Finally got around to changing out my alternator today and recalled some things that I remember were different about the 87GT I had 4 years ago compared to my 88GT.
1.No aluminum cooling tube directed at the alternator like the 87 had! Is there a heat sheild for the alternator? I have a curved one around the front manifold next to the alternator.
2.The 87 had heat sheilds around the exhaust manifolds (along the left side by the EGR valve just forward of the coil) and my 88 has the shiny high heat tape(original)
3.My 88 has these "Dot matrix" interior faceplates?
Are these things normal? Any other suprises I should look for now besides the obvious suspension and brakes?

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There are a lot of small differences, many of which you've noticed. In addition to what you've posted above, I can remember these differences off the top of my head:

1. Heat shielding is different on the exhaust crossover, and the crossover itself is different as is the rest of the exhaust system.
2. The exhaust tip length is different than previous year models.
3. The EGR tube is different, with a metal corrugated heat shield instead of the sewn blanket.
4. There is no shield on the alternator, instead it's on the manifold.
5. The alternator is different, smaller with internal fan.
6. An additional spark plug wire loom bracket is in the V where the throttle cable stop bolts to the upper plenum.
7. The engine is internally balanced, different flywheel/flexplate and crankshaft.

Anyhow, that's what I got off the top of my head right now...

JazzMan

Wow! Thanks Didn't know about the engine balance and the wire loom bracket and exhaust tip length I probably would've ever noticed! Do all 88's have this "dot matrix" interior trim pieces do you know?

[This message has been edited by Gokart (edited 11-27-2004).]

quote Originally posted by Gokart: Wow! Thanks Didn't know about the engine balance and the wire loom bracket and exhaust tip length I probably would've ever noticed! Do all 88's have this "dot matrix" interior trim pieces do you know?

Yes, the only way the '88 came was with the dot matrix.

JazzMan

besides the obvious suspension and brakes
the cradle is different and it is solid mounted
it has a shock type motor mount on the v6
smaller front tyres and wheels
anti roll bar on the rear

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Question wonder and be wierd
are you kind?

The "anti-radio-noise" suppression material is different - on the 88s its built into the decklid plastic, while the earlier cars have a metal grid attached to the underside that serves this purpose.

quote Originally posted by ray b: it has a shock type motor mount on the v6

If I ever have to replace the oil pan gasket will I have to remove the one closest to the alternator and support it with a bottle jack like I did when I had the 87?

quote Originally posted by ray b: besides the obvious suspension and brakes the cradle is different and it is solid mounted it has a shock type motor mount on the v6 smaller front tyres and wheels anti roll bar on the rear

They did away with the shock absorber on the '88, there's only the one engine mount and two tranny mounts. That probably had to do with the internal balancing of the '88 motor.

JazzMan

The coolant tubes are routed differently at the front of the car on the 88s. Or are we talking just engine differences in this thread?

At first it was engine and interior to some extent, but what the heck, let's do the whole car.

The '88 year is the only year to have "factory" installed T-Tops, which in reality just meant that there was an RPO option code, CJB.

The '88 was the only year to have the lumbar seat option available.

1988 GT's had body-color ground effects.

The '88 front suspension was wider than previous years, that resulted in the front GT/Formula "lace" wheels being 6" wide versus the 7" wide ones on previous year fastback GTs. All fastback GTs and the Formula had 205 tires in the front.

I believe that '88 was the only year that the gold "lace" wheels could be ordered.

More to come as I think of it...

JazzMan

Available in two models (Coupe and GT)

Introduction of "Formula" option on Coupe

Balance shaft design incorporated for 2.5L Engine

Completely redesigned indepenent front and rear suspension systems

Revised four-wheel disc brake system (vented discs front and rear)

Gold or Black diamon-spoke cast alum wheels available on GT

Hi-tech Turbo cast aluminum wheels standard on Coupe

Eagle GT+4 tires replace regular EagleGTs

Radial spare all-season tires replace bias-belted spare tire

Inflatable lumbar-support seat (available GT only)

"Soft" Leather Seat available (GT only)

Interior trim upgrade - Pallex cloth (standard on Coupe and Formula)

Interior trim upgrade - Metrix cloth (standard on GT)

Introducation of new Camel interior Trim color

Monochromatic exterior color scheme on all GT models

New exterior color Bright Yellow (available mid-year)

For Formula and GT, Pontiac's notable WS6 performance suspension package standard

Front Suspension:

Elimination of the steering damper assembly

30% shorter spindle length (90 to 64mm)

30% shorter scrub radius (49 to 35mm)

20% reduction in king pin angle (7 degrees to 6 degrees)

20% longer upper control arm length (177 to 214.2mm)

25% longer lower control arm length (280 to 350mm)

Larger stabilizer bar (22 to 28mm)

12% shorter turning radius (11.4 to 10.2m)

Rear Suspension:

Revised chassis cradle design for suspension attachments

New tri-link design allowing for specific tuning of each component

Increased rearward rear wheel motion with jounce for reduced impact harshness

Lower spring rates (44N/mm to 25N/mm)

Inclusion of 22mm stabilizer bar with the WS6 suspension package

[This message has been edited by Skybax (edited 11-28-2004).]

quote Originally posted by Skybax: Revised four-wheel disc brake system (vented discs front and rear)

Mine are not and I knew they were supposed to be! Former owner must of got solid rotors cheaper? Or maybe he didn't even know when he took it in for a brake job? Oh well, I'll replace them with what's supposed to be there when it's time.
Does anyone know about where the anti radio noise suppression is in the deck lid so I make my vent cut carefully? Maybe I drilled through it already when I mounted the scoop Also, will I have to go through the same agony I had to go through with the 87 replacing my oil pan gasket or are the mounts clear of the pan on the 88's?

[This message has been edited by Gokart (edited 11-28-2004).]

I don't know how solid rotors would go onto an 88, the vented discs on 88's are wider than the 84-87 years. Maybe you can go thinner, I know you can't just slap on vented rotors onto 84-87. The wider rotors accounts for the ease of swapping larger brakes onto 88's.

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96k Miles, 2nd owner

[This message has been edited by JamesCurtis (edited 11-28-2004).]

quote Originally posted by Gokart: Does anyone know about where the anti radio noise suppression is in the deck lid so I make my vent cut carefully?

As I understand it, the material was mixed, or baked, into the reinforced plastic material the decklid was made out of. Its something like Nickel Coated graphite. So unless someone says otherwise, I'd assume it is distributed throughout the plastic decklid, and wherever you cut it will all be the same.

quote Originally posted by JamesCurtis: I don't know how solid rotors would go onto an 88.

That's what's on mine! Solid on all 4! Could they have come off another GM car?

quote Originally posted by css9450: As I understand it, the material was mixed, or baked, into the reinforced plastic material the decklid was made out of. Its something like Nickel Coated graphite. So unless someone says otherwise, I'd assume it is distributed throughout the plastic decklid, and wherever you cut it will all be the same.

Maybe I can get the metal grid off a pre 88 and then attach it to the bottom of the scoop and ground it?

[This message has been edited by Gokart (edited 11-28-2004).]

If you have solid rotors then you have the '87 or earlier suspension and brake setup. It is not possible to retrofit the earlier solid rotor to the '88 chassis without swapping out the entire front crossmember and rear cradle, with lots of hard-core modifications required to even do that. Is your front shock inside the spring or next to the spring? Do you have a rear balljoint with grease fitting sticking down?

JazzMan

quote Originally posted by JazzMan: If you have solid rotors then you have the '87 or earlier suspension and brake setup. It is not possible to retrofit the earlier solid rotor to the '88 chassis without swapping out the entire front crossmember and rear cradle, with lots of hard-core modifications required to even do that. Is your front shock inside the spring or next to the spring? Do you have a rear balljoint with grease fitting sticking down? JazzMan

The rear pre'88 rotors are a separate disc from the hub just like the '88 rotors.

The pre'88 rear hub is the same as the '88 rear hub.

The '88 uses the same rotor on all four corners.

I would assume that the pre'88 rear rotors would fit on all four corners of an '88.

Why anyone would want to do it is another question!

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RickN
White 88GT 5spd
White 85GT Auto

quote Originally posted by JazzMan: If you have solid rotors then you have the '87 or earlier suspension and brake setup. It is not possible to retrofit the earlier solid rotor to the '88 chassis without swapping out the entire front crossmember and rear cradle, with lots of hard-core modifications required to even do that. Is your front shock inside the spring or next to the spring? Do you have a rear balljoint with grease fitting sticking down? JazzMan

Then there must be solid rotors that fit the 88's made after 1988 because I'm positive I have the 88 setup just by comparing the calipers with the ones from my 86 parts car.

I can't see how the '88 caliper pistons could avoid coming out of their bores with the much thinner solid rotors of the early years. Can you post a picture of your brakes? This has me interested.

JazzMan

Yes....I will try to post some pics tonight. I appreciate the interest and I'd like to get to the bottom of this too! Any suggestions about the hole I need to cut in the decklid for my heat extractor? If I can get a metal grid plate from an earlier Fiero could I just ground it and mount it under the scoop like I did on the 87GT I had?