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How To Build A Rally Car


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I think the full lateral bars have to be in one plane, the J4 drawing, which is why no-one puts them in conventional cars. Our main hoop in J2 is also in one plane.


We have 4 turrets tacked together, one under each of the main hoop & front laterals, and things do join nicely at the top... but just before we tacked the main hoop onto its feet we realised we wouldn't be able to get it out of the car if we did! It tilts back in the car to get it out while it is just a tight-fitting pipe, but once it has feet on we won't be able to tilt it.. We have larger feet on it than CAMS require as the seat crossbars also mount on the same turrets. Larger feet means more lift of the hoop to tilt it backwards..


So we're learning why people weld cages in instead of making them removeable! That merely require cutting the whole roof off while you weld the top joints, or cutting the floor/sills out to drop the cage down to weld the top. Removeable cages are usually smaller than the cockpit edges, and we're trying to jam one in AND make it removeable.


Tomorrow we will solve the tilting problem!


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Well, we're slowly eating the elephant, one bite at a time!


We have the turrets tacked into place, the boxes made up of 3mm steel that carry the cage feet. As you can see, we ran a strip of angle iron along the sill first to give it some guts, and welded 4mm strips into the ribs of the floor to level it.. The bolts are meant to be 8mm, but only the one through the sill is that small as we are a bit cramped in there. The other two are 10mm with captive nuts in the box.



We have used our fine Woolshed equipment in making all the junctions where we weld 44mm tube to the main hoop and slide 38mm inside it to be bolted together..



to produce tolerances that would make a 6-axis miller jealous!



Moving up from a steel picket for a dash, we have a dash bar. It fits right above the steering and leaves room for the instrument cluster. (more or less...)



The rest has all been fitted in for the front of the car, and it bolts up fine.



So this afternoon we took it out for some final tacking before it goes off to be professionally welded on the weekend.



It looks so small out of the car! I'll probably add a couple of diagonals down the front lateral legs to strengthen them, but they won't be the full-size things the FIA want. Steve is a big boy and wouldn't be able to get in and out of a WRC car! Now we start the rear diagonal bars and the big 'X' between them...


Of course, having made one cage, we could make a few more...

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An arm...


and a leg..


and probably your first-born...



Anyway, we went up this morning after a big storm last night to find we had a slight problem... no power!



Around the corner we found it hadn't done much for the Corona either...



and that looked even worse once we had gone back for a chainsaw and started cleaning up!



The power guys turned up and had it all organised in an hour or two, but no electricity until an electrician has connected it back to the Woolshed on Tuesday! So the car is on the trailer waiting to be taken to Tamworth at 7.30am tomorow to have the cage welded up. Then its farmwork for a few days...

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  • 2 weeks later...

Well,it got welded by Tim at Tamworth's Muffler Man, first in the car then we took it out so he could complete the welds. Didn't bother to put it back in.



Then we built the cross-braces in the back. What a nightmare! As soon as we tacked a diagonal onto the two side bars nothing would slide in and out of the stubs on the main hooop. So after a week of trying this and that and completely re-designing it, we had something that worked.



The fittings on those rear arms unbolt and slide inwards to allow the arms to drop down through holes drilled in the 3mm plate bases. The whole lots comes in and out just fine, and when we took it down to Tim again we had it checked and approved by our local CAMS man. So, finally, a bolt-in cage that works and is acceptable for CAMS registration!


Straight into painting the boot and interior!



Today we started with wiring and fuel systems, finding out what can be fitted from the Celica and what must be re-made. The adjustable cross-strut brace was one that needed to be altered to fit the KE70 turrets, but the whole fuel tank/pump/line setup drops in OK. Tomorrow we will paint the cage and fit that on Tuesday so we can build around it.

Progress at last!

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So we grabbed a rattle can and made the cage silver. It was a really hot day and it dried in a couple of hours, but when I took the pipes inside I got silver on my hands. The next day I assembled the cage in the car.. and got covered in silver! I must have washed my hands a dozen times and each time I handled the cage they still soon looked like this.



Prime candidate for Alzheimers from all this aluminium being absorbed! Anyway, found a couple of stray photos.. how to resize crush tube pipe that is too thick... Providing you have a bolt that fits easily through and lets it spin.



The mosquitoes get annoying occasionally, and some of us are very lucky when we don't think hard enough about where we left the burning mosquito coil!



We found this cut-off grinder in one of the sheds and it instantly became the favourite toy!



We fitted the cage for the last time. (I hope!) It got Locktite on the threads of all the bolts and only needed gentle persuasion at the very front.


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I got onto the braking system. The Celica master cyl is a 4-bolt system, while the KE70 only uses two in the booster. A bit of 6mm plate was drilled (very accurately!) and the 8mm holes were drilled again halfway down to 12mm diameter. Then I used the grinder to put a taper under the heads of the 8mm bolts and when they fitted nicely into the cones of the plate we welded them in. A quick grind off of the heads sticking up meant I now had 4 studs.



This fits neatly onto the booster and should have no problem with the 250kg of push generated when its spread over 4 bolts.... seeing the KE70 only uses two!



I stripped the limiter and found it completely gummed up and full of corrosion. It is actually a combination system that has a chamber for the front brakes which delays their coming on for a few milliseconds. This gives the rear shoes time to be pushed out and touch the drums before the front discs start to work. The rear section limits the amount of pressure going on relative to the front, which is the bit I'm interested in... If we don't have rear lockup I will make a few mods to that.



We have rear discs and calipers to fit, but they can wait for a major development that includes twin master cylinders & a bias adjuster later on.

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Meanwhile Steve worked on the rear end. The fuel lines and pump were fitted behind the piece of spare wheel well I'd left there as protection. The fuel line and the brake line are inside and appear through the rear seat-belt bolt-holes we drilled out.



The axles we had came from the two RA40s, T18s & his original F-type. We gripped the bearings in the vice and spun the axle against a screwdriver to check, and naturally found all the useful ones were bent! They all vary in length too.



We had a selection of diff casings as well. Once stripped we put them on stands and held the flat-edges (our spirit levels..) against the ends and measured across the diff at each end of the spirit level, which was about tyre diameter.



Then we turned them 90deg and measured again, one for toe and the other for camber.



Turns out the Celica had lots of negative camber and toeout.. which ties in with the bent axles and the tyre wear! Rocks, washouts, yumps, banks, trees, rolls... something to watch in the future!



The T18 was selected, cleaned and fitted with the new OS Giken limited slip, the best unmatched axles and the biggest brakes. We tried stock springs and the ones we had in the Celica, and figured the ones we had been using were softer..by measuring how much the car dropped when Steve climbed in the boot with the shocks not fitted! We fitted it today then came home. That was enough because he graduated yesterday with two degrees, one in Agricuture and one in Business, and naturally got well wasted last night... we'll be back in the Woolshed tomorrow!


Edited by altezzaclub
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Well, it helped to make the car lively in the rear! Anyway, we picked the straight T18 diff to use and 'retired' the RA40 one to the spares shed. We are using the same rear springs we had, off the back some tiny Corolla hatch at the wreckers. They go on upside down as they are tapered and the diff base plate is the larger size of their top. Softer than a stock KE70 we reckon.



We carefully flared the guards by using a large muscley man with a 4lb hammer



This wan't to fit the tyres, it was to bend the spot-welded edge back around so we could easily plate over the rusty bits that were lacking any strength. I thought the shell was rust free until we were fitting the diff up and saw the inner panel rusted away at the join.



Down at the front and we fitted the new AE86 springs, also upside down. The RA40 struts have a small diameter spring base, and the Kings RA40 springs we had used were too wide at the top to go up a KE70 strut tower.



In the end the answer was to buy a new set of AE86's as they are KE70-sized at one end and taper in at the other.



So that gets the suspension organised. Meanwhile I made a mounting for the Terratrip, but sadly the sun cover I planned on using had already seen too much sun and was brittle. There will be something else lying around...


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We pulled both motors in to compression test them in case one was a dud. Tried the big drill on one but it didn't have enough grunt to spin it over on compression stroke quickly enough to get a good reading. The other we fitted the flywheel to and used the starter, but its a reduction gear starter and turned quite slowly too. Anyway, another problem for later...



Then we spent the last day sanding the body and making it white. The doors and bonnet have yet to be done. I'm back in Orange and off to NZ next week for my Mum's 90th birthday, back in a fortnight. Steve has decided to go West and seek fame & fortune so rallying will take a back seat for a "while"... It took me over 8years to get back to NZ when I left on my trip to become independent!


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  • 4 months later...

Well, while Steve has been trying to earn money working on farms (apart from working for Pete, his dad) he's actually been breaking cars faster than he can fix them!


The 4AGE KE70 daily, MAO, died a couple of weeks back, leaving no error codes. Then Steve came down to Orange in Grumpy, the rat road Corona with the pink 18RG, and didn't make it home. Seeing I'd built that engine I figured it was time for a trip up there again.


We pushed the rally car outside and started on MAO. The lack of error codes had turned out to be a lack of error code light, so once Steve had a bulb in one hand and two wires in the other he was reading 22 and 12. Turns out the thermosensor was not working. We cleared the wiring and found the weight of the loomb across the back of the motor had torn a wire off, so we had to pull the plug apart and solder the wire back on, all very fiddly.


With the error codes gone it still wouldn't start, until I notice the engine didn't rock as he spun it. No compression....

5 minutes showed no cam belt turning, and then no teeth on the bottom of the belt! Luckily they're not interference motors and we ordered one for the Monday.


So we pushed MAO out and pulled in Grumpy, and lifted out the pink 18RG.


Unsurprisingly, taking the head off showed a lot of ring damage in the head, and a big piece burnt out of #3 piston, the cylinder that had the groove around the bore that the engine shop said would be fine... It probably would be fine in a stock 18RG, but not a high-compression one.


More worrying was one broken compression ring in every other cylinder, which means detonation.



That was that, push Grumpy outside and start on the next!


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We loaded the Slodeo up as a mobile workbench and headed for the hangar on the other farm


Gramps, his immaculate old Corona, was up for rego, but just like Grumpy had been for years before the rebuild, it blew oil and vapour out everywhere. The plan was to chuck in 40-70 oil and take it for a pink slip as rego was due and it hardly gets driven. But we did a compression test... and got zero on #4! Seeing rego was due and we didn't want to pull the head off that motor, we figured we would get The Big Girl's Celica 18RG out of hourable retirement and swap that in. It meant changing sumps & oil pickups, so the rally 18RG went up on the crane.



Then Gramp's motor, but when Steve took the sump off there was strange stuff inside!



So THAT motor was retired to the Wheelbarrow of Waiting and parked with the other 5 18RGs in the spares shed, all of which require rebuilds!



The rally car motor dropped into Gramps the next day and was pretty well all done by afternoon, the different throttle connection meaning we needed to swap the Solexes back on instead of Webers and we didn't get time.


The next morning we had the cambelt kit & MAO came alive. Within a hour or two I was in the Blue Beast and heading back to Orange, leaving Steve to finish off Gramps & get it through rego. All a rush, but that's what life is all about!

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