Finished up trimming the new nose cone and plugging it up. Ready for assembly. Still need to get the ring pinion and lock out to build up but wanted to compare my spare 4 speed 901 before I gave up on the 901. It nearly identical!!! Overall, Bell hosing face to tip of shift rod housing 73.5 vs 74.0 cm (Porsche to Subaru respectively), bell housing face to flange center 16.5 vs 20 cm (Porsche to Subaru respectively). My only fear is the actual position on the shift rod at 10 o’clock vs 6.

Nearing time for assembly. Clearanced the opposite case half for the differential to reside and rough cut the mid section which will become the nose cone for the tranny. Still need to clean it up more with a grinder flap disc and die grinder but after a hour with a sawzall making controlled cuts, my hands had enough. Awaiting completion of the REM polishing of the ring and pinion from Weddle then reassembly time. Stay tuned.

Now that cooling is essentially done, air is managed out of car and staying cool, time to start on the WRX 5 speed out of a 2010. It’s a TY758 and known to be quite strong. Here are a few shots taken during the tear down, pretty simple, lots of case through bolts, only 4 internal bolts, a few love taps and she opened right up . Btw, the new LSD pictured is a factory JDM STi 5 speed and will receive the Subarugears reverse ring and pinion and outside will get a 930 to Subaru flange.

Cooling mystery is solved and although it was a pita, I learned a ton about sensors, how they work, how to test and fool the ecu. Now to move onto more pressing projects like directing the radiator hot air out of the front trunk so I don’t have an eternal heater in summer days as well as off the gas tank. Will do some testing next weekend.

Ok, so I pulled the thermostate and boiled it, which opens as it should. tried running it car without the T state same thing. used my hand held IR and confirmed the radiator elevated temps were accurate and they correspond to the Autometer gauge. Needed to rule out erroneous ecu reading so if it were from the ecu, then I need to test the sensor or the ecu/wiring.

Sensor: its just a variable resistor with an inverse relationship to temp. as temps increase, the resistance decreases.

found this on the web quoting it came from a Hayes manual.

Temp in °F Resistance (ohms)
212 ———-176
194 ———-240
176 ———-332
158 ———-458
140 ———-668
112 ———-972
122 ———-1182
104 ———-1458
95 ———–1800
86 ———–2238
76 ———–2795
68 ———–3520
58 ———–4450
50 ———–5670
40 ———–7280
32 ———–9420

TESTING: pulled the sensor, used my Fluke to measure the resistance at room temp and with water boiling and it matched the vales above. Sensor is fine.

Wiring/ecu:

the ecu takes this ohm value and converts it to a temperature value based on calibration pre set by the ecu for this particular sensor. if its 2.5K ohms then the ecu says that 68*F, if its 176 ohm then its 212*F.

TESTING: went to radio shack and picked up a 0-5K ohm potentiometer. set it to 2.5k ohm and hooked it to the coolant temp plug and then looked up with the ecu was reading with the laptop, 68* so thats correct according to the photo above then set it to 176 ohms and it said 212*F which is what the chart above corroborates. (my boiling water test said 184 ohms but close). So its not the ecu/wiring.

Conclusion: not the sensor or the wiring or the ecu so back to the drawing board.

EDIT: figured out it was an air pocket in the crossover tube cuz I had re oriented a coolant tube. This reorientation caused the crossover tube to be the high spot so the sensor was not fully submerged. Reposition tube to its prior spot and all was back to normal operation. I’ll have to figure out how to more effectively burp the system.
 

For some reason the digital coolant temp sensor reading higher than motor (at least what the ECU says). This sensor is at the radiator T’d with the bleed line. Might me air in that line causing it to read higher. Freaks me out to have two different readings and having a hell if a time trying to bleed it. Hoping getting the motor higher than radiator will help.

Early morning wake up before dawn for the set up crew at Alameda Point, I’m sure my neighbor just loves that.  Long course that had a few fast sections (nothing over 50 mph honest )  Morning runs went fairly well with slowly chipping away at my times but the PM just wasn’t clicking.  Last run and 3/4 way thru I spotted a cone down and alerted that course worker and got a rerun.  Tires hot, course fresh in my mind and ready to go.  Result, my fasted time of the day

I’ve had a harness bar for some time but when I put in the ST roll bar I just bolted it in place. I finally got around to adding the harness bar to the roll bar and added some triangulation. To join tubing, u can’t just cut it at an angle and weld it together. Well…u could but it would be a strong joint nor look very good. It needs to be coped so the fit tightly together. Coping by grinding freehand is a pita and often just make one long tube into several short useless tubes from all the mistakes. I stumbled across a cool tool called a coping calculator. You enter the diameter if the tubing to be joined, it’s wall thickness, the angle and any offset and it gives you a PDF u can print and cut out and trace onto the tube then grind away. It worked awesome!!! Check it out at metalgeek.com.
Anyway, need to let the paint dry and I’ll post up final install tomorrow.

Edit: Done and installed. Despite tacking it all up in the car. It still pulled together and I had to use a scissor jack and a tube to spread em to get it bolted back in. That took nearly as long

Jack Olsen’s Black Beauty and magnificent work space.  Not much to saw but stunning.

Only a few projects taken care of lately, all surrounding cooling. I added a high accuracy electronic water temp gauge from Autometer with a full sweep mechanical needle. Near perfect match to the black on black Porsche units with white font. Took the car out for some spirited driving to try to stress the system and she stayed cool without breaking a sweat. I opened up the air inlet slightly in a method I’ve seen on other track 911′s that have oil coolers behind the headlight for more air flow. Few pics of its current iteration. This likely be it for some time but hoping to update the front brakes to aluminum S calipers and modified LWB trailing arms to SWB dimensions and M calipers to round her out. The suby tranny will be a long term project since the 901 is still hangin in there.