GC Coupe Speedway Car

[Blown Coupe]

This is my toy. A GC coupe speedway car...



It runs in the "Super Production" class under the ACT & NSW Motor Racing Board. This division is for steel bodied, production based sedans but has plenty of freedoms in the engine, drivetrain etc departments to allow us to assemble a fairly potent race car without necessarily spending a fortune.

We tossed the original Saturn 1600 and slotted in an Astron 2.6.
It has had all the usual tricks applied... removed balance shafts, custom ground Crow cam, and Pajero cylinder head.
Induction comes from a 500 Holley carb via a Toyota SC14 supercharger... a bit "over carbed", but it's what I had lying around at the time. ;)



Driveline is basically made up of stock bits and pieces... MMC gearboxes ~ 4 or 5 speed depending on what ratios we need. The rear end is standard, with either 3.89 or 4.63 diff centres ~ again to allow us to get the right overall ratio for the venue we're running at.

Here it is in action at National Capital Speedway, Canberra (our home track)...


Surfair Speedway, Moruya...


and Nowra Speedway...

[Mr Aerospace]

Hahaha! Gotta love where you stuck that flag!
Well, I must admit it's definitely one hell of a lot different to most of the other cars around here.

It's always great to see these cars competing in any form of motorsport!

[GC75]

nice

Next time tell me when your at Nowra and ill pay a visit!

like your scoop on the back btw! i want it for my coupe haha

[Blown Coupe]

Cheers guys. It sure is a heap of fun. I love being a bit different.

The coupe confuses most people that see it 'cause they have no idea what it is... is it a Torana? ... nope, only 4 cylinder ... oh, it must be a Dattto 1800 B then... nope, it says Mitsubishi on the bonnet scoop... ah, must be a Lancer then... nope, try again LOL.

I've been racing Galants since the early 90s. First one was a GA sedan in "1500 Sedans"... all the other guys had Datsun 1200 coupes so the GA stood out from the crowd. This is actually my second GC coupe. Had to retire the original one after a BIG, multi-rollover bent every panel, tore off half the running gear and ripped the engine mounts off the cross member This one served many years as a rally car before I got at it, so it's seen plenty of competition in it's lifetime.

The rear spoiler is actually an SLR 5000 unit with about 25cm cut out of the middle. I only did a rough job joining it back together, but if you're handy with fiberglass it would be an easy job. It suits the '70s styling of the car I reckon.

[GC75]

i know exactly what ya mean man when it comes to gc coupes... no cunt has any idea...

Quotes:

Tempe Tyres 'Bring ya datto up'

Some random dick nut 'drop a 308 in your datto! i had one just like this' ME: its not a datto.

You from Nowra or anywhere near here?

How do i get into speedway racing?

[Blown Coupe]

Nah, not Nowra. I'm up in Canberra.

Nowra speedway is operated by the Wollongong City Speedway Club. Best idea would be to shoot them and email or drop by one of their club meetings and introduce yourself. They'll be sure to sort you out with the necessary paperwork and help get you started.

Contact details are on the Nowra Speedway web site: http://www.nowraspeedway.8m.com/clubnews.html .

[DragonCypher]

Can you let us know what was involved setting up the SC14?

It looks like a drawthrough setup but can't really tell in the pic.. would love to hear how it sounds though


-
Chris

[Blown Coupe]

Yes. It is a draw through system.

The carby sits on top of a couple of boxes I made up from some RHS steel tube, cut to length, ends plated in and welded one on top of the other.

The top of the upper box has been cut out and had studs fitted to bolt up the Holley. A mandrel bent tube takes the inlet charge down to the supercharger. The presurised charge is routed up behind the original inlet manifold and into the second, lower box. This one has been cut out underneath and drilled to allow it to be bolted down to the original inlet manifold. The manifold itself was opened up so that the intake hole matches the volume of the supercharger plumbing.

The added hight for the carby means that it now protrudes through the top of the bonet - the perfect cold air intake.

These pix show the detail a bit better.

Looking across the engine bay you can see the two boxes fitted between the carby and inlet manifold...


Looking down - pipe to supercharger on the left and back from SC to inlet manifold on right...


Looking behind you can see the pipe coming up from the supercharger around behind the inlet manifold to the lower box....


The supercharger hangs from some custom made brackets bolted up to the left side of the block (same mounting points used for the A/C pump on a Magna). I also had to relocate the alternator to the other side as well to clear enough space for it.

The standard sigma crank pulley was replaced with a Magna unit, to allow me to run a 4PK belt for the supercharger and a V belt for the alternator. Ideally i'd like to have used something with a larger diameter to get more boost out of it, but the Magna unit bolted straight on - too easy. Oh, and I had to shorten the waterpump pulley so that it would line up with the new crank pulley and relocated alternator too.

[Blown Coupe]

Oh Yeah. My nephew had a similar but different setup on his speedway car. If you want to hear it you can check out his youtube video...

http://www.youtube.com/watch?v=es4v9zPhgyo

[GC75]

thanks for the info.

[boyracer]

.
.
Champion, used to go to the speedway, my fave was a rotary converted
626, which was a rare speedway racer, one night the rad got holed and he
drove it and killed the rotary didn,t notice the steam (I think).

Love the Hardtop.

[sigmare]

Gday,

Im just getting the last few things sorted to put an sc14 on my sigma and wondering if you know what the 3 barbed fittings on the s/c are for?

Also, being a draw through setup, how do you relieve back pressure when you back off the throttle?

Cheers

[Blown Coupe]

Not sure about the three fittings on the SC. I seem to recall reading somewhere that they were some sort of pressure equalisation system (?). I just blanked them off and haven't had any trouble so far.

Back pressure hasn't been an problem either... well except for when I had the timing wrong and it backfired and blew the pipe from the SC to the inlet manifold off. Ideally, some sort of spring loaded plate or valve fitted to that pipe would solve the problem. I have considered bunging in one of the cheap Bosche blow off valves to do the job, but it hasn't been an issue for me since I fixed the ignition timimg.

[sigmare]

Thanks mate much appreciated.

[amgis_obrut]

I got a few pics of the blue galant from a few years ago

Used to do a bit of work on a mates Cortina that used to race at Fairbairn until it got T boned whilst his father was racing it

You may know the him

[Blown Coupe]

Hey amgis_obrut, tell me more about this blue Galant. I didn't think anyone else was crazy enought to race one on speedway like I do.

There's a good chance I know your mate that had the Cortina too... I've been runing at Fairbairn (and most other tracks around here) for years now.

[amgis_obrut]

Hey amgis_obrut, tell me more about this blue Galant. I didn't think anyone else was crazy enought to race one on speedway like I do.

There's a good chance I know your mate that had the Cortina too... I've been runing at Fairbairn (and most other tracks around here) for years now.

My mates dad was billy blundell they have a race dedicated to him now

[Blown Coupe]

Ah, yes. I knew Bill fairly well. He was a great bloke. A real "larger than life" character and well missed around the tracks these days.