Hi guys, I recently registered here and this thread cought my eye...I have quite a bit of info on the 1.8T, which is very rare in the UK (thanks to Alfa marketing choices of long ago). At present I have two 1.8T's and a 12v 3liter. The 'daily' turbo is currently putting out 210hp @ 1.2bar boost (up from std 155hp @ 0.65bar): milled head for 8:1, O-ringed head gasket, 10548...intake cam, Aeromotive fuel pressure regulator set at 3.7bar, manual wastegate bypass set at 1.2bar and ignition advance dropped to 4*BTDC. I have also fitted a 76* thermostat for cooler running, everything else being std. I arrived at these values after thorough testing with the wideband O2 sensor and fiddling with the afm clockspring (~6clicks tighter). Exhaust emissions are ~1% CO, drivability is like the std car and good overall economy -unless I beat the crap out of it in the track! With ambient temps of ~35*C (darn hot!) I can only do 4-5 all out laps before I see the temp needle close to 100*C. I then cool down for a couple of laps in 45th/5th and exit for ~15 minutes until things get back to normal and back at it again!!
My aim is to increase performance in steps, with contained cost in mind. I think where the car is now, it would be absolutely great for any kind of driving and games as long as ambient temperatures stay under 25-30*C. Mind you, it does have a/c and this reduces engine cooling ability.
Having proved the 1.2bar scheme for months now, I'm ready to progress to 1.5bar. This will necessitate larger injectors, as the std ones maxed out at 1.2bar. My choice were the Weber IW-044 injectors from the old Sierra Cosworth. I should be able to run higher boost with these and at lower fuel pressure, ~3bar, very close to std. However, at the proposed boost level, std components will prove to be definitely inadequate (radiator, intercooler, ignition advance). At the same time, I'm planning a very important upgrade, by installing the GT2854R turbo in place of the std one. This will enable much quicker spool-up for substantially increased street performance. Estimates say it should boost as low as 2200rpm....we'll see in the next few months.
Incidentally, 1.8T's can make more than 500hp for a short time with stock internals, more than 2.5bar boost and aftermarket management.
The other 1.8T car was recently repainted and is sitting in the shop with no engine. Hmmmm, I have all the goodies for a 300hp job (pistons, rods, management, turbo and more) but I will first install my 24v 3liter engine, which was so far in my mechanic's car, doing the first 700km, getting ready for mapping.
Stay tuned for more news coming this way!