Thorley Headers Install Questions
03-15-2011, 06:04 AM
#1
Registered User
Thread Starter
Thorley Headers Install Questions
I am getting close to getting my 4Runner back on the road. After test fitting the Y-pipe together which required a couple pipes to be trimmed I am attempting to install the O2 sensor and then a flanged 2 1/4" pipe back to the new muffler.
The reducer from Thorley that also has the O2 sensor bung comes in @ 2 1/2" and reduces down to 2". (I think that was to allow it to mate up with the original diameter of the cat, muffler, tail pipe, etc.)
The 2 1/4" flange is slightly larger, but mates up to the Thorey reducer flange fine. But because of its 2" output, should I use the Thorley reducer or have the exhaust shop fab me a new reducer/O2 bung that only decreases to 2 1/4", or does it matter?
Also, the O2 sensor moves considerably rearward with the default pipe lengths Thorley provides. Should I trim the 2 1/2" pipe that joins the two separate input pipes to bring the O2 sensor closer to its original location?
Thanks.
The reducer from Thorley that also has the O2 sensor bung comes in @ 2 1/2" and reduces down to 2". (I think that was to allow it to mate up with the original diameter of the cat, muffler, tail pipe, etc.)
The 2 1/4" flange is slightly larger, but mates up to the Thorey reducer flange fine. But because of its 2" output, should I use the Thorley reducer or have the exhaust shop fab me a new reducer/O2 bung that only decreases to 2 1/4", or does it matter?
Also, the O2 sensor moves considerably rearward with the default pipe lengths Thorley provides. Should I trim the 2 1/2" pipe that joins the two separate input pipes to bring the O2 sensor closer to its original location?
Thanks.
Sub'd too, just in case.
08-26-2011, 05:26 AM
#5
Registered User
Thread Starter
I finished this up back in March, and it turned out great IMO.
My exhaust shop recommended using the Thorley O2 bung even though it reduced down to 2". They reasoned that such a small constriction point would add some back pressure, without hampering the free flowing effects of the headers, muffler & 2.25" pipes. So I used the Thorley O2 reducer.
The 2.5" pipe that runs from the union of the "Y" back to that O2 reducer was way too long and I would have had to extend the O2 sensor wiring to reach that far back. I cut that 2.5" pipe down to approx. 6" in length, which kept my O2 sensor closer to the original location.
I tried running with no cat, straight from the O2 reducer back to a Flowmaster 50 SUV but it was ridiculously loud. I had the exhaust shop install a resonator where the cat would typically be, and it sounds really good. Rumbles like a V8 at idle, and has a nice deep throaty tone during acceleration, not ricey at all.
I'll try to get a picture of the pipe work this weekend and post it, but I am quite satisfied with how it turned out. I've put 2K miles on it since March with no ill effects and no codes thrown.
One last thing, make sure to re-torque the header bolts after 500 miles or so. I used the original Toyota exhaust studs and nuts, and they all needed to be tightened after a few miles and a few heat cycles.
Good luck with it.
My exhaust shop recommended using the Thorley O2 bung even though it reduced down to 2". They reasoned that such a small constriction point would add some back pressure, without hampering the free flowing effects of the headers, muffler & 2.25" pipes. So I used the Thorley O2 reducer.
The 2.5" pipe that runs from the union of the "Y" back to that O2 reducer was way too long and I would have had to extend the O2 sensor wiring to reach that far back. I cut that 2.5" pipe down to approx. 6" in length, which kept my O2 sensor closer to the original location.
I tried running with no cat, straight from the O2 reducer back to a Flowmaster 50 SUV but it was ridiculously loud. I had the exhaust shop install a resonator where the cat would typically be, and it sounds really good. Rumbles like a V8 at idle, and has a nice deep throaty tone during acceleration, not ricey at all.
I'll try to get a picture of the pipe work this weekend and post it, but I am quite satisfied with how it turned out. I've put 2K miles on it since March with no ill effects and no codes thrown.
One last thing, make sure to re-torque the header bolts after 500 miles or so. I used the original Toyota exhaust studs and nuts, and they all needed to be tightened after a few miles and a few heat cycles.
Good luck with it.
Last edited by Wrenchinjoe; 08-26-2011 at 06:06 AM.
08-26-2011, 05:01 PM
#6
YotaTech Milestone-Two Millionth Post
if i'm right, there are a total of 7 joints.....i could be wrong....anyways, we ended up with 4 leaks. 2 1/2 were handled well by just tightening more....i scored one as a 1/2 because it's the cross pipe and is a PITA and just plain old wont seal. the other on that remains to leak is the connection to to passenger's side header.....bad joint spot, ad choice, by me, of how to place the clamp.
take your time.
take your time.
use some sort of goop at the joints when joining them, i would say, i wish we did.
these are quality pipes.....IE: PITA to cut.
take your time.
take your time.
use some sort of goop at the joints when joining them, i would say, i wish we did.
these are quality pipes.....IE: PITA to cut.
08-27-2011, 02:04 PM
#7
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I finished this up back in March, and it turned out great IMO.
My exhaust shop recommended using the Thorley O2 bung even though it reduced down to 2". They reasoned that such a small constriction point would add some back pressure, without hampering the free flowing effects of the headers, muffler & 2.25" pipes. So I used the Thorley O2 reducer.
The 2.5" pipe that runs from the union of the "Y" back to that O2 reducer was way too long and I would have had to extend the O2 sensor wiring to reach that far back. I cut that 2.5" pipe down to approx. 6" in length, which kept my O2 sensor closer to the original location.
I tried running with no cat, straight from the O2 reducer back to a Flowmaster 50 SUV but it was ridiculously loud. I had the exhaust shop install a resonator where the cat would typically be, and it sounds really good. Rumbles like a V8 at idle, and has a nice deep throaty tone during acceleration, not ricey at all.
I'll try to get a picture of the pipe work this weekend and post it, but I am quite satisfied with how it turned out. I've put 2K miles on it since March with no ill effects and no codes thrown.
One last thing, make sure to re-torque the header bolts after 500 miles or so. I used the original Toyota exhaust studs and nuts, and they all needed to be tightened after a few miles and a few heat cycles.
Good luck with it.
My exhaust shop recommended using the Thorley O2 bung even though it reduced down to 2". They reasoned that such a small constriction point would add some back pressure, without hampering the free flowing effects of the headers, muffler & 2.25" pipes. So I used the Thorley O2 reducer.
The 2.5" pipe that runs from the union of the "Y" back to that O2 reducer was way too long and I would have had to extend the O2 sensor wiring to reach that far back. I cut that 2.5" pipe down to approx. 6" in length, which kept my O2 sensor closer to the original location.
I tried running with no cat, straight from the O2 reducer back to a Flowmaster 50 SUV but it was ridiculously loud. I had the exhaust shop install a resonator where the cat would typically be, and it sounds really good. Rumbles like a V8 at idle, and has a nice deep throaty tone during acceleration, not ricey at all.
I'll try to get a picture of the pipe work this weekend and post it, but I am quite satisfied with how it turned out. I've put 2K miles on it since March with no ill effects and no codes thrown.
One last thing, make sure to re-torque the header bolts after 500 miles or so. I used the original Toyota exhaust studs and nuts, and they all needed to be tightened after a few miles and a few heat cycles.
Good luck with it.
Do you have the chance to post those pics?
I'm running an Aero Turbine muffler and was thinking (depending on how everything initially sounds) of adding either a Vibrant Performance Resonator or an Aero Turbine Resonator. Or maybe just straight pipe where my cat is at with my current AT2525 muffler.
Hey thanks for your post, it's answered a couple questions and some. "high-five!" thanks.
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