Aquamist HSF3 and J&S Safegaurd install

[b930]

Some new toys for my 930. First up J&S Safegaurd Intercetor knock controller. Sits between my ECU's 6 logic level sequential ignition outputs and 4xbosch 3 channel igniters (dual plug). It works superbly. It is set up to retard individual cylinders up to 10degrees, and has a gauge showing what its doing, and of course an output for the ECU to log. Its sitting under a rear seat.






The other is an Aquamist HSF-3 water injection system, the latest offering from ERL in England. A very nice unit that tracks injector duty cycle and uses PWM for water control.



A lesson learned with this is the long narrow tanks from Aquamist don't fit. I ended up using that in my mk1 escort (that runs an AEM water inj system), and took the tank from the AEM system for the 930, located by a bracket to the brake booster.



The control unit went up on the back shelf and some hardware in the engine compartment (fast acting valve, injectors etc). It uses a turbine flow meter to verify throughput and trigger failsafe's if necessary.





The net result of all this is that I was able to finely tune my timing by gradually adjusting it (a pot set up to add subtract timing), logging the systems (AFR, timing, IATs, water delivery, knock). Its allowed me to add around 3 degrees at peak torque and as much a 5 degrees ramping up running to red line past peak torque. The J&S also confirmed my motor can run a bit leaner with water, around 12.3 versus ~11.5 without water, boosting 20psi. Any leaner that that and I'd start seeing knock. The IATs running on 30+degrees C days actually go lower than ambient with water injection....very cool.

Next up with be some dyno runs. Some of the supra guys running J&S were seeing trace knock on the J&S well before dyno det cans picked up knock so it will be interesting to see how the two compare. Also, dyno's around here are hopeless at getting air through 930's rear intercooler, water injection will help prevent heat soak in the dyno cell.

The car feels absolutely ballistic with the extra timing, slightly leaner mix, and cooling effect of water injection.

[Tippy]

I'm jelly. Good stuff for protecting our engines.

Assume you had one or two cylinders that knocked before the others?

[Hams930T]

Do you have E85 available in your area?

[boosted79]

What knock sensors did you use and how did you mount them?

[b930]

The J&S will indicate which cylinders are knocking, there are 8 LEDs on the unit itself to indicate which channels are being retarded. The dash display also tells you how many cylinders are being retarded and by how many degrees. For example, of the 10 LEDs, if two LEDs appear, one at position 3 and one at position 6 are, that means two cylinders are being retarded, one by 3 and one by 6 degrees. The LEDS quickly run down to the the left as retard is removed. With this 'overlay' method you can quickly see any knock activity, but wont know which cylinders they are. The main advantage is timing is not pulled on the whole motor if it does not need to be so you don't see big power reductions like most factory systems.

The knock sensor comes with the kit, you can get either 10mm or 8mm bolt mount. Its mounted under the rear 'leg' of the throttle bracket bolted to the engine, the rear 'leg' is shortened by the thickness of the knock sensor. This area is directly contacting a large rigid area of the block, ideal for the knock sensor. I also used this location when I ran an SDS system years ago and it works good.

I have played around a bit with E85 but was not keen on it as meant running my injection system near its limit (needed around +25% on fuel duty cycle, it was already pulling near 75-80% at full power @ 20psi), and its potential corrosion effects on my old fuel system, although many say E85 in Australia is treated with inhibitors and use it regularly.

Being in a hot climate, high IAT and intercooler efficiency is also a concern that water injection addresses. I never got to tune E85 with the knock system as I switched to water injection and now have the car primarily mapped for premium 95RON fuel and then secondary mapping for water injection. Note I am only using pure distilled water, and not methanol/water so I am not exploiting the system to the full. I think water / meth would give similar anti knock properties to E85 but with additional charge cooling. I used to use screen wash in my water injected cars when I lived in the US as that was laced with methanol, but no such luck here.

I'll post up some timing maps for the car on water and without it.