Discussion and questions related to the course Practical Dyno Tuning
Is it possible to do this another way with the engine in a jet boat without a dyno or do I need to take the engine to a engine dyno shop to have it done. I have just started to go through the starter package, this is a bit of a grey area for me.
Hmmm, if it is a relatively commonly used setup as used in wheeled vehicles, you may be able to find a map someone else is using and use that as a basis for your specific setup?
Otherwise, you will just have to do it the old way, start with part throttle and, logging it, work your way to full throttle and rpm.
Depending on your budget you could do what I have done and buy a combustion pressure logger, or possibly hire one, I know there are at least a couple of performance shops in Aus who have them, most likely many more, you might like to contact Unigroup in Sydney if you can't find anyone else, it really is the best way to do it especially as your cooling, intake and exhaust conditions will be correct (if running intake:pressure ratio tune you can get around that somewhat but tuning with as close to in use conditions is best). Once I am familiar with mine I intend to offer some form of consultancy for instrumenting hulled craft for tuning I think but it probably won't be for a year or two.
Obviously there will be load/rpm points you can't maintain in steady state but given the application you probably want loads you only hit in transient to be tuned that way, idle, low speed staging/flat stick you can obviously hold pretty well with the resistance of the hull. If you can find a solid "sea anchor" you could probably tow one on a ski rope setup to slow things down a bit too.
There was a guy on here looking to sell a TFX unit second hand a while ago. I bought myself a Plex PCA2000.