High flow magnaflow cats, 2.5 downpipes, new xpipe and more
#21
01-28-2019, 03:51 AM
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Carnival Kid (01-28-2019)
#22
01-30-2019, 04:47 PM
Senior Member
I covered my dyno testing experience here
"Here you can see Pre cat and post cat. At 1350 kg/hr the Cat of the AJ33 SC account for about 200 mbars, while the ceramic monolith of the stock car would be about another 100 mbars on top of that. The rest of the system on the X100/AJ34 flows about the same as an X308, even though the silencers are different SC vs NA.
The earlier cats of the X308 , AJ26 and AJ27 are less dense and therefore less restrictive. I believe they were 600 cpsi if memory serves and the early cats didn't have the airgap. For the AJ27 SC flow rate of 1200 ish- 200 cpsi cats should reduce this- perhaps to 500 mbar EBP for a stock exhaust.
Oh, stock X308 SC is around 750 mbar EBP, X350 and X100 4.2 SC are at 750-800 mbar but they flow more air.
Convention is to measure in the cat cone, the whole industry does it this way. Its a good reference point for comparisons and benchmarking.
Some cars, have exceptionally low back pressures- like the E39 BMW M5- which is around the 250-300 mbar mark and is still refined and quiet. The M5 5 litre flows a lot less air than an XJR because the XJR must flow enough for the parasitics of the eaton blower itself."- from the post posted on 12.19.2016 at 915 pm.
In my XJR-550 thread.
https://www.jaguarforums.com/forum/j...t-52518/page7/
Going from the stock 600 cpsi to 200cpsi is likely to bring the EBP down from the stock 800 mbars to around 400-500 mbar and that's worth about 20 bhp.
"Here you can see Pre cat and post cat. At 1350 kg/hr the Cat of the AJ33 SC account for about 200 mbars, while the ceramic monolith of the stock car would be about another 100 mbars on top of that. The rest of the system on the X100/AJ34 flows about the same as an X308, even though the silencers are different SC vs NA.
The earlier cats of the X308 , AJ26 and AJ27 are less dense and therefore less restrictive. I believe they were 600 cpsi if memory serves and the early cats didn't have the airgap. For the AJ27 SC flow rate of 1200 ish- 200 cpsi cats should reduce this- perhaps to 500 mbar EBP for a stock exhaust.
Oh, stock X308 SC is around 750 mbar EBP, X350 and X100 4.2 SC are at 750-800 mbar but they flow more air.
Convention is to measure in the cat cone, the whole industry does it this way. Its a good reference point for comparisons and benchmarking.
Some cars, have exceptionally low back pressures- like the E39 BMW M5- which is around the 250-300 mbar mark and is still refined and quiet. The M5 5 litre flows a lot less air than an XJR because the XJR must flow enough for the parasitics of the eaton blower itself."- from the post posted on 12.19.2016 at 915 pm.
In my XJR-550 thread.
https://www.jaguarforums.com/forum/j...t-52518/page7/
Going from the stock 600 cpsi to 200cpsi is likely to bring the EBP down from the stock 800 mbars to around 400-500 mbar and that's worth about 20 bhp.
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#23
02-21-2019, 04:11 PM
Member
What is OE dia. inlet pipes to large, single, center muffler on X308 XJR? Magnaflow.com/automotive-performance/accessories/cross-over-xh-pipes/products.
Offers parallel inlet/outlet (OE set-up) X-pipe in/out 2.25, 12" (Part #10790); 2.5 in/out, 12"(Part #10791); and 3.0 in/out, 14"(Part #10792). Outlet pipes same as inlets?
Thinking of replacing my Mina rear resonator delete (unattractive) and going back to OE, while replacing center muffler (and adding X "up front"). Thanks !
Offers parallel inlet/outlet (OE set-up) X-pipe in/out 2.25, 12" (Part #10790); 2.5 in/out, 12"(Part #10791); and 3.0 in/out, 14"(Part #10792). Outlet pipes same as inlets?
Thinking of replacing my Mina rear resonator delete (unattractive) and going back to OE, while replacing center muffler (and adding X "up front"). Thanks !
#24
01-24-2022, 10:52 PM
Junior Member
I picked up 37hp going with a catless exhaust on my old WRX. That was a 2.5L 4cyl…
my 3.5” intake picked up 20hp in the midrange on my X350 XJR. The intake and exhaust tract on these cars is very restricted.
I deleted the resonators and mufflers and went with an offroad H pipe as well.
With just those mods I made 348whp 368wtq at 6400’ elevation.
I’m having a set of catless downpipes made as we don’t have emissions in my county. I’ll personally test this theory.
you need to remember that as you remove restriction from the intake and exhaust tract on supercharged cars, boost increases which adds to whatever gain you made off of the part.
55hp with catless downpipes doesn’t seem far fetched at all.
#25
07-11-2022, 08:33 PM
No not many. My V8 is only a little modified, just bolt ons. It's not the most modified or the most powerful but I haven't seen a faster time slip yet in 10 years since for an X308.
lmao... You seem to have poor reading comprehension don't you? The discussion and my comments were not about other V8's or other cars was it? This is specifically the Jaguar X308 sub-forum and the discussion was specifically about 4.0/4.2 Jag V8's. Maybe you picked up 37hp on your WRX; maybe other cars pick up more power, maybe not. But what other cars can gain from high flow cats/catless is irrelevant to what Jag V8's can gain.
Cool. I'm on my second WRX that has full catless turbo back exhaust. Didn't care to dyno it. Again, a turbo WRX is irrelevant to the Jag V8.
No doubt the intake is restrictive. I picked up significant power with a full 3.5" intake on my X308 XJR. The cats not so much.
[QUOTE=BansheeScreamerIntake;2489181]I deleted the resonators and mufflers and went with an offroad H pipe as well.
With just those mods I made 348whp 368wtq at 6400’ elevation.
Have you tested this theory yet? I have. You can look up the thread with my results. Dyno'd before and after catless downpipes. Very little gains.
lmao... You seem to have poor reading comprehension don't you? The discussion and my comments were not about other V8's or other cars was it? This is specifically the Jaguar X308 sub-forum and the discussion was specifically about 4.0/4.2 Jag V8's. Maybe you picked up 37hp on your WRX; maybe other cars pick up more power, maybe not. But what other cars can gain from high flow cats/catless is irrelevant to what Jag V8's can gain.
[QUOTE=BansheeScreamerIntake;2489181]I deleted the resonators and mufflers and went with an offroad H pipe as well.
With just those mods I made 348whp 368wtq at 6400’ elevation.
I’m having a set of catless downpipes made as we don’t have emissions in my county. I’ll personally test this theory.
you need to remember that as you remove restriction from the intake and exhaust tract on supercharged cars, boost increases which adds to whatever gain you made off of the part.
55hp with catless downpipes doesn’t seem far fetched at all.
you need to remember that as you remove restriction from the intake and exhaust tract on supercharged cars, boost increases which adds to whatever gain you made off of the part.
55hp with catless downpipes doesn’t seem far fetched at all.
#26
07-11-2022, 09:06 PM
Junior Member
[QUOTE=SteveM;2544155]No not many. My V8 is only a little modified, just bolt ons. It's not the most modified or the most powerful but I haven't seen a faster time slip yet in 10 years since for an X308.
lmao... You seem to have poor reading comprehension don't you? The discussion and my comments were not about other V8's or other cars was it? This is specifically the Jaguar X308 sub-forum and the discussion was specifically about 4.0/4.2 Jag V8's. Maybe you picked up 37hp on your WRX; maybe other cars pick up more power, maybe not. But what other cars can gain from high flow cats/catless is irrelevant to what Jag V8's can gain.
Cool. I'm on my second WRX that has full catless turbo back exhaust. Didn't care to dyno it. Again, a turbo WRX is irrelevant to the Jag V8.
No doubt the intake is restrictive. I picked up significant power with a full 3.5" intake on my X308 XJR. The cats not so much.
Post your before and after dynos sir.
lmao... You seem to have poor reading comprehension don't you? The discussion and my comments were not about other V8's or other cars was it? This is specifically the Jaguar X308 sub-forum and the discussion was specifically about 4.0/4.2 Jag V8's. Maybe you picked up 37hp on your WRX; maybe other cars pick up more power, maybe not. But what other cars can gain from high flow cats/catless is irrelevant to what Jag V8's can gain.
Cool. I'm on my second WRX that has full catless turbo back exhaust. Didn't care to dyno it. Again, a turbo WRX is irrelevant to the Jag V8.
No doubt the intake is restrictive. I picked up significant power with a full 3.5" intake on my X308 XJR. The cats not so much.
I deleted the resonators and mufflers and went with an offroad H pipe as well.
With just those mods I made 348whp 368wtq at 6400’ elevation.
Have you tested this theory yet? I have. You can look up the thread with my results. Dyno'd before and after catless downpipes. Very little gains.
With just those mods I made 348whp 368wtq at 6400’ elevation.
Have you tested this theory yet? I have. You can look up the thread with my results. Dyno'd before and after catless downpipes. Very little gains.
#28
07-11-2022, 09:50 PM
Junior Member
also, it would appear the 4.0 doesn’t respond as well to mods and Cambo was talking about picking up 55hp on a 4.2 X350.
Since you want to bring up the “Not all engines are the same” argument… why are you using old late 90’s 4.0 results to argue gains made on a 2003+ 4.2?
The same logic applies here sir. Practice what you preach.
#29
07-11-2022, 10:09 PM
looks like you picked up a little more in the mid range. Stock diameter? I may have missed it but I didn’t see what it was.
also, it would appear the 4.0 doesn’t respond as well to mods and Cambo was talking about picking up 55hp on a 4.2 X350.
Since you want to bring up the “Not all engines are the same” argument… why are you using old late 90’s 4.0 results to argue gains made on a 2003+ 4.2?
The same logic applies here sir. Practice what you preach.
also, it would appear the 4.0 doesn’t respond as well to mods and Cambo was talking about picking up 55hp on a 4.2 X350.
Since you want to bring up the “Not all engines are the same” argument… why are you using old late 90’s 4.0 results to argue gains made on a 2003+ 4.2?
The same logic applies here sir. Practice what you preach.
In some aspects the 4.0 responds better. Like the intake; it's more restrictive on the 4.0 and thus there's more gains.
The 4.2 is the same basic engine as the 4.0. And a more modern engine won't leave you more gains to be had. They're not 60's American V8's where simple mods got you big gains.
#30
07-12-2022, 10:05 AM
Let it be
No, 2.5"
In some aspects the 4.0 responds better. Like the intake; it's more restrictive on the 4.0 and thus there's more gains.
The 4.2 is the same basic engine as the 4.0. And a more modern engine won't leave you more gains to be had. They're not 60's American V8's where simple mods got you big gains.
In some aspects the 4.0 responds better. Like the intake; it's more restrictive on the 4.0 and thus there's more gains.
The 4.2 is the same basic engine as the 4.0. And a more modern engine won't leave you more gains to be had. They're not 60's American V8's where simple mods got you big gains.
tuning your headers and changing your intake manifolds to accommodate dual Holly double-pumpers are sadly gone.
However, the refined ride and elegance of the Jaguar does not hide its ability to "get up and go" should our mood be
so inclined. Sometimes when viewing these posts, I get the feeling that some members strive very hard to achieve
results that are minimal. I strive to keep The Duchess as she came designed from the factory, unless there is some
obvious advantage in the change. It could be that the efforts posted here are doing the same thing, only to a higher
degree.
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87LC2 (07-12-2022)
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