just a quick question. im not that familiar VRs, im looking to get a VR Corrado i understand its an ABV engine which apparently never changed from the (so called) OBD2 spec. does that mean its run on a dizzy or are there coil packs? does anyone know if there are variations in management and if so are there any distinct advantages? its a 1996 N reg car
The Corrado only got "OBD1" spec. 92-93 it was dizzy with a "2+2" VAGCOM connector. 94-95 it went coilpack with the proper 16 pin "OBD2" port 1995-96 it got an immobiliser (CP suffix ECU) and a 4 pin film MAF instead of the older 5 pin platinum wire MAF. I and others have retrofitted the OBD2 spec hardware to an ABV engine easily enough and I recommend it personally. OBD1 ABVs are renowned for stalling at junctions and other minor part throttle irritants. The semi-electronic throttle and better ECU of "OBD2" make it a far nicer engine.
excellent, thats a start for my VR knowledge. does obd2 spec hardware involve a new ecu also? does that have to come from a syncro mk3 vr6 as the rados never moved on from obd1?
It certainly does. From the donor car (any 96 on Golf VR6 will do) you need the following: Complete Engine harness, unchopped Intake manifold MAF, although the one from a 95-96 Corrado might work Throttle body Key reader (clips onto the ignition barrel) Key Immobiliser transponder box Engine ECU Lambda probe If you want the immobiliser deleted from the ECU, United Motorsport or Stealth Racing can do this or you can do as I did and just gaffer tape the Golf's key into the reader and shove them under the dash somewhere Either option means you can keep the Corrado's original key. I did it about 5 years ago and I paid ~ 250 for all that back then. Not sure how much a complete set is these days but the better VW dismantlers out there are well clued up on "OBD2 conversions" now.
but, wont the golf ecu have software for the 2.8 engine rather than the 2.9? im getting into this a bit further than id like at the moment, ive not even bought the car yet. i think id stick with the standard ecu setup and fiddle with the enginebay until the car worked correctly before changing it all
Yeah but the differences are very minor. I ran standard OBD2 on my standard ABV 2.9 no problem. The OBD2 ECU is far better at adaptation and has more lambda adjustment authority, so it can certainly self tune around the little 100cc difference, not that that actually makes any real world difference anyway. A decent 2.8 will be all over a 2.9's ****.
If you think about it, stock fueling tends to overfuel at approx 5000rpm upwards for component protection, so as not to have mega high EGTs. Making the engine breathe better whether via intake / exhaust should work well with a setup that tends to overfuel, in this case it was by adding an extra 100cc
Plus there is no such thing as "OBD2" here in Europe. The actual OBD2 capable ECUs have different part numbers to euro calibration as well as different hardware, emissions and cat heating philosophy.. The ABV and AAA in the Corrado runs a Bosch M2.9.1 system. "OBD1" here is irrelevant as the US and North America never got this engine and the calibration was set for 98 RON. The later M3.8.1 ECU that powers my post 95 Golf 3 can be fitted to a Corrado, but you may find very little benefit to performance and none for WOT. The car from the plot above was swapped from M2.9.1 to M3.8.1 and delivered similar WOT performance. If you wnat to know more about the systems please ask more and I can help as I have been through the calibration and its strategy and no a thing or 3 about it. For more on OBD/EOBDregulation just ask Ben S .
. And that depends on the state of the ABV engine. The plot above when to comapred to my vehicle, which has an reworked calibration, shows very little difference in peak power and peaktorque at WOT. My car has got a bit more response leading up to the max load due to bespoke road mapping. However the 2.9 engine still has a bit more torque as the engine accelerates to its peak VE. These plots were generated back to back the same day when my car was used as a correlation vehicle. If the ABV engine is fine tuned via proper calibration both on road and on dyno, the response, torque and power of the 2.8 will be no match.
Yes, as you keep saying. "OBD2" is just a short way of referring to Post 96 Golf ECU and associated hardware. You're not the only person who knows a thing or 3 about engine management
It is incorrect and has led to a whole bunch of people (incorrectly) referring to their cars as "onboard diagnostic 2". As Toyo said, this is for US spec vehicles
"OBD2" is an ignorant way of describing the Post Aug 95 M3.8.X system that runs on VAG vehicles which includes the 12v VR6 (Including "35" Passat 2.9 VR6 Syncro) and 1.8Ts. Because it is an adopted slang used on most forums, imported out of the US, to describe the Motronic controller update to 16 bit, does not make it the correct. This nonsense also occurs in the Euro BMW community, particularly with E36 vehicles when describing PCMs. You are correct, there are several folk on here who know about OEM engine management, the way it controls the engine and how this relates to emission monitoring and diagnostic function. Hence in this company it would be best to call the controller the correct term particularly for new folk who ask questions.
Matt, The controllers: M2.9.1 8bit = Coilpack engines on models pre August 95. M3.8.1 16bit = Coil pack engines post August 95, fitted to Golf 3, Transporter, Passat. The "OBD2" thing can also stem from the fact that the diagnostic connector in post 95 vehicles, changes to a SAE1962 16pin connector. Even though this connector is similar to PCMs ending in "259" the PID data available the K-line is reduced for Euro spec vehicles.
what ecu number is the 3.8?? I have the bottom end and loom from an R reg car with an AAA engine code so i want to get the correct ecu to suit
