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Sunday, August 19, 2018
  1978 Pontiac Trans Am
 
 


This car is currently undergoing a retooling. We have completed all chassis and engine work and will be assembling the car over the winter for the 2007 racing season. The specifications below are of the car as it was in 2005. In the coming months we will do an updated article on the car.


This car has been in our family since 1992 and has gone under many transformations, but this current one is by far our most ambitious one. John, the elder brother, has done a remarkable job in designing and executing the entire build.

The dyno results were simply outstanding. HP topped out at 598! The new engine is quite a powerhouse and still maintained 14" of vaccum @ 1000 rpm!

Click here to read the article on the new engine.

Car specifications:

  • TH400 transmission with Cheetah shifter and manual valve body
  • 10 bolt rear with spool and 33 spline axles, 4.10 gears
  • 6 point chromemoly rollbar
  • Competition Engineering Slide-a-link bars with stock leafs in rear
  • 90/10 shocks with Moroso Trick Springs in front
  • Welded frame connectors
  • Manual brakes and steering
  • Fiberglass front racing buckets with harness, no back seat
  • Centerline Convo Pro 15 x 8-1/2 with Goodyear 30 x 9 radial slicks in back
  • Centerline Convo Pro 15 x 4 with 205/75R15 tires in front

Weight with driver was 3600 lbs

Torque converter was locally built 10" unit that flashed to 3800 rpm, but didn't lock up so good on the top end. We calculated 12% slip crossing the finish line.

A professionally built 'right' converter for the engine should have been good for a couple of tenths and a few more mph.

Engine specifications:

  • 455 bored .040" over gives 464.7 cid
  • TRW forged pistons installed at 0 deck height
  • Eagle Pontiac rods
  • ARP studded 2 bolt mains
  • Block filled to bottom of water pump holes with Hardblok
  • Crane HIT-290 hydraulic flat tappet cam (see cam card for specs)
  • Lunati 1.65 aluminum roller rocker arms
  • SD Performance ported 5C heads (see flow sheet for specs and our flow test results)
  • 9.5:1 comp. ratio
  • Torker Intake (not Torker II)
  • Holley HP750 DP carb (#81 jets, 6.5 power valves front and back)
  • Hooker 1.75" Super Comp headers
  • HEI distributor with MSD box locked at 32°

Track results:

 
Best E.T.
11.791
11.716
Best MPH
114.692
113.017
Best 60 ft
1.613
1.625


*Engine idled at 1000 rpm with 14" vacuum

*Torker II intake was mismatched to heads (intake ports were bigger than head ports)

*Torker II was opened up to RAIV size ports, but head was standard size.


next page...

 

 

Dyno 06 and dyno 09 are same day comparison of Torker and Torker II intakes (pdf file)
Dyno 06 page 2
Dyno 09 page 1 (pdf file)
Dyno 09 page 2
dyno12 is same combo but with generic 1.625" headers (pdf file)
Dyno 12 page 2
Dyno 15 is best dyno run with above combo (pdf file)
Dyno 15 page 2
Dyno 12 vs 15 (pdf file)
Crane cam card (pdf file)
SD Performance spec sheet (pdf file)

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