The ideal N/A K3 using original Daihatsu parts

Hey guys this is basically an intellectual exercise, just toying around with the idea of what the ideal combination of factory parts would be to make a good N/A k3.
Would like to hear everyone’s thoughts.
Here’s where I’m at
K3-VE2 bottom end
3SZ-VE cylinder head with manifolds
Storia touring ecu
Rally 2/4 camshaft

Anyone have anything else to add or any input?

Choo Choo sounds :smile:

Sorry mate couldn’t resist

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What kind of choo choo sounds are we talking like steam train choo choos?


I’ve thought about this too. You would make sure to use the 3sz throttle body as it is bigger.
If we are talking about using some Toyota parts too: some of the yaris boys (with the 1NZ-FE engine, a distant relative the k3) are using pistons from the 1NZ-FXE (prius) engine as a high compression upgrade.

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But if you increase the compression more than you’d have to look at e85 and aftermarket ecu yes? I mean in standard form it’ll ping without 95RON, so even more compression would call for some pretty drastic timing adjustments and higher octane fuel.

Yea, true. Never really thought about those pistons with standard ecu. Was always planning on going aftermarket.
Wonder if anything could be done fuel side to increase power?

great topic!
you guys get slightly different versions to us here in nz i think
i’ve been trialing this a bit over the past few months
i’m all for bang for buck and keeping to a reliable package
my current vote is k3ve2 engine [i think you call it the rally? not sure what rally 2 is differently?]

ultimately if you want to go large throttle then that’s all good - but all of those are going to need aftermarket tune if you actually want to get something out of it - but will still free it all up a little if you want to - just no monster gains that’s for sure. I’ve tried to fit one from 3sz and getting factory sensors to work with ecu seems to be a little tricky - i’ve actually found using the detomaso throttle works better?

i’ve only done small dyno comparisons - but on stock computer, it seems a header shift and detomaso throttle goes nicely - then better bang for buck is spent on better gear ratio’s and a good plate LSD

Throttle and header for sure make a tiny bit - maybe 5%? But the standard gear ratio’s have such a massive rev drop and far too high total top speed - you can find 10-15% torque increase by taking stress away from the engine!

Anyone else tried this?

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I don’t know how well a bigger throttle body would work, a bigger throttle body alone could have a negative impact depending on how much bigger it is. But ive been told by some guys in the UK that aftermarket headers make a big difference, I was told about 10 Hp, but im not sure if this is supported by dyno results or just how it “felt”. As for the 3SZ cylinder head from what I can see the swap should give about 5 Hp more peak power and about 3 Nm more peak torque but im not sure how the power and torque curves would be affected. I have based this off the specs for K3-VE’s built before 2005 (same head as K3-VE2) 86hp @ 6000 rpm/ 120Nm @ 4400 and K3-VE’s built after 2005 (same head as 3SZ-VE) 91hp @ 6000 rpm/ 123Nm @ 4400.

The rally cam will give a solid 6-8Hp more and peak torque remains the same however the torque curve is affected in the lower rpm range

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The Storia Touring K3-VE2 is advertised as having 109Hp @ 7000 rpm but the motor is the same as the Australian and European delivered Sirion which is advertised as 102Hp @ 7000rpm, the theory is since the engines are identical the JDM variant is likely tuned for 98 octane whereas the Aus and Eu variants are tuned for 95 octane, however this theory is unconfirmed.


You’re right about the gear ratios, they are built for an unachievable top speed which benefits good economy on the freeway. I would be willing to sacrifice 20% economy for a close ratio and lower top speed.

I am hoping to swap the gearbox internals with the 1litre variant in order to get a better final drive, the only problem (from what I’ve been told) is that 1st gear isn’t as wide this more prone to damage

Just changing to the Copen 5.54:1 would do the job. I think it drops the theoretical top speed from 258km to 205km

I need a rear diff too, doesn’t leave too many options :frowning_face:

Only really have the 1litre awd or the m112 to choose from

Mapping it properly for the mod’s is about all you could do.

I wouldn’t go more than a couple of mm bigger in throttle body or else you’ll loose much mid range torque. Better is to mill the butterfly pivot, counter sink the screws and add a slight tapper to the inlet giving an almost knife edge to the leading edge. If you can send me one I can machine it up for you and send back (or send on if someone in Oz can get one to me for you).

Instant torque is your friend. That last Khanacross I did in the NA liberty had me finish in front of many turbo cars and in front of quite a few new Porsche (including a fairly new GT3). My high compression, std cams, head work, light flywheel, equal length headers, complete match porting of all junctions and 2500cc had the thing pull the instant the throttle is touched. Right foot on the throttle and left foot braking - sub 60sec tests mean one does not want to wait for turbo spool or cam to come in. Top ten cars in the field weren’t the most powerful but I guarantee they were those with most torque.


I will be back again in February by the looks of things, we will come and visit again for sure! If you could do up a TB for me that would be awesome! I was also hoping maybe you could prepare some strut legs for me so when I get back I can throw some Suzuki internals in them?


Feb, cool. TB, easy done. Could do some legs, but really need the donor parts to be able to make anything.

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