V12 Non-cat downpipes !
#21
[QUOTE=JigJag;2010840]
Ron,
Ive been meaning to ask you about clearance and routing of your pipes. Got any pics underneath? I’m considering a pair of sidepipes and have been trying to reason out the routing.
It seems unavoidable ( and desirable ) to have them exit right past the wheel well, but that’s also a nice spot to scrape or crush when the tire drops off any lip, pothole, or speed bump. Do you have any issues or do you just drive around such things?
Im considering perfing through the very bottom of the rear of the fender and keeping the pipes bottom edge just below the level of the cars lower edge. Lots of room by the lower sill to fit 3” plus their covers. Doors would just clear the top of the covers. But more work and money that way. Do you have any ground clearance issues?
quote; i have to be careful with tall speed bumps , and tight driveway angles/hills.
but 26 yrs and counting,
i have on occasion lightly dragged the inside pipe slowly tho! so build the exhaust system with some room to flex movement! ( but NO flex pipe stuff).
some times i have done systems to give extra clearence by flatten to an oval shape ,using couple wood 2/4 in a press, hey i'm old YANKEE make do with what you got, improvise!
ron
1982 Camaro , 7.6L aluminum V8, pipe off each side 4" flattened!
Ron,
Ive been meaning to ask you about clearance and routing of your pipes. Got any pics underneath? I’m considering a pair of sidepipes and have been trying to reason out the routing.
It seems unavoidable ( and desirable ) to have them exit right past the wheel well, but that’s also a nice spot to scrape or crush when the tire drops off any lip, pothole, or speed bump. Do you have any issues or do you just drive around such things?
Im considering perfing through the very bottom of the rear of the fender and keeping the pipes bottom edge just below the level of the cars lower edge. Lots of room by the lower sill to fit 3” plus their covers. Doors would just clear the top of the covers. But more work and money that way. Do you have any ground clearance issues?
quote; i have to be careful with tall speed bumps , and tight driveway angles/hills.
but 26 yrs and counting,
i have on occasion lightly dragged the inside pipe slowly tho! so build the exhaust system with some room to flex movement! ( but NO flex pipe stuff).
some times i have done systems to give extra clearence by flatten to an oval shape ,using couple wood 2/4 in a press, hey i'm old YANKEE make do with what you got, improvise!
ron
1982 Camaro , 7.6L aluminum V8, pipe off each side 4" flattened!
#22
Finally got around to installing the non-cat downpipes. My main goal was to gain some ground clearance. Mission accomplished. No more scraping.
A couple observations-
I can't really say there was much, if any power increase, at least not in moderate driving. From past experiences I wasn't really expecting any. Perhaps at high RPM something might be felt. I dunno. Haven't yet had the opportunity yet to really pour on the coals.
There is an increase in noise. Slight, but undeniable.
Installation was not as bad as I feared. As it often turns out, Jaguar (inadvertently or intentionally) left just enough room to sneak your way to the manifold nuts via some tiny corridors....which might not be seen without the car on the hoist and looking directly upward from below. In any case, the RH side was a breeze. The left just slightly tricky.
Cheers
DD
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Greg in France (11-21-2019)
#25
I'll be curious to hear what your impressions are of the driving experience, if it makes any difference. Intuitively, I'd want the sensors as a fine tune, I would expect better fuel economy and performance if it was running closer to optimum. Still, the European cars cars all ran without them, so it can't be that bad!
#26
I've been running the non-feedback ECU for a few months. Can't really judge the 'non-feedback' aspect specifically because Roger gave it the "SuperEnhanced" treatment at the same time. The throttle response is better. I don't think actual absolute maximum power is increased but the part-throttle/mid-RPM acceleration is stronger.I had the same result years ago when I used the SuperEnhanced ECU in my XJS although, on that car, I kept the O2 sensors.
The idle quality is now stable and consistent. Previously the engine idled a bit differently each day of the week, seemingly.
Also, a slight cold hesitation problem, which I was never able to fully nail down, is gone completely
In short, the car has never run better! Very pleasant as a daily driver.
Cheers
DD
The idle quality is now stable and consistent. Previously the engine idled a bit differently each day of the week, seemingly.
Also, a slight cold hesitation problem, which I was never able to fully nail down, is gone completely
In short, the car has never run better! Very pleasant as a daily driver.
Cheers
DD
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Greg in France (11-21-2019)
#27
Cool!
I bought the SNG pipes, but realized the old cats had slip-over connection to the next pipe, and the SNG part has bell shape.
I was going to delete the square mufflers anyway, so planned to have a muffler shop fab the pipes. But, I don't think they can do the bell. I may have to supply some ends of pipe that have the bell for them to weld on.
Simply Performance has the delete pipes; that's another route.
I'm undecided about the O2 sensors.
It would be nice to have even a little bit more space in the area the Cat sits in!
Thanks,
Rob
I bought the SNG pipes, but realized the old cats had slip-over connection to the next pipe, and the SNG part has bell shape.
I was going to delete the square mufflers anyway, so planned to have a muffler shop fab the pipes. But, I don't think they can do the bell. I may have to supply some ends of pipe that have the bell for them to weld on.
Simply Performance has the delete pipes; that's another route.
I'm undecided about the O2 sensors.
It would be nice to have even a little bit more space in the area the Cat sits in!
Thanks,
Rob
#28
Cool!
I bought the SNG pipes, but realized the old cats had slip-over connection to the next pipe, and the SNG part has bell shape.
I was going to delete the square mufflers anyway, so planned to have a muffler shop fab the pipes. But, I don't think they can do the bell. I may have to supply some ends of pipe that have the bell for them to weld on.
Simply Performance has the delete pipes; that's another route.
I bought the SNG pipes, but realized the old cats had slip-over connection to the next pipe, and the SNG part has bell shape.
I was going to delete the square mufflers anyway, so planned to have a muffler shop fab the pipes. But, I don't think they can do the bell. I may have to supply some ends of pipe that have the bell for them to weld on.
Simply Performance has the delete pipes; that's another route.
But, I have a non-stock exhaust anyway. I simply had the muffler shop mate the downpipes to the existing system using flanges. I cobbled (and I mean cobbled!) some pipe together for temporary duty so I could get the car to the muffler shop.
It would be nice to have even a little bit more space in the area the Cat sits in!
I should mention that I undertook this task while also replacing the steering rack, as the one I installed a couple years ago proved to be defective. Dealing with the column-to-rack coupling is certainly easier with the big converters out of the picture!
Cheers
DD
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ronbros (11-21-2019)
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