More water = ecu pulling timming.

[cmj]

I made some changes to my setup, and increased the amount of water. I knew that a retune was in order and logged some wot runs before the retune. The ecu was not happy and pulled timming, dropping my aim(WRX) to 2. I knew before hand that I would need to pull more fuel and add timing but i did not expect the ecu to pull timing.

Any ideas why this would happen?

[Richard L]

This is very strange! :shock:

[cmj]

I know, it does not make sence.

I upped the psi from 100 to 150 and went from a .6 to a .7.

[Richard L]

By increase your Shurflo pump to 150 may not necessarily yield extra flow from the same nozzle.

Please tell me how you trigger the system as I cannot remember your set up. Do you run the pump continuously?

[cmj]

I had a .6 jet right before the TB and switched it out with a .7 jet. I have now plumbed the .6 jet pre compressor but it is not in use yet.

My setup was a shurflo pump with a return line and valve set to bleed off just enough psi to keep the pump from switching on and off, an inline solenoid and an HSV. The new setup for the time being(my HSV is out of commision right now) is the shurflo with the switch bypassed, solenoid and pressure switch. the pump fires at the same time the solenoid opens.

These changes caused my ecu to pull 4 deg in the 4000 rpm range.

[hotrod]

How long are your lines from the pump to the solenoid and nozzle?
Do you run a pressure accumulator of any kind?

You may have just enough pressure build up delay that your not getting good atomization on that nozzle just as it turns on.

My guess is the engine rev's fast enough through the critical max torque rpms, that your too lean ( or have inadequate water flow) as the pump comes up to pressure and fills and pressurizes the lines. I would suspect that you need to trigger the pump a bit sooner to give it time to build pressure.

With a return bleed system your pressure rise might not be fast enough to get the water spray working at design flow in time to prevent detonation.
As a test I'd suggest you try lowering you trigger point so the nozzle has more lead time to get up to flow. With that larger nozzle you may have slowed pressure rise in the system just enough to push you over the edge.

Larry

[cmj]

This is not an issue with not having enough water, I?ve done the test in 4th gear and the pump is on a good 3 seconds before I'm in the 4000rpm range. Also I'm not running a return bleed right now.

This setup has caused about a 30hp loss with current tune, this loss was not caused by the ecu pulling timing as I have a UTEC and do not run ecu timing in open loop. I?m starting to think that a 150psi shurflo and a .7 jet is just way too much water with out an HSV.

[Richard L]

what are the chances that the jet is clogged?

[cmj]

The jet is not clogged, I checked. When the pump activates the car almost bogs, I'll start retuning this weekend.

[Richard L]

Just remembered, didyou managed to repair the HSV?

[cmj]

No, I didn't. I had the diaphragm in my shurflo go out on me allowing the water to migrate into the pressure switch causing electrolysis to all nearby metals in the system including the hsv. This happened over a long period of time and I did not catch it until the switch on the pump failed. I have now changed to a Viton diaphragm from the stock Santroprene unit so I will not have to worry about this in the future. At this point I feel that it would be safer to purchase a new one(when I have enough cash to burn), I might even try a 300hz. industrial unit.

[cmj]

Well I tuned and tuned and tuned with no luck, I checked every thing and I still did not find out why my ecu was pulling so much timing. I finaly used up all the fuel in the tank and went out for a refill, well turns out I had a tank of VERY bad fuel.

In the end the car is now tuned but its just not the same without the hsv.