LS6 IS300 Swap Sleeper Exhaust
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LS6 IS300 Swap Sleeper Exhaust
I am putting parts together to swap an LS6/T56 into my Lexus IS300. I want the car to be as low key and sleeper as possible so I can really surprise the hell out of a few guys around here. It will have to have custom fabbed LT headers to fit so that will make it a lot louder right there, a mild cam, which again makes it that much louder, and I wasn't planning on putting any cats on either. I was relying on this setup to suit my needs and provide plenty of power:
-3" pipes off headers merging into high velocity collector which turns into a 4"
-4" electric cutout
-Then stepped down into the stock Lexus 2.25" catback
My last T/A did GREAT with this 4" merge Y/cutout combo, even on a nearly stock catback. I figure the stock Lexus catback will do a lot to keep it quiet, even with longtubes, a cam, and no cats. I'm just wondering, even with the big 4" cutout open, will the exhaust slamming down into the restrictive 2.25" hurt the performance significantly?
-3" pipes off headers merging into high velocity collector which turns into a 4"
-4" electric cutout
-Then stepped down into the stock Lexus 2.25" catback
My last T/A did GREAT with this 4" merge Y/cutout combo, even on a nearly stock catback. I figure the stock Lexus catback will do a lot to keep it quiet, even with longtubes, a cam, and no cats. I'm just wondering, even with the big 4" cutout open, will the exhaust slamming down into the restrictive 2.25" hurt the performance significantly?
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Yeah, thats why I figured it would be so quiet though. On the other hand, it wouldn't be too good if it trapped too much heat and gasses when the cutout was closed, which would be the majority of the time. I'll just go with a stock f-body muffler or something like an SLP Dual/Dual (which is what I had before) if its totally necessary. Even that was louder than what I really want with this though, even with the cutout closed and a 224/230 cam.
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A dual/dual flows better then a stock f body muffler. The stock muffler should be dead silent though, at the expense of hp, obviously. Dual, Dual will give you a hint of sound but give you some hp back when the cut-out is closed. Tough decision.
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That's gonna be a sweet build ,my buddy did a is300 but with some jzitzu motor and a turbo,was a fun car though, a ls motor is gonna be pretty sweet,I don't know about the stock muffler,I see that beeing one hell of a restriction,I saw on 2 guys garage where they did a m5 with a ls3,they custom made a dual exhaust with a lot of magnaflow stuff,he didn't want it loud at all,but didn't want a restriction
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Dedicated-Matt was the first to do the LS1 swap in an IS300 with this car:
He made this first Y setup mostly out of aluminum so it was super light:
This first Y had only 2.5" pipes going into a 3" merge. Mine would be 2 3" pipes going into a 4".
This year he upgraded to an LS3:
He also went from the Y setup to a custom true dual:
This guy does some amazing work. He actually has this car up for sale right now for $25k, which is hard to immulate considering all the parts, fab work, and labor involved, not to mention other upgrades he has done like a $3k coilover kit. I was already in the process of putting together parts to convert my black '02 IS so I guess I'll just keep chippin away at it little by little myself. I have a great 35k mile LS6 out of an '04 Z06 to work with so I think it will turn out pretty nice.
He made this first Y setup mostly out of aluminum so it was super light:
This first Y had only 2.5" pipes going into a 3" merge. Mine would be 2 3" pipes going into a 4".
This year he upgraded to an LS3:
He also went from the Y setup to a custom true dual:
This guy does some amazing work. He actually has this car up for sale right now for $25k, which is hard to immulate considering all the parts, fab work, and labor involved, not to mention other upgrades he has done like a $3k coilover kit. I was already in the process of putting together parts to convert my black '02 IS so I guess I'll just keep chippin away at it little by little myself. I have a great 35k mile LS6 out of an '04 Z06 to work with so I think it will turn out pretty nice.
Last edited by bluebird71; 04-07-2011 at 09:58 AM.
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Dedicated-Matt was the first to do the LS1 swap in an IS300 with this car:
This year he upgraded to an LS3:
He also went from the Y setup to a custom true dual:
This guy does some amazing work. He actually has this car up for sale right now for $25k, which is hard to immulate considering all the parts, fab work, and labor involved, not to mention other upgrades he has done like a $3k coilover kit. I was already in the process of putting together parts to convert my black '02 IS so I guess I'll just keep chippin away at it little by little myself. I have a great 35k mile LS6 out of an '04 Z06 to work with so I think it will turn out pretty nice.
This year he upgraded to an LS3:
He also went from the Y setup to a custom true dual:
This guy does some amazing work. He actually has this car up for sale right now for $25k, which is hard to immulate considering all the parts, fab work, and labor involved, not to mention other upgrades he has done like a $3k coilover kit. I was already in the process of putting together parts to convert my black '02 IS so I guess I'll just keep chippin away at it little by little myself. I have a great 35k mile LS6 out of an '04 Z06 to work with so I think it will turn out pretty nice.
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#10
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IMO, it looks like you could run a Magnaflow #12599(dual 3" in/out) in place of the merger then run 3" mandrel bends out of it into a Magnaflow #11219 (3" in/out) on the left and right side. You wouldn't lose any flow so you could totally skip on using a cut-out, and considering your setup it should be fairly quiet. If you want it even quieter then run a Magnaflow # 12909 (3.5" in/out) right after the merger then run it into a single Magnaflow #14151 (3.5" in/out) or into 2 Magnaflow #11219's(3" in/out) one on each side, which should be quieter yet.
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IMO, it looks like you could run a Magnaflow #12599(dual 3" in/out) in place of the merger then run 3" mandrel bends out of it into a Magnaflow #11219 (3" in/out) on the left and right side. You wouldn't lose any flow so you could totally skip on using a cut-out, and considering your setup it should be fairly quiet. If you want it even quieter then run a Magnaflow # 12909 (3.5" in/out) right after the merger then run it into a single Magnaflow #14151 (3.5" in/out) or into 2 Magnaflow #11219's(3" in/out) one on each side, which should be quieter yet.