barracuda423 Posted November 8, 2013 Share Posted November 8, 2013 hi i just bought a 1986 subaru brat with a 1.8 carbureted engine. i was looking for a non catalytic converter y pipe but cant find anything, i was wondering if a uel single port headers from a 2.2 or a 2.5 would work with this engine ~Zack Link to comment Share on other sites More sharing options...
ford'ssubaru's Posted November 8, 2013 Share Posted November 8, 2013 I may be mistaken but what you are thinking is a cat is a crossover chamber. My boys and I ran dual exhaust on both rigs right after the crossover chamber. We purchased individual hi end cat for emissions purposes and placed them right before the cherry bombs on both sides. It does not mess with the back pressure and sounds awesome....... Link to comment Share on other sites More sharing options...
tractor pole Posted November 8, 2013 Share Posted November 8, 2013 No the flanges are completely different and I believe that the ea 81 is narrower between the exhaust ports than the ej. 1 Link to comment Share on other sites More sharing options...
Gloyale Posted November 8, 2013 Share Posted November 8, 2013 hi i just bought a 1986 subaru brat with a 1.8 carbureted engine. i was looking for a non catalytic converter y pipe but cant find anything, i was wondering if a uel single port headers from a 2.2 or a 2.5 would work with this engine ~Zack No the EJ headers will not work. Gotta make it or use one with a CAT. Link to comment Share on other sites More sharing options...
BoxerRebellion Posted November 8, 2013 Share Posted November 8, 2013 And the fortune cookie says... "custom exhaust is in your future." 1 Link to comment Share on other sites More sharing options...
barracuda423 Posted November 8, 2013 Author Share Posted November 8, 2013 darn i was hoping i didnt have to go custom so i could just bolt it on but if i have to then i will, the thing is i was looking for like a 3" exhaust Link to comment Share on other sites More sharing options...
Captin Hook Posted November 11, 2013 Share Posted November 11, 2013 3" is way to big for a ea81 motor. 2 1/2 is as big as you would want to go. Link to comment Share on other sites More sharing options...
ford'ssubaru's Posted November 11, 2013 Share Posted November 11, 2013 3" is way to big for a ea81 motor. 2 1/2 is as big as you would want to go. This is very true. Subaru engines are designed to have backpressure. Link to comment Share on other sites More sharing options...
MilesFox Posted November 11, 2013 Share Posted November 11, 2013 (edited) People always confuse the term 'backpressure' with 'scavenging'. The idea of scavenging is keeping the exhaust velocity up to pull exhaust out of the combustion chamber. The idea of 'backpressure' is the exhaust pulses reflecting in the system to give a charging effect, especially with expansion chambers in 2-stroke engines. Edited November 11, 2013 by MilesFox 1 Link to comment Share on other sites More sharing options...
el_freddo Posted November 13, 2013 Share Posted November 13, 2013 3" is way to big for a ea81 motor. 2 1/2 is as big as you would want to go. And with that said, I've got an EJ22 with a 2 1/4 inch exhaust and I reckon that's plenty big. Personally I'd be looking at a 2 inch exhaust, but if you're building the extractors you might as well port match from the head then go the two inch after the cat and do what you want from there. To big too early leads to a bad sound and poor performance... Cheers Bennie Link to comment Share on other sites More sharing options...
TomRhere Posted November 16, 2013 Share Posted November 16, 2013 I built a dual exhaust system under one of my BRAT's using 2" tube. It did not like it... 1-7/8" ID from the heads back to about a 26" length, then go up to a 2"ID system is about the best you can do. Link to comment Share on other sites More sharing options...
ford'ssubaru's Posted December 14, 2013 Share Posted December 14, 2013 I built a dual exhaust system under one of my BRAT's using 2" tube. It did not like it... 1-7/8" ID from the heads back to about a 26" length, then go up to a 2"ID system is about the best you can do. I learned this lesson too. Made it look really good too. Gotta have that crossover. Had to refab my fab....LOL. Link to comment Share on other sites More sharing options...
TomRhere Posted December 14, 2013 Share Posted December 14, 2013 Yeah, spent a long day building that system. Fit a piece, mark next piece, cut, refit, mark more. Run to the shop cut and tack weld. Refit and see what needed to be done next. Yadda, yadda, yadda. It sounded so good!!!! But it sure destroyed what little HP/Torque that engine had. Really didn't have much for oomph down low, but it ran good on the highway. 1-7/8" ID lead pipes for sure, and like I said, 26 or so inches long. Then,,, you can jump to 2" ID to finish things. Tying the 2 banks together is a good thing also, just have to decide that one yourself as to where it should be done. Old school exhaust build trick was to use some cheap White paint to cover the pipes. Give it a run around town, see where paint was the darkest as far as being burnt. That is where you need to put a crossover pipe in. Link to comment Share on other sites More sharing options...
ford'ssubaru's Posted December 20, 2013 Share Posted December 20, 2013 People always confuse the term 'backpressure' with 'scavenging'. The idea of scavenging is keeping the exhaust velocity up to pull exhaust out of the combustion chamber. The idea of 'backpressure' is the exhaust pulses reflecting in the system to give a charging effect, especially with expansion chambers in 2-stroke engines. I r a heavy equipment meknic....I stand corrected...:-). In the future I will use the proper term. It is stll correct that you can't go too large or you lose performance correct? When I first made mine it ran like crap with not very much oompf..( I use the word OOMPF loosely) with the EA82. I went back down and it sounded better and ran better. I spent a lot of time on that exhaust....LOL. Link to comment Share on other sites More sharing options...
skishop69 Posted December 21, 2013 Share Posted December 21, 2013 Correct. As previously stated, you loose the scavenging effect and suffer a loss of low end torque and HP. 1 Link to comment Share on other sites More sharing options...
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