Booster Plug - What's Actually Inside

[fruitcake]

I was sceptical of things like this but read good things (on here as well) and read the stuff on their website about how it adjusts resistance according to the temperature to avoid issues that simply putting a cheap resistor can bring.
 
I bought one and popped it on the TDM alongside what the manufacturers probably don't want people to have access to, my wideband AFR sensor  :good: .
 
I have new Black Widow cans on and they've caused slightly lean running around 3k which is one of the reasons I need to richen the mixture slightly. I ran it up to temperature and not much difference to the mixture was taking place, in fact it was still running lean around 3k revs.  The OEM O2 sensor should eventually pull the lean running down, but I'd hoped the booster plug would do more than it actually was.
 
Decided to take it off and see what's inside. It'll destroy it, but haven't seen this anywhere else so thought it important people know what they're buying here 
 
So here it is:
 

 
Yep, it's just a resistor  :138:
 
No chip, no fancy circuit, just a good old resistor potted in a big lump of rubber.
 
The back of the board is here:
 

 
You can see there's just basic tracks to link the circuit through the resistor and the 'temperature sensor' (the middle cable) goes through the main resistor in parallel. This allows the temperature probe (NTC) to add a variable resistance to the value of the resistor being used.
 
I should point out the manufacturer is therefore technically correct in that the resistance is indeed adjusted with the external temperature, however, seeing this, it's much more crude than I imagined and the cost quite shocking.  The website has a full explanation and I have to admit, having read through, it isn't making a claim that it's something it's not, however, a basic resistor and NTC can be bought for a couple of quid.

<div>This is literally the same as popping a resistor inline with the OEM temperature sensor and then wiring a NTC temperature probe (5 for 7 quid on Amazon currently) across the resistor.
 
Now I know the cost of manufacture and subsequent mark-up will add a fair bit, but this really is a part made for a few quid and being sold for around £130.
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For anyone that's bought one and it appears to work then that's fine, but if you asked me if it's worth buying one I'd say no chance.  I wish I'd invested in a power commander to be honest, although they are getting hard to come by now for the TDMs unfortunately, especially on the second hand market.

 

Just wanted to post to show what these are inside, not saying they don't work because they are clearly adjusting the resistance to the outside temperature.  Whether you feel it's value for money though can now be seen.