Kevin's 1985 Tuned Port Injection Trans Am

  First, a little background:  The car..... a black 1985 Trans Am that I bought back in February of 1998 with 74,000 miles on the motor and had rarely been driven in previous few years. Powered by the 305cid (5.0liter)LB9 V-8 Tuned Port motor, the engine came from the factory rated at 210 horsepower, but it generated so much torque that GM was limited to using the 700R4 automatic transmission as the Borg Warner T-5 could not handle it.   The following year, a lower profile cam (the so-called "peanut cam") and more restrictive exhaust among other government mandated changes to keep emissions legal choked the 305's horsepower rating down to 190 but eventually climbed back up to 230hp by 1992 with dual cats and the L98 cam. 

There are so many modifications that can be done to this car, the only limit  is how much you are willing to spend and the results you expect to see from that spending.  There are also a handful of "free" mods, all they take is your precious time.  Whatever the case may be, I have one suggestion:  DO AS MUCH AS YOU CAN YOURSELF.... If you don't think you can do it on your own then at least get your hands dirty while someone else is doing it!  There's no substitute for experience.  There's nothing worse than some pompous ass walking into a shop, throwing money at one of the mechs to perform some modification on the car that wasn't meant to be in the first place, and walking out until it's ready.... Little does he know, the mechs aren't laughing with him, they're laughing at him.... all while happily pocketing money this guy probably didn't even earn himself.

  Most of the modifications that I have performed (or have had performed) have been ones that I found out about from ThirdGen.org, an outstanding site for any third generation F-Body owner. Thanks to guys like Vader, GM Tech, Rob P and others who have answered an endless list of questions about what to do.... Detailed descriptions on how to perform many of the modifications listed below can be found there.  Many, many many thanks also go to Frank "Dr. Turbo" Baber  of Performance Pontiac in Portsmouth, Virginia who has helped me out of many tight spots, often while being knee deep in someone else's car, and last but definitely not least, the rag-tag members of the The Tidewater Trans Am Club and Roughton Pontiac who have helped me acquire the proper parts or pointed me in the right direction as far as where to go to get them, (sometimes straight to hell).  The list of mods is as follows:

Engine: Modified air-box, throttle body coolant bypass, removed mass air flow sensor screens, JET throttle body airfoil, ported plenum and port matched runners, MSD6AL with 6000rpm soft touch rev limiter, Accel HEI Supercoil, Accel 8.8 Spiral Core wires, Accel cap & rotor, Bosch platinum plugs, Mobil 1 10W-30 synthetic lifeblood, Buick Grand National Coolant fan switch, Syclone fuel pump, high flow catalytic converter, Flowmaster 3 chamber muffler.  New valve seals, homemade adjustable fuel pressure regulator, (instructions here) and fuel pressure gauge.  19lb. injectors serviced and flow matched by Rick at cruzin performance.

So far, the best mod performed has been removing the GM "870" ECM and replacing it with the GM "165" ECM.  The 165 ECM is 51 times faster than the 870 and replaces the VERY expensive MAF Burnoff module with two $9 relays.  A custom EPROM was also burned and the spark and fuel curves have been aggressively advanced about as far as they can go. Details of how to perform the swap can be seen here, and pictures of the swap can be seen here. Future mods:  Custom home-built cold air induction kit.  Moroso water pump, Wells/Conrad SU-145 MAF Sensor, top end rebuild to include 1.6 roller-tipped rockers, and a Walbro in tank fuel pump   

Transmission/Driveline: JG1 Aluminum driveshaft from a 1LE (Thanks Leo!)  Polygraphite transmission mount, as the stock rubber one is crap. A little note to all you other 9-bolt Australian rear end owners... DO NOT USE synthetic oil in that rear end!!! I put in synthetic oil before driving across the country from Virginia to Washington in 2001 and by the time I got to Wyoming the rear end had quite a hum going. I have since switched back over to regular gear oil but I am still waiting for the noise to go away...    Future mods: B&M TransPak with the Corvette Servo, TCI Breakaway Lockup torque converter, driveshaft safety loop.

Suspension/Brakes: Stock WS6 performance suspension package with 4 wheel disc brakes and larger front and rear anti-sway bars, Polyurethane front and rear sway bar bushings and the GM steering brace ("Wonder Bar").  Future mods: 1LE braking system, Eibach 1" lowering springs, Edelbrock IAS Performer shocks. 

Interior:  The reupholstery was completed in March 2004. Charcoal gray with black trim and new gray carpet from ACC. A Pioneer DEH-P77DH head unit has replaced the Pioneer DEH-45DH that was damaged during a break-in in August 2002, and a Pioneer CDX-P1270 12 Disc CD changer has replaced the old CDX-FM1235S 12 disc CD changer, that was also damaged during that same break-in. Pioneer 10" TS-WX75A subwoofer and Pioneer 6x9" 3 way speakers in the sail panels.  Future Mods: Fiberglass headliner from TA Custom Creations, 145mph gauge cluster swap as soon as I get the proper VSS and speed buffer. 

Exterior: Firebird/Trans Am decals by PhoenixGraphix.  Future Mods:  Complete repainting in Midnight Black and fiberglass aerowing spoiler.

Wheels/Tires:  Kumho 712 ECSTA Supra Z rated 245/50/ZR16 tires on stock high tech turbo wheels.  Future Mods:  Goodyear Gatorback 255/50/R16 tires on GTA black cross lace wheels.

  My goal if I keep the 305 in the car is to squeeze 300hp out of it, which while challenging  for a naturally aspirated engine is still quite attainable with the proper mix of the right mods.  If I don't keep the 305,  in will go a ZZ4 GM crate motor but I will keep the TPI setup and MAF system as it is more accurate in providing information to the ECM than the later speed density (MAP) system used from 1990-92.  

Additional:  Viper 550 ESP Alarm with remote starter.. (Really fun in the parking lots), 

Drag Racing:  Went to the track for the first time on Friday, November 10, 2000.... made 4 runs at Virginia Motorsports Park in Dinwiddie, VA.  Here are the numbers from that night.... not too good, but they'll get better:

If you have any questions or comments, e-mail me...

Links:

Mike in AZ's 3rd degree   

Phil Parsons' Best Damn Garage on the Net

Dan's Thirdgen Hobbyist Page

Thirdgen.org

Mike Davis' EPROM Project page

Southeast Thirdgen.org

R.C. Rabine's Homepage