Welding high flow cats to stock headers
01-22-16, 06:33 AM
#16
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Can you please post up a link or a pic of a dyno run of someone with an aftermarket exhaust (Joe-Z/Borla/ISS etc....) with gutted primaries that is putting out the same numbers as PPE/Sikky headers gains???
Just curious, because I have never seen one posted here on CL of a dyno run with gutted primaries/aftermarket exhaust only......
Thx
Just curious, because I have never seen one posted here on CL of a dyno run with gutted primaries/aftermarket exhaust only......
Thx
https://www.clublexus.com/forums/is-...o-d-the-f.html
01-22-16, 08:10 AM
#17
Pole Position
^^^^^Thanks for that link, after reading it I remember reading it last year sometime. That's awesome that you were able to hit 400WHP with a custom exhaust and gutted primaries!
I still can't figure out why the ISF has such huge variances in dyno runs with similar mods?? Example: Rafi in the RR-Racing tune thread he hit 350ish WHP with basically the same set-up as yours (Aftermarket Exhaust & Gutted Primaries)? The numbers should've been more close to what yours were IMO.........
I still can't figure out why the ISF has such huge variances in dyno runs with similar mods?? Example: Rafi in the RR-Racing tune thread he hit 350ish WHP with basically the same set-up as yours (Aftermarket Exhaust & Gutted Primaries)? The numbers should've been more close to what yours were IMO.........
01-22-16, 03:49 PM
#18
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^^^^^Thanks for that link, after reading it I remember reading it last year sometime. That's awesome that you were able to hit 400WHP with a custom exhaust and gutted primaries!
I still can't figure out why the ISF has such huge variances in dyno runs with similar mods?? Example: Rafi in the RR-Racing tune thread he hit 350ish WHP with basically the same set-up as yours (Aftermarket Exhaust & Gutted Primaries)? The numbers should've been more close to what yours were IMO.........
I still can't figure out why the ISF has such huge variances in dyno runs with similar mods?? Example: Rafi in the RR-Racing tune thread he hit 350ish WHP with basically the same set-up as yours (Aftermarket Exhaust & Gutted Primaries)? The numbers should've been more close to what yours were IMO.........
01-22-16, 04:40 PM
#19
The exhaust manifold design on the ISF is terrible IMO.I am guessing you are going by "what looks" pretty, and that concludes to a good flow design. How would you know the OEM exhaust manifold design is terrible and flawed? Do you have flow charts to back your claim up? While I do believe the PPE/Sikky headers do flow better, I wouldn't go so far to say the OEM design(as ugly as it is) is completely terrible in function. I believe there is one member here who claims his gutted ISF kept up with other ISFs with aftermarket headers. So yah, I wouldn't say OEM is terrible in design...it is the added cats that choke off the power. I have seen some ugly manifolds that perform better than custom made equal length ceramic coated headers. An even uglier example would be the log style manifolds for turbo engines, they look even ****tier than OEM...but they have less lag, spool faster, and give more torque than nice sounding tubular manifolds. Again, just because it doesn't look pretty or look like it flows well, doesn't exact mean the design/function sucks and robs your engine of power.
Last edited by Fsport2UR; 01-22-16 at 04:45 PM.
01-22-16, 06:07 PM
#20
Lexus Champion
iTrader: (20)
See sonicblu post to his link.
I am guessing you are going by "what looks" pretty, and that concludes to a good flow design. How would you know the OEM exhaust manifold design is terrible and flawed? Do you have flow charts to back your claim up? While I do believe the PPE/Sikky headers do flow better, I wouldn't go so far to say the OEM design(as ugly as it is) is completely terrible in function. I believe there is one member here who claims his gutted ISF kept up with other ISFs with aftermarket headers. So yah, I wouldn't say OEM is terrible in design...it is the added cats that choke off the power. I have seen some ugly manifolds that perform better than custom made equal length ceramic coated headers. An even uglier example would be the log style manifolds for turbo engines, they look even ****tier than OEM...but they have less lag, spool faster, and give more torque than nice sounding tubular manifolds. Again, just because it doesn't look pretty or look like it flows well, doesn't exact mean the design/function sucks and robs your engine of power.
I am guessing you are going by "what looks" pretty, and that concludes to a good flow design. How would you know the OEM exhaust manifold design is terrible and flawed? Do you have flow charts to back your claim up? While I do believe the PPE/Sikky headers do flow better, I wouldn't go so far to say the OEM design(as ugly as it is) is completely terrible in function. I believe there is one member here who claims his gutted ISF kept up with other ISFs with aftermarket headers. So yah, I wouldn't say OEM is terrible in design...it is the added cats that choke off the power. I have seen some ugly manifolds that perform better than custom made equal length ceramic coated headers. An even uglier example would be the log style manifolds for turbo engines, they look even ****tier than OEM...but they have less lag, spool faster, and give more torque than nice sounding tubular manifolds. Again, just because it doesn't look pretty or look like it flows well, doesn't exact mean the design/function sucks and robs your engine of power.
but i still rather have PPE headers, all said and done.
05-09-17, 08:04 PM
#21
Hi everyone, i recently gutted the primary cats on my ISF, and removed the secondary cats (OEM Exhaust). I drove the car for one week and the smell is unbearable. Today I installed the Magnaflow hi flow cats [ installed at the same spot (secondary cats)}. My question is it okay to install the Hi flow cats after the o2 sensors? Note: I have the rr Racing tune, and i'm planning to buy the Borla Catback in the very near future.
Thanks!
Thanks!
05-10-17, 03:10 AM
#22
Racer
^ Yes I'd also be interested in this, is it ok to install HCFs after the O2 Sensors?
05-10-17, 03:12 AM
#23
Racer
^ From this thread seems like Caymandive was planning on installing them after the O2 Sensors but from the pics seems like he went before the O2 Sensors, ---> https://www.clublexus.com/forums/is-...s-here-13.html
Caymandive can you let us know why you installed the cats before the O2 Sensors? also looks like you had to add O2 Extenders.
Caymandive can you let us know why you installed the cats before the O2 Sensors? also looks like you had to add O2 Extenders.
05-10-17, 04:02 AM
#24
^ From this thread seems like Caymandive was planning on installing them after the O2 Sensors but from the pics seems like he went before the O2 Sensors, ---> https://www.clublexus.com/forums/is-...s-here-13.html
Caymandive can you let us know why you installed the cats before the O2 Sensors? also looks like you had to add O2 Extenders.
Caymandive can you let us know why you installed the cats before the O2 Sensors? also looks like you had to add O2 Extenders.
05-10-17, 09:18 AM
#27
See sonicblu post to his link.
I am guessing you are going by "what looks" pretty, and that concludes to a good flow design. How would you know the OEM exhaust manifold design is terrible and flawed? Do you have flow charts to back your claim up? While I do believe the PPE/Sikky headers do flow better, I wouldn't go so far to say the OEM design(as ugly as it is) is completely terrible in function. I believe there is one member here who claims his gutted ISF kept up with other ISFs with aftermarket headers. So yah, I wouldn't say OEM is terrible in design...it is the added cats that choke off the power. I have seen some ugly manifolds that perform better than custom made equal length ceramic coated headers. An even uglier example would be the log style manifolds for turbo engines, they look even ****tier than OEM...but they have less lag, spool faster, and give more torque than nice sounding tubular manifolds. Again, just because it doesn't look pretty or look like it flows well, doesn't exact mean the design/function sucks and robs your engine of power.
I am guessing you are going by "what looks" pretty, and that concludes to a good flow design. How would you know the OEM exhaust manifold design is terrible and flawed? Do you have flow charts to back your claim up? While I do believe the PPE/Sikky headers do flow better, I wouldn't go so far to say the OEM design(as ugly as it is) is completely terrible in function. I believe there is one member here who claims his gutted ISF kept up with other ISFs with aftermarket headers. So yah, I wouldn't say OEM is terrible in design...it is the added cats that choke off the power. I have seen some ugly manifolds that perform better than custom made equal length ceramic coated headers. An even uglier example would be the log style manifolds for turbo engines, they look even ****tier than OEM...but they have less lag, spool faster, and give more torque than nice sounding tubular manifolds. Again, just because it doesn't look pretty or look like it flows well, doesn't exact mean the design/function sucks and robs your engine of power.
agreed somewhat. people see "tubular" shiny headers and think it will make more gains. On my s85 engine (bmw m6), its popular to just gut the cats . same gains but you keep the strong welds of the stock manifolds unlike the aftermarket units sometimes cracking with miles.
but i still rather have PPE headers, all said and done.
but i still rather have PPE headers, all said and done.
