enough knowledge to rule out what is wrong, and enough common sense to there might be more than one solution to the same result, but the one your gut says is right often isn't. Stick to the facts. That might mean a complete design direction change on your settings, simply because one day you've got an extra £20 spare and buy a new part. You're going to need your assumptions and rules of thumb to get you a quick, cheap baseline to work from.
On number 6 I can assure you that happens because I'll be heading in a completely different direction with settings once I get time to make some new parts up front, but for now, that way would hurt the car more than help it without the matching bits, so I need to keep refining the previous direction. Neither is right or wrong, just one is more right with the other parts and this one is more right without them.
7) Body control is more important that will be emphasised, sometimes you have to take damping well over critical to control the body at the expense of handling the tyres and contact patches, which seems terrible for a non-aero car. But rally cars have similar needs to heavy aero racecars, as strange as it sounds, and I've seen a perfectly working car taken to a single seater specialist, have some very trick terrain sensitive 3 way dampers fitted and setup over several test sessions, then promptly punched the whole lot clean through the bonnet because it kicked the rear up and came down hard on the front on the next bump the first time it went over something they hadn't simulated.
8) Realise you'll never know everything and will often be wrong, even if it's a 'right, but not quite perfect' situation. Then work out why you were.
You don't have to be right all the time, you just need to be right more times than the guy you're racing.
Edited by PhillipM on Tuesday 19th April 00:07
PhillipM said:
1) Make sure <snip>
Crikey. Thanks for the bespoke response. I was expecting a link or some such. Much appreciated.Having never done formula student or anything similar (or even been any good at dynamics), I think I may need to go back a bit further than I initially thought. Glad to know trial and improvement is still a valid approach though.
On point 4), I think you overestimate the amount of non-bulls
t on the internet...+1, great post PhillipM
(and bitwrx - I can agree with jst so much of it, working from the other end of things with a very light kitcar; the builder/first owner had done a fantastic job of developing the manufacturer's basic serving suggesting, and teasing apart how&why - and hence why this one was the one I bought on sight/test after 18months of searching - was instructive to me then. 6years in, no need to fettle... just maintain.)
(and bitwrx - I can agree with jst so much of it, working from the other end of things with a very light kitcar; the builder/first owner had done a fantastic job of developing the manufacturer's basic serving suggesting, and teasing apart how&why - and hence why this one was the one I bought on sight/test after 18months of searching - was instructive to me then. 6years in, no need to fettle... just maintain.)
Edited by Huff on Tuesday 19th April 21:40
Gassing Station | Readers' Cars | Top of Page | What's New | My Stuff