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Okay, I looked at things, moved a few things around and wrote up a big intro behind my reasoning for everything. Would appreciate any errors being pointed out.
To address a few of the other points raised in the post below:
-Everything is listed in order of difficulty, ie. basic is easy to do, advanced, not so easy. Everything gets progressively more invasive from basic to advanced. But I think they also correspond to what you can extract, powerwise.
-piggy back fuel computer intercepts and modifies (hence piggy back) the AMM signal to the LH (in our case) ECU. Still a band aid, see them on many turbo'd Japanese NA cars. Most common would be Apex'i S-AFC.
-I only listed performance modifications, not any reliability mods. I personally don't think you gain anything except reliability from silicone vacuum lines.
16v Turbo c900 and -89 9000 Performance Upgrades Nomenclature Proposal
Theory:
The 16v Turbo 2.0L (B202) engines installed in 1985-1993 (and 1994 convertible) Saab 900s, 1985-1989 Saab 9000s are fundamentally strong engines with excellent high performance tuning potential. The engines in these model years are also controlled in a relatively simple manner, with separate fuel, boost and ignition control modules. This separation and simpleness makes performance tuning relatively easy for the garagiste Saab enthusiast. It’s certainly not carbs, but it’s not all integrated electronics either!
Here is a breakdown of the various systems:
1985-1988 900 Turbo and 9000 Turbo
fuel - Bosch LH2.2 Jetronic
boost - Saab Automatic Performance Control (APC)
ignition - Bosch hall effect distributor, with mechanical vacuum advance
1989-1993 900 Turbo (and 1994 convertible) and 1989 Saab 9000 Turbo
fuel - Bosch LH2.4 Jetronic
boost - Saab APC
ignition - Bosch hall effect distributor, with mechanical vacuum advance
For a fuller explanation, see the Townsend Imports site at http://216.78.172.244/engine_folder/fivariants.htm
Tuning
There are three main goals when performance tuning these model years. First, allow the engine to breathe better, ie. pump more boost into the engine; second, improve the engine’s fueling to compensate for the improved air flow; finally, tune the engine’s ignition timing appropriately so as to make the best use of the improvements in the first two areas.
The B202 is a strong engine. The block is of a ‘solid deck’ design. The rods and crankshaft are stout. The cylinder head is of a modern yet relatively simple twin cam design, though without variable valve or camshaft timing nor additional balance shafts. All of these mechanical elements mean that a) the engine is reliable and strong and thus a good basis for performance tuning and b) the engine is relatively easy on which to work - ask anyone who has been into some of the flimsier Japanese motors or seen the intricacies of a balance shaft engine!
However, the disadvantage of the B202 is the way it is controlled. High RPM lean out has been well documented with the LH2.2 injection system, and the stock injectors max out duty cycle relatively easily. The mechanical distributor and vacuum advance is not very precise. The APC can limit boost unexpectedly and seemingly arbitrarily, though it is a fundamentally sound system.
Thus the recommendations for modifications proceeds accordingly. Each modification addresses a particular aspect of the three issues that need to be improved.
The modifications are listed in order of mechanical difficulty and cost. ‘Basic’ thus refers to a modification relatively easy to perform; Basic modifications are not too invasive and for the most part are ‘bolt-on’. ‘Advanced’ modifications are more invasive, and require more time and skill to perform correctly. It also happens that Basic to Advanced correspond very generally to the power levels that can be expected. Excellent power levels can be achieved with carefully selected and tuned bolt on modifications. That said, it does not take much to reach the limits of the LH2.2 and LH2.4 systems, and thus stand alone is highly recommended for high performance tuning. Really, many of the other modifications, (rising rate fuel pressure regulator, recurved distributor and vacuum advance unit, aftermarket ignition system) are ‘band aids’ to cover up the performance gaps in the stock engine control systems. Others will disagree with me, but retaining the LH fuel system and tacking on all of these band aids stresses the engine to its limits, and is rather inelegant engineering. It is like a small guy lifting up a heavy box. He can still do it, but he uses all of his strength. On the other hand, going stand alone is like a big guy lifting the same box. The big guy doesn’t need to use all his strength, and thus is more efficient. Furthermore, the big guy can lift more boxes, more often - all without breaking a sweat.
One cautionary note, however. By the time one has acquired most of the high price BPU, BPU+ and BPU++ (most notably modified APC, rising rate fuel pressure regulator, aftermarket ignition control), one has spent nearly as much as the cost of a stand alone engine management system that should outperform all BPU modifications. So, it’s like playing Gran Turismo on your PlayStation at home. At first, you might not be able to afford the best and most expensive items. But if you purchase all of the lower priced items and then proceed increasingly upwards, you will end up spending more. Unfortunately, putting a B202 engined Saab on stand alone is not an insignificant task, though it has been done and will likely be done again in the future. There are no plug-and-play programmable ECUs available like the Apex’i Power-FC or AEM’s similar ECU.
Another note. The youngest of these cars is now eight years old, with the oldest coming on 17 years. These modifications should only be done on cars that are in good mechanical health. Everything from simple rad hoses to a worn out head gasket or piston rings much be in good order. Performance tuning is about asking more of an engine than it originally had; if the engine is beat up and tired, one should not ask more of it. How would you like it if you just busted your ass with a 60 hour work week, and then your boss asks you to put in another 20 on the weekend, plus make it an 80 hour week for the week after?
Basic Performance Upgrades (BPU)
-drop in air filter, K&N or similar
-2.5" or 3" downpipe, 2.5" or 3" catback exhaust system, ‘race’/high flow catalytic converter: custom or Swedish made
-tweaked APC or manual boost controller (mechanical)
-rising rate fuel pressure regulator: SPG9, Swedish Dynamics, Trent Saab
-APC solenoid valve mod:
-recommended: boost gauge
BPU+
-24# or 30# injectors, with AMM tuning for idle quality if necessary - LH2.2 screw adjust; LH2.4 resistor mod: injectors available from SPG9, Swedish Dynamics; readily available from Summit Racing, second hand and much cheaper from eBay, http://www.stangnet.com
-recommended: A/F gauge
-modified APC: SPG9, Swedish Dynamaics
-‘Viggen spec’ BPV (turbo bypass valve)
-recurved distributor / advanced ignition diaphragm: DIY or SPG9
BPU++
-9000 front mounted intercooler (DIY) OR Abbott water cooled IC (Abbott Racing) OR intercooler puller fan install (KCSaab or DIY)
-water injection: Aquamist recommended: KCSaab
-2.1L or 2.3L head, port matched, polished - NOTE: will require 2.1L intake manifold
-MSD or Crane Cams ignition with boost retard: readily available
-upgraded cams and upgraded valve springs: Crower, Swedish Dynamics
-turbo upgrade, recommended T3/60 or T3/Super 60: Turbonetics
-piggyback fuel controller install, Apex’i, HKS or Greddy OR LH fuel system hack chip; NOTE: the LH hack chip is currently not readily available in North America; Europe is abound with them, but these are difficult to obtain. Piggyback fuel systems have not been tested nor installed extensively on Saabs. For the serious tuner, it may be worthwhile to jump right into APU modifications.
LH hack chip: Speedparts, but difficult to deal with; KCSaab maybe.
Advanced Performance Upgrades
-stand alone engine management, with either proprietary or stand alone electronic boost controller; APC, aftermarket ignition, RRFPR all removed: Haltech, Electromotive, Motec, Wolf3D, SDS, AEM
-low compression pistons, 1mm overbore, full engine balance and blueprint: JE custom forged or OE Saab pre-APC Turbos; these are difficult to find new
-turbo upgrade, T3/T4 hybrid, ceramic ball bearing option: Turbonetics
-fuel pump upgrade: Swedish Dynamics or custom, recommended Aeromotive or similar
-external wastegate: custom fabricated plumbing; Turbonetics, TiAL, HKS, GReddy, Apex’i or salvaged from 99 Turbo or Audi turbo
APU+
-headers - not readily available in North America, though available in Sweden from Speedparts
-oversized valves: custom, Schrick
-solid lifter conversion: Swedish Dynamics
-adjustable cam gears, NOTE: also not readily available, Scanwest Auto
-additional injectors: custom
-air outlet covers - +50hp!! This is da bomb.
other recommended modifications:
-89+ transmission upgrade, ie. larger pinion bearing - good
-91+ transmission upgrade, ie. larger pinion bearing and beefier gears and synchros - even better
-Jorgen Eriksson 4-speed rally-spec transmission, via Gary Moore / Three Trolls Tuning - ultimate
-short shifter: Gary Moore / Three Trolls Tuning
-9000 clutch and flywheel retrofit (289mm vs 215mm)
-kevlar composite clutch disc: Clutchnet or Swedish Dynamics
-for 900s, 88+ 9000 Turbo brake caliper and rotor retrofit
-PCV and emissions systems removal
-throttle body de-icing coolant lines removal
-air conditioning system removal
-wideband O2 sensor
-Koni or Bilstein shocks
-lowering springs
-sway bars
-poly bushings
-short wheel base modification
posted by 199.213....
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