Member Profile - Yowie's SH Forester XT

[bigBADbenny]

Keen to try this mod as I have an old school AutoSpeed waterspray controller to install, potentially with a Shan Motorsports spray bar and pump kit.

Plus an old school obdii gauge that also has dual 0-5v displays.

[Yowie]

Keen to try this mod as I have an old school AutoSpeed waterspray controller to install, ...

My gauges are these beasties http://thesensorconnection.com/egt-elec ... ge-display

There is standard wiring for an alarm to be triggered, so to my non-electronics-genius mind there is the potential for other things to be triggered too (eg water sprays).

Of course the gist of the Autospeed controller is that is is more sophisticated than a simple "hot triggers spray" circuit.

[Yowie]

Finally, an easy place to put the sensor-receiving fitting (hot side).








I moved the steel intercooler support bracket from the bottom to the top of the rubber mount on the intercooler (about 15-16mm rise).

This meant that the bracket needed shimming by 16mm and substantial other clearance work to still fit, including elongating the bolt holes at both ends.



Shown top to bottom is:

- top ground off flat (welded nut removal not shown)
- top (IC) hole elongated downward;
- blowoff valve body clearance grind;
- blowoff valve lower bolt access clearance grind (good for hex keys only, not sockets)
- wiring loom sharp-edge relief
- enlarged big holes (manifold end)
- 2x small holes for M4 bolts to hold shim pack

To the left of image you see the 6mm and 10mm alloy shims (the latter being threaded M4) as well as the steel top-plate for neatness. The idea is to have the bracket remain as one object (all bolted together with the shims) so that intercooler removal and re-fitting is not more frustrating than it needs to be. With the grinding compromising the OEM galvanised finish, painting with chassis and roll bar paint was in order.


Assembled shim pack and replacement longer bolts shown:




Replacement blowoff valve bolts with H5 hex-key headed bolts was a good idea so that BoV removal/attachment with the bracket in place was still possible:

[Yowie]

The hot-side K-type thermocouple probe installed:




Nothing is ever as easy as you hope. This clearance slot needed to be cut in the OEM engine cover. What looks like an error at the bottom of that slot is actually *ahem* a complicated engineering-reasons thingamagig you wouldn't understand so back-off ok!






[All temp observations below on the assumption that the sensors are reasonably accurate and not overly affected by the sensor hardware heat-soaking. Of course either/both could be a factor.]

Startup temps with everything ambient. Interestingly, after startup you get a brief period of sub-ambient temps as the heat sink effect of all that cool aluminium does its thing for a while.



The following photo was taken after shut-down, so the cool side is starting to heat-soak. Typical driving sees the cold-side within a degree or two of ambient temp (as shown on my OBD2 display). Once the turbo is warmed up the hot-side didn't really drop below high 40s or low 50s for most of the drive. Short low-boost stints would see the hot-side go up to the ballpark of 70 degrees.



The recorded peak temps shown below (47 degrees cold-side, 113 hot-side). This was during a full-boost (17psi) hill-climb lasting (say) 5-7 seconds. As you can see the little VF46 is getting out of its efficient zone and the heat-sinking effect of the stock intercooler is getting saturated. It will be interesting to see how hot things get for a longer boost stint - eg the main straight at Ipswich Raceway or the nearby dirt track. Temps returned to normal fairly quickly after this blast.



From the small amount of temp-monitored driving I've done so far, the stock intercooler is very impressive at holding the cold-side to ambient even with the VF46 sending manifold pressure to atmospheric-5psi ranges regularly.

Obviously for a sustained power run the stock intercooler and the second-smallest OEM turbo (of that generation of Subarus) have their limits in terms of heat management.

Thanks for reading.

[bigBADbenny]

The oem Sanden cores are said to be great for shedding heat/heat soak resistance: super light weight and tube and fin efficiency.

The weak point being the end tank crimps, and there’s solutions for that too.
I just need to source or locate some ally channel that locks the tabs in re-crimped position…
And then make caps for the ports to pressure test the cooler at high psi: sanity check.

Got a pic of the bare sensors?

From all the insulation they appear to be safe for a higher temp range eg exhaust use?

Fast reacting thermocouple sensors are a thing, the most basic expression being simply twisting together the ends of the resistive wire pair.

I’d say fast reacting have a very thin exposed metal web between.

Oem have the join suspended in resin… and this type is also available for off the shelf TC’s.

More insulation just means the output is more biased towards trending than instantaneous, and the sensor should last forever and be completely airtight in the gland: bonus!

I used TC’s daily for monitoring furnace and workpiece temps when I had a heat treatment technician job.

For steel workpieces we used a TAU, thermocouple attachment unit, a portable resistance welder to attach each resistive wire pair to the workpiece within a 3mm radius. Not sure if this would work on aluminium tho.

This approach measures the parent metal not the airflow stream so again it would be biased towards trending, not instantaneous output.

[Yowie]

Got a pic of the bare sensors?

There is a pretty good close-up of the tip in one of the pics here: http://thesensorconnection.com/category ... emperature

This is the fluid set I also bought (ATF monitoring is the next project): http://thesensorconnection.com/fluid-te ... e-assembly

From all the insulation they appear to be safe for a higher temp range eg exhaust use?

The supplier seems to specialise in Exhaust Gas Temperature (EGT) probes. With all the steel braid sheathing of the stock air-temp product I wouldn't rule out EGT origins of their air-temp product. I added plastic braid to the steel braid so it doesn't cut things on the car in half. I added some Jaycar high-temp braid to the hot side probe (up to the firewall, after which it is plastic). Probably unnecessary but does no harm.

[Yowie]

A few Dirt Day photos from February.

[Stifull]

That looks like you had a lot of fun. It's good that the Foz come stock with mud flaps so that having a bit of fun in the dirt doesn't damage the paint. I am looking for a set for the Liberty. The offset of the wheels and the camber both make for a very dirty car and potential for stone damage.

[bigBADbenny]

Kudos to the photographer!

That looks like so much fun, I would definitely do a dirt day like that if we even had those local in vic, as opposed to a proper track day.

I’d love to see in car footage…

Also for the tmic dual gauge, setup a camera just to record the temps on track or even a daily drive?

I’m not sure how I missed the ziptie on the bov return…
Does that pass an inlet pressure test?

[Yowie]

That looks like you had a lot of fun. It's good that the Foz come stock with mud flaps so that having a bit of fun in the dirt doesn't damage the paint.

Yeah, it's a fun day. Taking the spare wheel and all the cr@p out of the boot makes the back end quite lively - basically brake-while-cornering (trail brake) for some fun oversteer.

The stock forester 'mud flaps' are short semi-hard plastic pieces. Proper mud flaps would do more.

If you like your paint, a dirt day may not be your cup of tea. The witch's hats get covered in sandy mud, so if you collect one it leaves a mark.

Kudos to the photographer!

Yeah he does a good job. I'm under-selling him here by putting compressed images up.

I’d love to see in car footage…

Also for the tmic dual gauge, setup a camera just to record the temps on track or even a daily drive?

I don't have a Gopro or similar camera (or any video editing experience) but would happily give it a crack if I could borrow one (Brisbane Northside - payment in beer). The gauge mount system is so rigid I reckon I could fabricate a camera mount to hang off it.

[EDIT - I see there is a video camera hire place convenient to me with reasonable rates on gopros. Interesting...]

Footage of intercooler temps would do more than my descriptions can by a long shot. Even better those "race style" videos with overlaid other engine data (revs, boost and perhaps road speed most relevantly). Once again, being light on video gear and editing skill is holding that up.

I’m not sure how I missed the ziptie on the bov return…
Does that pass an inlet pressure test?

It's ok, it's a "drift spec" ziptie.

[rexhunta]

It's ok, it's a "drift spec" ziptie.

Only if it's it bought at supercheap

[bigBADbenny]

Are you considering adding waterspray to the tmic setup?

I’ll bet the gauge might have a selectable differential trigger with hysteresis?

That and a Hobbs switch might be a complete solution?

[Stifull]

The Hobbs switches for TMIC water spray work very well . I have them in my wrx and my wifes wrx. In my rex I use the sti washer bottle with the 2 pumps and my wife's car has a seperate water bottle on the drivers side. I used 90 degree garden irrigation sprays on the rex and my wife's has sti sprays. It is well under $100 for the complete kit. The hobbs switches are around $50 and is fully adjustabel. At the drags you can put ice cubes in the bottle for that little extra cold in the CAI... LOL.

[Yowie]

I'm not ruling-out waterspray projects but they are not at the top of the list. The stock intercooler performance is quite impressive when not in extremis and passable when it is.

Eg for the dirt day (where factors include a short main straight, need for low & midrange and my amateur mild driving) the cold side of the intercooler stayed remarkably cool lap after lap (you can check peaks after you come in).

The gauge has a user-adjustable "alarm" threshold designed to set off a buzzer or a light. In my mind that could be used to trigger a water spray, but it's certainly not a sophisticated system. As the Autospeed controller project notes point out, by the time the charge air is hot (and heat-sinking capacity of the intercooler is saturated) you're playing catch-up.

Having said all that, with a low enough alarm/trigger threshold (and/or running it off the hot side for a faster reaction) you could have the spray going for a quarter mile, the main straight on a track or similar - so "dumb but it works" could be fine.

As Ben & Stifull have mentioned, a Hobbs (boost pressure activated) switch could be the trigger for a spray, or part of the trigger (eg temp threshold AND boost threshold met = spray). Plenty of R&D and clever wiring potential there, but as noted a sprayer is low on the project priority list.

A bigger turbo would probably happen before a spray project, and a spray project would need to be weighed up against just getting a Verticooler or something. Simplicity versus the fun of tinkering perhaps.

Cheers for reading and throwing some ideas around.

[Stifull]

The Hobbs switch is triggered by boost levels and those can be adjusted with a small slot screwdriver into the top of the hobs switch. To "TUNE" mine, I had the hose spraying on the windscreen via the stock window washer sprays. You don't want it coming on all the time so road adjustments are the way to go. Ours only comes on around 5500rpm. Because mine shares the washer bottle I get froth coming out of the Bonnet scoop at high rpms...LOL...And a very clean intercooler..