Tuning a JTD
Nige
I assume that by 'we can do that' that you have a tuning company. £300 seems a lot. What do you do for the money?
One way to get more power from a Gen 1, and possibly gen 2 bosch HPCR setup (EDC15/16) (maybe problems with the Pump throttle (MPROP) on 16...?) would be to add some resistance into the HP rail pressure signal, and slug the signal to the turbo, so that you run higher rail pressure (therefore more fuel as you frig the ECU calcualtion for injection duration by uping the pressure. Same duration - higher pressure = more fuel), and you run higher boost, so more air + more fuel = more power.
My guess it you use some variable resistors and then 'tune' them on the road until you get excessive smoke, then back off a little.
What do you do with the EGR? my guess is you will leave well alone, but this may risk EGR valve failure as it may now be open at higher exhaust temps, therefore my fail, as they are a little sensitive to this.
So my question is, is this how you are tuning the JTD? This would be my best guess, but I'd love to know exactly how the professionals are tuning these cars with the 'black boxes' you see advertised.
If so, what testing do you do afterwards? What peak cylinder pressures are you reaching? what exhaust temps are you recording? To me there would be too much expense involved in doing these tests, so how do you judge whether you have gone a step too far?
How do you know the torque limit for gearbox durability? This is often a limiting factor with diesels. How do you check Turbo speed? what about overspeed proteciton if you increase altitude?
If you can't answer these questions, then £300 is a bit much for a few resistors and few minutes installation time, considering the risks you would be taking with this cowboy approach. This is ok for a racing application, but for real world durability, especially for those who regularly run full load, this is a little dangerous.
Not to mention the emissions performance - not very enviromentally friendly....
Of course I apologise if you have used a more thorough method to develop your tuning system, and then I take back the 'cowboy' comment.
