Post by skyquake on Dec 11, 2016 23:57:02 GMT
Warning, big update!
So, to continue the story, having managed to organise the discount code for Demon Tweeks, I went a little mad and purchased a whole load of shiny new parts. I very carefully selected the components based around the look I wanted for the car, and other personal taste things. Parcel day arrived, and it was just like Christmas!
Basically, what this pile included was the following:
So what did I get wrong? Well, let's start with the seats. I particularly wanted comfortable bucket seats. I quite definitely did not want one of those little glass fibre racing seats which are designed 12 year old girls, like everyone else seems to have in their kits! I am a man of ample proportions (a bit of a fat arse), and hence one of these little figure hugging plastic seats was never going to cut it. When I sat in Angus' demo Sonic at Stoneleigh, by arse was actually hovering about 2 inches above the seat, as I was perched up high supported either side by the bolsters! So, normal seats were out of the question.
I went away and did some research, to see what my alternatives were. Like many before me, I came to the conclusion that while there are a wealth of seats out there, very few will actually fit into the Sonic. Eventually I stumbled upon the R100s, which looking at the dimensions on the website, looked like they would actually go in. However, I was always expecting them to be tight. So much so that I was expecting to have to cut the seat back adjuster levers off the outer sides of each seat, to push them out as far as possible.
Anyway, the seats arrived, and they looked great.
However, dropping one of the seats into the car showed that there were a number of problems. Firstly, with the padding and the seat sliders taken into account, I'm probably sitting a good couple of inches higher than normal. This has two main effects, the first of which being that there is nowhere near enough room between the seat and the steering wheel. Now obviously I'll be procuring a smaller flat bottomed steering wheel at some point in the future, but as it stood I was a long way off. With the steering column in it's highest and furthest back position, the normal ford wheel was still intersecting my legs by some 20 or 30mm! Not comfortable. So I was going to have to lift the steering column mounting point, to give myself more room.
The second problem of the seat hight was the roll hoop, which sat comfortably at the same height as the top of the seat. No good. Now as it happens, I would probably have had do do something about this anyway, as even sitting on the box section, my head is only just below the line from the top of the roll hoop to the front cross member (meaning it's marginal for me as it is!) So while this is a pain, I'd probably have had to do it anyway.
So, what else. Well, the seats' height wasn't the only problem with them; their width was also an issue! They do go in, but with exactly 25mm between them in the centre. Thus neatly ruining the design I had for the central tunnel, and hand brake lever. It also became apparent from my driving position that the nice large centre console was out of the question too, as that was where my leg needed to be! Bummer! But as if that wasn't enough, there are two more problems. Firstly, the 25mm between the seats is not quite enough to use the standard hand brake lever, as I wouldn't be able to get my fingers around it (doh!). Also, if I were to allow the seat to move all the way forwards the sliders, I'd clash with the gear stick. This sounds like an easy fix (limit the travel), but I still need to find a way to put a cover around the gear lever and hand brake, as they're pig ugly when exposed.
So, this is all a pain in the arse. But, as my choices are a pain in the arse now, or a pain in the arse while driving, I'm going to stick with it, and make them work!
So, in order to get around this, I've added some additional mounting plates to the chassis, to enable me to lift the position of the roll hoop by some 50 or 60mm. I've also replaced the two metal tie straps (which were bolted at each end, and in my mind a little flimsy) with some decent sized tube, with a crush tube at the bolting end. This looks substantially tougher, and more in proportion with the roll hoop (personal preference perhaps?)
I've also raised the steering wheel position by 40mm, by cutting out the existing mounts, chopping the cross member and adding a bridging section above. I then replaced the steering wheel mounting brackets in the gap left by the cut in the cross member. According to my CAD model, as I've only raised the member by 40mm, the bridging section should still be below the dashboard, and I shouldn't have affected the design of the car too much.
I've left all of this tacked up for the time being, as I'm not yet convinced that I've raised the steering wheel enough. While it is perfectly comfortable for me, with the seat a long way back, when I install the girlfriend (with her dumpy legs and the seat all the way forwards), then there's still not enough room. As such, I'm going to order the replacement steering wheel and try it out, before I finalise that modification.
Moving on, Harnesses. Now these are proving difficult for several reasons, the biggie of which is the mounting points. The normal solution is a pair of bosses in the roll hoop cross member for the shoulder straps, and horizontal plates welded to the box section of the chassis for the lap straps. Now my Schroth harnesses comes with pretty large end fittings, which need to be mounted in the direction of loading, meaning that the shoulder straps are fine, but the lap straps don't work, as they'd be sitting horizontally on the plates. Equally, combining this with my nice wide seats, the mounting points would be underneath the seats anyway, hence no good.
Now my plan to get around this is to cut out the existing brackets, and replace them with 7/16 threaded bosses welded into the chassis members. In line with the EEC directive, these will be 50mm long bosses, which I can fully weld either side of the box section. I've positioned these 40mm rearwards of the rear seat support cross member, which is about 20mm further back than they were originally. This was deliberate, as my seats will be able to slide all the way back on the sliders, and I therefore need to bring the mounting points rearwards in order to maintain the angle of the belts in that 45-80deg allowable range.
Obviously this is nice and easy on the outer positions, as there's a nice big 40mm box to put the bush into. Not so in the centre. The best thing I can come up with here is a single bush, welded slightly above the box, and held in place by a pair of enclosing brackets each side. These brackets will be fully welded to the boss, and fully welded to the surrounding box sections.
As far as I can tell, this is a fairly sensible way of doing things, but other opinions would be most welcome. I believe the EEC directive allows me to share the one boss between both belts? Would anyone disagree with this approach?
So, with that hurdle crossed (assuming it is!), you'd like to think that we're sorted with the belts now. Well, not so, unfortunatly! Firstly, wherever I put the lap strap mountings, the belt has to cross over the one remaining back rest adjuster lever on the inside of each seat. Not only does this stop you adjusting the seats, but I'd be very surprised if the IVA examiner would be impressed with this belt routing.
So, looks like I can kiss goodbye to that remaining inner adjustment lever now! The easiest solution here is to fix the backrests in one set position, but that kinda defeats the object of having adjustable seats. Therefore, I plan to try and convert the mechanism to use a pull cable, which is accessible from the front of the seat. This should remain inboard of the seat edges, and solve the problem for good. Nice idea, but it remains to be seen whether it can be done. Watch this space.
So, we're done with the seat belts now then? No. Not yet. Finally, the upper mounting points don't work either, even though I thought they would be fine. Because my belt features a large strap adjuster at the mounting point end, it will jam on the seat apertures, stopping the belt from pulling through properly when the seat is fully rearwards. There's no way I'll get away with this at IVA.
As far as I can tell, there are three possible solutions to this. Firstly, stop the seat from travelling all the way backwards. Well that's no good, as I need it all the way backwards to be comfortable. Solution 2, remove the belt adjuster and get the seat belt sewn up in one position. Should be possible, but then I wouldn't have a massive amount of adjustment on the belt, and I'm almost certain that I'd invalidate the E4 marking if I modify the belt in any way. Which leaves me with one last idea. Weld up and grind flush the mounting bosses on the roll hoop cross bar, and add another pair of mounting bosses in the engine bay front upper cross member, directly below. This would allow the belts to route upwards, around the cross member tube and through the seat apertures.
I can't find a flaw in this plan; as far as I can tell, the legislation allows me to do this. Am I right on this? All opinions on the matter gratefully received!
And breathe! So with all of that mucking about done, the belts should be sorted! It will look cool when it's done though!
Ok, so moving on. Seat mounting. Now I know this has been discussed numerous times on this forum, but I'd like to throw another two suggestions out there. So, the widely accepted solution is to drill down through the two seat support members and insert crush tubes. This allows you to drop a nice healthy bolt down from above, and fit a nut and a spreader washer (or plate) from underneath the floor plate. This is certainly nice and strong, but the OCD in me has a slight problem with having a screw thread and nut protruding below my otherwise beautifully flush floor panel. Seriously though, I don't like the idea of having protruding bolts below the floor plate, as they're at real risk of catching debris or scraping speed bumps.
What's the alternative? Well, rivnuts are a definite no no, and the box simply isn't thick enough to support anything without a crush tube, so the alternatives have to be either welded in, or welded on. For me the obvious easy answer would be effectively to tap the crush tube, i.e, drill the box, insert a threaded boss, and weld it both sides of the box section. This would seem pretty reasonable to me, but there's still a chance that it could tear out of the box section in a crash scenario.
The other suggestion I came up with was a set of additional folded brackets, welded onto the rear of the cross members. These would be fairly thick (say 3mm), and welded all round three sides, to give them plenty of strength. This would then allow a shorter seat screw to be passed through from above, and a nut placed on the underside of the bracket (this could even be a weld nut), without breaking the floor plate. Should be pretty strong, but does still run the full load path through a weld, so I guess both solutions suffer from the same potential limitation. Neither has a direct mechanical overlap. Again, any thoughts would be much appreciated.
Right, I've been waffling for ages! Congrats if you've managed to read this far!
More to come later, stay tuned!
So, to continue the story, having managed to organise the discount code for Demon Tweeks, I went a little mad and purchased a whole load of shiny new parts. I very carefully selected the components based around the look I wanted for the car, and other personal taste things. Parcel day arrived, and it was just like Christmas!
Basically, what this pile included was the following:
- The previously mentioned complete set of Vibratechnics Engine Mountings.
- Pair of Sparco R100 Seats + Sliders.
- 4x Gaz Adjustable Shocks & Springs.
- Pair of Schroth Profi III-FE 4 Point 3" Harnesses.
- An Odyssey Extreme PC680 Battery.
So what did I get wrong? Well, let's start with the seats. I particularly wanted comfortable bucket seats. I quite definitely did not want one of those little glass fibre racing seats which are designed 12 year old girls, like everyone else seems to have in their kits! I am a man of ample proportions (a bit of a fat arse), and hence one of these little figure hugging plastic seats was never going to cut it. When I sat in Angus' demo Sonic at Stoneleigh, by arse was actually hovering about 2 inches above the seat, as I was perched up high supported either side by the bolsters! So, normal seats were out of the question.
I went away and did some research, to see what my alternatives were. Like many before me, I came to the conclusion that while there are a wealth of seats out there, very few will actually fit into the Sonic. Eventually I stumbled upon the R100s, which looking at the dimensions on the website, looked like they would actually go in. However, I was always expecting them to be tight. So much so that I was expecting to have to cut the seat back adjuster levers off the outer sides of each seat, to push them out as far as possible.
Anyway, the seats arrived, and they looked great.
However, dropping one of the seats into the car showed that there were a number of problems. Firstly, with the padding and the seat sliders taken into account, I'm probably sitting a good couple of inches higher than normal. This has two main effects, the first of which being that there is nowhere near enough room between the seat and the steering wheel. Now obviously I'll be procuring a smaller flat bottomed steering wheel at some point in the future, but as it stood I was a long way off. With the steering column in it's highest and furthest back position, the normal ford wheel was still intersecting my legs by some 20 or 30mm! Not comfortable. So I was going to have to lift the steering column mounting point, to give myself more room.
The second problem of the seat hight was the roll hoop, which sat comfortably at the same height as the top of the seat. No good. Now as it happens, I would probably have had do do something about this anyway, as even sitting on the box section, my head is only just below the line from the top of the roll hoop to the front cross member (meaning it's marginal for me as it is!) So while this is a pain, I'd probably have had to do it anyway.
So, what else. Well, the seats' height wasn't the only problem with them; their width was also an issue! They do go in, but with exactly 25mm between them in the centre. Thus neatly ruining the design I had for the central tunnel, and hand brake lever. It also became apparent from my driving position that the nice large centre console was out of the question too, as that was where my leg needed to be! Bummer! But as if that wasn't enough, there are two more problems. Firstly, the 25mm between the seats is not quite enough to use the standard hand brake lever, as I wouldn't be able to get my fingers around it (doh!). Also, if I were to allow the seat to move all the way forwards the sliders, I'd clash with the gear stick. This sounds like an easy fix (limit the travel), but I still need to find a way to put a cover around the gear lever and hand brake, as they're pig ugly when exposed.
So, this is all a pain in the arse. But, as my choices are a pain in the arse now, or a pain in the arse while driving, I'm going to stick with it, and make them work!
So, in order to get around this, I've added some additional mounting plates to the chassis, to enable me to lift the position of the roll hoop by some 50 or 60mm. I've also replaced the two metal tie straps (which were bolted at each end, and in my mind a little flimsy) with some decent sized tube, with a crush tube at the bolting end. This looks substantially tougher, and more in proportion with the roll hoop (personal preference perhaps?)
I've also raised the steering wheel position by 40mm, by cutting out the existing mounts, chopping the cross member and adding a bridging section above. I then replaced the steering wheel mounting brackets in the gap left by the cut in the cross member. According to my CAD model, as I've only raised the member by 40mm, the bridging section should still be below the dashboard, and I shouldn't have affected the design of the car too much.
I've left all of this tacked up for the time being, as I'm not yet convinced that I've raised the steering wheel enough. While it is perfectly comfortable for me, with the seat a long way back, when I install the girlfriend (with her dumpy legs and the seat all the way forwards), then there's still not enough room. As such, I'm going to order the replacement steering wheel and try it out, before I finalise that modification.
Moving on, Harnesses. Now these are proving difficult for several reasons, the biggie of which is the mounting points. The normal solution is a pair of bosses in the roll hoop cross member for the shoulder straps, and horizontal plates welded to the box section of the chassis for the lap straps. Now my Schroth harnesses comes with pretty large end fittings, which need to be mounted in the direction of loading, meaning that the shoulder straps are fine, but the lap straps don't work, as they'd be sitting horizontally on the plates. Equally, combining this with my nice wide seats, the mounting points would be underneath the seats anyway, hence no good.
Now my plan to get around this is to cut out the existing brackets, and replace them with 7/16 threaded bosses welded into the chassis members. In line with the EEC directive, these will be 50mm long bosses, which I can fully weld either side of the box section. I've positioned these 40mm rearwards of the rear seat support cross member, which is about 20mm further back than they were originally. This was deliberate, as my seats will be able to slide all the way back on the sliders, and I therefore need to bring the mounting points rearwards in order to maintain the angle of the belts in that 45-80deg allowable range.
Obviously this is nice and easy on the outer positions, as there's a nice big 40mm box to put the bush into. Not so in the centre. The best thing I can come up with here is a single bush, welded slightly above the box, and held in place by a pair of enclosing brackets each side. These brackets will be fully welded to the boss, and fully welded to the surrounding box sections.
As far as I can tell, this is a fairly sensible way of doing things, but other opinions would be most welcome. I believe the EEC directive allows me to share the one boss between both belts? Would anyone disagree with this approach?
So, with that hurdle crossed (assuming it is!), you'd like to think that we're sorted with the belts now. Well, not so, unfortunatly! Firstly, wherever I put the lap strap mountings, the belt has to cross over the one remaining back rest adjuster lever on the inside of each seat. Not only does this stop you adjusting the seats, but I'd be very surprised if the IVA examiner would be impressed with this belt routing.
So, looks like I can kiss goodbye to that remaining inner adjustment lever now! The easiest solution here is to fix the backrests in one set position, but that kinda defeats the object of having adjustable seats. Therefore, I plan to try and convert the mechanism to use a pull cable, which is accessible from the front of the seat. This should remain inboard of the seat edges, and solve the problem for good. Nice idea, but it remains to be seen whether it can be done. Watch this space.
So, we're done with the seat belts now then? No. Not yet. Finally, the upper mounting points don't work either, even though I thought they would be fine. Because my belt features a large strap adjuster at the mounting point end, it will jam on the seat apertures, stopping the belt from pulling through properly when the seat is fully rearwards. There's no way I'll get away with this at IVA.
As far as I can tell, there are three possible solutions to this. Firstly, stop the seat from travelling all the way backwards. Well that's no good, as I need it all the way backwards to be comfortable. Solution 2, remove the belt adjuster and get the seat belt sewn up in one position. Should be possible, but then I wouldn't have a massive amount of adjustment on the belt, and I'm almost certain that I'd invalidate the E4 marking if I modify the belt in any way. Which leaves me with one last idea. Weld up and grind flush the mounting bosses on the roll hoop cross bar, and add another pair of mounting bosses in the engine bay front upper cross member, directly below. This would allow the belts to route upwards, around the cross member tube and through the seat apertures.
I can't find a flaw in this plan; as far as I can tell, the legislation allows me to do this. Am I right on this? All opinions on the matter gratefully received!
And breathe! So with all of that mucking about done, the belts should be sorted! It will look cool when it's done though!
Ok, so moving on. Seat mounting. Now I know this has been discussed numerous times on this forum, but I'd like to throw another two suggestions out there. So, the widely accepted solution is to drill down through the two seat support members and insert crush tubes. This allows you to drop a nice healthy bolt down from above, and fit a nut and a spreader washer (or plate) from underneath the floor plate. This is certainly nice and strong, but the OCD in me has a slight problem with having a screw thread and nut protruding below my otherwise beautifully flush floor panel. Seriously though, I don't like the idea of having protruding bolts below the floor plate, as they're at real risk of catching debris or scraping speed bumps.
What's the alternative? Well, rivnuts are a definite no no, and the box simply isn't thick enough to support anything without a crush tube, so the alternatives have to be either welded in, or welded on. For me the obvious easy answer would be effectively to tap the crush tube, i.e, drill the box, insert a threaded boss, and weld it both sides of the box section. This would seem pretty reasonable to me, but there's still a chance that it could tear out of the box section in a crash scenario.
The other suggestion I came up with was a set of additional folded brackets, welded onto the rear of the cross members. These would be fairly thick (say 3mm), and welded all round three sides, to give them plenty of strength. This would then allow a shorter seat screw to be passed through from above, and a nut placed on the underside of the bracket (this could even be a weld nut), without breaking the floor plate. Should be pretty strong, but does still run the full load path through a weld, so I guess both solutions suffer from the same potential limitation. Neither has a direct mechanical overlap. Again, any thoughts would be much appreciated.
Right, I've been waffling for ages! Congrats if you've managed to read this far!
More to come later, stay tuned!