S300s S3 chipset (1985-1986 32V)
Take your S3 with X-pipe from 288 crank horsepower to around 350! Average 330 torque from 2500-5500 RPM!
Combined with higher fuel pressure from a S4 fuel pressure regulator (55±3 psi, 87 only fits S3) for better fuel atomization and lower injector duty (max email@example.comK rpm), the S300s chipset is an electronic supercharger! Faster rev'ing. Instant response. Separately tuned fuel chip for automatic and manual for maximum performance of each type. Extensively tested with stock cats and X-pipe. (X-pipe recommended for max power but not required.)
At wide open throttle, the stock/AT/eBay fuel chip is too lean in the midrange for max torque, and too rich at high rpms for max horsepower.
With low stock fuel pressure (36psi), injector duty is >80% before 5000rpm, and hits 100% well before redline!
The AT/eBay (all eBay are AT copies) fuel chip has a crude fuel dump at ¾ load in the cruise map, but is otherwise stock.
Stock EZ and LH WOT maps mean AT/eBay chips cannot dyno higher HP than stock, and the rev limit is stock @ 6400 rpm!
One fuel chip for automatics and manuals = lower performance for each. (EG. torque converter = different gear ratio.)
Version: 4.0 - the first 'clean sheet' chipset for 85-86.
What you thought a 4-valve/5-liter would feel like...awesome!
New programming in 4.0 = high precision fuel and ignition maps. Completely retuned from 700-6400 RPM (factory maps 500-6000).
Custom airflow and RPM scaling with >double the rows and columns dedicated to specific S3 (not S2 or SAAB!) torque and horsepower peaks.
HP/TQ valleys were a focus as well for increased overall power, plus newfound power at previously unavailable/untuneable RPMs.
Most notable, more new power in the 1300-2400 RPM range (perfect for autos), with markedly less pedal required at cruising speeds.
Fine control of fuel and ignition allows for super performance with lower octane fuel. (Follow recommendations.)
Sport Mode enabled/disabled automatically, disables O2 sensor for constant part throttle power.
- Higher cold idle speed
- Custom RPM/MAF scaling
- Higher rev limit (AT 6550, MT 6720)
- LH harness plugs enrich WOT (bad fuel or racing) (photo)
- MAF CO adjustment adds to WOT fueling (stock only affects part throttle)
- Load x AirTemp predictive retard map for max power possible w/o a knock sensor, and no WOT 'bog'
- Air and coolant temp maps rescaled for active ignition advance adaptation at running temps (165-195F/74-91C)
- Sport Mode | O2 loop bypassed over 2000 RPM at high load, anytime over 4000 RPM
- Sport Mode | latched until load is reduced (flat AFR <14:1 = consistent torque)
- Manual | idle: 700 RPM, max: 6720 RPM, decel fuel cut: yes
- Manual | slightly higher idle speed for better idle control, higher rev limit (lighter weight driveline)
- Automatic | idle: 680 RPM, max: 6550 RPM, decel fuel cut: no
- Automatic | no fuel cut on decel = RPMs do not drop to idle = better throttle-back-on response
- Intake refreshed
- Rebuilt MAF (CO 382 ohms)
- New CPS (crank position sensor)
- New TPS (throttle position switch)
- Cam timing: 0° (-2|0 cold, PK32V'r)
- New OEM O2 sensor (not universal)
- Check for vacuum at EZ at idle (17-19"hg) (photo)
- Accelerator cable taut (adjust at firewall under airbox, 13 and 17 mm wrench)
- Automatic: adjust transmission cable until socket drops straight on ball (stock)
- Professionally cleaned stock injectors (24#)
- Bosch WR5DC (7992) (stock WR7DC)
- MAF screens installed
- 87 S4 FPR, 92811019802/Bosch 0280160262 (photo)
or 88 S4 FPR, 92811019804/Bosch 0280160297 (with hose adapter)
or 928sRus.com sells a billet FPR with a 3.8 bar replaceable insert
89 octane or higher:
- 89 US/AKI (92 EU/RON)
- 91 octane (95 EU/RON) racing or extended full throttle driving (autobahn, dyno)
- EZ harness plugs (green wires) are for emergency use only for poor quality fuel. Shorts air temp sensor input = hot.
- LH harness plugs (brown wires) enable extra WOT enrichment for hot weather or heavy full throttle driving (autobahn, dyno) (photo)
86.5 manual w/X-pipe, electric fan, other simple mods, V4 vs. same car, stock w/X-pipe, RMB, AutoThority chips
STD 321 HP, 324 TQ
- LH chip
- EZ chip
- ecu labels
Rennlist pictorial install thread - PorKen chips install
Buy It! (stocked)
WOTpot - user adjustable WOT fueling w/S300s V3 chipset
Easily dial in the full throttle air fuel ratio on the dyno*, or logging with a wideband O2.
Individual MAF voltages vary at WOT. Precisely adjust for the safest AFR to make max power (<13.0 average recommended).
Installs in LH connector.
*Note: typical (dyno) tailpipe AFRs are at least 0.5 point leaner than measured at the X-pipe
PDF manual - WOTpot