Boost Question - Danger Zone

[NMAv]

OK, this is a strange question raised by some strange circumstances. I have a KB 3.6 LC with a 4.00 upper and 15% Innovator West lower. Currenty puts out about 17.2 lb boost. I had to remove the 4 inch pulley due to a slight oil leak by the sueprcharger shaft. Tightened a few bolts and that issue is resolved. When I went to put the belt back on it is a no go, The belt is just not big enough. Now I know the thought - it was big enough to get on there once, you should be able to get it on again. Well, I can't. I've tried everything and checked everything and there just isn't enough play to get the belt on (spoke to teh original installer and they had a horrible time getting teh belt on as well - two guys and the front clip of he car was off). To complicate things and why this was an urgent issue, the car is sitting in the middle of the garage and I have two large pallets of boxes arriving Friday, so I need to move the car out do get the pallets in.

 

What I have done for now is order a 3.5 and 3.25 pulley from KB (don't think the 2.75 will give me enough room) and will put on 3.5 if it fits, else the 3.25 which I know will work. That will allow me to start the car up and move it. As long as I don't slam my foot down there will be no boost issues to worry about. Immediate issue resolved.

 

The secondary issue is that I can't find a belt large enough (bigger than the one I have) to work with my setup with 4 inch upper pulley installed). So now assuming the 3.5 inch pulley works, that will put my boost at 20.5 lb plus 7.0 lb due to the lower 15%. I'm running 91 octane with a can of Torco per every tank which I'm told should bring things up to ~ 97/98 octane. Also, I have American Racing headers with high flow cats which should help the system breath better as as a whole so my boost may be a little lower than that. My actual high end boost is lower than what KB says the pulley/lower pulley combination will produce, but I suspect that is becuase of the headers and exhauster. I'm at 17.2 lb whereas KB predicts 22.5 lbs with the 4.00/15% OD combination. Even with a reduction of 5lb boost (attributed to teh exhauster and headers), I'm still looking at numbers in the 22.5 lb range. I'm really concerned about driving the car with that much boost - not in the market to rebuild the motor. So does anyone have any suggestions, recommendatiosn on where I can have custom belt made? Other thoughts?

 

I've thought about putting in a different tensioner that has a smaller pulley, which would hopefully allow me to gain a little room/space to get the 4 inch back on. The idea of pulling the 15% off doesn't excite me very much at this time as putting it on was a PITA. I think the idler pulley is as small as they can go. I've contacted Gates about a custom belt (you need to buy 10).

 

Fortunately the driving season is over here in CO for the foreseeable future (snow in the forecast) so I have until Spring to sort out the details. But I'm looking for input from the masses for suggestions in case I overlooked something or someone has an alternate suggestion on getting the original belt back on. For now my plan is to not drive the car.

[Freak]

If you only need to move it a short distance, just remove the belt altogether. You should get plenty of air through the bypass valve to putz around at low speeds to park it somewhere else. It's probably enough air to drive at low street speeds, but if the water pump or alternator is driven off that belt (I can't remember off hand what gets driven by that belt) I'd want to keep the distance to a minimum.

 

EDIT: BTW, thanks for getting Kenny Loggins stuck in my head.

[NMAv]

Could be worse, I could have made a Top Gun reference and then you would have a song and bad movie running through your mind ....

[NMAv]

I did manage to get the car moved out of the way but I didn't manage to get the belt on. I'm still struggling with that one. Guess I'll wait til Van gets back in town.