2 into 1 back into 2 dyno sniff AFR question

[05FLHTC]

What is the method being used on the dyno's out there to get the correct front & rear cylinder AFR readings on the new bagger X pipe exhaust setups?

IMO using the sniffer tubing in from the rear muffler you might be able to stuff one in far enough past the X chamber to get a read on the front cylinder but I see no way to get one in from the rear muffler to get a correct reading on the rear jug.

So what is being done out there to get accurate front & rear AFR readings?   Are some using adapters (if you have additional bungs) up close to the cylinder outlets and is this going to properly represent what the actual outlet AFR is on each cylinder after the exhaust goes through the X chamber & exist the muffs when taking any reversion into account? 

I'm not running this setup, but my cousin & I have been discussing this & wanted to hear how this is being accomplished...

TIA

[Powerglides]

With good advice from Gerrit Vosselman, I made these.

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[lonewolf]

If it doesn't have the 18 mm bungs I just take the right muffler off, feed the tubes up and then slip the muffler back on over the tubes. As a last resort I put the rivnuts in that I have to use to get past the cat.

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[wurk_truk]

Herko used to sell pop riv nut sets to do this with.  Take a small drill, drill the pipe and install the 'riv nuts' in the pipe.  I THINK the riv is 1/8" NPT, but not sure.  Then a hose is attached and goes to a block with the O2 sensor built in.

Works really quite well using the vacuum pump from the dyno.

I just recently saw the same base set-up in the new SE catalog...  but didn't see where they have the blocks.

When done, there is a small bolt that gets threaded into the riv nut and the exhaust is closed back up.  No one can tell if one drills the hole underneath of the heat shield.  Re-install the heat shield and you never will know.

Hopefully, someone with a kit like this can post up the parts and pieces needed to make the 'block' and also where to buy a handful of riv nuts.

[eddfive]

Bay Area Performance Cycles Oxygen Sensor Installation Kit



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[Powerglides]

I wasn't aware that there was anything commercialy available, so after being sent some pictures of another setup, I made my own.
1) After drilling a hole in each header I use a Masterfix tool to insert the rivnuts. The advantage of this tool is that it has a lot of "feel". The nuts need to be really tight so that an air leak can't develop in use.
2) Rivnut installed. These are readily available from a fastener supplier that I use.
3) The adaptors are modified steel hydraulic fittings. The pipes are stainless. I machined the manifold blocks, that the O2 sensors mount in, from 2" diameter Aluminium bar. The blue vacuum hoses are high temp silicone rubber that I bought from a rally car specialist.
4) The blue hoses run into pneumatic vacuum generators that Superflow provided. The generators are mounted into brackets that I made, and the whole assembly is bolted to the brake cover. They then run into the exhaust extraction ducting.
5) After tuning, the rivnuts are capped off with  stainless button heads that are hidden once the heat shields are reinstalled.

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