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Old 10-09-2010, 09:24 PM   #1  
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Default 1990 ASC/McLaren Turbo Grand Prix (long read)

For those of you who are unfamiliar with the Turbo Grand Prixs here a little bit of history taken from an article by Jim Walterscheidt:

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'* 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’* standards. ASC'* 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.

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'* 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'* 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’* 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.


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'* 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’* 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'* 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.

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.

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.

Author Jim Walterscheidt
Copyright © [J&W Auto Studios] 1996-2009

Now a little history on mine:

I do not now the entire history of my car but I've pieced together a good portion of it.
Last year, I got in contact with a previous owner of my car. His name is Brian or Gearhedd. Here is some information I've recieved from him via e-mail:

In the course of owning it, I had the instrument cluster re-soldered, & had swapped out the original DIC module/display in the console for one of the newer ones (from a '93, I think) with the complete fluorescent tube-type display. The one problem I always had with it was I could never get the front wheels aligned properly ( the passenger side wheel was shifted slightly toward the rear of the car), which gave it a slight pull to the right at all times. I tried removing the cradle & measuring / adjusting the control arm brackets, and even swapped in another cradle, but nothing worked - I never did get it figured out.

I also replaced the weatherstrip round the entire sunroof assembly. It was an aftermarket unit, but I don't remember the mfgr - American Sunroof Company sounds right, but I'm not sure. Replaced the headliner fabric at that time also.

I bought the car from a guy in Indy in '98, located near 86th & Keystone, just north & east of the Nora area. I don't know how long he'd had it, but I seem to recall him being the second owner of the car. I think it was sold new from the Pontiac dealership that was in in Noblesville at the time, but I could be totally off on that. I am pretty certain that it had lived in Central Indiana its entire life up until you bought it.

Brian bought the car in 1998. Brian sold the car to Jay (God910) in February 2004. Jay owned it until September of 2007 when he sold it to Matt (psych0matt). This is the earliest picture of the car i can find. Matt on the left is talking to Jay on the right.
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I bought the car from Matt early 2009. This is a picture of the car before I picked it up.
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I drove up to Michigan to pick up the car. Matt told me that the transmission was slipping in the car. He said that first and second gear work. When I got the car, only first gear worked. I drove the car home from Michigan to central Illinois at 35mph with only first gear. It took 7 hours.
In Michigan:

Shortly after I got the car home:

A couple weeks later I got to work on the transmission:

The car ran great afterward. This is a cell phone video.

A while later it ran 1/4 15sec at 90mph which was just awful considering the other TGPs that were there that day were doin mid and low 14s.

This is at a Northern IL w-body meet:

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Later I installed new topend gaskets and C302 injectors. I cleaned and painted the engine while it was apart.
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Old 10-09-2010, 09:24 PM   #2  
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Sadly, the front bumper on the car started to completely fall apart. So it made a trip up north to my buddy Roberts house to get a new bumper installed from a 96 grand prix.

Mine with the new bumper next to Roberts with the original bumper.

A month or so later I had a ASCMcLaren banner made:

About two months ago, the engine started to poop out on me. After taking it out and apart, the culprit was a stuck lifter. Enter project LX9TGP.

The new motor is a 3500 from a 2005 Malibu.

Stand alone engine computer (megasquirt2 v3.0)

Front mount intercooler from a Saab

New motor (3500) cleaned and painted

New motor in but far from done

Well, the car is not complete but I decided to pull it out of the garage and clean it anyway.

Figured I'd go ahead and add some current pictures and stuff:

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Old 10-09-2010, 09:30 PM   #3  
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wow amzing pics i love the ''buckets in the rear'' nice car man
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Old 10-10-2010, 12:16 AM   #4  
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Love the history and time-line.

Also love the fact you're keeping a great car from going to the wrecker.

I'm curious on the 3100 upper intake though. The 3500 flows a fair amount more IIRC.
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Old 10-10-2010, 01:12 AM   #5  
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the large-port 3100 upper(same as the 3400 upper, just number casting difference ) will flow enough for a turbo application and not see much of a difference, though i am fond of the LX9 UIM myself...but i believe jon was having alignment or location or connection issues, something like that....
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Old 10-10-2010, 03:40 AM   #6  
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Originally Posted by RobertISaar View Post
the large-port 3100 upper(same as the 3400 upper, just number casting difference ) will flow enough for a turbo application and not see much of a difference, though i am fond of the LX9 UIM myself...but i believe jon was having alignment or location or connection issues, something like that....
Ya, it was the easiest/cheapest way to retain the kickdown cable for the transmission.
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Old 10-10-2010, 07:48 AM   #7  
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Very nice. I like the new front bumper. It almost gives it a firebird look.
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Old 10-12-2010, 01:24 AM   #8  
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Great read and awesome pictures. I love the looks of that car.
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Old 10-12-2010, 07:01 AM   #9  
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Ohhhh how I miss those rear buckets.... And the million way fronts haha
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Old 10-12-2010, 12:05 PM   #10  
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Looks great I love that car
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