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ACV, LIM to Split air pipe to cat confusion…

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Old Jan 15, 2022 | 06:16 PM
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ACV, LIM to Split air pipe to cat confusion…

Trying to figure out if I have the wrong pipe here or if I’m missing something…

I removed the original pipe because it had cracked. I vaguely recall comparing to the pipe in the pic thinking they were the same and tossed the old pipe.

Ordered a new gasket and was attempting to install but the piping is oriented in the wrong direction as you can kinda see in the photo. It should be oriented towards the tranny and center tunnel.

Thoughts? Anyone have the correct pipe?

Thanks

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Old Jan 15, 2022 | 11:01 PM
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From: America's Dairyland
It looks like you have the wrong lower intake manifold. The air pipe studs are not in the correct position for a 1993 North America FD. They should be oriented as shown below. [Alternative explanation: Mazda changed the LIM design at some point and the air pipe you have was made for the other design where the flange is about 90 degrees off.]





.

Last edited by Retserof; Jan 15, 2022 at 11:58 PM.
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Old Jan 16, 2022 | 01:27 AM
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Flip it and bend it or cut it and replace the hard line length with rubber hose.
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Old Jan 16, 2022 | 08:37 AM
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From: https://www2.mazda.com/en/100th/
lmao, 1993, and 94/95 are different part numbers!
N3A1-20-870A vs N3B7-20-870B....

is that the intake manifold you're going to use? i've run into the same problem ( i thought the pipe was just bent), i'll go look at mine, if we're lucky we can trade
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Old Jan 16, 2022 | 09:26 AM
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From: America's Dairyland
Originally Posted by j9fd3s
lmao, 1993, and 94/95 are different part numbers!
N3A1-20-870A vs N3B7-20-870B....
Ha! That explains it. In checking the '93 vs '94 parts numbers, I see that Mazda changed both the LIM and the air pipe. Mix and match don't match.
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Old Jan 16, 2022 | 09:03 PM
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Originally Posted by j9fd3s
lmao, 1993, and 94/95 are different part numbers!
N3A1-20-870A vs N3B7-20-870B....

is that the intake manifold you're going to use? i've run into the same problem ( i thought the pipe was just bent), i'll go look at mine, if we're lucky we can trade
wow would never have suspected that!
I’m up for a swap. Let me know what you find with yours. Thanks
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Old Jan 17, 2022 | 10:35 AM
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Also the JDM lower intake manifolds are different in this respect. The pic looks like JDM since there's no EGR valve.

I found that out myself ages ago, for some reason the split air pipe is clocked differently.

You can either try and get the right pipe or just cut the pipe and put a hose and hose clamps on it and then you can position it however.

Dale
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Old Jan 17, 2022 | 10:56 AM
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Originally Posted by DaleClark
Also the JDM lower intake manifolds are different in this respect. The pic looks like JDM since there's no EGR valve.

I found that out myself ages ago, for some reason the split air pipe is clocked differently.

You can either try and get the right pipe or just cut the pipe and put a hose and hose clamps on it and then you can position it however.

Dale
dale,
reteserof’s pic is the jdm manifold?
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Old Jan 17, 2022 | 12:54 PM
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From: https://www2.mazda.com/en/100th/
i see an EGR on both, or the sport where the EGR goes
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Old Jan 17, 2022 | 02:24 PM
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Helps when I'm looking at it not on an iPad

Yes, both pics are US EGR LIM's. My bad on that!

Could also be the split air pipe is a JDM part and not a US part.

Regardless the cut and use a hose or re-weld still stands for how to resolve.

Dale
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Old Dec 5, 2022 | 10:47 AM
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I'm bringing this thread back to ask a related question. I have a newer jdm lower intake manifold that I wanted to use on my 93. I have the same air pipe issue but I also noticed the acv has no electrical connections on it. My 93 acv has 3 places where my harness plugs into. All the information I have found online shows the electrically controlled acv. Can I use the newer acv? I will be using a PFC if that makes a difference. I was planning on keeping the air pump for the cat.

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Old Dec 5, 2022 | 11:05 AM
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From: https://www2.mazda.com/en/100th/
yes, you can use it. the US cars have those extra bits, and the JDM cars don't. they don't do much, and the PFC wasn't using it anyways
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Old Dec 5, 2022 | 11:16 AM
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I found a thread on here a few months back on this but can't find it again atm but my memory of what I found was that the JDM ACV is different and the 2 extra plugs are a USDM thing.
If it were me, I'd swap the US ACV over for no other reason than reducing the need to have to take everything apart to do it again afterwards if there was an issue. Assuming the US part fits...
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Old Dec 5, 2022 | 11:30 AM
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An update to my split air pipe saga

j9fd3s eventually met up and exchanging pipes. Thanks j!

I test fit and it fit much better until the last 3-4 inches where it curved slightly to the passenger side and into the heat shielding...
At this point, I gave up on finding a proper fitting one and cut the last 3-4 inches off and got some high temp silicon hose to fill the gap. I used the same hose that RX7.com uses on their high flow cat to attach to the split air pipe further downstream near the cat. The hose is Purosil. Manufacturer is here: https://purosil.com/product.php?cate...er_vacuum&id=0
I think I found mine from a company that sells marine products that was also on ebay.

Hope this helps someone down the line. Bending the pipe was not an option. That walls on that pipe are surprisingly thick.
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Old Dec 5, 2022 | 12:05 PM
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Originally Posted by gracer7-rx7
I found a thread on here a few months back on this but can't find it again atm but my memory of what I found was that the JDM ACV is different and the 2 extra plugs are a USDM thing.
If it were me, I'd swap the US ACV over for no other reason than reducing the need to have to take everything apart to do it again afterwards if there was an issue. Assuming the US part fits...
That was going to be my last option. I wanted to just get rid of everything that my PFC wasn't looking for so I think I'll just try it out on the car and hope everything works as it should.
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Old Dec 5, 2022 | 01:53 PM
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Remember, the PFC doesn't care if you have stuff plugged in or not. No CE light, no limp mode, etc. As long as it has enough inputs/outputs to make the car go you are good.

Dale
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Old Dec 6, 2022 | 09:07 AM
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From: https://www2.mazda.com/en/100th/
Originally Posted by DaleClark
Remember, the PFC doesn't care if you have stuff plugged in or not. No CE light, no limp mode, etc. As long as it has enough inputs/outputs to make the car go you are good.

Dale
also a JDM car, which is what the PFC is setup to do, does not have those anyways.
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Old Dec 6, 2022 | 11:00 AM
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^good points
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