Mil-Spec Innovate Bosch LSU4.2 WBO2 Extension
 

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The WBo2 sensor cable that came with the LC-1 I bought was a little too short for my planned location in the midpipe, and I decided to extend them the proper way, reducing any chance of additional interference, voltage leaks and noise due to the extended sensor wire.

I know its extreme overkill, especially since it's on a WBo2 which has a limited lifespan, but I'd prefer accurate readings, especially since accurate A/F logs are essential to my progress in tuning right now. (And because I was a little bored too :p) Did not want to stick the LC-1 in an awkward angle and routed the Bosch sensor from the hole below the carpet (exhaust temp warn grounding entry to cabin) and mounted at the rear. I have no gauge, as this is not a permanent install. Will remove once done with AFR fine tuning.

Process:
Did a 1.5m extension, Raychem MIL-W-22759/44 shielded 18 AWG wires
Thermally stripped wires at 600 degrees celcius,
Total splices 10 pre-tinned (untwisted) lap splices soldered with leaded tin
Splice connectors sealed with dual wall PTFE/FEP heatshrink,
Sealant resin coated with Chemsol MIL-S-8516E epoxy resin,
Weatherproofed with a layer of neoprene heatshrink
Finished off with kevlar sleeving (had a little bit of fraying, had to waste more :( )
Checked with ohmmeter, no voltage dilution.

Costs?
Enough to buy another 5 brand new Bosch LSU4.2 sensors...
Ouch.

You spent 400$ to extend that 1.5m? Where did you buy your parts? It should be no more than $10 in material besides the Kevlar sleeving? With all of the mil spec material I'm surprise that you solidered the joints. Solider joints are a big no no.

EB Turbo

Generally, I am aware crimping is the preferred method of connecting the wires together ny most people, but for sensors you would need as even linear distribution of the current as you can get, and twisting the wires in crimping spirals the current all over the place, causing although unnoticable, a very slight current bottleneck.

The the soldering I did was according to NASA-STD-8739.4 specifications. I chose to solder the connections, of course making sure the wires were evenly pre-tinned to get even flow of the current with maximum recommended surface contact of the wires to get a straight current flow.

I guess maybe it would be all up to the individual on their preferences of connection, and of course if I'd choose to crimp if it were normal wires, not important sensor ones which require high response and sensitivity as crimping is so much less work than proper soldering.

Oh and the costs were high, as I counted in the additonal costs incurred due to the need of purchasing a minimal length of additional materials, the costs are higher in my country as the wires and shrinks etc have to all be imported since no one really bothers about such detail.

thanks for sharing, but I cant even look at the pictures with them being so large


took me a few seconds to find the box to even respond

Sorry about the pictures, having some wierd issues with imageshack, cant rescale.

I'm sure you did a good job soldering the two original wires together and it looks like you used very nice heat shrink and wire. However, wouldn't it be better to source brand new pins for the gauge and the O2 sensor connector, then build a new harness without any solder joints?

That depends on who you are and what you are working with. Someone who can source the connectors, yes. Someone that can't, no. What makes certain sensors more difficult than others is when there is a resistor for a calibrated sensor like in the 4.2LSU. Finding the male connector housing with no provision for a resistor may be difficult. In the case of a 4.9LSU or NTK the sensor does not have a resistor and both genders are available and easy to make an extension.

EB Turbo