Exhaust Want to add cats

Willybill32 · Mar 26, 2022

7991LXnSHO said:
@Willybill32 your drool reaction makes me wonder if asking you to walk my pets might be misunderstood as wok them.

@7991LXnSHO, sorry about that...I didn't realize the meaning of that emoji!

Bill

JD1964 · Mar 27, 2022

Ok I now understand I need to put cats as close to engine as possible for them to be efficient at what they are designed to do.

I need to look under my car to see what space I have to splice in cats up front. I'm running an X pipe now, not an H. The X is just aft of the bell housing so it's closer to the front than some of the other aftermarket X and H pipes I see online now. I like the current X I have because just aft of the X is my wideband sensor. I like it there since it will sample a mixture of both engine banks. I dont want to change to a pipe that puts an X or H aft of the wideband sensor.

7991LXnSHO · Mar 28, 2022

John Dirks Jr said:
Ok I now understand I need to put cats as close to engine as possible for them to be efficient at what they are designed to do.

I need to look under my car to see what space I have to splice in cats up front. I'm running an X pipe now, not an H. The X is just aft of the bell housing so it's closer to the front than some of the other aftermarket X and H pipes I see online now. I like the current X I have because just aft of the X is my wideband sensor. I like it there since it will sample a mixture of both engine banks. I dont want to change to a pipe that puts an X or H aft of the wideband sensor.

That brings up another issue. Your wide band sensor is in a spot where it’s a combined reading, but primary O2 sensors are also put ahead of the cats and work well hot. A dual reading gauge and two bungs for wide band sensors in front of your cats might be an answer to get it all to work.
Are you running the sensor to keep sn eye on how the car is running or is it hooked into an aftermarket EFI?

JD1964 · Mar 28, 2022

The wideband is there primarily to monitor fuel mixture under boost. It’s not being used for active engine management in any way.

7991LXnSHO · Mar 28, 2022

John Dirks Jr said:
The wideband is there primarily to monitor fuel mixture under boost. It’s not being used for active engine management in any way.

Then would it be bad to put a new O2 bung on one bank in front of the cats?

JD1964 · Mar 28, 2022

7991LXnSHO said:
Then would it be bad to put a new O2 bung on one bank in front of the cats?

Not necessarily bad but then the sampling would be from on bank only, rather than a mix of both.

JD1964 · Aug 7, 2023

2000xp8 said:
If this were me? I'd just buy a catted x pipe and swap it on.

I’m leaning towards Basssni catted x and fit it with two additional bungs for dual wideband setup. Two pod A pillar trim so I can watch A/F on both banks in real time.

I’ll be 59 1/2 in November which allows me to tap my 401k (federal TSP actually) without penalty. If I take the money from there, it’s only a drop in the bucket.

Willybill32 · Aug 7, 2023

JD1964 said:
I’m leaning towards Basssni catted x and fit it with two additional bungs for dual wideband setup. Two pod A pillar trim so I can watch A/F on both banks in real time.

I’ll be 59 1/2 in November which allows me to tap my 401k (federal TSP actually) without penalty. If I take the money from there, it’s only a drop in the bucket.

The Bassani catted X-pipe is a nice piece. I replaced the stock H-pipe on my ‘86 with the Bassani and really like it.

Bill

Mustang5L5 · Aug 7, 2023

I have the Bassani catted X-pipe on my car. Fit really well and was a quality peice.

AeroCoupe · Aug 7, 2023

You can monitor two wide bands with one gauge if you look around.

JD1964 · Aug 7, 2023

AeroCoupe said:
You can monitor two wide bands with one gauge if you look around.

Right now I have PLX. I'm not sure about anything new they might have. I do know the single PLX gauge I currently have can monitor multiple different individual modules but only one at a time. For instance, I currently have modules for vac/boost and wideband AF. I can switch between the two but I cant view both at the same time on one gauge. With a second PLX gauge, I know I could do both boost and AF (one bank) at the same time. Or both banks AF at the same time.

limp · Aug 7, 2023

JD1964 said:
I’ll be 59 1/2 in November which allows me to tap my 401k (federal TSP actually) without penalty. If I take the money from there, it’s only a drop in the bucket.

You will still have to pay taxes on it... I think they will take 20% for taxes.....
Its a weird change from putting money into it to when you start taking some of it.....

JD1964 · Aug 8, 2023

limp said:
You will still have to pay taxes on it... I think they will take 20% for taxes.....
Its a weird change from putting money into it to when you start taking some of it.....

Yes I understand the tax implications. It’s not much different than paying taxes on your regular paycheck.

Pay ‘em now or pay ‘em later.

JD1964 · Aug 12, 2023

I'm thinking about seeing if theres room to weld these in just after the factory o2 position. That way they will be closer to the engine for good exhaust conversion. This will let me retain my current X which has the wideband location just after the X and samples both banks with 1 sensor. I know theres discussion about error in wideband readings after cats but any errors are not big enough to scare me. If anything it might be up to 3% lean reading after the cat. I see no problem in that event because if I tune to 11.8 at WOT under boost I'm really at 11.5 ish. Nothing scary there as the error nudges you to the safer side of the spectrum anyway.

JD1964 · Aug 16, 2023

It’s been a while since I drove the LX but I just got back from a little cruise. Man it’s fun to drive, especially with some tunes playing!

I’m chomping at the bit to get some cats on it, get the blower back in service and start tuning

JD1964 · Aug 17, 2023

I got the car jacked up good and got under to see where there's room to splice in a pair of Magnaflow 2.5" cats with metallic substrate.

My mid pipe loos like a custom made piece and I've not seen another like it. The X is directly under the gearbox portion of the transmission and I mean totally forward of the trans tail housing. Most other mid pipes I've seen have the X or H fully after the trans tail housing including BBK, Bassani and Pypes.

One option is to put the cats forward of the X which would be nice and close to the engine and would get the cats really hot for good exhaust conversion. However this location is a tight squeeze and would require some custom bending and welding. This would also put the cats forward of my wideband which is not ideal but I could live with.

Option 2 is a simple install which I could even do myself using stainless steel band clamps. The position is aft of the X and directly parallel with the trans tail housing. Lots of room there which is great for heat clearance to any of the components in that area. It's also aft of my wideband which is a plus too. The downside of this position is that its further back from the engine although I don't think its too far back for the cats to work well.

I measured the position of option 2 and its 3 1/2 feet forward of the mufflers and 2 feet aft of the engine. So, is 2 feet aft of the engine too far to get good cat function to kill the stink? If it's not, then option 2 is a no brainer for me.

I attached some pictures but the car was on jackstands. Wider angle pics with the car on a lift would have been better for perspective.

Pic 1 is the forward position. Pic 2 is the aft position. Pic 3 and 4 are wider angle shots for perspective.

2000xp8 · Aug 17, 2023

This has headache written all over it.
Just buy a quality stainless pre made catted pipe.
In the long run, i bet it will be cheaper.

I could see giving this a go if the existing pipe was stainless, but clearly it is not.

JD1964 · Aug 17, 2023

2000xp8 said:
This has headache written all over it.
Just buy a quality stainless pre made catted pipe.
In the long run, i bet it will be cheaper.

I could see giving this a go if the existing pipe was stainless, but clearly it is not.

I understand that response no problem. I wont argue with you about it. However, I'd still like opinions on if 2 feet aft of the engine (right at the position of the trans tail housing) is close enough to the engine for the cats to work right. Heck, that's closer than the cats on the Bassani mid pipe right?

JD1964 · Aug 17, 2023

BTW, this pipe may not be stainless but its rock solid, seriously. And if I'm using band clamps there will be no deforming of the pipe or cat inlets so the cats could always be easily removed and used in other applications or vehicles.

JD1964 · Aug 17, 2023

I think the pipe material is aluminized. Old yes and a bit of surface rust, but rock solid.

Exhaust Want to add cats

But at least it's tight!

there is enough sticking out to grab on to

wanna catch the space herp

there is enough sticking out to grab on to

wanna catch the space herp

there is enough sticking out to grab on to

there is enough sticking out to grab on to

But at least it's tight!

That is…until I whipped out my Bissell

lube between the nut and the face. I know my lubes

there is enough sticking out to grab on to

wrap a little cheese around it and its a done

there is enough sticking out to grab on to

there is enough sticking out to grab on to

there is enough sticking out to grab on to

there is enough sticking out to grab on to

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there is enough sticking out to grab on to

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