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1985 900 Turbo -- a couple of quick questions

Hi,

I picked up the 1985 T16 mentioned here recently. I've never driven a turbocharged 900, and after owning two naturally aspirated 1984 900s, and all I can say is...Wow!! I had a really fun drive home!

That said, I have a few questions:

Where should the needle on the turbo pressure guage sit when driving? The needle stays at around the 10:00 position, in the solid white, until I accelerate hard, when it jumps up to the orange briefly, then goes back down to its original position. I was shifting, so it's not like the boost went down by itself, and maybe this is normal. I checked the owner's manual (still with the car, thankfully), but it doesn't state where the needle should be under normal driving.

Also, has anyone else had the hood/bonnet hinges completely rust out? One side is actually detached from the hood itself. Needless to say, it's a chore to open and close. This will be my top priority. Probably need to get a new hood, rather than try to weld?

Other than that, the engine, transmission, front end, suspension, brakes, and exhaust all seem very solid. The headliner isn't even sagging! There's some body rot around right rear and left front fenders and a little more around the hatch lip, and the hatch supports won't hold it up. I paid $500 for the car, plus an extra set of four rims and tires, so no complaints!

Thanks,

-jw

-- '84 900 S hatch - 160K miles - deceased '84 900 S sedan - 210K miles - deceased '85 900 Turbo hatch - 220K miles - the next chapter!

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Reply to
jw
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It's a vacuum gage when the car is idling (no boost) and a pressure gage on the "other side" of zero (where white turns to orange). You might get it into red in second or third while turbo-stomping, depending on many things. I'm not sure if that answers your question, but when the engine is off, that's zero. When it's running, it's pulling a vacuum relative to atmospheric pressure, and when you're stomping, it's a pressure vessel.

I'm sure you can find another hood for the car. You need pre-1987 (???), pretty sure it changed when the grille did.

Great deal. Does my description of your pressure gage make sense?

Dave Hinz

Reply to
Dave Hinz

Yes it does, Dave, thanks for helping out a c900 turbo newbie.

Vacuum vs. pressure. When I'm just cruising along at 2500 RPM, I guess the turbo is inactive and drawing vacuum (hence the needle is sitting in the white), but when I stomp on it, the pressure kicks in and the needle jumps up to orange. As I understand it, it's falling back down because all I'm doing is shifting at 3500 RPM, thus the pressure and needle moving up into the orange, and then immediately back down to white. If I want to keep the turbo boost, just keep my foot on the gas and let 'er rip?!

I'll have to get it out on the open road a little more, but from what I'm hearing it seems that all is in order with the turbo boost.

-jw

-- '84 900 S hatch - 160K miles - deceased '84 900 S sedan - 210K miles - deceased '85 900 Turbo hatch - 220K miles - the next chapter!

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Reply to
jw

No problem. You can thank me by, er, selling me your car. How's that sound?

Yup.

That's the way. Watch for doppler shift and/or red and blue flashy lights behind you.

Does it get into the red, maybe 3/16ths of an inch or so?

Reply to
Dave Hinz

Well.... technically, the turbo never 'draws vacuum' . It's the down movement of the pistons that 'suck' and create some degree of vacuum. The turbo starts generating 0,5 - 0,7 bar boost (over 1 bar atmospheric pressure) from about

2500 rpm. You will notice that 90% of the time the APC/turbo guage is in the white.
Reply to
MH

Thanks for the clarification. All seems to be in order with the turbo.

Now, anyone have a c900 hood/bonnet that they want to sell, cheap? :)

-jw

-- '84 900 S hatch - 160K miles - deceased '84 900 S sedan - 210K miles - deceased '85 900 Turbo hatch - 220K miles - up and running

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Reply to
jw

That's a pretty big item to ship around... You might want to mention the locale you are in.

Reply to
Malt_Hound

I kow, sorry. It was kind of a joke, but I will be looking for the part if it's impractical to weld the hinges/brackets back onto the existing hood. They're pretty rusted out anyway.

I'm in Providence, Rhode Island, USA.

-jw

-- '84 900 S hatch - 160K miles - deceased '84 900 S sedan - 210K miles - deceased '85 900 Turbo hatch - 220K miles - up and running

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Reply to
jw

If they're that rusted out, just find a new hood. It's not worth trying to patch that up.

Reply to
James Sweet

Hello, As a person who just replaced the hood, fender, bumper and radiator mount (I was hit by a semi or lorry, for those across the pond), I can tell you that any classic 900 hood/bonnet will work because they all are the same. In fact there is no difference on the front end at all from the pre-87 and the post-87 900's. The bumper, cowl and headlights are the only different things, but they still attach the exact same way to the exact same frame mounts. I know this because my '86 now has an '88 bumper, lights and cowl, '89 radiator mount, '92 hood, and a new oem fender.

The one thing you should check for when getting a used hood is rust along the edges, that is a very common issue on the 900. Look inside the fold along the back side of the hood (near the windshield) with a flash light to make sure you are getting one that will last a while.

I got one from a Saab shop in Bow, NH. They go by the name Jocary on ebay About a two hour drive from you up I93 (@ the Junction of I89). Also check with Rte 128 used auto in Waltham, MA B&D Used Auto in Shirley, MA.

Jeremy B.

James Sweet wrote:

Reply to
BK

Thanks for the info. Interesting front end swap you did.

I'll try those three after checking with my local shops in RI. I shouldn't have much of a problem locating a classic 900 hood in New England.

Maybe I'll find out that's another good thing about my car. The hood will fit in the trunk (or the bonnet in the boot, for those across the pond).

-jw

Reply to
jw

Reply to
Jeremy Brown

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