Can you fit a 89+ Upper intake on a S4 lower intake?
Thread Starter
Rotary Enthusiast
Joined: Mar 2002
Posts: 818
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From: Phoenix
Can you fit a 89+ Upper intake on a S4 lower intake?
Just curious, I was looking at the gaskets that go between the lower and middle intakes , they look about the same.
I was wondering if you could use a S4 lower intake but use the S5 upper intake on top of it. Id like to do an S5 intake swap but I want to keep my port air working since I have to pass emissions. ANy ideaS?
I was wondering if you could use a S4 lower intake but use the S5 upper intake on top of it. Id like to do an S5 intake swap but I want to keep my port air working since I have to pass emissions. ANy ideaS?
More Than Meets the Eye
Joined: Mar 2001
Posts: 259
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From: Lynnwood, WA
Yes this can be done with a few modifications. I will list what I can remember that you need:
1. S5 fuel rails upper AND lower.
2. Block off plate for EGR.
3. You have to grind off part of the rear rotor housing (or something like that) to get the new intake to seat properly. There is a bump or something that prevents this.
4. Hoses to hook up the different style of BAC valve
5. If you want to use the S5 style throttle body, you will have to go premix because there is no linkage for the OMP. Otherwise you can adapt the S4 throttle body by filing off a little nipple that keeps it from mounting flush, and then bending the OMP linkage so it works right for the new location.
6. You have to remove the EGR solenoid (you dont need it anymore anyway) cause it is in the way.
7. You have to figure out a way to activate the VDI function of the manifold. You might be able to tap into the 5th and 6th port actuation system and use the EGR solenoid you removed. Then you would have to get an RPM switch set at I believe 5000RPM to control it.
8. You have to cut (or bend out of the way) the extra support that help support the back of the old manifold. If you are clever, it wouldn't hurt to rig them up in a way so that they support the new manifold.
This is a mod I have been wanting to do for a while, but I just havent taken the time to really look for a manifold yet.
1. S5 fuel rails upper AND lower.
2. Block off plate for EGR.
3. You have to grind off part of the rear rotor housing (or something like that) to get the new intake to seat properly. There is a bump or something that prevents this.
4. Hoses to hook up the different style of BAC valve
5. If you want to use the S5 style throttle body, you will have to go premix because there is no linkage for the OMP. Otherwise you can adapt the S4 throttle body by filing off a little nipple that keeps it from mounting flush, and then bending the OMP linkage so it works right for the new location.
6. You have to remove the EGR solenoid (you dont need it anymore anyway) cause it is in the way.
7. You have to figure out a way to activate the VDI function of the manifold. You might be able to tap into the 5th and 6th port actuation system and use the EGR solenoid you removed. Then you would have to get an RPM switch set at I believe 5000RPM to control it.
8. You have to cut (or bend out of the way) the extra support that help support the back of the old manifold. If you are clever, it wouldn't hurt to rig them up in a way so that they support the new manifold.
This is a mod I have been wanting to do for a while, but I just havent taken the time to really look for a manifold yet.
Senior Member
Joined: Mar 2001
Posts: 652
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From: dinwiddie VA
i have a S5 intake that i just pulled off my S4 the housing has to be ground down bout 1/2 inch to keep the UIM from hitting,I have the S5 dynamic chamber,upper intake manifold,and lower,the lower has the actuators removed and filled in,i have pics if anyone is interested i just pulled this off my car which was only on there for about 11 months.
More Than Meets the Eye
Joined: Mar 2001
Posts: 259
Likes: 0
From: Lynnwood, WA
I finally found the page I have been looking for. A good writeup found here: http://homepage.mac.com/carldavis/intake/intro.html
He is using the 89+ lower intake though, so he has to go through a few extra steps. If you want to keep it simple you can use your old lower intake and keep the 6-port action the same. I am about to do this swap and I think I will just wire the VDI open to keep it as simple as possible.
He is using the 89+ lower intake though, so he has to go through a few extra steps. If you want to keep it simple you can use your old lower intake and keep the 6-port action the same. I am about to do this swap and I think I will just wire the VDI open to keep it as simple as possible.
