crasster Posted May 4, 2011 Share Posted May 4, 2011 Okay on another thread I'm talking about a possible catalytic converter that I'm possibly having trouble with. Now I made an ever weirder discovery. The opening hole on the catalytic converter is 2". It "looks" like the pipe is 2" coming out of the exhaust manifold after the O2 sensor. After the catalytic converter, it looks as though the pipe "flares down" to 1.75". If I cut out all the pipe after the converter (it's pretty bad rusty pipe anyway) and installed 2" pipe, could that possibly give me more HP? (I found a new "universal" catalytic converter 2" weld on for $50 with shipping probably would be worth it) (the muffler is 2" with "flare up & flare down" connectors"). Just wondering if it would be significant HP, or pretty redundant. Thanks Quote Link to comment Share on other sites More sharing options...
Derek up North Posted May 4, 2011 Share Posted May 4, 2011 I doubt it would hurt, but I also doubt there would be a noticeable increase. 22RE, right? Quote Link to comment Share on other sites More sharing options...
crasster Posted May 4, 2011 Author Share Posted May 4, 2011 I doubt it would hurt, but I also doubt there would be a noticeable increase. 22RE, right? Yeah 22re 1987 Dolphin Quote Link to comment Share on other sites More sharing options...
waiter Posted May 4, 2011 Share Posted May 4, 2011 Interesting, Every time I walk behind my Dolphin and see that tiny exhaust pipe, I ask the same question! Probably if I was replacing the exhaust, I would opt for a larger diameter pipe. John Mc 88 Dolphin 4 Auto Quote Link to comment Share on other sites More sharing options...
Allen Posted May 5, 2011 Share Posted May 5, 2011 If you intend to replace your catalytic converter too, now would be a good time to start upgrading everything to at least 2.25" or 2.5". 2.25" is the outlet size of 22R/RE headers made by either Doug Thorley their Try-Y header (http://dougthorleyheaders.com/) or LC Engineering (http://www.toyotacat...lass=154&Page=2). If you indeed have a 22RE, than a 2.5" exhaust system will be just fine. If you have just a 22R (i.e. carb), then I would only go with the 2.25"*. LC Engineering sells 2.25" bolt in catalytic converters (http://www.toyotacat...cat%20converter) for our Toyota motorhomes (i.e. 2WD pickups). If you want a 2.5" catalytic converter, then a MagnaFlow 22767 should work just fine (1/8" shorter than stock). From Wikipedia (http://en.wikipedia..../Exhaust_system) under Exhaust System Tuning: "Many automotive companies offer aftermarket exhaust system upgrades as a subcategory of engine tuning. This is often fairly expensive as it usually includes replacing the entire exhaust manifold or other large components. These upgrades however can significantly improve engine performance and do this through means of two main principles: By reducing the exhaust back pressure, engine power is increased in four-stroke engines By reducing the amount of heat from the exhaust being lost into the underbonnet area. This reduces the underbonnet temperature and consequently lowers the intake manifold temperature, increasing power. This also has positive side effect of preventing heat-sensitive components from being damaged. Furthermore, keeping the heat in the exhaust gases speeds these up, therefore reducing back pressure as well. Back pressure is most commonly reduced by replacing exhaust manifolds with headers, which have smoother bends and normally wider pipe diameters." Have fun! *Note: I also have a 1985 Toyota pickup w/ a 22R, and I installed a Downey 2.5" CAT back system. Unfortunately, the carburetor even with an O2 sensor can not fully compensate for the now free flowing exhaust and I lost 2 mpg (from 25-27mpg to 23-25mpg), but it does have more power at the higher RPMs and sounds great! Quote Link to comment Share on other sites More sharing options...
elderthewelder Posted May 8, 2011 Share Posted May 8, 2011 (edited) If you intend to replace your catalytic converter too, now would be a good time to start upgrading everything to at least 2.25" or 2.5". 2.25" is the outlet size of 22R/RE headers made by either Doug Thorley their Try-Y header (http://dougthorleyheaders.com/) or LC Engineering (http://www.toyotacat...lass=154&Page=2). If you indeed have a 22RE, than a 2.5" exhaust system will be just fine. If you have just a 22R (i.e. carb), then I would only go with the 2.25"*. LC Engineering sells 2.25" bolt in catalytic converters (http://www.toyotacat...cat%20converter) for our Toyota motorhomes (i.e. 2WD pickups). If you want a 2.5" catalytic converter, then a MagnaFlow 22767 should work just fine (1/8" shorter than stock). From Wikipedia (http://en.wikipedia..../Exhaust_system) under Exhaust System Tuning: "Many automotive companies offer aftermarket exhaust system upgrades as a subcategory of engine tuning. This is often fairly expensive as it usually includes replacing the entire exhaust manifold or other large components. These upgrades however can significantly improve engine performance and do this through means of two main principles: By reducing the exhaust back pressure, engine power is increased in four-stroke engines By reducing the amount of heat from the exhaust being lost into the underbonnet area. This reduces the underbonnet temperature and consequently lowers the intake manifold temperature, increasing power. This also has positive side effect of preventing heat-sensitive components from being damaged. Furthermore, keeping the heat in the exhaust gases speeds these up, therefore reducing back pressure as well. Back pressure is most commonly reduced by replacing exhaust manifolds with headers, which have smoother bends and normally wider pipe diameters." Have fun! *Note: I also have a 1985 Toyota pickup w/ a 22R, and I installed a Downey 2.5" CAT back system. Unfortunately, the carburetor even with an O2 sensor can not fully compensate for the now free flowing exhaust and I lost 2 mpg (from 25-27mpg to 23-25mpg), but it does have more power at the higher RPMs and sounds great! I have a Doug Thorley tri-y that i bought off craigslist, when I get around to putting a new motor in my rig i was considering running the tri-y and new 2.250 pipe into a magnaflow muffler, deleating the cat all together. anyone see a issue with this? my rig is no longer required to go through any type of inspections, and i am looking to pick up a little more HP. I have the 22RE and the 02 sensor is before the cat right now, and is on the tri y header when gets installed Edited May 8, 2011 by elderthewelder Quote Link to comment Share on other sites More sharing options...
Allen Posted May 10, 2011 Share Posted May 10, 2011 If you have an 85-88 22RE, and you run a very efficient exhaust system that gets the heat out, you might have to change your original style 1 wire oxygen sensor to a 89 and later 4 wire heated oxygen sensor. I had a problem with mine that it ran rich at an idle and was failing emissions, since the oxygen sensor was not running hot enough to work correctly at an idle. It was fine on the highway. See the following link: http://toyotamotorho...h=1 . In addition, depending on your chassis, you might need a special adapter that routes the exhaust from the tri-y around your driver side torsion bar. I did. It did not come with the header. Doug Thorley sent it to me free of charge. You can see a partial picture of this in my member pictures. Note: Doug Thorley makes a few different tri-y headers for our motorhomes/trucks. They differ because of emission equipment. Hopefully the one you have will work for your application or can be made to work.. If you do not have your Magnaflow muffler yet, you may want to consider getting either an Aero Exhaust Aero Turbine AT2525 (a little loud) or an AT2525XL (w/ built in resonator) while you can. They made a very efficient muffler, but unfortunately they went out of business. I am running the AT2525 on our Sunrader, and my wife's 2002 Malibu. You can find out more about the muffler here (Aero Exhaust's website had a lot of great information on it, until it was taken down): http://www.parleysdi...rmance-mufflers . From looking on the Internet tonight, there is at least one site that used to sell Aero mufflers, and are sold out. Since you have the 22RE, you might want to consider going to a 2.5" exhaust if you are replacing the entire system. Good luck! Quote Link to comment Share on other sites More sharing options...
elderthewelder Posted May 10, 2011 Share Posted May 10, 2011 If you have an 85-88 22RE, and you run a very efficient exhaust system that gets the heat out, you might have to change your original style 1 wire oxygen sensor to a 89 and later 4 wire heated oxygen sensor. I had a problem with mine that it ran rich at an idle and was failing emissions, since the oxygen sensor was not running hot enough to work correctly at an idle. It was fine on the highway. See the following link: http://toyotamotorho...h=1 . In addition, depending on your chassis, you might need a special adapter that routes the exhaust from the tri-y around your driver side torsion bar. I did. It did not come with the header. Doug Thorley sent it to me free of charge. You can see a partial picture of this in my member pictures. Note: Doug Thorley makes a few different tri-y headers for our motorhomes/trucks. They differ because of emission equipment. Hopefully the one you have will work for your application or can be made to work.. If you do not have your Magnaflow muffler yet, you may want to consider getting either an Aero Exhaust Aero Turbine AT2525 (a little loud) or an AT2525XL (w/ built in resonator) while you can. They made a very efficient muffler, but unfortunately they went out of business. I am running the AT2525 on our Sunrader, and my wife's 2002 Malibu. You can find out more about the muffler here (Aero Exhaust's website had a lot of great information on it, until it was taken down): http://www.parleysdi...rmance-mufflers . From looking on the Internet tonight, there is at least one site that used to sell Aero mufflers, and are sold out. Since you have the 22RE, you might want to consider going to a 2.5" exhaust if you are replacing the entire system. Good luck! what are your thoughts on deleting the cat? Quote Link to comment Share on other sites More sharing options...
Maineah Posted May 11, 2011 Share Posted May 11, 2011 Depending where you are a lot of inspections are visual. Also it is illegal and it's part of keeping the air we all breath clean. Quote Link to comment Share on other sites More sharing options...
waiter Posted May 11, 2011 Share Posted May 11, 2011 what are your thoughts on deleting the cat? If your in Calif, don't do it, you'll never pass another SMOG inspection. I don't believe there is an O2 sensor after the Cat Converter, so it would probably be OK as far as emissions controls are concerned. HOWEVER - If the Cat Converter is plugged, this is a sign of another problem, either running to rich, or silica in the exhaust (water - antifreeze). John Mc 88 Dolphin 4 Auto Quote Link to comment Share on other sites More sharing options...
elderthewelder Posted May 11, 2011 Share Posted May 11, 2011 If your in Calif, don't do it, you'll never pass another SMOG inspection. I don't believe there is an O2 sensor after the Cat Converter, so it would probably be OK as far as emissions controls are concerned. HOWEVER - If the Cat Converter is plugged, this is a sign of another problem, either running to rich, or silica in the exhaust (water - antifreeze). John Mc 88 Dolphin 4 Auto do not live in Calif, just passed my last emission inspection for this vehicle, 02 sensor is BEFORE the cat, existing cat is not plugged and i have no check engine lights. just see no need for the cat when I re-do my exhaust Quote Link to comment Share on other sites More sharing options...
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