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ECU location, removal and refit
David Boniface (Oxford Blue 1589) in Japan contacted the V8 Register for information on fitting an Optimax chip and how to remove the ECU. We put him onto John Barnes (Woodcote Green 0636) in Wellington New Zealand who produced this useful note based on his experiences of fitting an Optimax chip supplied by RPI in the UK. (Jul 02)

David Boniface contacted the V8 Register with a note saying "it seems that the RPI Optimax chip is well liked and I am considering fitting one. However a quick look indicates that to get at the ECU just to get the chip numbers, requires either moving or removing the AC evaporator unit and I guess removing/replacing the refrigerant. Any advice would be welcome". We put him in touch with John Barnes in Wellington New Zealand who responded with the following note.

I have an RV8 which was imported in May 1997 from Japan and like all RV8s originally exported to Japan it has air-conditioning fitted which I have retained. I have fitted an RPI Optimax chip which I think has improved torque and bhp but I know it has definitely improved petrol consumption. On a lengthy trip at Christmas at an average speed of 110kph up and down hills and on the flat, it averaged 32mpg.

I intend to put the car on a dyno in due course so I can see what the torque and bhp improvements are. Before I re-chipped the RV8 I put the car on the dyno and with some adjustments improved the bhp at the rear wheels from 120 to 141. This is about right for 190bhp at the flywheel. I removed the catalytic converters as they are not required in New Zealand and inserted a non-cat diode. The O2 sensors are off.

RV8s in Japan have the vacuum advance on the left hand side of the plenum chamber which means the timing becomes fully advanced on start up. This helps with lowering emissions but does not help performance. As with all cars imported from Japan, the vacuum advance pipe is moved to the right hand side. Thus at idle it has little advance - mine has 8 degrees at idle which rises to 28 degrees at 4,000rpm. Please refer to RV8 Workshop Note 60 "Advance and retard pipe" in Volume 2 of the series.

Removing and replacing the ECU needs no surgery and is simple. It takes 10 minutes. Please refer to my note below on ECU location, removal and refit. You must be very careful when handling the ECU. You will need a torx screwdriver to open it. See also RV8 Workshop Note 124 "More legroom for the air-conditioned". The photo below shows the right hand drain hose and the single bolt which holds the ECU in place. Before embarking on getting a chip you should contact Chris Crane, the head of RPI Engineering in the UK at rpichris@rpiV8.com, and seek his help and advice. They also have a very comprehensive website at www.rpiv8.com which is well worth visiting.

Now my checklist on ECU location, removal and refitting:

ECU location
1. Non air-conditioned RV8s - it is located on the passenger side under the fascia.

RV8 air-conditioning cover in place. Above the right hand drain hose, there is a single bolt which holds the ECU in place. (Photo: John Barnes)

2. Air-conditioned RV8s - it is located in the passenger footwell behind the evaporator near the bulkhead.

Removal & refitting on non air-conditioned RV8s
3. Removal. Release the clip and disconnect the multiplug from the ECU, then remove the two bolts securing the ECU to the fascia support and slide out. Finally remove the ECU.
4. Refitting. Reverse the sequence.

Removal & refitting on air-conditioned RV8s
5. Removal. Remove the two bolts securing the evaporator closing panel to the fascia and remove the panel. Release the left hand evaporator drain hose from the unit. At the rear of the evaporator unit, locate and remove one bolt securing the corner clamp (on the right hand side of the ECU) and slide the ECU to the right and down. The left hand side of the ECU has two locating lugs that slip into a frame to hold it in place when bolted up. Then release the clip and disconnect the multiplug from the ECU.
6. Refitting. Reconnect the multiplug to the ECU, slide the ECU locating lugs into place to secure the left hand side of the unit, and then bolt up the right hand corner clamp. Reconnect the evaporator drain hose and replace the evaporator cover panel and bolt up.

If I can be of any more help, please contact me at warn((atat))xtra.co.nz by email.

Footnote: In a matter of days, David Boniface responded "many thanks for your comprehensive email (Editor: which is reproduced as the workshop note above) which I read with Volumes 1 to 4 of the RV8 Workshop Notes series. I have a CD coming from the V8 Registrar with the latest working draft of Volume 5. I am aware of the vacuum pipe fix and bought a new pipe the last time I was back in the UK. However my car is due for its "Shaken" test next week - a thorough test every two years covering safety and emissions and so on) so I am not changing anything until that is passed. I had assumed that the ECU on cars with air-conditioning was in the same location as non-AC cars hence my question. However thanks to your help, I had my ECU out, opened up, chip numbers recorded and back within 15 minutes today and have ordered the Optimax chip from RPI in the UK. I also took the opportunity of checking the drain pipes were clear. Later this year I am going to order a new camshaft from RPI too".

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