Sometimes it's all too easy to tempt fate. I was out driving the other day (on the prowl for a killer price on a used Magna Sports) when I spied a little black Suzuki Swift GTi outa the corner of my eye. You know, the old-school 1986 shape. And - unless I was mistaken - wasn't that $2350 marked on the window? The return trip around the block was a fast one. How could that be, I wondered, a GTi for barely two grand? Sure enough, the price was $2350 and - according to the writing on the window - the car even came with a 'pullout steroe'. I hear they're much better than an everyday pullout stereo... Anyhow, as you might expect, the car was a little rough. Looking through the yard's wire fence, I could see that the sun had started to fade the factory black paint, there were a few dings here and there and - for some reason - it only had 13-inch steel wheels (rather than the factory alloys). On the other hand - if you could still believe what was written on the window - it did have a new engine. Or maybe that was supposed to be a blew engine...
Shortly after having spotted the vehicle, I seemed to be agitating quite a few people. They'd try to have a conversation me and I'd be floating off in Swift GTi land. My mind was fixed on bolt-on turbocharger kits, ex-Toyota blowers - and more. Inevitably, it wasn't long before everyone gave up trying to communicate with Michael the Motor Head and I was released to hit my collection of old Wheels and Motor magazines. Like a kid scrounging through Christmas presents, I chucked issue after issue over my shoulder until I found the ones I wanted.
Swift GTi road tests - gimme, gimme, gimme!
After turning the place upside down, I'd found only two relevant stories - one traditional road test and another feature pitting the Swift GTi against a contemporary Corolla Twin Cam and an old Mini Cooper S. (The idea of that one was to test the "it drives like a Cooper" line that had started to emerge in the mid-80s). So what did I learn? Gee, the Ti is a light fella. Only seven hundred and fifty kilograms it is. And, yep, it's got some power too - 74.3kW at 6700 rpm and 108Nm of torque at a high 5500 rpm. It's no 200SX, but - without question - the early Swift was certainly the quickest of all GTis. Its light weight enables it to get to 100 km/h in 9.1 seconds - later models struggled to do it in 9.5 seconds.
Now that I knew what kind of starting point the early GTi was, I dug into my collection of modified car magazines. Ahh, it all came rushing back to me. The GTi (the later model) was the cult car of the early-mid '90s. It was the vehicle at which you had to throw Auscar Shadow Spokes, a big muffler tip, lowered springs and a subwoofer... But I found there were two extremes of GTi engine modification... As you might expect, Suzuki engineers had already highly-tuned their little DOHC, 16-valve G13B motor. Back then, not many engines could produce 56.9kW per litre (naturally aspirated). The aftermarket crew tried their usual hot-up techniques - an aftermarket intake, exhaust and a custom chip.
And it all yielded, well, bugger-all more power.
Then (after everyone realised that these mods were achieving almost nothing!) there was a flurry of big turbocharger installations - with some owners claiming some truly tremendous power outputs. Sure, these cars were damn fast, but the limiting factor for each appeared to be the stock gearbox. It kept going "bang"...
Mental note: An early Swift GTi with - say - 5-10% more power from "the usuals" gives only slightly improved acceleration. Mid 8s to 100 km/h is about the best you'll get. The same car equipped with a serious turbocharger - producing around 80% more power than stock - gives excellent straight-line performance. With enough traction, probably into the 5s for the 0 - 100 sprint - but with imminent gearbox hassles.
"Hmm," I groaned as I stroked my chin - surely there was a cost-effective performance middle ground. I didn't want to spend heaps on a cheap little car and I didn't want to push it so far to make it an unreliable shitter. At the same time, I wanted a decent performance improvement. And then I standard to rope some ideas in from left field...
I discovered that the G13B engine in its top Japanese form, produces 86kW at (wait for it!) 7500 rpm. That's 16% more power than the local version. This screamer uses an 11.5:1 compression ratio, a new intake manifold, new extractors and revised ECU mapping. It probably has different cams and probably a number of other things as well. This engine swap sounded like a pretty good way of getting more power - but it didn't appear to be an engine that smacks of torque (remember, I'm used to turbo cars!). These engines are also very rare and expensive.
A milder option might be to pull apart a stock 74.3kW Aussie-spec motor, shave the head to give (say) an 11.0:1 compression ratio and maybe look at de-dagging the head (I wouldn't expect to gain much here, though). Once reassembled, get a thorough chassis dyno chip-cook running on at least 96 octane fuel. Maybe even the new 98 stuff. Pretty well any brand of premium unleaded should be enough to prevent detonation, because when the 10.0:1 stock motor came out in '86, all you could run it on was the local 91 octane cough syrup. With these mods (in addition to the usual exhaust and intake) I'd expect an output of somewhere around 85kW (a gain of around 15% over stock). Not too bad - but probably not enough for me...
Taking the pull-the-engine-apart theme a little further, I remembered one very attractive approach to Suzi power. Fitting the 1.3 litre GTi DOHC head atop of the 1.6 litre G16A bottom-end. This conversion was sure to give increased peak power and give a stronger spread of torque across the board. Even the stock throttle-body-injected, SOHC G16A generates 133Nm of torque at 4000 rpm - versus the GTi's 108Nm at 5500... Without digging too far, I learnt that the two engine's bore diameters were nearly identical and there didn't appear to be too many mods needed. You need a new cam belt, a cam cover (anything will do here!), a Vitara head gasket and some tinkering with pulleys and belt tensioners. Of course, then there is the management system - I wonder if it's possible to run the standard ECU with some custom dyno-mapping and tweaking? If not, you'd be looking at an aftermarket system. A bigger set of injectors may also be required to accommodate the extra power. Speaking of which, I'd assume that a G16A/G13B hybrid engine - depending on its compression ratio - should generate around 95kW with an exhaust and intake (a 28% improvement on standard). (See "Head Start" for more details on the Suzuki head swap.)
The other option I plucked out of the air was the fitting of an import wrecker Toyota 4A-GZE supercharger. This blower could easily cope with the demands of the 1.3 litre four and, without going crazy with boost, should give a strong torque improvement. An improvement all the way through the rev range. Mildly supercharging the stock-internal motor shouldn't be a problem, so long as it's well intercooled, running on high octane unleaded and - if necessary - using retarded on-boost ignition timing. With around 7-8 psi boost, I'd guess you'd get around 100kW at the flywheel. A power gain of 35% - with strong torque through the revs - should do quite nicely indeed. Import 4A-GZE superchargers can be bought for $350, I'd pay someone with a full workshop to perform the necessary bracket fabrication and I've got an import intercooler ready-and-waiting to go. The engine management side of things, however, could easily blow-out the overall cost. I've seen people with turbo'd Swifts run everything from just an extra injector to a fully programmable ECU. Maybe even a re-mapped Delco system could do the job. Hmmm.
So there was potential for making a pretty quick and reliable GTi streeter. None of the iterations was really cheap, but when you compare tricking any atmo car with a factory turbo one, it's always gonna be that way.
With this in mind, I had to wait until Monday to ring the car yard and negotiate a price. I wanted this car bad. After waiting what felt an age (Ooohh, I hope nobody else grabs it first!), I got my chance. But after barely 20 seconds on the phone, it turns out that car's new motor was actually a 1.3 litre SOHC, 8-valve carburettor'd Barina engine...
I thought the car was awfully cheap!
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