cibercoco
24-02-2007, 20:18:28
Project Performance Spec V
Part IV: AEBS Header
Installation and Dyno Testing
By Naji Dahi (http://www.nissanforums.com/member.php?userid=452)
http://www.nissanperformancemag.com/june04/specv/images/final_header_tn2.jpg
In our last two installments we removed two restrictions on engine breathing - the stock intake system and the stock exhaust. In this installment we remove the last restriction, the stock exhaust manifold. To help reduce cold start emissions, Nissan saddled the Spec V with a pre-cat mounted at the mouth of the exhaust manifold. This design has not only made the Spec V exhaust manifold pretty restrictive, it has created a very serious problem. The pre-cat internals have a tendency to disintegrate under intense heat. When that happens, the small particles of the converter are drawn back into the motor, scoring cylinder walls, causing oil consumption, and unfortunately, leading to the untimely death of the motor. Nissan has issued a recall to try and fix this problem, but we believe that this problem will not go away and it is much safer to remove the pre-cat all together. Our AEBS (Advanced Engine Breathing System) header is, therefore, intended to produce more power and remove the pre-cat to prevent the untimely demise of our engine.
Description and Dimensions
The AEBS header is a three piece 4-2-1 design. The four primary pipes merge into two, then the two pipes merge into one right before the flange that attaches the primary to the secondary. This makes the primary into one long 90 degree piece. While this design makes the header much more flow efficient, it makes installation more difficult. We had to remove the cross-member and the radiator fans in order to install the AEBS header from underneath the car. By contrast, the flex pipe equipped secondary is pretty short. The final part of the header is the hi-flow catalytic converter.
The AEBS header design is somewhat unique. Rather than merging the primaries from the two top dead center cylinders as is commonly done, AEBS merged the primaries from the cylinders that open their exhaust valves one after the other, in hope of lining the two pulses in sequence at the collector. Their tri-y header merges the number one and two cylinders while the three and four cylinders are together. AEBS claims that this produces top end horsepower for big displacement four cylinder engines like that of our Spec V.
http://www.nissanperformancemag.com/june04/specv/images/aebs_stock_1_tn.jpg (http://www.nissanperformancemag.com/june04/specv/images/aebs_stock_1.jpg)
The AEBS header comes with all the necessary hardware that you will need for the install. The most important part of the hardware is the second oxygen sensor extension wire. You will have to extend the second oxygen sensor and relocate it from after the stock pre-cat to AEBS hi-flow cat. When extending the second O2 sensor harness (Blue Connector) using the loom provided please pay close attention to the following: The O2 sensor has four wires: Black, grey, and two white. The two white wires do not have any markings on the insulation. That is why it is very important to mark one of them before the harness is cut. We used a green paint pen and put a strip down the entire length of one of the white wires, then cut the harness in the middle. The AEBS Loom also has 2 white wires. We used an ohm meter to match the ends and marked them with green paint. Now comes the easy part. Just strip the ends, match the colors and crimp: Black to black, Grey to Grey, white to white, white/green to white/green.
The AEBS header is made of mild steel and is ceramic coated to help in heat dissipation. The four primary pipes range in dimension from 1.6 inch to 1.9 inch. After the four pipes merge the two pipes have a dimension of between 2.2 to 2.3 inch. Finally, the collector on the primary is 2.523 inch in diameter on the outside and 2.467 inch on the inside. The secondary has a diameter of between 2.5 and 2.47 inch. All in all, the AEBS header is very consistent in diameter and its phalanges are constructed of 3/8 inch thick steel to prevent heat induced warping. Furthermore, the AEBS header weighs in at 20 pounds, 10 pounds less than the stock exhaust manifold and secondary.
Installation
The AEBS header comes with all the necessary hardware as well as detailed instructions. At first we decided to disregard the instructions about removing the cross member, the top radiator hose (you must drain some of the radiator fluid to do this), and the radiator fans. We thought (erroneously) that we can remove the stock header and install the AEBS primary from the engine bay. While the former was possible (after removing the heat shields), the latter was impossible. So please do not make our mistake and simply follow the following instructions.
Part IV: AEBS Header
Installation and Dyno Testing
By Naji Dahi (http://www.nissanforums.com/member.php?userid=452)
http://www.nissanperformancemag.com/june04/specv/images/final_header_tn2.jpg
In our last two installments we removed two restrictions on engine breathing - the stock intake system and the stock exhaust. In this installment we remove the last restriction, the stock exhaust manifold. To help reduce cold start emissions, Nissan saddled the Spec V with a pre-cat mounted at the mouth of the exhaust manifold. This design has not only made the Spec V exhaust manifold pretty restrictive, it has created a very serious problem. The pre-cat internals have a tendency to disintegrate under intense heat. When that happens, the small particles of the converter are drawn back into the motor, scoring cylinder walls, causing oil consumption, and unfortunately, leading to the untimely death of the motor. Nissan has issued a recall to try and fix this problem, but we believe that this problem will not go away and it is much safer to remove the pre-cat all together. Our AEBS (Advanced Engine Breathing System) header is, therefore, intended to produce more power and remove the pre-cat to prevent the untimely demise of our engine.
Description and Dimensions
The AEBS header is a three piece 4-2-1 design. The four primary pipes merge into two, then the two pipes merge into one right before the flange that attaches the primary to the secondary. This makes the primary into one long 90 degree piece. While this design makes the header much more flow efficient, it makes installation more difficult. We had to remove the cross-member and the radiator fans in order to install the AEBS header from underneath the car. By contrast, the flex pipe equipped secondary is pretty short. The final part of the header is the hi-flow catalytic converter.
The AEBS header design is somewhat unique. Rather than merging the primaries from the two top dead center cylinders as is commonly done, AEBS merged the primaries from the cylinders that open their exhaust valves one after the other, in hope of lining the two pulses in sequence at the collector. Their tri-y header merges the number one and two cylinders while the three and four cylinders are together. AEBS claims that this produces top end horsepower for big displacement four cylinder engines like that of our Spec V.
http://www.nissanperformancemag.com/june04/specv/images/aebs_stock_1_tn.jpg (http://www.nissanperformancemag.com/june04/specv/images/aebs_stock_1.jpg)
The AEBS header comes with all the necessary hardware that you will need for the install. The most important part of the hardware is the second oxygen sensor extension wire. You will have to extend the second oxygen sensor and relocate it from after the stock pre-cat to AEBS hi-flow cat. When extending the second O2 sensor harness (Blue Connector) using the loom provided please pay close attention to the following: The O2 sensor has four wires: Black, grey, and two white. The two white wires do not have any markings on the insulation. That is why it is very important to mark one of them before the harness is cut. We used a green paint pen and put a strip down the entire length of one of the white wires, then cut the harness in the middle. The AEBS Loom also has 2 white wires. We used an ohm meter to match the ends and marked them with green paint. Now comes the easy part. Just strip the ends, match the colors and crimp: Black to black, Grey to Grey, white to white, white/green to white/green.
The AEBS header is made of mild steel and is ceramic coated to help in heat dissipation. The four primary pipes range in dimension from 1.6 inch to 1.9 inch. After the four pipes merge the two pipes have a dimension of between 2.2 to 2.3 inch. Finally, the collector on the primary is 2.523 inch in diameter on the outside and 2.467 inch on the inside. The secondary has a diameter of between 2.5 and 2.47 inch. All in all, the AEBS header is very consistent in diameter and its phalanges are constructed of 3/8 inch thick steel to prevent heat induced warping. Furthermore, the AEBS header weighs in at 20 pounds, 10 pounds less than the stock exhaust manifold and secondary.
Installation
The AEBS header comes with all the necessary hardware as well as detailed instructions. At first we decided to disregard the instructions about removing the cross member, the top radiator hose (you must drain some of the radiator fluid to do this), and the radiator fans. We thought (erroneously) that we can remove the stock header and install the AEBS primary from the engine bay. While the former was possible (after removing the heat shields), the latter was impossible. So please do not make our mistake and simply follow the following instructions.