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Discussion Starter #1
Some interesting info on the GQV and 159TBi-Ti: I was trying to find as much information about the QV and Ti engines because I am considering remapping or whatever, but didn't want to lose what little lowdown torque the Ti engine has because of the mass of the 159 body. It turns out:

Ti and QV engines have the same heads and cams.
Ti and QV engines have different compression ratios as well as piston shapes. The Ti will initially respond better to software and boost mods, but up to a point. The QV will generate higher power outputs because of this piston shape and compression difference meaning it can run higher boost levels.
The Ti engine will also be more fuel efficient due to higher compression.
QV engines on UK dynos push out around 241bhp (179kW)
Ti engines push out around 205bhp (152.5kW)
The turbos are different, and the boost differs. This translates as follows:

Ti: 320Nm @ 1400 - 1700rpm
QV: 340Nm @ 1900rpm

Ti: 147kW @ 5000rpm
QV: 173Kw @ 5500rpm

The 159 really does spool up much quicker than a QV.

Unfortunately due to piston design, when fitted with the same software, the gains will be different: A QV on Novitec will push out 194kW :wow: (about the same as my GTV :D ) but the Ti will be under-achieving (relatively) 180kW but will be using less fuel...:thumbs:
 

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Ian would you like to use my novitec
 

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dont push it lol
 

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HG is that Novitec for ALL Alfa turbo petrol cars???? How can you just use your unit with his??? Doesn't make sense!

Great info there Ian...that's nogal quite interesting that the GQV has different pistons...maybe forged units to handle future planned GTA boost levels to up power to 300BHP???
 

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Discussion Starter #7
The pistons are all forged, the Giulietta has a flatted crown probably only because of lowered compression. The 300bhp engine will probably have even more different pistons and even lower compression.
 

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eish we have to hand it to Alfa...BUT...even in the late 80's the Lancia's ran production turbo motors and so did the Uno Turbo and some other Fiat's...so we have years of turbo experience!
 

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because all the 1750 use powerjet 3 and all the 1.4 use powerjet 2..
 

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The pistons are all forged, the Giulietta has a flatted crown probably only because of lowered compression. The 300bhp engine will probably have even more different pistons and even lower compression.
It would be interesting to see what will happen if you fit the QV turbo. I have yet to see a production turbo car with a good exhaust.

It would be good to know if they stuck to standard turbos on the different models. Then you should be able to change the turbo and the mach wouldn't even know the difference. The TI turbo could be the upgrade for an MA. What make turbos do they use?
 

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Discussion Starter #13
I don't know what the make is, couldn't find that out yet. Mine is hidden under the exhaust heat shield. I suspect the turbo housings are the same but the turbines and impellers are slightly tweaked between the GQV and Ti.

I suspect that Alfa Romeo,:cheese: being very environmental, stuck a cat right after the turbo... I haven't seen one there but in order to make Euro 5 emissions, who knows...:rolleyes:
 

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lol yeah the Cat is right there. I must admit the exhaust is pretty decent hey. 2.5 inch right through with one resonator and a back box. Thats it. pipe is straight with very few bends.. nothing more than about 15deg with the exception of the DP.


PS with the cat out you have such a nice chamber for the rubo gasses to escape.
 

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Originally Posted by johns159
Is it exagerated?

I thought the 1750 Tbi in the Giulietta was kicking out 235BHP as standard, so 285 is not unreasonable??? or is this whp something different?
The standard hp quote is measured on the flywheel. You will lose about 25% of that through the gearbox. So whp is normally 25% lower, unless the operator do a calculation in his computer from the whp to estimate the flywheel hp. Now here lie the dragons, and the figures easily become creative, so we prefer whp quotes.

But like I said before, a good exhaust is always needed to get the best out of any turbo. The torque curve looks good, it is typical what a small turbo would give as the engine takes away more than the turbo can deliver. This car needs a turbo one size up for performance and then the torque curve would be horizontal at the spot where the waste gate opens. It can be compared with a curve I posted some time back.

It is said that the exhaust is 2.5"/63mm and if you look at the turbo flange, that is of the same size. That can give us an idea of the size of the turbine, my guess is the outlet is about 57/60mm which is from a T3 or T2.5 with a large trim wheel. This is perfect for a 2 ltr engine. On the compressor side it is definitely too small and my guess is it may be smaller than a T3.
 

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Ian I think you can use a larger turbo and software in your engine. You are correct that the compression will allow you less boost before it will start knocking. Then you have seen pressures on the TI almost as high as on the QVs. From experience we know that the Alfa CPUs will pull the timing back a lot when it start to knock, even on none turbo engines that we turbo. For instance your 3.2 does not use a map for the timing, it advance the timing till it sense knock an then just back off. The CPU then learns how you drive and use that spec until you change something. That is the big difference between the 3.2 management and the 3.0 and before.

An example of this: A few years back before ARCOP went to the strip as a group. Hennie read the description of how the CPU work. He then bought ten or so 20ltr cans of 104 octane fuel. He filled the car up with it, and gave it hell every time he takes it out. With the racing fuel the engine didn't knock so easily and the timing could advance more, making more power. This carried on for more than two weeks and the CPU learned what is expected from it. At Smiles' he left all the other 3.2s for dead, running 15,7 and none of us quicker than 15.9s
 

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I struggled to find the specifications, but you know I am electronically handicapped.

The 159 TI compression ratio is 9.5:1 (wiki) and
the G QV's compression ratio is 9.25:1 (carnewsandreviews)

This is such a small difference, I am surprised that they went to the trouble of having both pistons.

By comparison the 147 kW GTI has a 9.6:1 compression ratio
I could not find the compression ratio for the 188kW GTiR/Audi S3
Somebody on the forum is working for VW maybe he can help.

But there are many GTI's with top end mods and chips that prove reliable?
 
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