ALFAGTV6.COM

[Jim K]

Yes it does, but when you are modifying for much more boost, you disconnect the Pierburg solenoid valve which activates the wastegate driven by the knock cct. You then install a simple bypass valve between the compressor pressure outlet and wastegate (costs ~40Euros here). This valve is manually adjusted to whatever max boost you want to run. However, the knock cct still functions, reducing advance when pinging occurs; it just can't open the wastegate anymore if knocking persists. Ideally, you must adjust the distributor so that you have zero pinging at max load. If so, you have no way of knowing whether the knock cct is intervening or not. Obviously, if pinging occurs, you have exceeded the capability of the knock cct correction. I believe that if you adjust advance at the abolute limit -which is not easy as its a function of temperature, load, fuel quality, humidity, max boost value stability etc- the knock cct is surely operating at some point or even most of the time.
Jim K.

[jamal555]

I cannot find the 33 version from which that bosch number u gave (0237507009) originates...

service manuals gives 2 other numbers : 237.540.173 for regular 1.7ie and 237.601.014 for 1.7ie for markets with catalyst converters and emission regulations... the models with hall sensor... LE Jetronic injection...

now, the one that is only vacuum regulated goes up to 10* so in normal cruise with part throttle u have about 4-5* advance...

could that make problems if the pedal was sharply depressed at lets say 5500 rpm... and u get instant 5-10* advance at that rpm? even dangerous for the engine?

these are the respective curves:

1.jpg (123.4 KiB) Viewed 7274 times

the "regular one" without automatic (mechanical?) advance:

3.jpg (172.49 KiB) Viewed 7275 times

and the catalyst, polution regulated one, with advance:

2.jpg (150.99 KiB) Viewed 7274 times

[Jim K]

There's only one way to find out if and how well (or not) this distributor will work...I'll put it on my engine probably next week sometime. I just had it machined to make it fit in the 1.8T and just a while ago I was reassembling it after a good cleanup. I called my Alfa garage where I got it and they said its from the 33 1.4 cat ’90-‘92 model with Bosch management. Note that the same car was available with Marelli distributorless management.
Well, I went to the dyno again today and I'm happy to arrive where I wanted for an everyday driver: 210hp at 5400rpm and almost 31kgm (224ftlbs) at 4400rpm are very respectable numbers, so I’m declaring the end of power mods for this car, as the other 1.8T will see a lot more changes. Sure, not everything is perfect: afr still goes weak after ~5k but I can live with that. I may investigate -just for the hell of it- if it’s the injectors maxing out or the adjustable regulator playing games. This power was made with an average boost of ~1.2bar (17.6psi) which is very safe and comfortable with the entire setup. I had to finally settle for 4*BTDC at idle, to totally forget about pinging. I believe these results to be close to the max potential of the stock management system. Note also that the intercooler is still where the factory put it!
Here’s the dyno sheet showing the before and after curves. Remember the ‘before’ curves were made with 1bar (14.7psi) boost.
Jim K.

[BradGTV]

those are great hp numbers jim!
what turbo are you using?
does the standard intercooler even work i think it needs to be replaced with a front mount or made into a water to air intercooler for better performance

[Jim K]

All with the ancient stock T3. I bought a GT2854R to put in this car for better low speed response, since its a daily driver, but seeing how well the thing works now...I may just leave the T3 on. We'll see, after I get rid of the V6 book with final mapping; can't deal with too many things at one time.
I'm leaving the std intercooler where it is, given that yesterday (Sat.Oct 30) we had a track meet here and the car behaved impeccably -I could barely hear some occasional pinging around 4500. The only potential problem can be water temp, which after 5-6 really hard laps, rises to 90-95*C and that's when I go out for a few minutes until it drops back down to ~80*C. Another problem with the local track is hard working brakes; with the std discs/calipers, DS2500 pads get to smell quite a bit but they hold up -borderline. I don't want to go to bigger brakes as I like the Ronal A1 wheels. Besides, the other 75Turbo has all the good stuff, including a water/air IC (the std unit modified for water circulation.This is the first step, before having to go to a front mount one).
Jim K.

[marco/hamburg]

I solve my water temp problem with 2 small additional water cooler (from the heater) in the wheelhouse.
That work very well and when the fan starts a schmal electrical waterpump starts too.




http://media.teilesuche24.net/parts/pie ... EN_WEB.PDF

greeting
marco

[Jim K]

Maybe the most practical solution is to install the large radiator from the Alfa 75TD cars along with the twin fans. I have this in the other Turbo as shown in the attached second pic. A friend with a 75T with the same system, has 287 rwhp at 1.8Bar (26psi) and never exceeds 85*C in the track even in the middle of summer. My car will be similar spec in a few months and I'll be able then to have more detailed info. Notice also the water/air intercooler, the radiator for which is behind the bumper; flow is via a small water pump.
The first picture is from the daily Turbo.
Jim K.

[marco/hamburg]

Maybe the most practical solution is to install the large radiator from the Alfa 75TD cars along with the twin fans. I

Yes of course, that is the best way. But in my enginebay is not enough space for a wider cooler and befor I made the coller allready thicker.

Notice also the water/air intercooler, the radiator for which is behind the bumper

First of all I have no experience with water to air intercoller but in my opinion ist the best way a large flat air to air cooler (rather surface than thickness), when you have the space in the engine bay.
Because the medium to cool down the air inside the cooler ist the air temp outside and this means for the same effect you have to cool down the water temp compare to the outside temperature.

Just my two cents

greeting
marco

[Greg Gordon]

A liquid intercooler is more effective. There is a good reason the engine itself is liquid cooled.

Greg

[Giuliettaevo2]

A guy on the Dutch forum had a question abot the 1.8Tb engine. He has a very nice 75 which has undergone an extensive restoration including a full overhaul off the suspension, brakes and other stuff. This is seriously one of the best looking 75's in Holland!

His engine is not so good unfortunately and he is oing to get it rebuild. Now he's wondering if upgrading it to a 2.0 would be a wise idea.

My arguments against it where the thinner liers which would be more prone to cracking and the fact that you can make enough power to kill the transaxle with the 1.8. I think the money would be better spend at a new turbo or camshafts and headwork. He has a programmable managment and a front mount intercooler and some 440cc injectors already.

What do you guys think about this?

some pic of the car in question...








The build can be followed ( in Dutch..) here;
http://forum.alfaclub.nl/viewtopic.php? ... sc&start=0

[Duk]

Giuliettaevo2, your friends car is indeed very sexy!!! It just goes to show how good a 75 can really look .

2 thing's I would do differently:
Longer inlet runners to help boost low-mid range torque. Off boost it's still 'just' a 1.8 litre engine.
A duct that forces the air that enters the central air inlet in the front bumper bar/air dam/spoiler to actually go through the intercooler and radiator rather than being given the opportunity of taking the easy route and sneaking off under the car.

[Jim K]

You are right about the 2liter liners being a problem. The 1.8T has proven reliable here with almost 3bar (44psi) making 475hp on BP Ultimate pump gas and 550hp on race gas. 1.8T liners have split at 3.2bar (47psi). If you really want 2liters, you must definitely go to a monosleeve and you're looking at 1500Euros plus block machining. In the 2liter, you will also need forged pistons, while the 1.8T goes to 450hp with stock internalls. Is it worth it? In my opinion, no.
Jim K.

[Giuliettaevo2]

That should be an adequate answer...

I knew these engines were strong but that is just insane, 3bar pressure.

[Zamani]

I wonder if this 1.8T is the one which beat the 360 in Greece.

[Jim K]

That's the one, 550hp on race gas!!
Jim K.