A standard Saab turbo 16 engine with its 160 horsepower (175 in cars without catalytic converter) is surely not a rocket engine. On the other hand, like many other turbocharged powerplants it has a very good potential for simple and cheap performance increases. Unlike most other turbocharged engines from 80's and early 90's the Saab B202 engine has quite an advanced electronic control system, the turbo boost control module of it is called APC - that's a magic word in the Saab circles. Because of this (as you'll see) performance tuning a Saab doesn't neccessarily mean getting your hands dirty... I had to separate this page into four sections, the links are below.
In 1998 when I bought the car I was happy with its performance for, let's see, a week or two. Right after that I started investigating the ways to get more power out from the engine. The internet was a good source of information: there are several pages describing the guts of the APC turbo control box, and good tips on how to modify its behavior. I decided not to experiment by myself and instead of that left the job for real professionals.
While surfing the web, I found the web site of BSR AB, at www.bsrab.se. BSR is a Swedish company specializing in performance-tuning Saab, Volvo and VAG cars. They were offering a substantial performance upgrade for my Saab with a very reasonable price. I had already looked at Abbott Motorsport and Group6 upgrades, but was seriously questioning their competence and incredibly high prices. I ordered the upgrade together with injection upgrade (below).
I sent the APC box for modification (you can drive the car without the box, but it'll become a light-pressure turbo) and got it back a week later. The installation was a reverse of removal... According to the accompanied instructions, I tweaked the pressure cut-out switch from the standard 0.9bar cut to about 1.4bar. Finally I took a test drive with my brother turning the pressure potentiometer (dash-mounted) according to the display of an additional charge pressure gauge I installed in the center console. The pot was set to restrict the maximum pressure to 1.2 bar (17PSI). And the car flew... BSR promised a 230bhp max output and +25% torque. I had no reason to doubt that.
Tweaked APC control box with an external pressure adjustment potentiometer installed on the dash. Boost is adjustable between 0.5 and 1.4 bar. Knock protection is left untouched (unlike in many other modifications), this means that I won't be getting a constant max. boost under all conditions. This modification makes it possible for me to have a street-legal 160 hp car while driving on public roads and a one-second mutation into a beast (only on closed tracks, of course. I wouldn't want to end up in trouble with my insurance company).
Lucas 14CU Fuel box reprogramming
Last Update 20th July 1998
The 900T16's sold with catalytic converter in europe are equipped with a Lucas injection instead of the traditional Bosch LH-Jetronic on normally aspirated and other turbo models. The Lucas system is quite similar to Bosch but there are some major differences such as an air mass meter working with a different principle (side channel and measurement plate, not a hot-wire type) and a standard fuel pressure regulator of 3.0bar (Bosch 2.5 or 2.8 bar). Because of this, the first step with Lucas doesn't have to be the replacement of the Fuel Pressure Regulator. Instead of that, BSR offered a fuel chip upgrade to complement the APC-box tune-up. The upgrade involves opening the fuel computer box (in right footwell) and carefully replacing one Eprom chip installed into a socket. The reprogramming involves adjusting of the fuel maps (for a richer mixture). These fuel chips are available from other shops such as Superchips, for example, as well. For some odd reason they don't seem to be available in the States. The difference the chip made is hard to tell without measurements: What I am happy with is the fact that with 3.0 bar FPR and 1.2 bar charging pressure the A/F ratio is still good (not leaning out) even in the highest RPM/power range (tested on a dyno). So I won't have to bother with a rising-rate fuel pressure regulator at this time.
A reprogrammed eprom chip to be installed into the Lucas 14CU fuel ECU.
Dyno tests
Last Update 12th November 1999
I've been quite happy with the car's performance ever since the APC upgrade. In fall 1999 i took it for a dyno run for the first time. It was a very bad time to do the testing: I had some serious boosting problems which were cured later by retarding the ignition to 14 degrees and replacing the ignition cables.
The dyno test turned out to be just what I expected: The charging pressure would not go over 1.05 bar and at the top rpms (5700-) the APC would back up the boost even more. Of course this seriously affects the performance figures. I am still quite pleased to see such numbers with only 1 bar of boost as I am usually running with 1.2 bars.
Max moottoriteho = Max engine performance = 153 kW = 207 bhp
Max momentti = Max torque = 313 Nm = 230 lb-ft
Max nopeus = Max speed = 181 km/h = 113 mph
Max charging pressure = 1.05 bar = 15 PSI
http://www.netma.fi/jouko/saab
