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Turbo PI Anyone?


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That's truly 'orrible!  And power gained from boost would have been lost again in the exhaust....errr..... arrangements and it can't have made much boost as more than a few psi would just blow the plenum off, clips or not.  Not sure what a PI MU makes of boost either!

I was also slightly amused by the condition description "used".  Damn right.....  "very used and long abandoned" even!

While I have occasionally contemplated a Vitesse turbo over the years, a short squint under the bonnet to check on the packaging challenges always cures the urge!


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I don't know if this post will work, but many years ago, in a small magazine called "Jalopy" now gone the Great Garage in the Sky, one "RA Franklin" - no mean engineer - wrote of "Turbodging" his GT6.
It's worth a read.

Inspired by the Blue Peter spirit of adventure,
R. A. Franklin added boost to his Triumph GT6, and lived to tell the tale…..
Why do people like me become bodgers? I’ve just accepted it. Perhaps it’s be-cause I knew from the moment 1 started bending the pieces of my Meccano set that it was my destiny. Sellotape and cardboard often found their way into my childhood creations. It was as if I was in a frenzy to get the thing to work, and anything would do so long as it sewed the immediate purpose. Not only that, there was the satisfaction of making the kit do more than it was intended for.
Strangely enough, I ended up as a Chartered Engineer, specializing in control systems. The Bodger is still there though, lurking in the background, waiting to be unleashed at weekends. Any bodging exercise of mine has the following rules:
1) It must be safe
2) It must work
3) It doesn’t have to look good
4) It must be the most cost-effective method of achieving the goal

Take rust, for example. What causes rust? Oxygen, comes the deafening reply. So what’s the best way of stopping a car rusting? Yes, immerse it in a bath of sticky oil. Or better still; don’t make it out of steel. Either is preferable to the ghastly and futile process followed by the wash-your-car on¬ Sunday brigade. You know, AAAAARGGGHH, I’VE GOT A BUBBLE ON MY WING, dare I burst it, per¬haps it hasn’t gone all the way through. Oh no, I knew this would happen, I should have had it steam cleaned like it said in the local paper. Should I bite the bullet and burst it? That means I’ll have to chip the lovely paint off, the lovely paint that I have lavished all these Sun¬day mornings on. There must be at least fifty thou of Turtle Wax on this paint, do I really have to? And then what? Rust eater? Horrid black patches followed by disgusting touch-up paint. But I’m definitely not going to look inside the wing. What if there’s more rust? Perhaps I’ll get the hose though, and give it a really good clean. .Then I’ll feel better, at least.  Perhaps if I just use a hypodermic and inject some Jenolyte it’ll get better by itself? Perhaps.
No, my friend, it will not get better. It will get much, much worse. Your car has cancer. Terminal, malignant and abso-bloody-lutely incurable. You have not been a Good Owner. You have given it Turtle Wax when you should have given it Waxoyl, but you’ll still be out there every Sunday, hopelessly sloshing more detergent-loaded water into its cavities, supplementing the corrosive mixture lurking in the mud plastered into all the little places that your Hydro-Turbo-BlastoMatic plastic nozzle that you bought down the local market from a chap who said it converted mains pressure to 2000 millibar, can’t dislodge. Sorry.
My old Triumph GT6 was a trifle rusty when I got it. It was also a trifle rusty when I sold it six years later. But that car was not rusting when I sold it, just rusty. Waxoyl, see?

But O, what bodgery I did enjoy with that car. The original 2-litre straight six put out a careful 95bhp.  Hardly Boys Own stuff. So, I thought, why not turbo-charge it? I managed to secure a turbo of approximately the right dimensions (oh, all right, a bit on the big side...) but it was a turbo, and all I had to do was fit it! Right, Sleeves rolled up. Cut three inch exhaust stubs off that old tubular manifold.  Weld them to a two-inch square tube collector, bugger the gas-flowed corner, we’ll have a dead end after the turbo flange and the gas can find its own path.
Next: compression ratio. Easy. One eighth-inch plate spacer, with metal gasket each side - 6.5 to 1, or there¬abouts. Oil feed: straight from the main oil galley. Can’t bodge this, turbos need about half a gallon a minute, at l0psi. That means a specially built pressure regulator capable of handling hot oil, and a drain to the sump, downhill all the way.

Ignition needs an extra spring, on the other side of the vacuum advance diaphragm, to back off the timing under boost. 8psi of boost will need about 6-8 degrees of retardation. If you know the boost and the size of the diaphragm, you can figure out the force sup¬plied by the diaphragm. Knowing the movement of the diaphragm required to achieve the retardation you’re after, and knowing Hookes Law as all bodgers should... I’m sure you can work out the rest (We’re way ahead of you. Ed)
Boost control: no problem. Radiator cap and neck with extra exhaust ports as a blow-off valve, brazed to the air cleaner body. A trifle noisy on the overrun, but real safe. No possibility of over-revving the turbo, which is not recommended. The blade tip velocity at full boost is around 1000 ft/sec-ond, a bit faster than the bullet from a Browning 9mm automatic. You definitely want those blades to stay in that snail-shaped thing.
Fuel: tricky. Blow-through carburettors. Pressurised float chambers.
Blown seals on throttle spindles. Many, many different needles. You need to add boost pressure to the lower side of the diaphragm of the fuel pump (see diagram), and add an air seal to the diaphragm rod. Very tricky. But it was all worth it for that one ride when the right amount of fuel went in at the right ignition timing for l0psi of boost, leaving the gum-chewing, earring-wearing Capri 3-Litre crea¬ture in a black rage, bouncing up and down in his seat, making a dent in his firewall where the throttle pedal goes.

I did try suck-through carburation. Briefly. After all, no true bodger would be put off by the prospect of a leak in a pressurised system full of petrol/air mixture at stoichiometric ratios or thereabouts, would he? Naaah. Or by the prospect of having to install another (completely leak proof) butterfly valve downstream of the turbo in order not to subject the turbo oil seals to full engine vacuum? Er, naah. No, what put me off was the way that the fuel puddles merrily in the bottom of the compressor casing on idle, and virtually puts the fire out when it is eventually whisked into the engine in a huge gush when you open the throttle. Not to mention the dense clouds of black smoke enveloping the poor bloke behind you. Or the supernovae from the rear of the car as the blow-off valve (now vented to the exhaust pipe, well downstream but still hot enough to ignite the mixture) lifted on gear changes and overrun.

But as you all know, you quickly get used to increased performance. Like, the following day. So when the TR6 engine complete with fuel-injection was spotted, it was duly acquired and slotted in. Now the turbocharger was the right size. And fuelling was a matter of playing with springs and fuel-enrichment devices and rolling roads. Boost was up to 20 psi. This was war. I had declared war on the car. It pinked. I added water injection. This was pure joy. A plastic water container (stiffish) pressurized by boost air through a one-way (yes, screen wash) valve. Squirting a jet of water through a 0.050 jet straight at the eye of the turbo impeller. It stopped pinking.
It then blew head gaskets. I added 0-rings to the head and took away the head gaskets. We saw flash readings of 270bhp at the back wheels.
It munched differential pinions. I bought an XJ6 back axle, and was about to fit that, when the noise in my left ear became intolerable. I sold it. She stopped.

But the bodging goes on. Now with a Scimitar (not an SS1, a proper one). The body does what it should, that is, keep wind and rain out. The paint, which is non-functional on this car, does what all paint wants to do, íe change colour and fall off I don’t mind, I won’t have to Turtle Wax it. The chassis has been completely fixed; all the bits that were too thin (from lack of Iron) have been replaced with new bits. And yes, it has been smothered in Waxoyl, in¬side and out. The Ford V6 engine and auto box was treated as it should have been, ie. removed, ham¬mered into manageable pieces and given to a pas¬sing traveler.
Bodging was halted whilst the suspension bushes were replaced as a matter of course whilst they were get-attable. And the brakes were Properly Done, including replacing the pitted and scored discs, sorely tempted though I was to reface them with a big abrasive wheel. You have to arrive at the T-junction at the bottom of a steep hill just the one time with smoke billowing from the wheel arches, both feet on the brake pedal and the steering wheel bent nearly double, to appreciate the full horror of brake fade... that’s after having the fillings rattled out of your head from the vibration due to thin, heat-distorted discs.
Never again. Oh God, never again...
Oh yes, and a Rover V8 was slipped in. Kind of. But that’s another story.

From Jalopy, February 1994

Ho!  It did work, with bit of editing to compensate for the change of format, and shows that you can turbo a Triumph sx, up to a point.  The point being when you get rid of it.

PS This can't be the same engine, can it?  Look at the end of the exhaust manifold - pic 4,  And Quote, "Radiator cap and neck with extra exhaust ports as a blow-off valve, brazed to the air cleaner body."

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