Ok, I put this biitch on Saturday. I made an all day job of it. First off, the MAC 70mm will bolt up, but it does not seal off the whole intake passage. The TB is actually a very compact housing and therefore the top of the intake manifold mouth where the EGR passage is is slightly exposed. To combat this I bought some aluminum sheet and made an adapter plate to go between the provided gasket and the factory gasket. Then the linkage lever was 180 degrees out even when I mounted the TB upside down. Therefore I used a dremel and cut the svt lever off and the one from the MAC off and swapped them. I tack-welded the linkage from the svt onto the mac. The SVT spring wouldn't fit because the shaft was maybe a half inch shorter than the svt TB. I just kinda bent the cable bracket over to the left to match them up.
Next problem. The aluminum stop (that limits the maximum opening of the blade) for the MAC linkage would actually stop the SVT linkage way to soon. So I cut that off.
Then it opened too far with the pedal, So I mounted a piece of metal to the top right bolt that created a stop for the svt linkage.
Fortunately, the 'close' throttle stop actually works fine.
Ok, now I have it mounted up, cables on and working smoothly, and the throttle stops are good.
I fired it up and it wouldn't idle below 2500 rpm!
So I checked the gasket area first, and had use rtv silicon betweent the gaskets. That helped alot, now it was idling at about 1800. Next I plugged the little hole in the TB with some JB qwik epoxy, and that brought the idle down to around 1200. I could completely disconnect the IAC tube and check that it had no vacuum on it which indicated it was completely shut off, and it was still sucking air somehow.
After all that, with the computer completely closing the iac, the thing will idle about 1200 rpm.
I took a cup of water while it was running and I found that when I poured it around the throttle shaft on the linkage side it would make a gurgling noise.
Apparently it is sucking air around the edges of the throttle shaft. So I took some grease and packed it around the shaft and that reduced the idle to about 900 rpm when the IAC is closed.
So that is where I am at. What is a good way to seal off the ends of the shaft?
I have thought about rtv, but when the shaft rotates I would guess that it won't seal anyway, and would make a mess.
I think high-vacuum grease used on various vacuum pump systems would work, but I don't have any at the moment and I don't want to keep replacing it.
I have a feeling that the problem might be that the air is going through the bearing, but I didn't look at it that close when I had the shaft linkage off.
AS far as how it feels. It seems to be much more responsive now, and pretty quick up top. I think I may have lost some low rpm torque, but I can't tell. My original calculations told me that 67mm was a big enough increase, but that is only a qualitative guess.
Any thoughts/solutions are welcome.
warmonger
