Hello, I own 1991 Audi S2 coupe with 2,2L 5syl 3B engine, and my main goal is to make it run on VEMS and get power between 350-400BHP. Right now my best ET at 1/4 mile is 12,82 seconds.
Engine
- big intercooler with opposite direction air flow, by-pass in new location and drilled intake manifold.
- Intake: AEM 4" air filter
- original K24 7000 turbo
- I recommend some uptodate turbo design (garret ?) not K26/27 like MembersPage/MarcellGal/PowerAndTraction where turbo wakes up a bit late (above 4200 RPM in gear 2) for the power (406 Hp)
- Exaust: RS2 manifold, wastegate wiht stronger spring (old 10VT audi one), stock downpipe, straight through pipe to last original silencer.
- Fuel: stock fuel pump but modified elecrical system, mallory FPR.
- Gauges: VEMS Round WBO2 and EGT (2mm EGT sensor, RPM input (signal from ECU wire, setting 5 and 229), analog input for boost (settings below), analog output for stock ECU NB lamda), autogauge boost.
VemsAudiAan shows a straightforward wiring recipe for this engine, wether
- using motronic ECU
- still needs some wiring, eg. WBO2
- using v3harness
- or building custom harness
- best fit, but most work and likely the most costly as well
for ignition upgrade, you can either go distributerless, eg.:
- apply a 2x2 wasted spark module to drive ign2,5 and ign3,4 like MembersPage/MarcellGal/PowerAndTraction (ign1 driven by factory ign transformer)
- apply AAN-type ignition: power output stages + transformers
- or without power output stages, just the transformers (driven with power "IGBT" output, of course)
- use 5 logiclevel COPs (not recommended, these COPs don't live long in high performance engines)
- or use 1 channel CDI and keep the distributer (make sure it is positioned well, especially if using ALS - not recommended though)
The most appropriate ECU:
- assembled v3.x
- 6 IGBTs + 2 logiclevels
- write in the order note: "255 Ohm logiclevel output" to allow even for the (otherwise not recommended logiclevel COPs)
- with the 4 stepper channels, this allows up to 6 logiclevel and 6 power outputs
- no 1 wire
- 30V flyback
- primary trigger=VR
- secondary trigger=auditrigger
- 300 kPa internal MAP sensor
- or 400 kPa, but without serious internal engine upgrade higher than 1.8 bar boost is not feasible anyway
- no screws (easier to mount in the audis without screws)
Chassis
Brakes: 4x zimmerman discs, ferodo brake pads, Motul RBF600 brake fluid. Front brakes are waiton for upgrade, alredy buyed wilwood 4 piston calipers and audi A8 320mm discs.
Suspension: 4x kony yellow shocks, original springs are wating for lowering ones.
Body: The car got new paint a year ago, for better cooling it has modified RS2 replica front bumper, a little wider rear bumper, loesed lower door covers, tinted windows.
Other: 034 short shifter
Plans:
- Need to change the 2mm EGT sensor with 6mm one.
- especially if the sensor is before the turbo (although I guess it is after the turbo, in the manifold in the factory place)
- Bigger MAP sensor for boost logging.
- Change the ingniton system and eventually VEMS ecu (this takes for some time).
Turbo update is already in my plans, garret GT3071r i think, but all this comes with VEMS ECU.
The EGT sensor replacement is becase it is now in manifold, wiht old manifold it was after the turbo.
Today I started to "play" with boost logging option.
First i needed to measure voltage @ different pressure points. I had precise boost gauge and compressor with variable output. I connected the gauge to compressor and started to measure difrent pionts with stepping 10kPa at 100kPa to 200kPa (200kPa is orginal boost MAP) now i writed all the numbers and from them calculated average step (31,5), thats what I came up:
At athmospheric pressure it shows @gauge 1300
@ 0kPa - 985
@ 10kPa - 1016,5
@ 20kPa - 1048
@ 30kPa - 1079,5
@ 40kPa - 1111
@ 50kPa - 1142,5
@ 60kPa - 1174
@ 70kPa - 1205,5
@ 80kPa - 1237
@ 90kPa - 1268,5
@ 100kPa - 1300
@ 110kPa - 1331,5
@ 120kPa - 1363
@ 130kPa - 1394,5
@ 140kPa - 1426
@ 150kPa - 1457,5
@ 160kPa - 1489
@ 170kPa - 1520,5
@ 180kPa - 1552
@ 190kPa - 1583,5
@ 200kPa - 1615
Gauge settings ate: linear curve, calibration is 255, offsett is 0
From all that I generated formula to get kPa for logging:
( value - 985 ) / 3.15
and inserted it to the round.ini file.
This log file shows that everything should work fine: 