: Safe to drive maggied V without jackshaft drive belt?



PJGross
07-11-13, 08:56 PM
In a bit of a pinch. Wife's Traverse is in getting its 4th timing chain set diagnosed as bad, so we are down a car.

Today my Gates K080220 22" 8 rib jack shaft to blower belt decided to shred. It was about 9 yrs old and has about 80k miles on it, and about 2 yrs ago made some contact with a wire harness so had a wear spot in it, so I got about as much out of it as can be expected.

In the belts defense, it was still intact with 3 ribs remaining so not too shabby. The only damage is it cut the pressure sensor hose, but that hose was too long anyway. :)

Ok, so it was 5:30 EST. I called Magnuson, got the part #, and then called the local parts store like the Magnuson tech said to do b/c "it is a common part". After a few minutes, the parts guy said, "good luck, that part is not listed". A quick google search showed that as early as 2009 that Gates part was hard to find, as in not available in any catalog.

I can get it from Lingenfelter for $35 + ship, but in the morning hope to get one from a local Magnuson dealer in the Detroit area and avoid waiting until next week.

Tonight I cut what remains of the belt off the rear when checking for any damage.

My question is:

Any reason I can't drive the car in "grandma put-put" mode over to which ever shop has the part? My thinking is that as long as the throttle is not floored and the intake stays in vaccuum, the bypass remains open and it shouldn't matter that the blower isn't spinning.
I should be pulling in the same amount of air with or without the Maggie connected.

Therefore, I should be able to make a nice easy 15 mile trip to which ever shop to get the belt, correct? As long as I stay in "closed loop" I shouldn't be asking those 60lb injectors to fire any more than usual is my thinking. I would just avoid open loop.

Next question is besides X amount of throttle what other inputs would put the system into open loop so I can avoid doing so?

Thanks for any feedback,

PJ Gross

OneFast V
07-11-13, 09:58 PM
you can buy a belt from a local auto part store to hold you over too.. a 6 rib 101.5" belt would work until you can get an 8 rib. you could go with a 102" also if you need to. i would not recommend putting around 15 miles to get a belt.

EDIT: my mistake didn't read it closely enough, rear belt..... duh.

rand49er
07-11-13, 10:05 PM
Since the bypass valve is not allowing any flow through the normal boost route, it seems like it should be okay to grandma that thing around. Without the internal blower parts rotating, it's just a crazy-shaped plenum in there, isn't it?

Hey, PJ, takes some pics of the belt and maybe some of putting on the new one when you get it.

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... 101.5" belt would work ...That may be just a wee bit long.

DMM
07-11-13, 10:59 PM
Not a good idea. The coating on the rotors is there to create a seal between the rotors and are supposed to wear to the rotors mating surfaces to create a seal, otherwise you'd never get any boost out of it. The supercharger always makes boost, but is bled off by the bypass. What you are considering is about the same as you trying to suck icecream through a coffee stir.

rand49er
07-11-13, 11:50 PM
Not a good idea. The coating on the rotors is there to create a seal between the rotors and are supposed to wear to the rotors mating surfaces to create a seal, otherwise you'd never get any boost out of it. The supercharger always makes boost, but is bled off by the bypass. What you are considering is about the same as you trying to suck icecream through a coffee stir.I really didn't know, so this is good stuff.

PJ ... do you have a bicycle as a backup?

NCOGNITO
07-12-13, 12:58 AM
Just a thought, but call enterprise "they'll pick you up" and just rent a roller-skate for $30 with tax a day, cheaper than damaging your car and takes the pressure off needing the part for the same price you'll spend on temporary belts, etc.

They usually have weekend specials that might cover you through Sunday too?

Hammar
07-12-13, 10:08 AM
Just to add more logs, there isn't any reason you can't/shouldn't drive it around with the REAR jackshaft belt off.

At low speeds/idle, it'll pull all it needs through the bypass. If it wants more, the engine will suck it through the lobes of the blower. It may run bad due to the restiction, but you would expect it to run rich if anything (all the fuel but struggling to get enough air). Not sure what'll happen if you floor it, but easy driving wouldn't worry me at all.

I'm sure all of us turned the blower drive before we put it on, it takes almost no effort to spin the assembly when you aren't building boost. Engine vacuum will do the same, albiet it'll be less air than if it's being belt driven. But for an easy cruise.... no worries here.

You have a wideband right? Just watch that for really out of bounds AFR's and go easy.

Hammar
Maggied 2005 V

PJGross
07-12-13, 01:59 PM
60k miles of maggied bliss for me, 80k maggied total, no wideband, but a very safe dyno & street tune with California gas from previous owner's shop.

I agree that under vacuum, the bypass allows non-squeezed air to continue down into the intake unobstructed. Wouldn't be a problem to drive normally. However, this morning I picked up a rental and after calling several Magnuson dealers that didn't have the belt, just ordered it from Lingenfelter.

So, to close out the thread, I determined it is just fine to drive without the belt attached and keeping the MAP in vacuum. My bypass valve is very noisey so I would here if it was closing anyway, but in a drive around the block everything was fine as Hammar suggested above.

I can take pics of rear belt going on, but I imagine it will "roll" on just fine turning the pulleys by hand.

-PJ

PJGross
07-15-13, 11:31 PM
Quick update. I have the belt. Spent 20 minutes attempting to walk it on by turning the jackshaft and putting tension on the belt. Not going to happen. Yes, this was done without loosening the adjuster do to the following:

I can feel the 3 studs and nuts holding the rear jack bracket along with the adjuster. However, after trying 4 different wrenches I don't see how on a V1 those 3 can be loosened with the maggie still on the car. There just isn't much room to do much of anything back there.

I haven't had the maggie off myself and to ensure I don't screw anything up I'll be driving it to a local shop to have them pull the maggie and ensure everything goes back the way it comes off. That and after 80k it would be nice for someone to just observe everything and make sure everything seems alright while they're in there.

Not sure why I'm so worried about pulling the maggie. Are the gasket(s) rubber and reusable or not? Part of me says I should just pull it and be done with it. Guess I'll rtfm.

-PJ

rand49er
07-16-13, 08:48 AM
For one think, that sucker is heavy especially while leaning over like you have to do. When I installed mine (by myself), I rigged up a "hoist" to help me swing it into position and lower down on the motor ... REALLY crude, let me tell you.

Just for the weight factor, unless you have incredible strength, taking it to a shop might be a wise decision.

OneFast V
07-16-13, 12:10 PM
Quick update. I have the belt. Spent 20 minutes attempting to walk it on by turning the jackshaft and putting tension on the belt. Not going to happen. Yes, this was done without loosening the adjuster do to the following:

I can feel the 3 studs and nuts holding the rear jack bracket along with the adjuster. However, after trying 4 different wrenches I don't see how on a V1 those 3 can be loosened with the maggie still on the car. There just isn't much room to do much of anything back there.

I haven't had the maggie off myself and to ensure I don't screw anything up I'll be driving it to a local shop to have them pull the maggie and ensure everything goes back the way it comes off. That and after 80k it would be nice for someone to just observe everything and make sure everything seems alright while they're in there.

Not sure why I'm so worried about pulling the maggie. Are the gasket(s) rubber and reusable or not? Part of me says I should just pull it and be done with it. Guess I'll rtfm.

-PJ

If you have two people pulling out the maggie is not challenging at all.

2007V
07-17-13, 11:50 PM
I agree, with 2 people it is easy. If you mess up a gasket pulling it buy a set for a 5.3l silverado and cut the tabs off. No need to take it to a shop.