C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

Expectation Management ...

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Old 04-04-2017, 07:52 PM
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WPK
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Default Expectation Management ...

O.K. ..

So my 94 Coupe (LT1) was wandering all over the road ... I mean REALLY wandering. Seemed fundamentally unsafe.

After a roller coaster ride to the Bay Area and back, I had the dealer check ball joints, front suspension ... all looked good. Then, I noticed a leak in the steering rack. Replaced steering rack.

That helped a bit, but not at high speeds. It was still the same problem. Front end felt light, and drifted back and forth. Not so much at slow speeds, but in excess of 60 MPH, it was wild. It seemed to actually lift off the road.

Pulled on front wheels to make sure bearing was O.K. Looked for more leaks. NOTHING.

Tires are in very good shape, not new, but very good. Shocks are aging a bit, but they are aftermarket Bilsteins. I would expect better.

Then one day, after about 9 months, I was standing behind the car and noticed. THE SPARE TIRE seemed to be hanging low. It's a little hard to see behind the body work, but it just didn't look right. I reached down, and could lift it 8 or 9 inches. I could bounce it up and down with just two fingers. A little more exploration revealed that the long bolt that needs to be wound up to tuck the tire in place was wound DOWN to the lowest point. It was still connected, but hanging low. Took three (3) minutes, screwed it back in place, and no more problems.

Go figure.

I figure that someone servicing the car checked the spare for air, and simply forgot to wind it up - and at 80 MPH, it was like driving a lightweight Cessna 150 with the flaps down. If I ever hit 100 MPH, I'd probably take off. At 130 MPH, I'm sure I would have slipped into low orbit. At 170, I'm positive I would have given Elon Musk a run for his money on my way to Mars.

Well, I'm back on all fours now, and very happy about the easy fix. I was one of about five or so people (mechanics, etc.) who spent a fair amount of time trying to solve this puzzle over a nine (9) month timeframe - most of them smarter than me.

The moral of the story is that sometimes your answer is where you least expect it - but your expectations keep you from seeing it ... even when it's staring you in the face.



- WPK
Old 04-04-2017, 08:11 PM
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billschroeder5842
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Jeeeeeeez.

So, was the spare tire dragging on the ground and lifting the front?
Old 04-04-2017, 08:26 PM
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ddahlgren
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Sure sounds like a reach to me. I have a plié of experience on race car aero and not much happens at 60. GM has the down position to store the normal tire and wheel if you need the spare. Do you think they would do something to make the car undrivable?
Old 04-04-2017, 11:45 PM
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WPK
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It wasn't dragging ... just hanging down just above the ground. Definitely had an effect. (And ... just saying ... i might have been going a couple MPH over 60).
Old 04-06-2017, 04:24 AM
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bill mcdonald
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So you are saying that a spare tire carrier, made of plastic and a strip of aluminum, with a maybe 30 pound spare tire sitting in it, had the ability to lift the front of the car?

Now for the design of the carrier. It has 2 sets of hinges. One for keeping it tucked under the car real nice and tight. The second is to drop it low to fit in a 9" wheel.

If it was as loose as you are presenting here, it would be bouncing around, and fall out of real nice and tight setting. And enter the long slots of slop. So now it is hanging down. free to bounce around.

Next we have aerodynamics.
so a 30=35 pound floppy flap at speed lifted the front of the car, which is probably 800+LBS at each corner. And at no point would all that air rushing under the car actually lift the spare tire carrier instead which is mounted on 2 sloppy slots and 1 long bolt?

Does this mean when people say you should be able to stand on your front splitter or you are just running with poser gear?

What about the rear wings that people drill through the body to mount into the frame rails to actually push down on the frame rail?

perhaps I could put the gas filler door up and gain 10MPH cornering speed. JK



I think you would of seen this, I am sure you were wishing you saw it earlier. No telling how much money you would have for gas with basically having to work with a gremlin parachute.

Maybe I am too critical, I tend to be with things I am passionate about, and try to be thorough.. I enjoyed your post. Maybe the purpose is lost on me. I guess april fools was a few days ago. Maybe you posted form mars?
Old 04-06-2017, 06:51 PM
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DGXR
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Aerodynamic discussion aside, the rear bolt on the spare tire tray has two steps just like the hooks that hold the front of the spare tire tray, like bill mcdonald explained.

You need to lift the bolt to the upper step, then tighten it. The upper step is kind of hard to see and even harder to feel, but it's there. The upper step is the standard storage position when the donut spare tire is in the tray.

When the donut is in the tray, there's no way you can take up all the space from the lower step just by tightening the bolt.

Edit: at least now you have a new steering rack

Last edited by DGXR; 04-06-2017 at 06:57 PM.

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