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Mark's '73 Pontiac Trans Am

This is a '73 TA I found in a machine shed in '99. It actually belonged to a friend and I didn't know that he owned it. It is an original show car that he bought and started using for everyday transportation. It started to surface rust on the hood underside and a judge at a car show somewhere asked him to not put the car in judging. It was fine for him to bring it to the show but they could not judge it due to the surface rust. So he put it in the machine shed at a friends house and totally dismantled the car.

When he offered it to me he had completely taken out the motor, drive train, rear end, and dropped the front frame stub out the bottom. Because the spoilers and flairs were all moulded in and painted he could not dismantle the sheet metal so that is how I found it. Sitting on make shift saw horses like a model car body, completely intact with no frame and or running gear.

Once I started to reconstruct it I had to build it all back together with the sheet metal all installed. The pics you see above are the first days on the street. First car show in 2002. While it was apart I built the motor (see below for specs).

The Trans Am as I found it.

Turbo system installed in 2008

Dyno results with the turbo system installed:

The first run was at 10 psi and it hit 788 HP and 744 ft-lbs of torque at the rear wheels. The next 2 pulls were at 12 psi and it reached 789.7 HP and 827.9 ft-lbs. The last run was at 15 psi and it hit 886.8 HP and 822.3 ft-lbs of torque at the rear wheels. The drivetrain loss is 20%, so that converts to 1064 HP and 987 foot-pounds of torque at the motor.

I built the turbo system completely by myself with a real welder finish-welding the parts. The TA is in the shop because they won't let me run down here without side bars on the roll bar so I'm getting a full cage (good for an 8.5 second ET) installed for future use. If I can get that 1064 HP down I might actually be pushing that area.


Specs as of 2002
Block:Original but Service Replacement 455 (now 462 cid)
Pistons:Forged TRW SD single trough
Rods:Fully floated, blueprinted, polished, and ARP'd cast rods
Heads:Fully ported 6X-8
Cut and chamber ported to 97cc
Comp ratio:9.1 : 1
Cam:Solid Crower 264/268 degrees @ .050
.552/.558 net lift 108 C/L
Lifters:Cool face solid lifters
Headers:Headman 1-3/4 inch
Intake:Edelbrock Torker II
Carburator:830 Holley
Transmission:TH400
Rear end:10.5" 10 bolt, 3.73
1/4 mile ET:12.0 sec @ 110 MPH
Mods in 2003
Power adder:Cheater nitrous plate system
1/4 mile ET:10.9 sec @ 121 MPH
Mods in 2006
Intake:Wenzler tunnel ram
Carburation:Twin 600 DPs
Twin plates to use the cheater nitrous thru
Water pump:Meziere electric
Other:Removed the heater system
Power steering replaced with an S10 manual gearbox
1/4 mile ET:10.25 @ 133.8 with a 200 shot nitrous (Oct '07)
Mods in 2008
Power adder:77mm turbo w/.96 A/R turbine
5 inch exhaust exit, 4 inch electric dump valve that will
open on request and exit out thru the front passenger
fender. When closed it exits back under the car and out the back.
From the turbo the charge goes thru an air to water
intercooler before going back up to the blow-thru 830 Holley.
Rather docile on the street and with the electric exhaust valv
should sound wild at the drive-in.
Cam:Boost-compatable 248/248 @.050 .520/.520 net solid with a 114 LCL
1/4 mile ET:Should be easily in the 9s.

Related

Night at the track with Marks73TA
Turbo installation on Mark's 73 TA
Mark's '73 TA Videos
More cars of the 1970s
More Pontiacs

Comments

Anonymous on May 21, 2008 at 08:40 a.m. said:

very nice

raspantienator on Aug 19, 2008 at 05:15 a.m. said:

Nice-I had a 74 455 but I prefer your style bumper to the 74's

snakepitt1 on Aug 11, 2009 at 06:38 a.m. said:

Pontiac power is alive and well!!!!

Anonymous on Sep 11, 2009 at 05:42 p.m. said:

sweet ride ,good luck

Anonymous on Sep 15, 2009 at 05:07 p.m. said:

Thanks for sharing this with me, Mark! You always were my auto expert.

~ Al Thomas

Anonymous on Dec 23, 2009 at 03:56 a.m. said:

Very nicely done,super rwhp numbers WOW !!! That (if you can get it to hook) will easily make some low 9's runs, tune it a season, you got that 8's ET slip we all so want! Congratulations on finishing the turbo setup, must have been a bit of nerve racking experience to learn about what all you needed to match it all up to each component. If you don't mine could you send me some info on the turbo,"electric dump gate" and what is in the engine now down to the smallest level. I am getting ready to do a "Turbo" on my 66', 421 four bolt main, now a 462ci engine for next year. Please contact me at freedomsoul36@hotmail.com

Kind Regards, jts

Anonymous on Dec 28, 2009 at 10:34 a.m. said:

thats badass dude

Anonymous on Jan 16, 2010 at 02:38 p.m. said:

Hi, that's a mega nice looking car, well done for getting it going again.

Andy, Wales, UK.

Anonymous on Feb 25, 2010 at 01:18 p.m. said:

car looks good



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