Stu & Mikey's Sonic7 1.6 Build Thread

[buildityourself]

Cycle wing brackets

We used Ford Cortina uprights instead of the normal kits Rally design alloy uprights (decided against these due to mixed reviews on the forum). This meant that the supplied cycle wing brackets were not suitable so replacements were needed. I purchased plates suitable for the cortina uprights from kitspares.co.uk/. Then had some 12mm round bar bent at right angles for the arms. The plate was offset from the hub using round tube with bolts running through to have the same distance between the bars and wheels as the rear wheels. The bars were clamped to the plate and I tack welded these in position.



I checked the clearance to the body and headlight and it was ok.





With one bracket done, the other was mirrored for the other side.




Fitted them both to the car to check the passenger side.



This side touched the headlight though, so after lots of checking this seemed to be caused by the steering rack. Despite previously spending much time setting up the rack so that the steering wheel turned exactly equal amount to the left/right on full lock it seems that turning to the right means that the left wheel is closer to the chassis. This is either down to the tracking not being parallel as measured or the rack brackets not being quite in the right place in the chassis. I've managed to adjust the toe to avoid it hitting and still be parallel but am at the limits of the track adjustment, and now the steering lock is different between the sides on the wheel. This will need further investigation. 

I'd be interested in the distance of the rack bolt holes from the outside of the chassis bars on each side on other owners cars.

Due to the bar size my welder was not up to fully welding so these were welded up and a curved brace bar added by the local blacksmith. I intended the curved bars to match the arc of the wheels , but they didn't quite get this right. 



I'm happy with the overall design though as it avoids a piece of angle iron bolted to the upper ball joint used in the old MEV/RTR kits.

Luckily the brackets would just fit in the oven for powder coating but due to the shape could not be hung.



Final fitting to the car.



Next update the cycle wings.

[buildityourself]

Engine Cover

To support the cover between the hinges a piece of angle aluminum was cut, powdercoated and bolted to the rear panel and a strip of foam stuck to the top edge.



I wanted to hinge the engine cover so that if working on the car or have to stop at the road side I don't have to remove the engine cover and find somewhere to put it without damaging it. Looking for suitable hinges that would be ok for IVA I found these tailgate glass window hinges for a Nissan Pathfinder 2005-2012.



The hinges are handed so after working out which way they fitted best (luckily the same as the markings). Drilled and fitted to the rear panel first before drilling the engine cover.



Due to the slight curve on the engine cover the hinges had to be trimmed to follow the contour to sit them nicely.



Used large washers and M6 bolts on the otherside to secure to the threads in the hinges.



As the hinges were matt black on the gloss panels it looked a bit odd, so powder coated the hinges for a better match.



To secure the engine cover at the front, rather than use some of the usual catches we bought a set of quick release bumper catches to secure it. These are normally found on drift cars to hold the bumpers on. Initially I was worried that after removing I would loose the rubber bands. Had a light bulb moment and realised that if the lower reel was positioned close to the side panel this could prevent the rubber band from complete removal. Another benefit of fitting here as they have sharp edges this keeps it out of reach of the IVA test sphere.



Gear Knob

I've been working on Mikey about his previous gear knob choice. 



With the short shift kit and the large heavy skull it was quite difficult to select 3rd gear in the gate. I had previously purchased a ford puma alloy gear knob. This had a M10 thread which was too small for the thread on the gear stick. The current gear knob had plastic inserts for different sizes. So to try the puma knob we filed down the thread on the gear stick



Then re cut a M10 thread with a die set.



As the alloy knob was cold to touch to take the edge off it and to match the scheme we powdercoated the knob green. Marked the gears/pattern with a permanent marker and looks great!



The improvement over the gear shift feel was well worth the change and the colour matches perfectly with the body now.

[buildityourself]

Mirrors

The focus came with wiring and a switch for electric side mirrors and reverting back to manually adjusted mirrors seemed a step too far back in time. We followed a previous tried and tested solution using Ford Fiesta electric mirrors. Previously these were wired up to the loom via connectors but the main task remaining was to decide where to position them and drill many holes in the side pod body work. 



The angle and height of the mirror was very difficult to work out (guess) as the mirror base goes through the body so it can't be tested in the final position. Hopefully the adjustment on the mirror will help meet the IVA requirements that are near impossible to confirm at build time inside limited space.

As the mirror was lowered the plastic base had to be trimmed down to better match the angle of the side pod.

Once the holes were painstakingly created the mirror would fit into its final position. 



As the body angle of the Sonic7 is different to the Fiesta the mounting thread is not square with the body and protrudes quite far so a fat angled spacer was required. Using a tip from stevew these were made from Epoxy resin.

The two part resin was mixed and poured into an aerosol cap held at the required angle.



I had expected this to gel after about 30 minutes like polyester resin, but it took hours and hours to go firm despite careful mixing.

Left to fully cure until the next weekend these were then drilled to match the mirror fixings. 



You can see how this squares up the fixing bolt so the nut will sit squarely on the thread when pushed through.



Some chassis foam was cut out for the side touching the rough fibre glass body to aid fit to spread the load evenly.



The mirror was fitted, spacer added and secured with a nut inside the side pods (successfully without dropping it!). Wiring connected up and after a bit of electrical fault diagnosis the side repeaters working.



Before they can be finished off the covers need painting (when warmer). They also have a molding flash line that ought to be removed before painting too.



We are getting close now with the list of remaing tasks fitting on a single piece of paper!

[stevew]

I'm glad it helped.

Cheers
Steve

[daydreamer]

I like the idea with resin. more elegant than my solution.

[buildityourself]

Bonnet

After looking at some photos of completed Sonic7, I realised there was something wrong with our bonnet. Rather than being convex in shape it was concave in the middle. 





Now I'm not sure when this occurred as after collecting the kit the body panels were stored for at least 2 years during the build. They were supported, but maybe not enough, but it indicates that the panel could do with some reinforcing/strengthening. 

Pushing down on the inside of the bonnet popped the dip out but then promptly popped back on releasing. I tried leaving it out in the sun for a day but it wasn't really hot so this didn't do anything. Time for more proactive rectification.

Decided to try to add strengthing ribs and fibre glass these in place.

To create the ribs thought using pieces of rope was a good idea, however it turned out not to be as the rope would not lie straight and flat however so doesn't look particularly pretty. I was so worried about the resin going off in the pot that I didn't take the time to check the position and straighten it out neatly before applying the layers of fibre over the rope to form the reenforcers. 



Whilst doing this and waiting for the resin to fully cure dent pulley suction cups were placed on the bonnet with weights hanging to pull the dip out. 



The result is functional but far from pretty or as professional as I would have hoped. Its mostly hidden from view anyway but did provided great learning and a new found respect for quality laminating. 



Its done a pretty good job, but the bonnet still has some slight dips.



Until the protective film is removed at the end of build I won't really know whether its good enough or not though so will have to carry on for now at least until IVA is obtained etc. 

[wishful4444]

Good day buildityourself


The rope reinforcing is interesting. Did you not consider using flat aluminium or steel strip?

[buildityourself]

Mar 16, 2022 13:23:58 GMT wishful4444 said:

Good day buildityourself


The rope reinforcing is interesting. Did you not consider using flat aluminium or steel strip?

I thought that flat aluminium would try to straighten itself rather than retain the curve of the bonnet (at least whilst setting)  and maybe not provide a high enough ridge to resist flex. Plus I had plenty of rope and not any aluminium ;-)

[kiwicanfly]

Flat aluminium on its edge would be really strong, you would have needed to contour it to the right profile but it would not have needed to be perfect, just touch in a few places with a good layer of tiger seal to join the two and fill gaps.

However not criticising your solution to the problem.

[buildityourself]

Bonnet Fitting

An 8mm threaded bar was cut to length and fitted through 2 holes in the side of the bonnet. A piece of stainless steel tube slid over the threaded bar allowing enough thread for a nut and washer.



The previously made alloy air diverter plates were cut out to also provide a slot to allow the threaded bar to slide in and latch when the bonnet it opened. 



This is how one side looks.



This slides the bonnet up and back and then allows it to pivot without hitting the grill. The general idea was stolen from s7coupe on the EKC demo car. 

Then moved onto the rear fittings to keep the bonnet secure. 

Due to space issues we couldn't use the aero catches purchased, so had to opt for 1/4 turn catch locks as they require much less space under the bonnet. I rounded off the edges of the load plates as they had sharp edges on them that the IVA man might not like.



Then a hole drilled in the bonnet on each side and fitted.



To mount the catches for the locks, some alloy was marked, cut out and folded to take into account the angle of the bonnet in both direcitons. 





Rivnuts fitted to secure the brackets to the bulkhead.



Powdercoated and catches fitted.



Both brackets fitted to the car.





Now we have the annoying problem of holding the bonnet open whilst doing other work so a stay of some sort will be required at some point. 

[buildityourself]

Clutch Problem

Recently, I was working on our build and had pushed the kit out of the garage to work in the sun. When I ran out of time I started the engine to drive it back in. I could not get it to drive forward or backwards as the clutch seems to been permanently disengaged.


My theory was that the clutch pedal has been over extended (Michael yesterday sitting in the car "driving it" ) and either the master or slave piston had moved too far and got stuck in the bore. The fluid has gone down from max to halfway, but no obvious leaks.

I decided to crack open the slave cylinder bleed valve. This was so tight the spanner slipped so reverted to a socket. The inside of the socket was sprayed with brake fluid as it released. I retightened it and tried the clutch. It didn't feel quite as heavy but still not as light as I remembered. To avoid starting the car, I tried pushing the car in gear and a could now feel the compression of the engine Indicating that the clutch was now reengaged.

I believe the slave had remained "pressurised" even with the pedal returned. I still don't understand how this happened if the clutch should restrict the slave max movement? However I suspect its related to the size of the MC piston causing too much travel?

Any way as the pedal is already light with the 0.75 m/c swapping to a smaller one for further travel would just make it feather light. Decided to make a pedal stop to limit the clutch pedal travel to stop it happening again.

Template made in cardboard to avoid mistakes.



Cut out in alloy.



I used a bump stop? once found at the side of the road to mount to the panel. 


Bolts flush fitting so the panel will fit to the bulkhead without requiring new holes.



The stop was fitted to 2 existing bolts to avoid having to drill extra holes in the bulkhead with the fuel tank already fitted on the other side. 



Hopefully this will limit the travel sufficiently as stops just beyond the normal disengage position and it was the full depression  to the bulkhead that caused the issue.

I'm surprised this issue hasn't been encountered before on Sonic7s, but it does seem to have occurred on some Rockets.

[kiwicanfly]

Very nice, I still have two bits of wood fixed to the bulkhead with silicon!

I didn't have the same issue just wanted to only be able to depress the pedal "enough" and no further.
each time I see that wood I think I should make it neater.

[buildityourself]

Roll bar

We didn't opt for the kit options for the roll bar as I was always a bit nervous of stories of open face cars like the Sonic7 where people have misjudged a bend and ended up going through a wired fence with serious consequences. With that in mind the decision was made to go for a roll bar with a front "windscreen" bar. This would deflect any fence wire etc offer a bit more protection. After siting in the Sonic7 in the garage with a "normal" modern car in the driveway towering above the bonnet it seems like a good decision. 

Having not tackled something like this before it was a bit daunting. First a number of mockups in microsoft paint. 









The last one above was a later favourite but initially this option was kindly mocked up by skyquake from a sketch in a Sonic7 CAD. I had wanted a cross brace between the front/rear bars.



Much later in the build with the seats fitted I decided that we ought to mock it up in the real world to see how it would look/work in practice.

To do this I was planning on using copper plumbing pipe but after a suggestion from petes , I bought some PEX alloy cored plastic pipe. This can be bent by hand and retains its shape and can be restraightened too. 





Pipe lagging was also bought to help give it the right size as the pipe looked too weedy to appreciate. 



The desired shape was formed and worked ok for me, but when Mikey tried it out with the seat as far back for his long legs, it became apparent the rear bar was too close to his head from the side and above. It make it very difficult to get in and out (more so than any sonic7 owner will already be used to).



Due to his height, the design kept having to be tweaked until it provided enough clearance. Also the rake of the windscreen had to be increased as with the seat in a closer position it was too easy to hit the front bar in a "simulated" crash.

With this the pleasing asthetics ok for me only as a driver had to be put aside for practicality and safety for both planned drivers and future drivers. This is the basic geometry we had to go for in the end.



Even with this design the cross bracing had to be ditched for a single straight bar as it made getting in and out harder and when wearing a helmet it was going to be close. I wasn't overly happy with the outcome of the looks as it had ended much higher than I'd been aiming for. However having been through the physical process I could accept there wasn't really another better option. Some comfort was taken that it wasn't a million miles away from the only other Sonic7 caged car I've seen.





I sketched out the 2 bar hoops in 2D covering the dimensions and required angles. After trying a local tube bender in the end an online supplier bent the bars "roughly" to the drawings using 45mm stronger CDS tubing. 

After cutting down to the correct length, they were propped in place with a spirit level, as Mikey was away at college.




I tack welded some 6mm plate for the mounting points to the bars. 







Then fitted into the car and the mounting drilled through the plates and the chassis.

I then had the mounting plates professionally welded due to the thickness of the metal and being a safety item.

The rear bar is different to all other Sonic7 as its full height so the bars go right down to the chassis floor plates. I'd done some reading about cages and its very important that they transfer any energy into the base of the chassis in a roll over event.



Testing it out for the first time.



A straight notched piece of CDS added between the two hoops to brace the front bar. 



The brace bar and brackets for the harness bar brace were professionally welded ready for powder coating.



The finished result in the car.



This sub project has been expensive and taken a long time and been paused at various points. Arranging professional services with covid around caused lots of delays but its all done now. It certainly makes it much easier to get in and out of the Sonic7 if nothing else!

[buildityourself]

Roll bar brace bars

To brace the rollbar to the rear chassis, we needed to make some brace bars. Some 25mm CDS tube was purchased. To make it simpler to make decided to flatten the ends of the tubes in the press to form the mounting point at both ends. 



Holes drilled to give the required spacing.



The ends were rounded and then welded up to seal the ends.



And then powdercoated to match.



The bars were then bolted to the chassis and the rollbar brackets.

[alison]

Hi - thanks for posting your build log which I have found very useful. Back in July you were fitting the wheel bearings and you wrote "It was immediately after that I realised that this shouldn't have been done yet, as needed to check the driveshaft clearance first to allow the shaft to move freely through the bearing centre." Could you please tell me a bit more about this as I'm about to fit the bearings myself and I don't follow why there wouldn't be enough clearance. Many thanks.