Does anybody make a pulley replacement set for the GT? I would like to get a belt that has some teeth.
Pulley Set
- Thread starter Fubar
- Start date
- Feb 22, 2006
- 370
I would check with Whipple before going to a cogged belt system. It can be hard on a supercharger.
BlackICE
GT Owner
...and changing the crank damper would most likely require PULLING THE ENGINE! :thumbsdow
Fubar what problem are you trying to solve?
Fubar what problem are you trying to solve?
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BlackICE
GT Owner
I suspect so.ething else is the problem. Something doesn't smell right. The gen 3 is supposed to be more efficient, therefore at equivalent boost levels use less power thus less belt tension, yet the belt is slipping and it is burning more fuel.
I think I am running into belt slip but it is always on the shift. If I shift to quickly in to 4th my boost drops to 10lbs. I can't hear a screaming belt. I am not sure if it is the belt or the computer doing something weird because of the slight drop in fuel pressure. I am still playing with the problem. I have no lean A/Fs so I am still just playing with solutions.
BlackICE
GT Owner
It may be normal for the boost the drop. I haven't check so I don't know for sure. But if you lift the throttle while shifting that not only produces a vacuum in behind the throttle blades, but also opens the blower's bypass valve. So I would expect the boost to drop. To prevent this from happening you need to shift using WOT. Of course that may not to too good for the engine unless you have additional engine controls so that the engine doesn't over rev. but instead holds a specified RPM during shifting. That can be done with some modifications.
Under this condition would the bypass valve stay open? When I shift from 3rd to 4th, I lose boost but I never get it back?
Sounds like belt is slipping. As soon as you close the throttle blades the Bypass valve should close and boost should come back. The Ford gt's/Gt500s have a killer belt system, I have seen a centrifical blower make 31lbs and not slip the belt on one of these systems. What blower pulley are you runnin. Also if problem continues you could put a overdriven balencer on it and put a larger blower pulley on it also. Factory crank dia is 7.375 and aftermarket is 8.125. Just have to do the math and figure out the best option for blower pulley. Btw alot of the GT500 guys go this route and there are far more gt500's with whipples and kb versus Ford Gt's.
BlackICE
GT Owner
The bypass valve activates whenever there is a vacuum behind the throttle blades. If vacuum is detected it will open. It is also be controlled by the ECU at times such as when the limp home mode is activated. The boost should come back soon after you open the throttle again (< 1 sec).
Beach-GT
GT Owner
If the supercharger is over rev'd and pulls a vaccum on the aircleaner can this cause the bypass to open? I see a decline in boost after 5500 RPM from 17 psi down to about 13 psi at 6500 rpm. I figured it was due to too much restriction in the aircleaner choking the supercharger but maybe the bypass is starting to operate. I doubt that my belt is slipping. When I did a dyno tune I didn't think to remove the aircleaner at the time. I was still puzzling about what I saw. I also verified what I saw on the track.
I wonder if there is a solution for making the bypass more friendly for higher boost applications? This may be a moot point, as I do not understand exactly what conditions activate the bypass.