auzivision

How does one tell the difference? Does the VIN contain a code to identify?

I wonder if this is one of the coveted 89 GTs misclassified on Craigslist?

http://seattle.craigslist.org/see/cto/1378458886.html

This would be a steal… Maybe Heinrich needs another one.

THis one appears to be overpriced:
http://sfbay.craigslist.org/sby/ctd/1375846794.html

docmirror

Stamp numbers in the block. Maybe the redline on the tach. S4 should be 6600, GT should be 6800.

<edited for corrected values>

docmirror

Both overpriced.

Tom. M

The one in west seattle is an early vin..usually the GT's were greater than 1100 vin. Also other cues are stock s4 flats vs CS rims...standard S4 rear muffler instead of double outlet GT muffler...shifter is taller on the 5sp vs the shorter GT shifter.. along with the other stuff mentioned above..

Ragnar Joensen

I would not buy a car as a GT unless I saw the M639 option code on the sticker. Having said that there are several examples where Porsche for some reason did not show the optioncode on the sticker, although it was fitted on the car. But I would want to see the M639 on the sticker.

There are other indications such as engine code, exhaust and a few more, but they can be manipulated. With or without intent.

With regards to the non-CS wheels,there is an option code for those (M393), and if the sticker doesnt show that, You should not expect those wheels to be fitted. With regards to the longer stick, I had a 1990 GT (with the M639 code) and it had the longer stick. Remeber that the world and also Porsche was in a tight spot back then and if You could save a dime, You would. And therefore Porsche tried to use up all those surplus parts from the manual S4's, rather than throwing the parts away. And they admit this to be so.


Ragnar

hans14914

The idle is higher on a GT because of the cam, so wouldn't there be a coding plug specific to the GT? That would be a good indicator that most people wouldn't change.

dprantl

Idling below 700RPM is a dead giveaway that it is not a GT. Not sure this is configured in the coding plug or the LH brain itself. Just fire it up and look at the tach at idle.

Dan
'91 928GT S/C 475hp/460lb.ft

Jim M.

The GT has more precise pistons, smaller well between valve pockets for exact 10:1 compression, high lift and longer duration cams. The GT cams are stamped on the ends no’s are 271.01, 272.01, 273,01, 274.01 the casting numbers are 928 105 271.OR, 928 105 272.OR, 928 105 273.OR, 928 105 274.OR. Lighter and freer flowing exhaust, revised engine computer mapping, idle at 775 vs. 675, rev limit at 6800 vs. 6600, torque peak at 4100 vs. 3200, 326 hp vs. 316 hp. 8" and 9" wheels vs. 7" and 8", 17mm rear bolt-on spacers for wider track, factory rolled fender lips for clearance with wider track, 20mm shorter shift lever. (10% less travel), Limited Slip (40%) and standard Sport Shock/Spring Option, slightly different instruments, Straight Cut racing type ring and pinion. The S4 has slightly more torque on the low end for normal drivability, however once the GT hits 4000rpm it’s a freight train and with the close-ratio 5-speed all of the up shifts hit right in the torque peak between 4100-4300. The GT likes to be driven hard and rewards you when doing so. It’s also a much stiffer ride than the S4, and is much rarer than the S4 and therefore worth more. It was a prototype for the 90-91 transition of all 5-speeds being a GT and all autos being S4’s. When you move up into the 90 GT there were slight differences, but have the same engine etc. Here is what was lost and added on the later normal 90-91 GT: 8" and 9" Club Sport forged wheels replaced with 7.5" and 9" cast Design 90. Deleted the 17mm bolt on rear spacers. Fender lips not rolled because of the narrower track. Normally cut ring and pinion gears, 40% fixed LSD replaced with computer-controlled variable PSD, dual airbags added. Oil cooler added below the lower radiator support plus an extra air slot in front spoiler. The 89 90 GT heads are a different part number to reflect a slight amount of hand porting.

dr bob

Jim--

If I happened to be searching for a 5-speed car, the '89 S4 would be a preference for me. Rarer in the US I think than the rare '89 GT, the S4 gives up some high-RPM performance for better "normal" driving manners. The sport suspension is part of the option package included in the M639, and would be a plus along with the LSD. The straight-cut GT R&P has lower friction but is definitely noisier.

I suspect that the GT is more 'collectible' than the S4, and there is enough interest in the higher-output motor and included options to justify a premium price. Generally, it's coming down to the condition and history of an individual car to really establish its value these days. Premium cars deserve premium prices as always. But we've seen some pretty tired-looking GT's at lower prices too. Seems to be a buyer's market these days, even on the GT's.

Tom. M

Klingenburg Palloid cut..not straight cut rear diff... I also believe that there were more 89 5spds made than the 89 GT.. Haven't looked at this in a few years, but that is what I recall..

VehiGAZ

Not strictly true, as my GT idled below 700 rpm before my intake R&R.

The first link is not a GT (pretty though!) because of the too-tall shifter. The second one could be (shortened shifter + dual exhaust) but with 99k on the clock, it's overpriced even if it is a GT.

Rolled fenders is a another way of confirming an '89 GT, but you need to know exactly what you are looking/feeling for to be able to tell.

Not all GTs got the M639 option code, though, IIRC.

SwayBar

For starters, I would take a look at the engine/transmission code by the oil filler neck and verify it's an M 28.47.

If that's good, verify it's a GT tranny.

Jim M.

When I totalled my 89 GT I used a quote from Panorama that only 50 89 GT's were imported into the USA for the insurance company. Weeks later and much debate back and forth the insurance company finally conceded that yeah, 56 were imported. So I think the GT is more rare. YMMV.

Vilhuer

All these have to match for '89 5sp to be GT with correct type engine and gearbox.

- US VIN WP0JB092_KS861100 or larger and has to be on this list of 109 GT's
http://www.928registry.org/1989-928G...sting-page.htm
- ROW VIN WP0ZZZ92ZKS841585 (this might not be exact correct first ROW GT VIN but it should be fairly close) or larger
- Engine type M2847-85K in option sticker
- Gearbox type G2855 in option sticker
- Option code M639 in option sticker
- Engine number M2847 85K0... stamped to block
- Gearbox number G2855 2K 0.... stamped to casing

docmirror

I got the redline wrong in mine, Jim got it right. S4 is 6600 and GT is 6800. It's a quick check item that can sometimes be caught in the first picture of the car in question.

I can confirm the more aggressive ride, handling, and power of the GT over the S4 of similar vintage.