AEM Wideband on 2.7 CIS

[Ginger77]

Hi guys, I’m in the process of tuning my CIS after overhauling the whole system with new gaskets, sleeves, alloy airbox and such. It seems I’m currently running lean at idle and I haven’t even driven yet.
BUT I came across a new in box AEM wideband for half retail price and decided to pick it up. While diving through the realms of CIS wisdom on the forum I came across other users that installed this AEM UEGO gauge. But some guys swapped the O2 sensor in place of their CIS O2 sensor. But my ‘77 has a 2.7 without O2 and the later introduced gadgets and I have Dansk heat exchangers and a 2in 1 out muffler similar the SSI system. Not stainless but you get the idea, I hope.

My question now is:
1) I need to place the O2 Bung. Where should I put it? The left bank driver’s side right after the merge and above horizontal? Or at the tip of the muffler so that I pick up the signal like a CO sniffer would?
2) How do you guys route the loom from the engine to the dash? Where’s the entry into the cabin e.g. And where to place the gauge? I have a small 914 fuel gauge that I could sacrifice and mount the wideband in in place of the clock or hang it below the ashtray in a pod?

I’m curious to see and open to suggestions. I know most people say to use the search function and I did but I couldn’t find answers to questions above

[Cory M]

Bisimoto sells an extension cable you may need for rear engine configuration. I bought the same part for my 911 but installed on my miata racecar, so i don't have the other answers.

[icarp]

Bung 3"-6" after the merge . Make sure it is on a angle pointed down ( the sniffer in the exhaust )
That way no moisture can collect in the sniffer , and kill it . Wire end high and sniffer end down
Ian

[911pcars]

Originally Posted by Cory M

Bisimoto sells an extension cable you may need for rear engine configuration. I bought the same part for my 911 but installed on my miata racecar, so i don't have the other answers.

If the same as the one Bisi sent me, it’s not an extension (w/male + female ends), jus a longer main harness. As I recall, about 10-11 feet. Might work depending on your harness routing. Or call and confirm.

Sherwood

[Reiver]

'83 SC Euro w/SSI's AEM in dash in place of the clock with wire routed thru the tunnel and out where the lines emerge then to drivers side wheel arch and plumbed into the left SSI just beyond the merge of the 3 pipes. Numerous plastic ties on nearby lines and all connectors covered in silicone tape.
Has been in place and operating like that for 5 years now. One of the best things done imo. I KNOW when the WUR (Euro WUR provides fuel delivery amount) is working properly etc....

[Ginger77]

Thanks for the replies. So the tunnel is the best place to route the wiring? I know from my Cal Look hot rodding that with VW bugs it's possible to route wiring along the door sills or through the roof. But if I choose to route through the tunnel I think I need to jack up the car and have a good look underneath.

Reiver, did you need an extension cable or longer harness with the AEM kit? It seems the me the wiring is long enough.
icarp, that's exactly how I meant to describe the mounting position in the header. But sometimes there's an O2 bung in the muffler. So I was trying to figure out what would be more ideal. I can take the muffler off and have someone weld a bung on. I'm a little hesitant to take the header off because I don't want to break any studs.

[Ginger77]

I suppose what I mean to ask is can I also mount the O2 bung in the bend of the tip on the muffler? I have no cat. Just two heat exchangers going into this muffler:



It would be out of sight. Plus I can take this muffler off and have someone weld it in. Mount it back up and get tuning

[Reiver]

The supplied cable wire is just long enough to reach this point...not enough to go to your muffler and am not a fan of that location.

Wire was routed thru the tunnel with it attached to bailing/fence wire...rear to front..
You can see the attaching points I've used...the assembly on the SSI is a nut welded to a sleeve (available most car part stores) so all you do is drill a hole on the pipe and attach...never leaked. This has been in place for 5 years now with no issues.

[Ginger77]

Thanks for posting those photos, Reiver. This really paints the picture for me. I came across those sleeves since AEM sells those. They're not cheap where I live but then I would just have to measure the size of the heat exchanger collector, order the item and do the install myself.

Can you drill the hole with the exhaust in place? I mean the steel particles will end up in the exhaust and have to pass all the way through the muffler to come out..

[TwoBluPorsches]

The pictures by Reiver show the typical and about the best possible scenario.
On my car it is a bit further aft and doesn't interfere with the valve covers. I don't know if his setup will causes any issues there. Putting it on the outlet of the muffler is not recommended. It would be too far back and could be inaccurate due to dilution with outside air and the temperature will be too low. One tech manual says to make it 18 inches from the exhaust valve unless temperature will exceed the rating of the device. Bosch manual says to put it in area that is representative (after collector, before cat), hot but not too hot. Wiring end up /vertical as possible.
Search the www for "bosch motorsports lsu installation notes" and you can look over the bosch notes.
Wiring through center tunnel is the way to go. The factory harness and everything else go through the tunnel (battery cable, heater cables, brake cables, clutch and throttle cable, brake lines and shift linkage) You can fish something through from one of the top openings (near the throttle pedal) and you have access to the space at the back of the tunnel (where the shifter coupling attaches to transmission) and you can make your own hole or try to sneak it out one of the existing holes that might have room.

The clamp is okay I guess but the bung is super cheap and easy to weld in. Either way you have to drill the hole. It isn't the end of the world if the chips go into the muffler and live there forever or maybe get blown out. However, it's easy enough to remove the muffler and put in new muffler gaskets when you put it back on.

With the muffler off Definitely make a couple trips up and down the block with open exhaust to impress the neighbors.

[Ginger77]

Great. Thanks for the info! I understand the bung is easy and cheap. Heck, it's even supplied with the kit. But taking the car out to have a bung welded in is quite an undertaking. The car culture is much less prevalent here in Europe. So in that case the clamp or sleeve could make for a good DIY alternative. It's just odd that it costs $50 for what it is.

Thanks again. I'll get to it