History as it stand!  There will be further updates/corrections if anyone has info to pass on.  There will also be more data after taking McLaren up on their offer to a visit and a review of their files on this vehicle.  This info is based from known good sources, either proven first hand, or given by contacts who worked at GM, McLaren, ASC etc, or from articles in trusted publications.

When the new GM10/W-Body Platform was launched in MY (Manufacturing Year) 1988 it was met with rave reviews, even with a version of this platform; a white Grand Prix SE garnishing the coveted Motor Trend car of the Year Award.  A response from Pontiac of an image building vehicle of the Grand Prix was decided, though there was talk of this already in the works as GM felt its W-Body line was to be a resounding success.  So the Excitement Division/Pontiac was given the go-ahead to do a sporty and image building show car for the Grand Prix line-up, hence the Turbo version of the Grand Prix SE 2-door.  To attempt such an involving and exclusive endeavor, the following team was enlisted: Tom Nash/Pontiac Grand Prix Product-Engineering Manager, Pontiac Design Leader Terry Henline, Pontiac Product Planning Group, Phil Pearson/Powertrain Specialist, General Motors CPC Engineering Team, Mark Huebner Plant/Project Manager for ASC, Alcoa, GM's Huges Aerospace division, Wiley McCoy Executive VP and COO of McLaren Engines and, AutoStyle who skinned the original concept car in 1988 that had the 305 hp turbo engine setup.  Many thanks go to our founding fathers!

As with the infamous work to make the fantastic 1987 Buick Regal GNX (and 2 GNX Police Pursuit cars); Pontiac enlisted the expertise of ASC/McLaren Specialty Products, made up of ASC (so named at the time: American Sunroof Corporation) and drivetrain partner McLaren Performance Engines (so named at the time) to take a fully loaded Grand Prix SE to the next level, and into production status.  The plant responsible for putting together all the pieces that made the conversion was constructed faster than any other ASC plant in history, and was ready to start production in November of 1988, with first sales said to start in January/March of 1989.  Aside from the only options of a CD Player (in 1990), Leather Seats and Moonroof, the Turbo Grand Prix was already fully equipped with ever other option in the GP SE lineup, and with class leading technologies such as ABS and HUD display as well as a water-cooled/intercooled turbo setup, made this a car few could compare to.  Efforts of ASC working with Pontiac design studios resulted in one of the best aero complimenting packages made on a American car, even by today’s standards.  ASC's partner McLaren tackled the drivetrain project; turbo conversion, thermal testing, tuning, validating and certification (emissions and driveability), with a vast list of well thought out components and upgrades to round out this setup.  GM as well as ASC also participated in testing the Turbo Grand Prix setup in hot-cold climate test with dyno cels as well as remote locations such as in hot climate Texas and high altitudes in Colorado.  Though robotic efforts had already been started at GM doing vehicle finishing/painting, the Turbo Grand Prixs all received a higher quality hand finish by skilled workers, compare the 6 mil finish of a Turbo Grand Prix to other Grand Prixs of that era and there is a noticeable an appreciable difference. 

Before and during those periods from 1987+ till 1990, the Turbo Grand Prix had other brothers, the luxurious Grand Prix Turbo STE 4-door, and a 1988 gold Grand Prix SE with just the turbo drivetrain and louvered hood (no aero kit and a trimmed down interior) that ran at Pikes Peak, and a concept version; the 305hp Grand Illusion Turbo Grand Prix, and 7 Pace Cars, and even a one-off convertible version.  There were many proto-type versions as well and all those known at this time are listed below.

Break Notes, key players and a little of their history: 

The generic use of the name "McLaren" has caused some confusion over the years, so here is the best attempt at clearing up those details.  The name "McLaren" began with Bruce McLaren Motor Racing/Team McLaren back in 1963 (his first Formula 1 victory was in 1959!), at the time a singularly entity, which is also when he built his own/first "kiwi" cars.  In 1969 Team McLaren opened a branch in the US to support their Can-Am interests here.  For this new location, what better choice than in the Motor City area of Detroit Michigan, the Car Capitol of the world!  You can not possibly imagine the amount of technical resources and suppliers in that area, anything from concepts, development, engineering and manufacturing, to supplies and testing, anything to do with the automobile can be had there!  After setting up shop, Team McLaren raked in 5 championships out of the nine years that the Can-Am series was run, not bad for a start.  But it was a sad day in 1970 when Bruce McLaren was killed while testing a car at the Goodwood race track in England, to his credit the name McLaren has lived on and with great respect and admiration!  Next up was the Indy 500, with a win in 1974 by driver Johnny Rutherford, and yet another win in 1976, also Emerson Fittipaldi winning the Formula 1 Championship in 1974 and again in 1974 with driver James Hunt.  Then McLaren Engines went and did it, their first “turbo” project, done to an M12 BMW 4-cylinder engine, that earned them a “first win with a turbo setup” in 1983 with Nelson Piquet and Brabham, the sound of victory was “blowing” in the wind! 

In 1980 Team McLaren split and a portion returned to Europe, where they joined with Project 4 to create McLaren International, which continued and furthered their winning work on Formula 1, Can-Am and Indy racing series.  Later in 1984 Techniques d’Avant-Garde Group (TAG) joins, there soon after the new name TAG/McLaren does its work to racing engines for Ford, Honda, Porsche and McLaren to totally dominate the same 3 race series with victories in each class year after year.  McLaren International also did the Mercedes-McLaren SLR, just another one of their pieces of craftsmanship.

During that same time in the 80s, a Division of Team McLaren now called McLaren Engines stayed in the US and took advantage of their vast knowledge of advanced drivetrain development to serve the automotive industries here, thank you!! 

Later they became known as McLaren Performance Technologies.  Their involvement lead to Chevy and Buick at first, and soon thereafter work in the Marine/off-shore segment as well, with many heralding achievements in these categories.  After using one-off proto-type examples of what “could-be” to enlighten the automakers here, projects were set into place to design engineer and construct special niche vehicles for manufactures, those such as the:

1984-1990 ASC/McLaren Mercury Capri and Ford Mustang.

Behind the scenes dyno services for the Buick Turbo Regal/T-Type. 

1987 Buick GNX setup, which recently became one of Automobile Magazine’s top 100 coolest cars of all time, agreed! 

1989-90 Turbo Grand Prix of which most visitors here are interested in.

1990 Turbo Grand Prix STE 4-door.

Concept offering of the GMC Syclone with a Buick V6 turbo motor.

Twin-Turbo V8 Cadillac Northstar LMPs that raced at LeMans in June 2000.

Ford Racing Technologies to create the Mustang FR500.

The SEMA show stopper Ford Focus FR200/FR100.

Dodge Viper Diamondback with 615hp and the most extensive use of Carbon Fiber at the time.

McLaren Lincoln LS (an unfortunately unknown great performance luxury car), with many upgrades including a 350hp V8.

Supposedly a limited run of Pontiac 6000 STE AWD Turbo, no one has every shown one but I am sure it will happen!

“ASC” once stood for American Sunroof Company but was later changed to American Specialty Cars in January of 2004.  This was an overdue change since ASC had long been more than just a manufacture/supplier of quality sunroofs, as you read below this will become rewardingly evident.  The name changed also happened when ASC sold off its entire sunroof operation to Dutch firm Inalfa Roof Systems, and thereafter Inalfa relocated from the Netherlands to Wixom, Michigan.  Surprising to some but the sunroofs in production T G Ps and TSTEs was not an ASC system, but an Inalfa System, and a quality one at that, since 1989 I have never heard of any serious failures of these units, other than a few micro switches failing, that is it!  

ASC in its own right has a long, detailed and much acclaimed existence.  Started off in 1965 by Heinz Prechter coming out of Germany and with only $11 as he hit the shores here in the US.  ASC has since grown today into a multifaceted half a billion dollar company that is termed as a “Full-service specialty-vehicle partner for all of the world’s automakers”, and claimed as the American version of Pininfarina (trivia note: Italian coach building legend Battista “Pinin” Farina is where this name comes from, also an inductee of the Automotive Hall of Fame at the same time of Prechter).  From the start and with only $754 worth of tools, Heinz made sunroofs out of a sub-leased 2-car garage for custom-car designer George Barris.  His passion, drive and dedicated workmanship brought on offers from the film industry partners where he did specialty cars for big name celebrities such as Frank Sinatra, James Garner and Steve McQueen.  And later for political leaders such as President Kennedy and President Johnson.  And many more projects anywhere a “Special” and unique touch was needed.  That special touch/those specialty cars caught the eye of one of Detroit’s big boys; Ford, that lead to Chrysler and onto to GM’s Cadillac division convincing them to install a (first time ever) sunroof in a Cadillac! 

This is when it really took off for Heinz and ASC, projects flourished with many manufactures from around the world and many more areas than just “sunroofs”.  There were such special efforts to provide for GM composite hoods and other components for the Pontiac TransAm WS6 model taking estimated sales of only 6,500 in over 3 years to an actual 40,000 units over 5 years. And of course the aforementioned Buick GNX and Turbo Grand Prixs through their drivetrain partner was McLaren Engines.  There were even special Bentlys made for the Sultan of Brunei, oh to have such financial influence. 

For his historical efforts, Heinz Prechter was nominated an inductee into the Automotive Hall of Fame on October 2004

Other substantial projects for ASC are the following:

Buick Cielo Concept

Buick Lacross Concept

Chevy SSR Sport Truck(?) providing body panels, engine dress, retracting-hardtop construct.

Chevrolet TrailBlazer

Chrysler PT Cruiser Big Sky Concept with AWD and 5-panel glass roof.

Dodge Ram SportSide Concept

Dodge SRT-4 providing finished aero trim, hood and spoilers

Dodge SRT-8

Dodge Viper SRT-10 providing body panels such as hoods

Dodge Viper Diamondback 615hp

Lexus RX300 Concept

Mitsubishi Stage 1 Concept

Pontiac Grand Am SC-T image created and resulted in unanticipated skyrocketing sales.

Pontiac Sunfire H.O. 2.2

Pontiac GTO Stinger

Pontiac Vibe GTR

Saturn L Series

So-Cal SSR

Suzuki Grand Vitara “Dune,”

Specific involvement with either a Full Conversion or System Supply Convertibles:

BMW (Z3, Z4)

Buick (Reatta, Riviera)

Cadillac (Eldorado)

Chevrolet (Camaro, Cavalier, Corvette, SSR)

Dodge (Shadow, Dakota)

Hot Rods & Horsepower (Dearborn Deuce Convertible™)

Infiniti (M30)

Mitsubishi (3000GT, Eclipse)

Nissan (240SX, 300ZX)

Pontiac (Firebird, Sunbird, Sunfire)

Porsche (944 S2, 968)

Renault (Alliance GTA)

Rover (Metro)

Saab (900 Turbo)

Toyota (Celica, Paseo, Cyno Solara).

July 13, 2005 marked the companies 1 million convertibles made

Their history also includes such “firsts” as:

First Factory Installed Sunroof in North American

First Modular Sunroof

First inwardly-folding convertible top

First modern retractable hardtop

First retractable hardtop on a truck platform

First glass panel sunroof.

Much can be said for the company ASC, I only wish the thanks from the many proud owners of the Turbo Grand Prix could only compare.

A total of 26 proto-type Turbo Grand Prixs and TSTEs were built, starting off with 2 gold 1988 Grand Prix SEs one of which was sent to be assembled and setup by Frank Peterson Racing/Leo Payne Pontiac and raced at Pikes Peak taking the Show Room Stock win over the heavier AWD GMC (prototype as well, possibly with the Buick GN Turbo Motor) Syclone at the time.  There was also initially 1 burgundy LE that was a turbo test-bed, and 1 white Turbo Grand Prix 2-door, 2 red Turbo Grand Prixs 2-doors, 4 black Turbo Grand Prix 2-doors and 2 red TSTE.  There were also 7 Pace Cars of which headed up the 1989 Daytona 500 and 5 which were used in the 1990 movie Days of Thunder with Tom Cruise, Nicole Kidman, Randy Quaid and Robert Duvall.  There was also mention of a rear wheel drive Turbo Grand Prix Pace Car.  There was also a yellow 2-tone down the center, Turbo Grand Prix.  Last there was one convertible red Turbo Grand Prix that was likely a custom aftermarket.

Info on the 1988 Grand Prix SE Turbo Pikes Peak Racer.  The first turbo version of the FWD Grand Prix.  Assigned proto-type status as #ID42318/JM GH and commissioned by Pontiac to ASC in Fairfax Kansas and in full partnership with drivetrain experts McLaren for work on the first rolling test-bed turbo Grand Prix, though soon to be followed by the 1988 Turbo Grand Prix/Grand Illusion (below article) in full Red Turbo dress.  This turbo prototype started as a base Grand Prix SE in gold with few options, that to ensure the lightest “Showroom Stock Class” example and to achieve the best race/track times later in its career.  It did included a full compliment of test-point locations for reading temperature in-out of the radiator, in-out of the air-to-air intercooler, one for manifold boost with a very large boost gauge still installed on the front roll cage bar, and another port after the air filter/before the turbo to measure vacuum/filter restriction.  A stock 1988 Analog/Digital combo dash as well the same wiper/light controls, and tan cloth bucket seats.  A 1988 automatic transmission shifter center console with no DIC.  A custom handmade radiator and an intercooler which was slightly larger and thicker than production units.  A larger/aluminum fab'd air filter box with larger hoses than production.  Smaller than production tranny cooler lines custom welded into the radiator side tank.  Hand fabricated aluminum radiator overflow tank with coolant level view-line similar to a catch-can.  Vacuum power assist brakes (instead of the standard ABS Delco Moraine III on the production version) with the vacuum supply fed from the back of the upper intake manifold.  Custom crossover pipe insulated and covered with the same wire-mesh braiding the stock downpipes used.  Stainless steel heat shield instead of the mineral fiber blankets used over the turbine housing on production units.  Stock T25 turbo as on production cars, but was it different/bigger back during the hill climb?  Different/larger and threaded wastegate actuator that gave it a faster spool (though chip tuning or a manual boost controller can achieve the same or more in regards to quicker spooling).  Stock injectors and production chip contents (copy verified) at this time though with a large "McLaren Engines" (with flying Kiwis) label on the ECM MEMCAL access panel and on the ECM's MEMCAL.  Aluminum pipe from front crankcase vent/valve cover to air filter box.  Hand made-up fuel line setup near brake master cylinder.  Hand welded take-off feed from stock coolant line to turbo center section's cooling line.  Hand fabricated aluminum intercooler outlet pipe to throttle body.  Production 16 inch gold crosslace rims though for the race, 225mm tires were used.  Mud flaps to help protect the paint during the stone-throwing race up Pikes Peak.  No battery cover and a different style windshield washer bottle.  Custom 2-peice upper radiator hose and thermostat neck.  And last, non-production for the Turbo Grand Prix a “ 3.1 Multi Port FI ” stamped upper intake manifold.    After much testing and validating this test-bed turbo Grand Prix was sent to Frank Peterson Racing, Lakewood Manufacturing Company in 1990 to add to its lineage by participating in the prestigious race at Pikes Peak, where it also faired better against the (pure prototype at the time) showroom stock class GMC Syclone.  Sponsors included Leo Payne Pontiac, 9 News, Coors Racing, DMI, Bars Meats & Cheese, BF Goodrich, Amore Auto Detailing, Pontiac Motorsports and Allison (if this is the "Allison" I am thinking of then for turbo consulting I would guess since they make turbo/diesel engines).  Frank Peterson Racing reassembled the engine into the car with a GM/Hydra-Matic Motorsports race-spec 4T60 tranny, then lightened the car by taking out the back seats, and the stock gas tank which was replaced with a small fuel cel on the backseat floor area.  There was no radio or steering wheel radio controls.  The exhaust was changed to just a 3 inch straight pipe (later a catalytic converter was added for street use).  There was a full roll cage installed with the rear bars penetrating through the rear deck speaker openings, and a tied-in 5-point Simpson racing harness.  Parking Brake was moved over next to the regular brakes (to get the backend out during hill climb, you know, to drift it out!).  Manual Brake Line Proportioning Valve next to driver’s seat (to allow favoring the rear brakes for pulling the backend out around dirt corners).  Last seen at the Auto Collections at the Imperial Palace in Las Vegas, where it was listed for $17,000, later to list for $15,000.

http://www.autocollections.com/index.cfm?key=1668&action=details&tab=inventory

The magazine test-use only; 1988 Grand Illusion Turbo Grand Prix with 305 hp at 4,800 rpms and 220 lb-ft at 3,000 had a larger T3 turbo and an Isuzu manual transmission (with a 3.61 axle ratio) which was stronger than the front wheel drive getrag 282 and 284 manuals of that era.  Compression ratio was still stated as with all Turbo Grand Prixs/Turbo STEs at 8.8:1 but with the resulting 305 hp, the chip tuning had to be tight and the intercooler very healthy, unless 100 octane no-lead was used.   It also had slightly larger 255mm wide Goodyear Gatorback tires, on the 16 inch dual-lip crosslace rims from the Firebird WS6 package.  Side mirrors were color-keyed, with production being black even on the red Turbo Grand Prixs.  Solid mast antenna, full amber front turn signal lenses, no silver trim around front grill inserts, and chrome trimmed exhaust tips round out the last exterior differences from a production Turbo Grand Prix.  Interior had leather inserts on the door panels, seats were more fully covered in leather with no cloth trimming as in production cars, tan leather was also used on the steering wheel.  Had to also be the first Grand Prix then to have a full analog gauge cluster!  No HUD was used at this time, later added to round out the uniqueness of this car's image.  Used old-school power brakes, and large radiator overflow tank bulking up the view of the engine bay.  Larger intercooler and cold air intake/filter setup.  No trim/heat management cover over the battery location.  Different routing of upper coolant and intake hose plumbing.  No trim cover over the cable bracket at the top-back of the engine.  Different turbo had improper running of coolant lines going down that was later corrected on production.  Also metal heat shield over turbine side was later replaced with a thick ceramic blanket.  Tests had not yet reveled the need for a securing clip over the throttle body vacuum lines.  Weight was quoted at an amazingly light 3,038 lbs, helping for sure the 6.3 zero to sixty, and 14.05 quarter mile times, who owns this treasure??...dinners on me!

GM initially wanted a single exhaust/false dual exhaust setup, but the ASC assembly shop pushed that the expense would be a small increase and worth it for this car to go with real duals, and that in the colder months it would not look good to have only one exhaust tip puffing white and the other not.  Also the initial idea was to use a sheet metal formed tip with a chrome trim which thankfully was upgraded by ASC’s suggestion to the use of the better final finish cast aluminum ones as seen in production!

Though ASC did make sunroofs, the ones installed on the Turbo Grand Prix and Turbo STE where Analfa units installed at Local Zone Shops (GM certified and operated).  Analfa is a very fine French supplier of Moonroofs (vent and open) and Sunroofs (vent only).

McLaren had 15-20 people working design and fabrication.  ASC had 30+ on such items as rims, aero construction/fitment/finish, drivetrain testing, and vehicle assembly.

Resulting thermal tests by McLaren and GM's dyno cels warranted the use of a much more efficient, costly and thicker copper/brass radiator for production verses the stock aluminum/composite plastic radiator used on production w-body cars.

In 1988 Pontiac regained the number 3 sales slot that it had lost 15 years ago, this slot is regarding vehicle sales of the big three, now Pontiac was only behind Chevy and Ford.  This was greatly assisted by the release of the new front wheel drive Grand Prix in 1988, and production of the new Grand Prix was not even up to full speed yet!.  There were only 17,088 (rear wheel drive) Grand Prixs sold in 1987, but in the first year of the new front wheel drive Grand Prix in 1988 sales had greatly increase to the 76,723 mark, 751 of those being Turbo Grand Prixs.  This was followed in 1990 with even higher numbers of 128,073, that being 65,887 coupes and 62,180 sedans, and 3,714 of those coupes being Turbo Grand Prixs and 1,000 sedans being Turbo STEs.

Not well known at the time but Pontiac offered a "Grand Prix Guarantee", which allowed all Grand Prix buyers from October  and December 1988 to return their vehicles for a full credit towards the purchase of any other 1989 Pontiac if they were not totally satisfied with their Grand Prix.

With wider 245mm tires, the allowed suspension travel had to be reduced so the tires would not rub the fender wheel well opening and aero trim.

1990 saw the first year of the Grand Prix being released for sale in Europe, and there is a picture of one in the Preferred Pictures and Links at this web sight, just look for the light blue color and rectangular (not composite) head lights. Turbo Grand Prixs that were shipped overseas had no changes, other than those required at the destination country, such as fender side-markers and headlight washers (also in the Preferred Pictures and Links location).

All Grand Prix in 1989 that had the V6 engine only had the 2.8L choice, except for the 1989 Turbo Grand Prix, it was the first Grand Prix to have the soon to be released 3.1L motor in all FWD W-Bodies.  In 1990 all Grand Prix V6 engines were based on the 3.1L .  This motor is called the 60 Degree V6 which was initially designed and released back in 1978………………………….lot more on that when time permits.

Assembly notes:
The Pontiac Grand Prix Assembly Plant in Fairfax had 3,500 workers on 572 acres creating approximately 650 Grand Prixs a day (325 per shift). Though not a record at taking a day and a half to complete a Grand Prix, priority was on quality but also the new paint process involving extensive corrosion protect as well 2 steps for the color coat then the clear coat requiring more time to complete, add to that hourly quality reports on body panel quality/fit/finish and you get the idea. One of the most modern plants for GM and most of the modern world, dedicated to only making Grand Prixs ran to the tune of over 1 billion dollars. This new concept plant was first at breaking ground in making and ensuring a consistent quality product, to the point that halting the assembly line to correct a problem was more than acceptable, it was expected. And the line was not started up again until the issue was corrected, and any cars already made/afflicted with the issue were corrected, or if the problem too severe to resolve, scrapped, that is a serious commitment to ensuring a quality product delivered to the customer. Control/operation of such a sophisticated assembly system required some ground breaking technology for the automotive field at that time, so elaborate PLC (Programmable Logic Controllers) were employed throughout, not to just control the individual assembly processes but to also work very much in unison with each other, while monitoring the entire assembly line process timing. Each car has a transponder attached under the front body that communicated not only where this car was but what the car was to be such as; a 2-door, 4-door, 4-cylinder, V6, red or blue in color. Thanks must go to the cooperation of the management team lead by Bud Darnell as well the hard committed workers of the Local 31 Union.

Further testing aside from assembly personnel is that random bodies are pulled off the assembly line and committed to some serious destruction, that to inspect some 840 welds made by 225 robots, ensuring penetration, and alignment to within 1/25th of an inch. The process to just “paint” the vehicle starts with its bare metal surface run through a phosphate bath followed with a bonding agent, then a dip using an ELPO (electrode position) to electrically charge coat the corrosion-resistant primer. Next a sealer is applied and baked for an hour at 350 degrees. After that the vehicle is hand inspected for flaws, slight imperfections are hand sanded, then its given an alcohol bath, dried and dusted using ostrich feathers (these do not create static electricity that would attract dirt/dust/lint to the body). Next the body is placed in a paint booth and setup with an electrical charge of 80,000 volts, there a painting bell rotates as fast as 30,000 rpms discharging the base/color coat, using this process there is nearly zero percent overspray/waste/fly-off emissions…..all this is done in 1.5 minutes to a complete color coated body! Next the color coat is baked dry, a clear coat is applied in similar fashion and again, baked dry, total shop-time to paint, 10 hours!

Next up the body is sent to have the doors removed for glass install, trim and accessories, while the body separate receives the same at its location. While this is going on the drivetrain is being assembled to the subframe; engine, tranny, suspension, hoses, electrical etc, all being prepared to the big day of being joined to the body. As the doors are reattached the weather-protection seals are applied, doors are aligned and checked for proper fit. After that final marriage of the key vehicle parts is completed as the drivetrain/suspension is brought into place, aligned and attached. Next up is wheels/tire, remaining molding, bumpers etc, then once again checks for fit and finish. After that the headlights are aimed and wheels aligned. Last is the real shake-down, a monster umbilical cord attaches for a 30-point system check of the workings of the electrical systems, gauges, lights, engine performance, transaxle performance, steering etc.
After all this the vehicle is driven to storage and awaits transport to its new owner! Other awards were Americans best domestic sedan by Motorweek, best in class interior by Automotive Industries.
 

Keep in mind, all details here were either as they were found, proven or stated by confirmed sources, or quoted in reputable articles, publications, reports etc but there could be differences in what was.  Much was left out that could not be confirmed to keep the information contained here as correct as possible!