View Full Version : Measuring turbine shaft speed

18th March 2004, 10:27
Pavlo mentioned he would be doing this some time ago, but nothing ever came to fruition.

I am wondering how plausable it would be to have a working system in place by the tme I go on the dyno in under a month (pg)

Any thoughts?

Andrew Carr
18th March 2004, 10:53
Duncan Grant had a working prototype in his GT-B.

Might be worth asking him.


18th March 2004, 11:15
don't know who he is.

18th March 2004, 11:28

Your pectel should not have any problem with this, it's boost control system will happily run closed loop on shaft speed targets. smile.gif

You simply have to get someone to engineer an optical shaft speed sensor setup into your turbo before the dyno day.

Basically, the tricky bit is engineering a sensor setup into the turbo. You would need optical fibre/s to feed light in, a suitible mark on the compressor or its shaft (maybe on a turbin blade, maybe on the shaft itself) and another optical fibre/s route to pickup the light level change events.

Once you have this stuff in the turbo, the rest is pretty straightforward, being mostly just a light source and a fast photoreactive sensor of some sort.

I would contact some turbo specialist companies and ask them about fitting such a sensor system, I suspect you might find that some of them have dealt with such work for the rally teams... there might even be some clever premade sensor unit you can get hold of. smile.gif

18th March 2004, 11:40
yes it works nicely.

Reflective optical fibre transceiver on compressor blades. They cost about 90 and can be got from RS.

18th March 2004, 11:51
That would do the trick. smile.gif Might put the compressor wheel off balance though. ;) smile.gif

18th March 2004, 12:06
Yes moray, probably better to put the fibres on the compressor cover and just let the wheel deal with the light being aimed at it.

I haven't looked in detail, but if you can get one with 12v supply and TTL out it would be easier. All I have are 24v supply with push-pull output. Fibres are expensive though for what they are. Typically they are polymer ones, and have a m3 or m4 threaded barrel at the business end. SO it's a case of drill/tap compressor cover and mount flush or sub flush to inlet tract.


Andrew Carr
18th March 2004, 14:08
Originally posted by Adam M:
don't know who he is. What Paul and Moray have described is what Duncan has done.

He posts on here sometimes, with your big brother moderator powers you should be able to track him down :D