Sirion Track Car

Hey everyone! New to group but looking for some advice and Ideas. We are building a Sirion M101 for a track day car and if we can drag some perfomance out of it perhaps further develop into an Australian Imrpoved Production car ( been involved in IP for over 10 yrs now) Looking for a 135 HP type option in the end. Anyone had any experience in popping turbo and/or larger engine options into the earlier Sirions. Maybe K3- VET or the like - also not entirely sure whats available in Aus.
Any clues would be good and any ideas.

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Just been reading some of the posts and I have seen people quoting 180 plus hp - any advice on these options would be amazing. I am re thinking my options here. :slight_smile:

I have really had any experience with sirion’s I have just used siroin parts on mira’s and moves but a gtvi with a k3 engine would be the eaiset option for a starting base. If you already have an ejde sirion I’m sure you could change over the k frame etc and get the k3 engine in there. @FrAsErTaG Had or still has a k3vet turbo engine he imported over. It may be worth sending him a message to see if he has it.

Thanks evilhighway - gives me a starting point - love to hear any other info people would have to offer. Cheers… Gman

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What are the rules in IP regarding suspension? Also, does boosting it move it into a different class?

Suspension is pretty much free…

Boosting means the car moves to another class based on the swept volume times a factor of 1.7
So a 1.3 litre car x’s 1.7 = 2.21 litres , moves it to class c which is 2001 cc to 3000 cc . To be competitive here would need 200 hp or more to give a good power to weight ratio.
So normally aspirated the car would be Class A up to 1.6 litres.
Low to mid 100’s hp 130 - 150ish would be pretty competitive.

A kj-vet engine 936 cc times 1.7 = 1591 cc and would place the car in class a up to 1600cc and at 130 plus hirses would be super competitive. Issue is I would need to check on legality of the engine as I am pretty sure it was never released here in Aus. SO I would need an IP eligibility offocer to make a call on it before i went up that path.

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Does the engine have to be stock?

The rules around the engine are - they must be from the same manufacturer or a manufacturer that supplied to the vehicle/ make, so as Daihatsu and Toyota collaborated on engines I can use the equivalent Toyota badged engines.
Must remain in the same formation so east/west FWD in this case. - So I don’t go cramming a 5 litre v8 under the bonnet lol (That is a different group of course not IP)
Engine then becomes pretty much free to modify… Cams , induction, internals etc can be changed for performance enhancements.
Boring to larger swept volume simply may change the class you are in.
In IP there are Datsun 1200’s running SR20DET’s for example, escorts with cosworths, etc etc

You could look at importing a 3sz-ve if you can’t get a kj. They are 1500cc and are based on the same block as the k3. About the same stock power as a k3-ve2, but with more torque. With some more compression, cam, ecu and etc I think you’d get close to 130hp.

Edit: something that is often talked about, but hasn’t been done is replacing the head of a k3-ve2 with that of the 3sz as they have a better design, bigger ports and valves. Later k3s came with this head, but, we didn’t get them in oz.

Sounds great. The IP class looks awesome. We have a similar class here in nz and I’m building a car for it at the moment too
The m1 sirion is a great base
180hp from the k3 non turbo is quite an ask
Be careful of those who theorise but are t actually racing them. I’m sure you have seen them in your ten years experience :wink:

If to go into the 2ltr plus class you would be OK with 200ish then the turbo option is good

If you can’t get the factory turbo option easily, then you can rebuild the 1300 with better pistons and turbocharge that. You would be ahead of the factory turbo option already because the head is better

The 3sz engine has theoretical advantages, but there are very few that are pushing them on more than a dyno run. For decent circuit work so far my discovery is that they aren’t reliable enough unless you have massive budget

I would say the ideal is to find a front cut from a yrv turbo and convert that to a sirion …can be the 1ltr version …that’s a very good platform …with basic engine management the standard engine if happy should do your 200hp reliably

Then I’d work on decent suspension and gear ratio mods …because for circuit work the ratios are terrible …but there are great after market options coming up and factory race LSD’s are very nice.

The suspension needs some decent work as well …front swaybar mounting needs relocating and depending on your style uprating (but the yrv turbo version goes quite well)…having some independent mounting will bringfeel back mid corner and help introduce some castor which in my opinion is very much required

Brakes need some work too …but with a friendly engineer at hand, there are some options available without going nuts

That in my opinion would make for a decent starter. Again there are some monster figures being quoted on the dyno etc …but the near standard

Were in Auckland, but a few of us here are racing the k3 engines and starting to get some results. Send me a pm if you would like any gaps filled in

Good on ya for getting out to race a decent class without submitting to mass opinion and doing another Honda or something common :stuck_out_tongue:

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Awesome info Patrick! just a quick correction, he was saying if he keeps it NA he is only chasing 130, not 180 :stuck_out_tongue:
I think 130 is doable for an NA k3 or 3sz.

EDIT: Unless we are talking WHP. In that case… yea, nah.

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Earlier post he said people had been quoting 180hp
130whp is probably OK. But it’d be a proper race engine. I’ve spoken to a few guys in Japan with that kind of power. But they’ve been quite unreliable

Not sure if you remember the Sirion GTVi that Rick Bates campaigned years ago in the Production car series. Those cars had their engines built by an engineer based in Canberra by the name of Neil Trama. Apparently those engines were getting at the wheels what Daihatsu had at the flywheel (75kw).

That would make it close to K3-VET power without a turbo and would keep you in your class!

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