Air Pump Removal?
12-03-2010, 08:18 PM
#2
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Join Date: Mar 2008
Location: Clifton NJ
Posts: 132
You'll actually lose power buy taking out the air-pump on an N/A... the air-pump not only prevents your cat from destroying itself, but it also opens your 5th and 6th intake ports at higher rpms. without a functioning air pump you wont open... these ports, thus loosing a lot of top end power.
YOU COULD use and electric air pump activated at a specific rpm to open them, its been done before... But doing this isnt really worth the 2hp you might gain from taking 1 belt off the crank pulley. If you had a 4-port N/A motor, this wouldnt be a problem and you could just take the pump and cat out...not legally of course
YOU COULD use and electric air pump activated at a specific rpm to open them, its been done before... But doing this isnt really worth the 2hp you might gain from taking 1 belt off the crank pulley. If you had a 4-port N/A motor, this wouldnt be a problem and you could just take the pump and cat out...not legally of course
12-03-2010, 09:05 PM
#3
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Thread Starter
Join Date: Nov 2010
Posts: 104
You'll actually lose power buy taking out the air-pump on an N/A... the air-pump not only prevents your cat from destroying itself, but it also opens your 5th and 6th intake ports at higher rpms. without a functioning air pump you wont open... these ports, thus loosing a lot of top end power.
YOU COULD use and electric air pump activated at a specific rpm to open them, its been done before... But doing this isnt really worth the 2hp you might gain from taking 1 belt off the crank pulley. If you had a 4-port N/A motor, this wouldnt be a problem and you could just take the pump and cat out...not legally of course
YOU COULD use and electric air pump activated at a specific rpm to open them, its been done before... But doing this isnt really worth the 2hp you might gain from taking 1 belt off the crank pulley. If you had a 4-port N/A motor, this wouldnt be a problem and you could just take the pump and cat out...not legally of course
wasnt the 13b in 88 a 4 port? and i live in Michigan, and theres no emissions testing here, soo anything goes
12-04-2010, 12:58 AM
#4
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Join Date: Mar 2008
Location: Clifton NJ
Posts: 132
I'm pretty sure only 86' models had 4-port N/A 13Bs, and that everything after that was 6-port... But I could be mistaken.
I mean you could just check: Follow the hoses back and see where they go...
1) If you have two hoses (one of which runs towards the intake manifold) then you have a 6-port... in which case you NEED the air pump for auxiliary port actuation and for the cat.
2) If you have one hose running to the split-air pipe for the cat, then you have a 4-port... in which case you only need the air pump for the cat. So if you take the cat out, Theres really no need for the air pump.
12-04-2010, 12:54 PM
#6
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12-04-2010, 04:37 PM
#7
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12-04-2010, 04:53 PM
#8
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Location: Clifton NJ
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There may be a few subtle differences that probably just gave it a few more horses...
Like the Lower Intake Manifold on the s5 is a little more responsive, s4's have mechanical OMPs while s5's have electric ones, s5's have a higher rev limit i think, minor stuff like that. There are more differences though, those are just some examples.
12-04-2010, 05:06 PM
#9
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Join Date: Nov 2010
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There may be a few subtle differences that probably just gave it a few more horses...
Like the Lower Intake Manifold on the s5 is a little more responsive, s4's have mechanical OMPs while s5's have electric ones, s5's have a higher rev limit i think, minor stuff like that. There are more differences though, those are just some examples.
Like the Lower Intake Manifold on the s5 is a little more responsive, s4's have mechanical OMPs while s5's have electric ones, s5's have a higher rev limit i think, minor stuff like that. There are more differences though, those are just some examples.
soo what kinda HP increases would i see from just adding a RB header and removing the cat and running a straight pipe to the Y-pipe?