Turbo speed sensor

[Wez]

Hey All,

Owen developments list a turbo speed sensor priced at £352.21 +vat.

http://www.owendevelopments.co.uk/produ ... ?prodId=21

[pat]

This shaft speed sensor was designed to be used with "conventional" rev counters, and as such has a few caveats when used in conjunction with a Solaris ECU :

From the ECU's perspective :

• One pulse is expected per blade
• The number of blades is defined in the sensor setup, so that the shaft speed can be calculated

From the Owen / Oxford RF shaft speed sensor amplifier's perspective :

• The amplifier needs to be told how many blades are on the wheel
• It only outputs a pulse every 10 revolutions

This can cause a problem because the signal into the ECU will be way too slow and a failed sensor condition will be detected. The suggested workaround is to define the number of blades in the amplifier as ONE, and to use a non-integer multiplier in the ECU. For example if a turbo has 12 blades, it will generate 1.2 pulses per revolution, or 6 pulses every 5 rotations. If we define the number of blades per revolution in the ECU as ONE then it would read RPM*1.2, so a Speed Scaling multiplier of 0.8333 must be set to scale the RPM signal back down and read correctly.

Once a satisfactory speed signal has been acquired, it will be possible to log it for later analysis / comparison to expected or predicted operating point on the compressor map, and also use it live for turbo protection with the turbo speed strategy, which is part of the standard boost control strategy.

Cheers,

Pat.

[Wez]

Are you aware of any other turbo speed sensors that will work?

[Wez]

TurboDynamics appear to be cheaper at £260 +vat

http://www.turbodynamics.co.uk/shop.htm

[pat]

Wez,

The Turbo Dynamics one appears to be the "Garrett" one, and may be beased on different technology to the the Owen / Oxford RF one. Prodrive also have one, but at UKP 2k a go, they are really not intended for the man on the street who wants their road car to go quicker than it left the factory

There have been various optical versions over the years, but most performance air filters don't filter all of the dust, and that can cause issues, either with reduction in the reflectivity of the wheel or indeed clogging up the sensor. The RF version doesn't suffer from this problem. I'm not suggesting that the Owen one is the only decent one out there, but it is a known quantity, it works, despite its foibles, so it's one that can be recommended. If someone wants to try the TD / Garrett one then we'de be happy enough to assist in setting it up, and of course interested in feedback, both short and long term.

Regards,

Pat.

[Benkku]

BorgWarner has an rotational speed sensor for the EFR series turbos (PN 179430), this could be adapted to other compressor housings also. Eddy current measurement principle, blade counting, output square wave TTL 50% duty cycle, frequency proportional to speed. Cost fex. 140 USD, from Treadstone Performance.
http://www.treadstoneperformance.com/pr ... kit+179430