Engine mods. What
to do and what to buy, and what are the specs?
Well, there's only one limit to the engine mods and that's money!
But everyone doesn't have a lot of cash. So? What to do?
T.O.C
1. Engine block
2. Cylinder head
3. Intake manifold
4. Pistons, rings and rods
5. Crankshaft
6. Fuel system
7. Exhaust manifold
8. Exhaust
9. Air filter
10. Sparkplugs
11. Turbo
Engine block B202
The block is made by a special cast-iron and is cast in one piece.
Specs (source SAAB 900 workshop manual, 2.1 Engine):
| Cylinder
diameter
|
90
mm |
3.54
in |
| Stroke |
78
mm |
3.07
in |
| Volume |
1985
cc |
121.1
cui |
| Weight |
150
kg |
309
lb |
| Engine
type |
Year |
Octane
need RON |
Comp |
Power,
hp at RPM |
torque
Nm (lbf ft) at rpm |
| B202i
cat |
1986- |
min 91,
rec 95 |
10.1 |
130/5500 |
173(128)/3000 |
| B202,
turbo |
1984- |
min 91,
rec 98 |
9.0 |
175/5300 |
273(200)/3000 |
| B202,
turbo cat |
1985- |
min 91,
rec 95 |
9.0 |
160/5500 |
255(188)/3000 |
| B202,
turbo cat SPG |
1987- |
min 95 |
9.0 |
165/5500 |
265(195)/3000 |
Cylinder diameter other than stock
| Stock
(A) |
90.00-90.01
mm |
3.5433-3.5437
in |
| Stock
(B) |
90.01-90-02
mm |
3.5437-3.5441
in |
| Oversize
I |
90.50
mm |
3.563
in |
| Oversize
II |
91.00
mm |
3.583
in |
Mods:
- "O-ring" the block.
- increase the Cylinder diameter (92 mm is max)
- Add oil cooling for the pistons
Cylinder head B202
The cylinder head is precisioncasted in a metal alloy.
Specs (source SAAB 900 workshop manual, 2.1 Engine):
| Height,
new head |
140.5
mm +/- 0.1 |
5.533
in +/- 0.003 |
| Height,
min after regrind |
140.1
mm +/- 0.1 |
5.516
in +/- 0.004 |
| Intake
valve size |
32.0
mm |
1.26
in |
| Exhaust
valve size |
29.0
mm |
1.14
in |
Mods:
Go to your local junkyard a look for
- SAAB 9000 2.3L cylinder head from the "Long block" or a SAAB
900 2,1i 16V 1991-92 cylinder head (B212).
Then leave the cylinder head for some cleaning and restoring.
Polish the intake manifold. Get a smooth surface. Inside!
Adding the new cylinder
head and intake manifold will get you a better flow in to the engine. The 2.3L cylinder
head has a "nicer" combustion space than the stock.
Intake manifold
Specs:
The B212 has larger ducts than the B202.
B202 intake
B212 intake
Comparison between B212 (left) and B202
(right)
Mods:
- Intake manifold from a SAAB 900 2,1i 16V 1991 -92 to match the larger
ducts in the cylinder head.
Pistons, rings and rods
The pistons are made of an metal alloy. They are not forged.
Specs (source SAAB 900 workshop manual, 2.1 Engine):
| Make |
Mahle |
| Speed
@ 5000 RPM m/sek (ft/sec) |
13
(39.7) |
O- top groove diameter
A- depth of groove
| Engine
type |
year |
O
mm(in) |
A
mm(in) |
weight
g (oz) |
| B202 |
1984- |
64(2.52) |
4.7(0.185) |
514-526(18.5-18.9) |
| B202 |
1986- |
64(2.52) |
3.85(0.152) |
519-531(18.7-19.1) |
Turbo (Mahle)
| Stock
A (no spare) |
89.960-89.970
mm |
3.5444-3.5448
in |
| Stock
AB |
89.970-89.978
mm |
3.5448-3.5451
in |
| Stock
B |
89.978-89.986
mm |
3.5451-3.5454
in |
| Stock
C |
89.986-90.002
mm |
3.5454-3.5461
in |
| Oversize
I |
90.460-90.475
mm |
3.5641-3.5647
in |
| Oversize
II |
90,960-90.975
mm |
3.5838-3.5844
in |
Nominal piston clearance:
0.022-0.050 mm (0.8668-1.9700 in)
Turbo (Mahle - Schmidt)
| Stock
A (no spare) |
89.978-89.988
mm |
3.5451-3.5455
in |
| Stock
AB |
89.988-89.996
mm |
3.5455-3.5458
in |
| Stock
B |
89.996-90.004
mm |
3.5458-3.5462
in |
| Stock
C |
90.004-90.020
mm |
3.5462-3.5468
in |
| Oversize
I |
90.482-90.497
mm |
3.5650-3.5656
in |
| Oversize
II |
90.982-90.997
mm |
3.5847-3.5853
in |
Nominal piston clearance:
0.009-0.035 mm (0.3546-1.3790 in)
| Piston
Rings mm
(in) |
upper
comp. ring |
lower
comp. ring |
oil
ring |
| thickness |
1.73-1.75
(0.068-0.069) |
1.98-1.99
(0.078-0.078) |
2.63-2.73
(0.104-0.108) |
| clearance
in gap |
0.05-0.09
(0.002-0.003) |
0.04-0.07
(0.002-0.003) |
|
| Gap
in new cylinder |
0.35-0.30
(0.014-0.022) |
0.30-0.45
(0.012-0.018) |
0.38-1.40
** (0.015-0.055) |
** segment
The rods are forged.
| Diameter
crank end |
56.000-56.019
mm |
2.2047-2.2055
in |
| piston
bolt bushing diameter |
24.005-24.010
mm |
0.9451-0.9453
in |
| Max
weight difference between rods in the same engine |
9 g |
0.32
oz |
Mods (if you want to
pass 300 HP):
- Exchange the piston to forged ones, "Venolia" is a tip.
- "Shot-peen" & Polish the rods
Crankshaft
The crankshaft is forged and got grinded hardened bearings that is treated
by "tenifer-treatment"
Mods:
- Just check the crank, to make sure it's in good condition.
- balance it
Camshafts
"Hotter"
cams aren't easy to find. To get "Hotter" cams you'll need to ask
someone to make new ones. Not cheap!
Specs (source SAAB 900 workshop manual, 2.1 Engine):
| |
Int Lift mm
|
Exh Lift mm
|
IVO (BTDC)
|
IVC (ABDC)
|
EVO (BTDC)
|
EVC (ATCD)
|
Valve Overlap
|
Int duration
|
Exh duration
|
| B202i
1986- |
8.65
|
8.65
|
16.0
|
44.0
|
61.0
|
13.0
|
29.0
|
240.0
|
254.0
|
| B202 Turbo -1985 |
8.65
|
8.65
|
10.0
|
56.0
|
56.0
|
16.0
|
26.0
|
246.0
|
252.0
|
| B202 Turbo 1986- |
8.65
|
8.65
|
16.0
|
56.0
|
61.0
|
13.0
|
29.0
|
252.0
|
254.0
|
Mods:
- get other cams.
For more info go under Tech -> Camshafts.
Fuel system
For higher boost you'll need more fuel. There are several parameters here.
- Fuel injectors
- Fuel Chip
- FPR
Many just smacks on a "hotter" FPR and hopes that would do the thing. It could do,
but only to a limit. Because the injector only handles a specific fuel
pressure. Then the spray will be deformed and the injector will take damage.
A fuel chip is a good thing to start with. What you do is that you alter
the duty cycle of the injectors. Which makes it possible to increase the fuel
inserted in the engine. But you must know that the amount of fuel in the fuel
rail is enough to support the new program.
For more info go under Tech -> Fuel system.
Exhaust manifold
The stock exhaust
manifold should be able to handle up to circa 250 hp without any modifications.
But if you want to go
higher the you'll need some high power headers ("Extraktor grenrör"
in Swedish). I can just recommend that you buy it from a serious maker. Sloppy
jobs and low budget tubing can destroy the turbo. And if the header isn't done
properly you'll get problems with runaway boost pressure. And that's not fun.
Well at first, YES-POWER. But when the head gasket blows, NO-*no more cash*
But you could also "port" the exhaust manifold slightly to improve the
flow.
Here you can see a "ridge" inside the manifold that blocks some of the
exhaust fumes. (the picture is lousy, I know).
Use a tool to grind the ridge down a bit. I used a "Dremel multitool"
to do the work. But be careful. The manifold is expensive.
Here is the "slightly ported" manifold.
Exhaust
What you need is
a 3" from the Turbo and that down pipe should be circa 1,5 meters or down to
the "cat" if you got one. Then if you want to save a little go down
to 2.5" for the rest of the exhaust.
If you got a catalytic converter (cat) you'll need to exchange it to a 3"
race version. It's expensive but it's good!
Spark plugs
For spark plugs
use "NGK BCP 7 ES" or "NGK BCP 7 EV". The EV is the
platinum plugs and they are expensive.
I run the ES and I change the plugs every 5000 kilometres if needed. They work
fine.
Air filter
"Cool air is good" so upgrading to a shielded open-air filter will do
wonders for your car. Remember the air must be "cool". Exchanging the
stock air filter box for an open air filter could actually give worse result
because the air in the engine room isn't cold.
I've seen different solutions to solve this problem. The most popular seems to
move the air filter behind the right turn signal.
How to
- Remove the air filter box.
- Move the APC Somewhere it'll fit after the mod.
- Take an aluminium tubing that fits the "air mass meter" and put it
through the side of the engine room wall(drill & saw). The tubing should
now end approx. 1 inch outside the engine room wall where the APC was mounted.
- Mount a 90 degree aluminium tubing. So it points forward and down.
- Add your open air filter to the end of the tubing.
Now when going to the "drag" just take away the right turn signal
housing. You'll get a lot of "cool" Air.
Turbo
There are several
turbos mounted on the Saab 900. They are:
- Garrett TB0321 (Oil cooled)
- Garrett TB0339 (Oil cooled)
- Garrett TB0357 (Oil and Water cooled)
- Garrett TB0358 (Oil and Water cooled)
- Garrett TB0382 (Oil and Water cooled)
- Mitsubishi TE05-12B (Oil and Water cooled)
The TE05 is newer design and has much less "turbo-lag" than the
TB03**.
Mods:
If you got an older TB03* the first step is to upgrade to a TE05-12B.
Then You could either go on a TB03 "Trim 60" which has some
"turbo-lag" but it "pushes" a lot of more air on the top end,
and it's a bolt on.
Or You could go for a TD04-16T, but then you'll need to mod the exhaust manifold
or get a conversion pipe. And then you'll also need to mod the water and the oil
pipes to and from the turbo.
The TB03* should manage up to 220 HP
The TE05-12B should manage up to 250 HP
The TB03 "trim60" should manage up to 300 HP
The TD04-16T should manage up to 300+ HP
Power
graphs
Here are the power
graphs of the different B202 engines
B202S
(LTT/LPT), 90
B202S
(LTT/LPT), 91-
B202
Turbo, -89
B202
Turbo, 90-
B202
Turbo 16S cat (US)
B202
Turbo cat, 90-
B202
Turbo cat
B212i 91-