Well today we got around to installing the 200 cell high flow magnaflow cats and the 2.5 downpipes. We checked the xpipe location using tthe scorch mark method and adjusting accordingly. Also some fun facts the outlet of the stock manifolds are 2.5 inches, and the outlet of the stock cats just under 2inches. Sounds very good a bit deeper and quieter no rasp or tin sound. Flow is amazing and the car feels great havent dynoed was too tired long day, but no codes thts always good. Also had to modify a blower snout for a fellow board member for a 3lb pulley, put new bearings and seals in as well.

 

excuse me if I sound like an idiot, what exactly model of the high flow magnaflow cats you used and to get it , because I want to get one for mine.but I am not good at mechanic stuff, just don't want to get the wrong part.thank you

 

well the model is 59956 they are a 200 cell high flow model spun stainless steel my guy hand made the flanges and if you want a set he can make a duplicate set for a reasonable price for anyone wanting a set. Now tht is if you plan on doing 2 1/2 all the way out if not Id get the 2 1/4 me personally I woulda went with the 2 1/4 but hindsight is 20/20 it will fit just a bit better.

 

you mean the the entire exhaust system , or just the high flow magnaflow cats part that your friend will make it for us?

 

nicely done

 

well 2.5 works fine and works good for the manny being 2.5 just takes some finesse

 

What about the 100 cell cats? Better? Worth it?

I've found a guy in Australia selling the Magnaflow 2.5" 100 cell for $130 each!

 

The main question: Do you need to pass emission test in your country? 100 cells may have problems to do that, but depends of course what are the limits.

 

Yes we have emissions testing here, Australia too.

I'm just curious, how much more HP would you get out of 100 cell compared to 200 cell compared to OEM?

I just had a look at the last test done on my XJR in the UK, it's nowhere near the limits;

Fast Idle Test
CO % Vol: Max 0.200, actual value 0.005, Pass
HC ppm Vol: Max 200, actual value 5, Pass
Lambda: Min 0.970, Max 1.030, actual value 1.003, Pass

Natural Idle Test
CO % Vol: Max 0.300, actual value 0.004, Pass

That's with OEM cats, interesting to know what to expect with 200 cells and 100 cells...

 

The big increase comes when you change from the orginals to 200 cells. If you have a stock or just a bit modified engine, I do not see a lot of improvement with 100 cells against 200 ones.

 

Still on the subject of cats....

Been chatting with a guy in South Africa who completely removed the cats from his X350 XJR (no emissions testing there) and based on the before & after dyno runs he's picked up around 55HP. That's right 55HP...

Here is an interesting picture;



On the left is the OEM cat from a 420HP Ford 5.0L Supercharged V8 from Australia on the right is a 100 cell Ballistic Racing cat.

So i'd be really interested to know what the difference would be between the various options;

OEM (400?) +0HP
200 cell +??HP
100 cell +??HP
Decat +55HP

Any ideas?

 

Does anyone have first hand experience completely eliminating the cats? I'm planning on doing an exhaust for my 2000 XJR, and was planning on doing a manifold back 2.5" system (maybe 2.25" over the axle as it sounds like a pain to fit 2.5s) as I want way more sound (the car's too bloody quiet!) and as a method of weight reduction. I want to eliminate the cats completely as my state doesn't have emissions testing (it does have a catalytic converter in place requirement, but I have a bunch of friends at inspection stations that will do the "pass it as long as it's safe, emissions be damned" inspection for me), and I can drop like 20 lbs, get way better sound, eliminate a bunch of cost, and pick up a bunch of power by running catless downpipes. But I am worried that no cats will make the downstream O2 sensors pitch a fit and put me in limp mode. Anybody know for sure?

 

Not first hand but as I mentioned above, the fella I know in South Africa completely removed the cats from his X350 XJR.
You need little gizmos like these O2 Simulator Mini Cat Cel Fix to trick the O2 sensors

 

well personally I wouldnt remove the cats completely for legal reasons but i dont think 55 crank hp let alone wheel is gunna happen but then again I havent messed with the x350 series but still hard pressed would need alot more data. 100 cells will decay fast and 200 cells last a good bit longer from what I have seen.

 

55 hp from deleting cats is bullshit. His must not have been working/clogged in the first place. Or just a messed up dyno/run.


Yes, you can search this forum and find exactly what you're looking for. "Nameless downpipes" or similar.

 

OK so here are the measurements;

Dyno run with cats was 262.7HP at the wheels. Drivetrain losses calculated as 21% as "drag" on the dyno = 332.5HP at the flywheel.

Now the elevation is 1600m / 5238 feet. Temp 16°C, humidity around 50%.

Plug the elevation into Wallace Racing - Braking HP Loss at Altitude Calculator and it shows 400HP at sea level. Which funny enough is the factory rating of the 4.2L S/C.

Dyno run after the cat delete was 304.5HP at the wheels, with 21% losses = 385.5HP at the flywheel. Same thing again with the altitude correction calculator & we get 458HP at the flywheel at sea level.

Bullshit or not that's what the figures said...and they do add up.

 

I'm not saying those number are made up or anything like that. I'm saying you can't gain 55 hp from deleting cats that are not melted or clogged in the first place. Gains from a cat delete are about 10hp or so on XJR's.

 

Most UK Jaguar tuners say 10-15bhp increase on hi flow cats and exhaust, which along with a pulley, cold air intake and remap would hopefully give around 50bhp.

The issue with your maths is the wallace racing thing, if we knew how that is calculated I could see the error.

 

XJR-0220 id be interested in talking to your flange guy. Who made your Xpipe?

 

The last time XJR-0220 was active on the Forum was Feb 2013.