More automotive doppelganger action there with the Maverick!
My Mom bought one new (her first car) back in early 70's.
That's the car i learned to drive in. Its still in the family but slowly deteriorating from neglect.

Your exhaust plan seems good. Can't wait to hear it with that set up.
I hope your 2 pipes can fit under there. I don't even remember what the underside of an X-Type looks like (but i'll be under mine tomorrow).
Do you have to worry about passing an emissions test where you live? Will the new set up meet regulations or do you have to swap exhaust every couple years like we do in California to pass smog tests?

Performance-wise I would personally put the headers into one cat and then one 2.25" pipe with a resonator back to a Y.
Less restriction and more velocity that way.
Especially, if you could do that and not have to swap exhaust set ups for emissions testing.

However, since the power gains (if any) either way are minimal, you get more cool points for having something unique.
Which sometimes is more rewarding than horsepower.

When you guys talk about tuning Contours, what software are they using to tune them? Would that software not work on the X-Type?
The piggy back should work on any car where you can access certain wires to hijack and change the data.

 

Diavolo, torque is really a function of the horsepower times a constant, then divided by the RPM. So, to make more low RPM torque, you need to make more horsepower. To make horsepower, you either need to make the engine more efficient (ie, converting more of the explosive pressure of the gas to mechanical work which requires mechanical changes to the engine itself) or you need to add more air and fuel to make a larger explosion. More fuel at a given RPM means less MPG at the RPM.

There is a certain amount of gain that can be had by either evacuating the old exhaust from the cylinder in a more efficient manner (ie, less back pressure - to a degree) and/or to make it so there is better mixing of the air and fuel so the burning of the fuel occurs in a more efficient manner. Both of these can result in more power while also netting etiher a constant or improved MPG. But, this is where getting things just so is either a lucky guess or you have an engineering degree and can figure this stuff out.

In the old days, if you wanted more low RPM torque, you simply added a longer duration to the cam shaft and had it open earlier to allow the cylinder to fill fully. But, the downside to this is that if you leave the valve open too long, as you raise the RPM, the valve will tend to "float" and what you end up with is the intake valve remaining open as the cylinder attempts to fire and you most likely end up with the motor firing out the carb (which is never a good thing). Modern day cars can get around this a little bit as they can control when the fuel is injected (in a direct injection motor) and to a degree with a fuel injected car as the fuel is injected next to the intake valve, so, most of the intake has only air in it, not an air/fuel mix.

 

I like the idea of a single, bigger, pipe leading back to a Y but I don't like the idea of getting rid of a cat or sensor or trying to trick a sensor. I'm going to take a lot of suggestion from the installers as well. If they can squeeze in 2 cats somewhere then Y into a single 2.25inch then Y back out to the mufflers that's what I'll do.

For now, I'm thinking the duals will be easiest but I've never done this and this is all with estimated measurements from laying under the car on ramps haha it all seems possible while daydreaming and not having to be the guy doing the work!

 

As I remember SCT sold a plug in tuner for the contour, I think Diablo also did, and there is a company called sniper that sold software to tune many different cars from a laptop. They even sent you a USB to obd2 cable and the rights to tune two different fords so I was going to get it for my mustang and the contour. None of them offer anything for the x type, I asked haha. You can't use another cars tuner on a different ECU either. I haven't looked into using a power AFC yet but I hear great things about them. I have heard of someone using a Mazda ECU from one of the duratec v6 mazda6s but I heard it was a nightmare to wire up. There is someone on here using megasquirt on his x type after he swapped from auto to 5 speed but the stock gauges wouldn't work anymore, and I think he is now using a 5 speed ECU. I think if I can't find a way to tune the stock ECU I'll be looking into a power AFC. If that won't work, megasquirt and one of those fancy racepack digital gauge clusters. There I go dreaming again haha.

 

Thermo,
Uh, what? Some of that is not necessarily true.
Are you trying to save face with an even more confusing sounding post?
I put part of your quote above in bold that contradicts what you wrote before
(about low RPM torque = bad gas mileage) but, now your post gives an impression that you think tuning is a "lucky guess"?

My other car is a marvel of modern technology. Someday in another thread i'll write about it. Its tuned; by science not lucky guesses, and makes a lot more torque than when stock, and gets better gas mileage: Turns out you can have your cake and eat it too.
Its about efficiency.

We're here to learn from each other. I don't know it all either.
It's ok to make a mistake, we all do.
I was just pointing it out before, to stop misinformation from spreading:

Torque is a measure of how much work the engine can do.
Horsepower is the engine’s ability to do work, expressed as a rate.

The more horsepower you have the faster your engine can do work.
So as mentioned; when you go to pass someone quickly thats when horsepower comes in. You wants your ponies to do the work quickly.

The ability to develop your maximum torque at low RPM would matter less at high RPM when you go to pass.

Science!

 

You are venturing into uncharted territory for sure, but if you're going to get your feet wet, you might as well go swimming.
Have you considered the weight difference of the two pipes then?
Or potential for rattling noises?

Didn't you say that the shop doing the work, works on Subarus and DSMs?
Ask their suggestion on a resistor mod to bypass a sensor.
I'm sure they have done it before or just tuned sensors out.
Doing so is not that big of a deal.

My other car has a sensor eliminated, and my custom tune just tells the computer to ignore the missing data, so no CEL comes on, but i've used a resistor on a friends car before to accomplish the same results. We installed similar hardware on his car, but i reflashed his ECU with an off the shelf map that was still looking for that particular sensor.

Remember, all those downstream sensors do is send a voltage signal based on the efficiency of the catalytic converter it is behind.
If they detect a rich condition coming out of the cat, it creates a voltage spike and the computer interprets that as the cat not functioning.

I'm 99.999% sure they have nothing to do with the A/F ratio adjustments.
That is the job of the upstreams while operating in a closed loop.

Hypothetically, (if i am correct) with this set up your car should still function as designed; Your two upstreams making A/F adjustments as intended. Headers going into one cat. That one cat's efficiency measured by one of the O2 sensors voltage.
The other O2 sensor replaced by a resistor that just constantly tells the ECU everything is good.
You really don't need either downstream unless you want your CEL to come on when that cat goes bad.
Its going to be a new cat so it shouldn't fail for a long time anyways.

Unless the one cat is unable to clean up the exhaust from both banks to keep the 1 downstream O2 sensor happy, no CEL will come on.
That kind of set up would also be the most likely to give the best power gains, and best sound and, it would weigh less.
Otherwise you're kind of just replacing the stock system with an overly complicated version of itself, and no potential for gain except what the headers may offer. The sound won't even be that different than just changing mufflers on the stock system.

Whatever you decide, I hope the money you're planning to spend yields results you're happy with.

 

Wow. So it seems the Jaguars ECU is a pain to access.
I suppose not many would want to, so thats why theres no aftermarket support, rather than it can't be done?

I had an S-AFC i wanted to install in one of my RX7's but never did.
I ended up giving it away to a friend who moved out of state.
He donated (dumped off) some car parts to me that he didnt want to take with him on his move.
I knew that he wanted a S-AFC for his G35 coupe, so I gave it to him as a sort of trade. At that point the thing had been sitting in a box for a couple years anyways. He installed it on his Infiniti, and seemed happy with it.

If you can locate the proper wires going into the Jaguar ECU then theres no reason (i can think of ) that it shouldnt work.

 

Diavolo, when I say that it is a lucky guess, a lot of what we do is because someone else stumbled on something that happened to work. I don't know many of us that are mounting sensors in the cylinder and exhaust to see actual numbers and tuning a car that way. Some of it can even come down to lots of experience in building a motor/exhaust system. But, again, this is simply knowing that if I install X, Y, and Z, I can get this out of the motor. I would say that most of us don't even have that experience. We are trusting what others have done before us and what their results were.

As for the contradiction that you mention, an efficient exhaust system is a compromise unless it is built for 1 thing. An exhaust system built for a drag race is completely different than one built for say a circle track. Both are racing and needing the quickest acceleration possible, but one needs the motor pretty much at redline and the other needs to cover the motor over a much larger range. The same can be said for a daily driver. You need a system that has sufficient scavaging for high RPM power, yet, not so much that you are robbing the cylinder of the necessary backpressure for low RPM torque.

 

All the ideas I've had and have been suggested are hypothetical situations. If S.I.M thinks they can get away with a single cat, single pipe and a resistor then, by all means, I'll have them do that. A single pipe is really what I want...

I don't track my car but I do drive rather spirited sometimes. At this point, basically any physical/actual gains will be worth the money but I also just want to be able to say I did it. Haha

 

Best reason ever!
I was under my X-Type today looking for leaks and stuff.
While I was down there I tried to imagine how two pipes could fit side by side.
Whatever you do, I'm going to want to see some step by step pictures.
So you better document it!

 

*bump*

any updates? its been a few weeks.

 

No major updates yet, unfortunately.

I've got all the parts needed sitting here in my basement waiting to be installed but buying my house kind of put the squeeze on any luxuries for a little bit.

But, I'm also very seriously considering selling the X to get back into an S type or just simply replacing the X with a newer and cleaner, less miles 3.0l vehicle and swap over all my mods thus far. The second option is more plausible...

 

Just to throw a proverbial wrench in the works.
Have you considered larger injectors and a port polish?

 

Jag's ECU doesn't know how to handle much of a cleanup, unlike my Land Rover...getting rid of the 16# injectors for a set of 19# and a radius of the throats REALLY woke that thing up, even without a remapping. Going to 22# and a remap was good for 35 hp and over 45 lb/ft on the dyno, but the Rover trans and transfer case could handle the extra power...I think the computer is the major downfall on performance mods. Not that is necessarily a bad thing, since the factory trans and transfer case are pretty much at their limits in stock (at least with the 3.0) form.

 

The 5 speed trans can take more power, the mtx75 is a decent trans, and frankly there is always talk about the transfer case not being able to handle more power but no one has really tested that theory out. For as weak as people claim they are I also don't really hear about them failing very much, at all.... rarely actually.


X-typeMentality it seems that the race is on to see who does this first, me or you haha. Its going to be a slow race I think haha. I'm still not sure if I want to wait until I get a 3.0 to replace my 2.5 or just put the headers on the 2.5 and do the exhaust. I've also thought about doing the exhaust without the headers, them doing the headers later when I get the 3.0. then there is my xk8 project... and I'm seriously thinking about going to look at this XJR, with the supercharged inline 6, that's for sale around here. I have an addiction to buying cars even when I know I shouldn't.

 

Yeah man I hear ya, my Maverick is quickly becoming the main focus for a build. I got it from my grandpa's estate for $1700. Get this, 1971 with the 302 with 24k original miles. Mint freaking condition! It books for like $7500 right now!

The X is still going to get the header treatment it'll just be a month or so until I can save up the extra funds. We're flying out to Colorado late September so I'm trying to set a goal of having it in the shop while we're gone for the week.

But, I think after the exhaust, I might be done modding the X-type. I'm ready for some go fast and the Maverick definitely has that potential.

I'll be a Jaguar owner/enthusiast for life though. If business keeps progressing the way it has, I'll have my eyes on a used XF-R in a few years or so.

Here's a picture of the direction I want to go with on the Maverick. Enjoy.

 

That sweet, I love those rpf1s. I wanted a set for my x type but they didn't make the size I wanted in 5x108. I like mavericks, cool cars, and with a decently modded 302 pretty quick, most people don't expect it haha.

 

Did you ever do anything yet? I clearly haven't haha

 

Nope, haven't done it yet but I'm scraping my pennies together trying to somehow move and still get It done At the same time. I know it's going to be expensive so I'm just hoping I can squeeze it in while still moving.

I'm moving mid March so I'm trying to get it done around then or shortly after. I have TONS of work lined up so theoretically I could afford it but I also need a house full of ****, I gave everything I had to my ex when we split including my DD x, which I got back obviously lol. So it's either a new 70 inch or the exhaust? What to do, what to do? Haha

I'll for sure take pictures of the set up and video of the sound! You should try to beat me to it! Haha

 

I have been trying to ha ha, but I bought an explorer to daily drive and of course I had to spend money on it, I can't drive stock, just cant.