Significant update this time.
For a while I have been pondering ECU options, the two main options I was considering was the MoTeC M84 and the Link G4 Plug and Play for the ST205. I did a lot of research and in the end decided to go for the Link.
This decision was based on a few different factors:
1) There are a number of respected mappers who can work with it
2) The plug and play design means there is no wiring work needed and no need for an adapter loom.
3) The Link G4 seems slightly more capable than the M84 and the software is much more user friendly from the time I spent looking at both.
4) The Link G4 was about £300 cheaper than the M84
I decided to use Thor Racing in Coventry for the mapping, this was also based on research, they have a good reputation and had a recent positive review from another member on here. My email discussions with them were very positive and they responded helpfully to all my queries.
So last Wednesday night I loaded up the car with my tool bag and overnight pack and headed upto Coventry, first thing Thursday morning I made sure the fuel tank was brimmed with Shell V-Power and then headed to Thor. On arrival we went through a few things for the courtesy car (a nice touch) and then I had a chat with the Mechanic who was installing the new Denso 860cc injectors that I had to fit. That done I settled into the waiting area with my laptop and hot coffee.
Whilst my car was having its injectors fitted there was an Aston Martin V12 Vantage on the dyno having some work done, it sounded fantastic and was quite a distraction from the work I was trying to get done. After a couple of hours the injectors were fitted and it was time to fit the ECU and start the process of mapping the car. I was really pleased that Peter (the chap that mapped it) sat down with me for about 30 minutes before starting the mapping discussing the various modifications the car had and my goals for the car. I explained that I wanted everything kept nice and safe and not to wring every last horsepower out of the engine. It was also nice to hear Peter comment that it was one of the nicest ST205’s he had seen and one of the most well thought out.
So the process of mapping began and whilst my car was nowhere near as loud as the Aston I could hear it merrily buzzing away in the background. After a while I used the courtesy car to pop out and run some errands and grab some lunch. On returning Peter came to give me an update on how things were progressing after the first couple of hours, the car was coming along but they had identified a problem with the boost in that the boost was coming on quite slowly and then not holding very well. A number of causes were suggested ranging from the cat that I have fitted to the actuator possibly being defective. It turns out that the actuator was to blame and this is costing the car a fair chunk of power.
Asking nicely I was allowed to have a quick peek into the dyno cell and take a quick snapshot of the car on the machine.
Mapping continued as lots of the lower boost areas and cruise sections could be worked on regardless of the issue with the actuator. By 5pm Peter was happy that I had something that I could drive away so I headed back to the hotel. The plan was to spend the evening driving the car around in different styles and different boosts/loads etc and then report back to Thor in the morning for some tweaks. So armed with my laptop hooked up to the ECU a notebook and my datalogger running I did about 100 miles of driving, noting down any odd points or peculiarities that occurred.
In the morning I had the opportunity to start the car from cold and see what the cold running was like. Returning to Thor I then spent about 45 minutes chatting through the various issues which to be fair were mostly confined to the cold start and idling areas, about 90 minutes was then spent tweaking various areas of the map to improve.
I left Thor at about midday for the drive back to Hampshire. The car is fantastic to drive, I am really pleased with the cruising and low boost performance, the full throttle experience is also quite dramatic with the car accelerating hard in all gears. There is still some tweaking needed to the idle and I plan to investigate the idles stabilisation valve as I have a suspicion there may be a problem here. So the end result was I left Thor with 297hp at the hubs which should be approximately 360ish or a little more at the flywheel. This was running 1.35bar of boost. The torque being made is also strong with 270lbft at the hubs which I guess is approximately 325lbft at the flywheel.
Peter seemed confident that there was plenty of scope to run more boost through the engine so I am hopeful that at 1.4-1.5 bar the car will be making even more power.
So the plan at the moment is to spend a month continuing to drive around whilst logging and noting any issues, then to return to Thor for a few different bits of work to be carried out:
1) Additional mapping at higher boost with replacement actuator (I’ll be fitting a new actuator and have already sourced from Turbo Technics)
2) Fitting of wideband lambda sensor and reconfiguring the Link to run this.
3) Utilising some additional outputs on the Link to drive the engine cooling fans as these starting up seemed to be causing a couple of issues at idle
4) Fitting of a new boost control solenoid to allow the Link to control boost rather than my Apexi AVC-r which is controlling at the moment. This should provide a better setup as the link will be in control of most of the variables.
So in summary, so far:
1) I’m really pleased with the setup and service, I’m annoyed I didn’t get this done sooner as I think even on a more standard car it would yield good benefits.
2) Having a standard airbox, a standard chargecooler and a catalytic converter is not a barrier to creating a decent performing fast road car.
3) The new chargecooler radiator has shown a significant reduction in charge temperatures such that running temps are now in the order of 20 -25 degrees whereas in similar weather conditions before I would easily be seeing 40 deg C. The fluid temp is also lower rarely exceeding 17 or 18 deg C at the moment. So whilst an FMIC may give better temperatures an OEM system in tip top shape certainly seems to perform quite adequately.
Alright – that’s enough of an essay, a gold star if you have stuck with me this long!
Cheers folks
and Kris will admire your front Cusco brace I'm sure 
