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Old 12-31-2016   #11
Hog
 
Join Date: Jul 2010
Location: Woodstock, Ontario, Canada
Posts: 1,271
Default Re: $ 105,000 for an 87 GNX,and the bid goes on?

The GNX was the quickest North America car. I always wished it was a turbo V8.
If the Buick got the B2K's modified L98 powerplant it would have added so much to that car.

But that 3.8 LC2 went on to inspire some pretty cool GM products, which were built by Production Automotive Services(PAS)
]
The 1989 3.8 litre Turbo Trans Am 1555 copies were built.

The Turbo Buicks and the TTA were all great stoplight performers, in part due to the THM-200R$ automatic transmissions that harnessed tehse torquey beasts. IMO the TH-200R$ had the best gear ratios of any GM automatic ever, including the new 6 and 8 speed autos.
The 200r4 had a 1str gear that was right in between the high 1st gears of the thm-350 1.52 and thm-400/4l80e/85e with its 1.48:1 and the other extreme, the very low 3.06:1 1st gear of the 700r4/4l60/4l60e/65e/70. While the 3.06:1 1st gear made foi great holeshots, it leadt a huge rpm drop when it shifted into 2nd gear, while the 2.50'ish 1st gears of the th-350/400/4l80e made for a very long 1st gear, with a great 1-2 upshift with minimal rpm drop. Well the thm-200r4 was right in the middle of bot extremes, respectable launch along with respectable 1-2 upshift characteristics. This was all coupled with the highest Overdrive ratios of all the GM slushboxes, including the newer 6 speeds which matched its 0.67:1 4th gear. Another benefit for the turboed 6's was that the 2.75:1 loaded the turbo nicely s well.

th-200r4 2.75:1-1st, 1.57:1-2nd, 1:1 3rd and 0.67:1 OD
th-700r4/4l60e/65e/70e 3.06:1 1st, 1.62:1 2nd, 1:1 3rd and 0.70:1 OD

GMC wouldnt use a B-O-P trans in their performance trucks(even though the B-O-P 200R$ was an option in the 1989 Caprice coupled with the Chev TBI 305 and 2.44:1 rear axle ratio made for a super cruiser on the highway), so the Chev 700r4/4l60( with its 3.06:1 1st gear would be used in the AWD Syclone and Typhoon. (The electric shift 4l60e didn't debut in the S-trucks?Camaros and Corvettes until 1994, the fullsize trucks in 93) No matter which trans PAS was forced to work with, both the 3.8 LC2 turbo and the LB4 turbo 4.3 got specific torque converters to help spool the turbos. Install a torque converter designed for a turbo 3.8 into a naturally aspirated 3.8 application and everyday driving is affected.

2,995 1991 GMC Syclones in the 4.3 LB4 V6 280hp @ 4400rpm/360lb/ft torque @ 3600rpm
4697- 1992 (2497)-1993 (2200) GMC Typhoon AWD 4.3 LB4 V6 280hp @ 440rpm/360lb/ft torque @ 3600rpm

PAS closed its doors in 1994. Seems as though the early-mid 90's fun was quickly coming to an end all over GM, no matter what engine was involved.
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