Long time listener... first time caller...

I’m about to begin building a '73 Datsun 1200 Coupe for racing in 3J Improved Production class, this being one of the most popular classes for early model vehicles, thanks to no weight restrictions (albeit standard panels and glass required) and the ability to use same manufacturer motors... in turbo guise!

I'm hoping this thread will help others who are looking to build a track/race 1200 and that others in the same boat will be able to assist me WHEN I fall in to unknown territory. Please note that I'm not looking to build a show stopper or period correct car, and I have already planned all modifications to the car, just keep it in mind if replying.

Please also find the rules of 3J IPRA at the below link if you wish to comment on something technical.

http://www.iprasa.mx.com.au/Files/PDF ... ules%2019%20July%2007.pdf

The key of these rules is:

2.6 The entire vehicle must remain unmodified except for specific freedoms allowed in these regulations and modifications necessary to comply with the General Requirements of Section 6 of the CAMS Manual.

So if the part is not listed anywhere in this book, it must remain standard and in place.

I hope to keep the thread regularly updated and look forward to sharing the build!

Thanks,


Myles.

Ok first post...

Having a number of mates currently racing the IPRA class in SA (some of which I have previously raced with in Sprint Karts) and finding myself lacking energy to continue racing SuperMoto (thanks to lack of events and tracks) I decided IPRA this was the class for me. For those of you who don’t know the basic rules behind IPRA, I'll put a post up soon so you can follow.

The first step was choosing a car, and with hundreds of options, I spent the next two months doing the math..! I quickly counted out ANY late model option (post '85) as here you will be held to many more restrictions such as; weight, track (width), turbo and so on.. so early model it was.

What I was looking for was something light, (as though you must run standard panels and glass, you do not need to add ballast to make up any difference to other cars) something with good/easy engine options (able to use same amount of cyl. from same manufacturer) and something that still had appeal.. unlike my good mates RA40 Celica ; )

Weighing up the advantages of suspension arrangements vs vehicle weight vs engine options vs cost... Datsun in general was ahead in my books, mainly based on the availability and cost of CAs and SRs, availability of replacement & upgrade parts and the classic Jap styling. The next decision was WHICH Datsun to choose, I looked in to 1600s, 180B, 200B, 1000, 1200 and the rest... checking write up's others had on these cars, looking in to past race performance of each and locating conversion bits I would need. After much deliberation and after almost choosing to go with the heavier and IRS-bandit 1600, I decided the 1200 was key for power to weight and modability (unfortunately the 1000's transverse leaf lets it down, if it weighed what it does, but with a similar 1200 front-end, it would be a machine!!)

With that decision made, I had the option of buying something completed, half completed, started or stock. I started with a 1200 sedan in mind, CA18 already in place, good engine mods, reasonable sus mods and an R31 rear end... problem here was that too much would have to be changed to suit IPRA and I'd still be left with a sedan (not what I wanted, as this would make using rear bolt-ons a bigger issue as others have found and the roof line of the coupe is lower with the flatter windscreen, making it more aerodynamic).

The next option I looked at was a 1200 coupe, again with CA18 already installed, some good engine mods and bolt-on guards already in place, but again, with the rules of IPRA, the front suspension would still need to be changed out, I would have needed to replace parts of the radiator support panel, the diff was still stock.. so the cost just couldn’t be justified.

I then decided to just start from scratch. Being that I didn’t need rego and I wasn't keen to pay for modifications I had to remove/replace, I would rather put the money in to NEW parts and know every inch of the car when I first hit the track. Yes, It will cost more in the end but it will likely take the same amount of time (some saved, some lost) but have a more personal/tuned result.

So I looked for a car, all I needed was a stocker... with good rails/floor, good bay and decent roof/rear guards.. bolt-on panels not bothering me in the slightest. After looking a quite a few options (and there are a few still out there), I found the old dull-green paddock-machine listed on eBay as wrecking for parts. I found a thread on Datsun1200.com that explained he had a visitor (member from here) who looked over the car, he posted of the car's condition and while maybe not great for someone looking at building a sexy streeter, the clean rails and general lack of rust/damage was all I was after. I spoke to the owner and we had a good chat about the car, he explained the condition of all of the areas and I made the choice to purchase on the spot (over the phone). After sending a deposit, a headed over to Melbourne (from Adelaide) to pick up the car... WHOA... talk about DIRTY!!!

When collecting the car, it was caked in red dust (as explained) and sitting in waist high grass... looking just a tad neglected to say the best. But as described, the floor of the car looked very good, the engine bay was neat and the car un-molested.. just what I needed. We chucked it on the trailer and headed home, straight to Dazzlers Car Wash... $10 later, there was STILL dirt coming from every join and gutter in the car... it was ridiculous. After much scrubbing and more washing at home, the car finally go wheeled in to the garage (probably the first time its been under-cover in some time).

Getting the car back on Friday night (last week), I started cleaning up my garage in prep for the build as I'd noticed half my tools were missing and I was in desperate need of a new air compressor. That continued over the weekend and last night, I started stripping.

First order was to remove all of the front panels (bar apron) which took all of about 1 hour... and underneath the guards and grill the body looks perfect, good news so far. I then started on the interior as the dash has to come out to get the doors off, so seats came out followed by carpet, to find a extremely good condition floor underneath, very straight, no rust and good original paint still in tact. More interior panels kept coming off and still no signs of rust or repair, all with nice looking original green (this will change).

I'm up to removing the dash and doors tonight, then I need to do a big clean up of the interior before removing the sound deadener for weight reasons. Once that is completed, I'll be moving to the bay and getting the motor/box out (for sale) and begin tiding up the bay ready for the conversion.

For those of you who didnt see it, below are some photos of the car at purchase... I'll have some of the interior shortly and then progress shots as I go. Hope the first post has been entertaining, looking forward to coming back with more...

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After 15 minutes of high pressure washing... (photos can be decieving though, dont get too excited).

Ps. Engine and Auto box for Sale - PM me if interested

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Myles, good score on the body. Will you be running as a turbo or as naturally aspirated. The problem with the CA18 as a turbo is it goes into 3001-6000 or whatever the upper limit is at the moment. An turbo'ed L18 which comes out as 3009 cc's however is under the 3 litre capacity, due to the plus 2 per cent rule. 2 per cent of 3000 is 60 so you can be 3060cc. I've always thought that if you got a Stanza L16 block to get the right sump orientation, an L18 or Z18 crank & piston set, a Z18 head with the manifolds & such, how well would this work. The L16 block would be so the normal L series gearboxes would fit as well. I know it's no different than just fitting a Z18 turbo, but where do you find a complete one of those now, let alone the bell housing for the transmission. Or maybe just go for capacity & see if you can run a KA24DE with a turbo. there's an extra 400 cc's just for turning up. Even with a restrictor plate it'd make heaps of torque, & torque times revs is horsepower. You'd probably be able to drive around Mallala in top gear.

Thanks for the response b310gx, you've obviously looked in to the rules and understand the class, great tips there for someone looking to compete!

As for me, I'd already purchased the engine package before I actually purchased the car. Basically, continuing from the above post... I'd decided on the 1200 coupe and while trying to find the most appropriate vehicle, I started to consider all of my motor options.

Being a Nissan/Datun, many, many options are available (as you can see from b310gx's post), though the choice was first made that I would run a newer Nissan DOHC turbo motor for raw power and tourque. The idea is to build a front running car outright, so rather than building a car for a lower class or something atmo, I wanted pure grunt and something reliable. My options, CA18, FJ20 or SR20. I instantly ruled the FJ down to size, weight, power, baically everything... its just too old-school. As I dont have to worry about having it engineered for rego, it was between an SRDET or a CADET. Pros and cons, slight weight differences, interals, price etc... it wasnt an easy decision though based on needing maximum tourque and bottom-end power, I chose to run with an SR over the CA. The CA is nice a revvy but being that I need to restrict the motor, this wont be an advantage. The CA fits muh easier in to the bay but this issue doesnt outweight the restricted power I can make with a 2lt over the 1.8.

The motor is going to be a big squeeze as the rules of class are that the standard radiator support must stay and not be modified, the tunnel may only be massaged to accomodate the box and the standard cross-member must be used (modified mounts allowed). Due to costs, the standard SR20 5spd will be used initially though a straight-cut gear set will be the first mod on the cards after completion.

So I looked around for a motor package and found one locally in a smashed up S13. It's a basic red top package that made 160rwkw on the dyno (FMIC & Exhaust were only mods). She's a bit dirty as the Silvia ran backward off the track before hitting the wall and covering itself in dust. I'll hit the engine with some degreaser and get it as clean as possible before putting it in the car (i'll post pics when doing so).

As I'll be building a car for competition, I wont be discussing the engines internal mods as such (giving away secrets) but I'll be looking to make 220rwks with the 36mm turbo inlet restricor in place.

Here is a pic of the motor..

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Myles,
Good luck with the build, I will be watching with interest for sure.
BTW IPRA restrictor size is 36mm not 26mm.

Bryan

Thanks for the luck Bryan! And yes, 36mm, typo fixed! Thanks for pointing it out.

So I had some more time inside the car last night and have almost managed to completely strip the interior.. including roof lining and wiring etc... Still very happy with the condition of the body and bar a few spots to clean up, wont need to spend any time on panel work before paint.

The weight of the interior is starting to add up and I've filled THREE garbage bags full of plastic, rubber, bolts, hinges, brackets etc... there is so much in these things! Including the weight of the seat, carpet and underlay (half of which is still stuck to the floor), there is a decent amount to be removed and never returned, i may even weigh it all to work out exactly how much.

I've also found there are a HUGE amount of brackets tacked to the body (as seen in pictures) all of which can be removed (including boot latch which will weigh a fair bit on its on. Basically any unused brackets are able to be removed but no un-nessasary holes or cuts are allowed to be made.

So my goal is to have all unused brackets and sound deadner out by the weekend, so I can begin pulling the motor/box out ON the weekend and get the bay ready for paint. I've made a quick start on the sound deadner after the below pics were taken and found that as it's so thin (unlike newer cars I've previously done), I could simply scrape it up/off with a paint scraper.. interesting..!! I've used a heat gun and glue rid previously which is quite time consuming... my mates have used dry-ice and claimed this is the fastest way... but judging by the effort my paint scaper has already done, I'll be able to just peel it up with that.. see how we go!

Here's some interior pics as of last last, still dirty but I wont bother cleaning it (or removing the last of the underlay) all until I've finished grinding and removing sound deadner..

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Hmm,looks to be a half decent shell!Don't forget the original dash has to go back in.
I'll watch your build with interest,but you will need a lot more than 220 ATW to be at the outright pointy end and in front of some of the rotors at state championship level.

Cheers

one of the v8 boys ran a 1:16 at sandown a month or so back in IPRA. thats 3 seconds shaved off the previous lap record! getting it to handle and have good corner speed is where you'll find lots of time too. its definately not all about the power

looking good so far :)

Having just gone through the hassle of removing sound deadner from my coupe I can say cold is better then heat. When it is cold it chips away, when Hot it is more sticky/tacie and sticks to everything.
I did mine on a cold weekend using a flat screw driver and metal wedge, took a while but its all gone now.
I was supprised at the weight of the stuff overall.
Hopefully your motivation will get me motivated to get cracking on my build as well.