One answer to this is adding an aftermarket ECU. This effectively replaces the cars standard ECU and allows the user to program a custom fuel and timing map. The benefits are even greater on turbocharged engines when this is mated to an electronically controlled boost controller.
http://www.cartuningtips.com/260-aftermarket-ecu

I'd only have one concern over that route: the CAN network? How would that be affected by an aftermarket ecu??

I stumbled across this on ebay:

http://www.ebay.co.uk/itm/FORGE-ADJUSTABLE-ACTUATOR-for-Fiat-Grand-Punto-1-4-Tjet-/350177342015?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item518832323f

Seems pretty good? And is adjustable - longer/shorter rods and stiffer/softer springs. First thought was that it would come in handy seeing as I would be fitting the turbo to a smaller cc engine than the turbo was designed for and would then make the requirement of lowering the compression redundant, and also eliminate the risk of overboost?

MarkThompson4 said:

I stumbled across this on ebay:

http://www.ebay.co.uk/itm/FORGE-ADJUSTABLE-ACTUATOR-for-Fiat-Grand-Punto-1-4-Tjet-/350177342015

Click to expand...

That does the same job as the OE.

Controlled via an electronic boost valve.

This company make and tune aftermarket ECU's ...
http://www.simtekuk.co.uk

The what does?? The ecu, or that thing I posted?

Stop drinking man!! LOL

MarkThompson4 said:

The what does?? The ecu, or that thing I posted?

Stop drinking man!! LOL

Click to expand...

Hick* Hick*

The thing you posted is basically the same as the actuator already on the standard turbo.

Check out the DTA S60 Pro on the Simtek site. Its able to do everything you need it to as far as I can tel ..

Yeah I was just looking at that, seems like the dogs bollucks >

So you get that and an electronic boost controller as well or is there no point in one of them with this?

I assume with fitting one of these ecus it's a case of finding which wires on the current ecu are for which input and wire them for the new ecu? Is this company able to set it all up for you?

And see where it says "full throttle shift cut" does that mean that when you're going full throttle and dip the clutch to change gear you can keep the gas pedal to the floor as the ecu cuts the fuel? If so it sounds kinda of awesome

you would surely need a low pressure turbo? with the amount of power you would get from it and the risk using a high compression engine with the turbo and all the extra cooling and oil piping you need to do would you be better off just putting a 1600cc engine in? if you want extra poke from a 1.2 have you thought of nitro or running bike carbs? still love to see the turbo job if you decide to do it.

I have to admit its probabely going to be more hassle than its worth and probabely going to cost a small fortune but that sadi I have to admit I'd like to see if it could be done.

Well that's what I'm not sure about, what are the extra cooling and oil piping that it would need?

I have no idea when it comes to carbs :/ would need more modification to the standard fuel system than a turbo I'd assume?

I think if I modify the actuator or in a previous post I showed a forge adjustable actuator where you can adjust the starting point and change the actuator springs for stiffer ones, which on a 1.2 would be handy initialy to set it up - stiffer spring would mean more boost pressure required to move actuator - something not available on the 1.2? Reduces the risk to the standard engine? If all is well then swap in softer springs to allow more movement of the actuator and thus more boost and see how it copes?

I think I could source an inlet manifold and fuel rail/injectors etc and swap onto mine with little modification required, the turbo/manifold will bolt straight on and thus the intercooler/piping will fit plus I have plenty of room under the bonnet for it all. But my only question is how to fit extra oil lines? Could you offer advice?

If I can sort that, and everything does bolt on as straight forward as it seems, then if I can get the actuator changed to reduce the amount of movement/boost then I think I may have a good shot at it?

Im on my phone so struggling searching at mo,
Ther was a guy with name dax I think, was trying to Turbo an abarth and I don't remember him ever getting there.
I think Nikos or similar name managed to turbo a 1.6 or 1.8 but went on to bigger things.
I've no idea what turbo is t-jet, but I'm guessing it's just a standard wastegated turbo. They look similar with actuator but they're not really the same, the actuator on the wastegated turbo is connected to a flap valve usually that vents excess exhaust pressure to maintain a set boost pressure.
Say actuator is 12 psi, the exhaust gas will drive turbine up to a speed wher it will deliver boost depending on exhaust gas/shaft speed, as pressure in boost side reaches 12 psi the boost pressure passing down the pipe to the actuator and overpowers the actuator spring which causes the rod to open the flap inside the turbo and vent exhaust gases to bypass the turbine and maintain 12psi, pressure drops below 12 and flap closes shaft speed increases boost increases. And so on, as development would be required I would think an adjustable actuator ideal.
Your already thinking about compression ratio, also think modification to ignition system turbo may require stronger spark.also you will need modification to ignition timing?you may need increased engine cooling and most likely increased oil cooling, turbo camshafts usually run different timing,
What sort of torque would a 1.2turbo generate and what torque will Rods take?
What nm will gearbox take, clutch take.
Exhaust will probably need increasing in size a fair bit as well.
Mapping and control? It will need to burn clean enough to pass your vehicles emisions parameters for mot time?
What's the pressure range on your cars map sensor?
Don't want to put you off but there's a reason everyones not doing it.
Have a look for some UNO conversions to turbo or even x1/9 turbo conversions to see what involved.
Here's a link to engine / gearbox nm levels right at bottom is gearbox input torque, it looks like you may be going from 100nm to 200+ nm, a fair jump.
http://www.tezana.pl/files/do pobrania/FPTOVERVIEW.pdf

Thanks for the reply Sussexa. I am aware of Dax and his 2.4T Abarth conversion, he tried to keep it as "standard" as possible, cross referencing as many parts as he could and failed only at the last part getting hold of a Fiat Examiner. I asume my engine comparitively easier to work on?

I agree things will need changing on the ignition side, I'm thinking of just buying things for TJets and trial fitting them on my engine ie spark plugs, coils maybe?

Initialy I would keep it a low boost setup, minimal just to make sure everything runs and then make adjustments to the actuator to raise the psi, but I doubt I would go over 1.2bar. The TJet turbo is a VL38 turbo, looking through the GP TJet threads they seem to run no higher than 1.3bar, 1.2 being the norm. I would assume ignition timing can be sorted through means of an ecu remap. And is my engine at an advantage as it has no MAF? Makes remapping easier??

There is one turbo'd 1.2 Stilo I know of in Greece, they stuck a Maserati 3200GT turbo on it and got 150bhp on standard internals gearbox etc. VL38 is a much smaller turbo so my predictions are much less, if initially I reach near 100bhp on lowest boost then I'd be happy, but to get it running is first priority. There are uprated clutches available shoul I need one.

I may dedicate to track/ drag strip use if I go ahead with this so no need.

So the installation of an oil cooler would be advisable for the turbo? How could I increase engine cooling?

Having looked at the link you provided I think it's fair to go by the lower spec 1.4T at 120bhp and 190nm, though these figures wouldn't be what I'm aiming for initialy, another 10 or 20 of each and that would be where I'd like to be, so for standard 1.2 16v @ 80bhp & 113nm a jump to 110bhp say and 170 maybe can't be a dangerous limit can it?

Earlier versions of the 1.2 16v in NA tuning have been known to reach 120bhp with modifications to intake/exhaust.

Also likes of these threads
https://www.fiatforum.com/cinquecento-seicento/233699-turbo-rolling-roaded-mpi-gt17-big-turbo.html
Should pick up a few tips / pitfalls.

Here's a pic of a T-Jet turbo.

While it does look like it could be a VGT its not and its definately not used on the JTD. I really should drink less.

Cool So what does that mean? It's a "fixed geometry" turbo or something? Are these easier to work with?

But if it's not a VGT then what is the actuator doing?? :s

MarkThompson4 said:

But if it's not a VGT then what is the actuator doing?? :s

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Perhaps I should rephrase that. I'm pretty sure its not a normal "dump valve" type turbo and I'm 99% sure its not the same as a JTD, VGT(Variable-Geometry Turbo).

There are different forms:

VVT - Variable Vane Turbine
VNT - Variable Nozzle Turbine
VTG - Variable Turbine Geometry
VATN - Variable Area Turbine Nozzle

And they all confuse me. Which one the Bravo is I have no idea, maybe non of them.

Ah ok they all sound like fancy terms for same thing

Will it still be operated from manifold pressure anyway?

And see that shiny circle between the two turbines facing straight out, is that one of the oil lines??

MarkThompson4 said:

Ah ok they all sound like fancy terms for same thing

Will it still be operated from manifold pressure anyway?

And see that shiny circle between the two turbines facing straight out, is that one of the oil lines??

Click to expand...

Yes they're all just different ways of increasing and decreasing the boost but exactly how they work is beyond me. Most are controlled electronically using a vacuum and control valve.

Yes that shinny circle is were the oil line bolts on.

Cool, do you know the electrical side of it? What do the electronics do if the actuator's opened by vacuum? Do the electronics prevent it from opening? :s

Awesome. So where does the turbo get its oil feed from? Is it directly from the sump?

MarkThompson4 said:

Cool, do you know the electrical side of it? What do the electronics do if the actuator's opened by vacuum? Do the electronics prevent it from opening? :s

Awesome. So where does the turbo get its oil feed from? Is it directly from the sump?

Click to expand...

Not really but here's my understanding of it.

I'm not sure if the actuator on a Bravo opens or closes what ever it is attached to so I'm unsure if it would be increasing boost or decreasing boost when the vacuum pulls on the actuator.

Boost is usually measured in the inlet manifold via the MAP(Manifold Absolute Pressure) Sensor. This sensor tells the Engine ECU how much pressure(Boost) is in the inlet manifold. The Engine ECU then decides in a split second if the turbo should produce more or less boost depending on throttle position(100% throttle = Max Boost). It uses a Boost Control Valve to regulate the vaccum which controls the actuator which controls the boost.