Questioni have a 146 ti...
i want to make it go faster...
can u gimme some effective tips...
if u need any details about the engine...this is all i have:
front transverse 4 in-line engine,
4cylinder,
16 valve,twin spark(8 spark plugs),
1970 cc,0-100 kmh in 8.5 secs
150 bhp,187 n-m,
DOHC+toothed belt,elec. variable valve timing,
bosch motronic M 2.10.4 MPI electronic ignition integrated with ignition
AnswerMikey,
I live in the US and have never seen an Alfa 146. I'm familiar with the car from articles and pictures.
I have to tell you that 150hp from 2 Liters is very respectable.
Without installing a Turbo or Super charger, there is little you can do. Compression ratio wouldn't be a good idea because you might not be able to find fuel to burn. The Bosch Motronic is a very good EFI/Ignition system, so there isn't much improvement to make there (with the exception of what I describe below) The exhaust system is probably as good as you are going to get and I'm sure transmission gears would be very expensive.
The only other places to improve performance would be with camshafts that open the valves further and for a longer time and enlarging ports or valves to let more fuel/air mix into the engine.
One thing you might want to try is to install a variable resistor into the wires to the sensor for the water temperature. The Bosch system uses a thermal sensor in the coolant to tell the ECU when the engine is hot or cold. When you first start the car and the coolant is cold, the ECU richens the mixture for easier and smoother operation when cold. As the coolant gets hot, the ECU gradually leans out the mixture for better economy and fewer emmisions. The problem with this, is that the hotter the engine gets, the leaner it runs and the leaner it runs, the hotter it gets.
One way to find a few horsepower, is to fool the ECU into thinking the engine is cold and it will fatten the mixture for more performance.
A variable resistor (potentiometer) with a value of about 300 ohms, installed in series with either of the wires going to this sensor will allow you to adjust the mixture from the driver's seat. You can mount the knob anywhere you like. When you add resistance after warm up, you will hear the engine become richer. If you go too far, it will start to stumble and burble from too much fuel.
We use this in our race cars and I have one in my GTV6. It won't help with fuel economy, but on cool dry days, I can feel the difference.
Also, you can search for a free flow air filter. Nearly ALL Alfas have restrictive paper filters. I don't know where you are, so I can't recommend a particular brand.
If you want to pull the engine apart for modification, I can give you some ideas but it will be expensive and a lot of work.
Good luck,
Dave Miller
Daytona Beach, Florida USA
