I put this together...

Before:



Gutted out:



After:

 

Nice "sleeper" set-up. Should really appeal to anyone that has to pass DMV visual inspections.

 

The objective is to make an arrangement to send atomized water individually to each compressor. The path to the secondary compressor is opened only after transition and when the two turbo compressors work in parallel. You can see the solenoid valve mounted on the side.

 

i like it. it is always nice to see new ideas...

hc

 

Thanks Howard.

The objective is to measure the effectiveness of evaporative cooling inside the compressor. Hope those PJ nozzles will help...

My plan is to take T measurements at the air box and at the compressor out, pre I/C and compare with and w/o water. I could not find good data so I will be trying generating my own... we'll see...

- Sandro

 

Thats a cool setup.

Let us know when your done mucking around you stick two descent size jets in their.

 

ah,ah... don't worry i can swap nozzles in a breeze... let me start with these couple of PJ10 I got, I tested them at 130 cc/min each

 

That's clever, Sandro. Nice work.

B

 

Thanks Brian.

 

i alwasy thought the elbow into the second turbo was always crying out for a jet very close to the compressor wheel.

 

You are right. But the air box makes it easier to install the components, test, etc.
Some mist will be wasted onto the pipes walls though.

 

I like it, very good work.

 

Thanks Brent

 

ready to go...





65 micron filter and nice swiveling fittings





and now... you got FOG!







inside the cloud





and behind it

 

looks good man. I realize you're just bench testing now, do you have 2 solenoids you're going to run to have a staged system for each turbo?

I think you're the first person that's reported running preturbo on the twins, I'm curious to see how it works out.

 

My initial thought was using one solenoid valve only to align the "secondary water rail", to be actuated by a primary-secondary transition signal, as sketched below.

Today I had some siphoning at the "primary nozzle" after shutting down the pump, but the water tank was sitting high well above the nozzle. I'll have to take some measurement in the car and see if the nozzle will be high enough to break the vacuum. If not, I will need one more valve.

Transition signal below (taken from the PFC by adding a very high impedance Solid State Relay, not to add any meaningful current to the pin driver):



If I will have a siphoning issue, I will run the power to the WI solenoid through the same pressure switch I will use to start/shut the pump.

 

where are you getting the transition signal from, and is it constant the whole time after transition?

 

Pin 4R - Turbo Control Solenoid Valve(s) - it's on so long you stay non-sequential, above 3,000 rpm or more - adjustable with the PFC. See this thread https://www.rx7club.com/power-fc-forum-47/transition-signal-880346/

 

Very cool, I wondered if some of those could be used to activate different things. Lets say you've gone single turbo or something, could this pin be used to activate a relay or solenoid in that case? I'll look at the link you provided.

 

Yes, definitely. You just have to be careful not to increase the current through the PFC drivers (pins). I don't know what the limits are. NeoTuri indicated better not to exceed 1Amp. To play it safe, I am using a SSR. http://www.omega.com/Temperature/pdf/SSRDC100V.pdf The resistance of the triggering circuit in the SSR is very high, which limits the additional current through the pin to a minuscle 8 mA. A typical 50 ohm relay instead would add like 0.25 A, which may or may not be a problem. An other potential issue I just wanted to avoid dealing with, is that when a regular relay is switched off, there are EMF http://www.allaboutcircuits.com/vol_3/chpt_3/9.html which may or may not damage the PFC transistors. Probably not, because for instance the same pin I am using, already drives the two TCN solenoids, which are inductive loads as well. Most likely, the transistors in the PFC already have protections built in. I don't know. In doubt, I am using this arrangement, which may be over conservative. arghx for instance indicated (in the thread I referred to earlier) that he has been using relays directly connected to pin 3D and had no issues with that. So, it is likely that "I am thinking too much", and I could have just connected the WI solenoid (also about 50 ohm) directly to the the pin. Each of the the TCN solenoids should be about 40 ohm. So, with the two TCNs and the WI solenoid in parallel, you would have < 1Amp. Assuming the PFC drivers already have built-in protection against EMF, 1Amp should be not a problem for the PFC driver.

- Sandro

 

Although in the case of a single turbo the tcn solenoids would be removed so i imagine you could run about any small solenoid or relay directly from the pin. Are there any pins on the pfc that are boost activated? The one we have been refering to would make a good rpm switch, anything that would make a good boost switch? The voltage switch that was posted in the other thread looks pretty cool.

 

No...

 

Sandro -
Just try to keep the main mass of those things out of the air streem to keep the air flow numbers high. Those turbos blow a lot better than they suck...

Next time I'm in Summit we can put them on the flow bench and see what it does for the airflow

 

Thanks Aaron. Yes, I thought about that. To minimize obstruction, I placed the water rails a little behind and used extensions to bring the nozzles at the mouth of the hose openings, without sticking inside them. It shows somehow in the second pic. Nozzle jet is about 90 deg and wanted to send the mist inside the hoses, not inside the box. It's the best compromise I could think of...

 

I have been wanting to move my WI pre turbo. Right now its in the elbow but I have been struggling to think of a way to make the second nozzle come on.

Good luck and thanks for sharing!