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Randy's

1981 Pontiac Firebird

Trans Am LS Swap

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Build Points

252

  • Color: Black
  • Horsepower: 425
  • Drivetrain: RWD
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  • Vehicle Overview

    I've been working on this project for 20 years. I bought the car in pieces, painted it and put it back together. I am not a painter, I taught myself how to paint and painted it in the garage one piece at a time. The paint is not perfect, but then again it is a driver, I put about 5000 miles on it every summer. Hard to keep the bugs off the front of it. The first engine was a ZZ3 350 ci crate engine. Then years later I built a 383 SBC with AFR heads. Now I am working on a 6L LS for it. Last winter I changed from a Turbo 350 and Coan torque convertor to a 4L60e with a Coan lockup torque convertor. I was going to use a 700r4 because I was still running a HP ECU, so I had one built. Then I got a deal on a Dominator ECU, so I changed to a 4L60e and sold off the 700r4. The Dominator controls sequential MPFI, Holley CNP, shift light, PWM rad fans, AC fans, AC pump, Transmission cooler fan, electric crankcase vacuum pump, low crankcase LED warning light, transmission pressure sensor, fuel pressure sensor, oil pressure sensor, knock sensors and two 3.5 inch displays in the dash. I also have an input set up for testing that will alter the Target AFR table and Timing table using Advanced tables and another input to start internal data logging. It has 10.2/1 compression and I have it tuned to run on 89 octane. I can get over 20mpg out of it right now. With the overdrive and 3:42 rear gears it runs at 1900 rpm at 65 mph. This fall I plan to put it on a chassis dyno to get a baseline, just in case I get the LS engine done early and get it in by spring 2020.

    Vehicle Story

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    Completed Modifications

    Drivetrain/Transmission/Differential (2)
    Engine Management (ECU) (11)
    Engine Parts (10)
    Exterior (1)

    Future Plans

    The car has been an evolution over the years. So this winter (2019) I plan to tear out all the wiring (except the factory wiring), move the ECU to the trunk and put in a relay fuse box in the trunk as well. I bought the Holley Unterminated 15' Flying Lead Main Harness and I found a used LS main harness on E-Bay. I cut up the LS harness to use all the plugs and loom off it. I have the J1A and J1B connectors from the used LS harness with about 40 inches of wire left on them. So if anyone needs to extend your main harness, give me a shout. The winter of 2020 I plan to change the engine to the 6L LS I am working on. The goal is between 450 to 500hp and still get 25 mpg. The rotating assembly is complete. I had the crank turned, block decked and the cylinders honed. I assemble the rotating assembly myself. The mains measured good with the first set of bearings I bought but I ended up getting 3 sets of rod bearings before I got the clearances I wanted. I bought the LS3 style heads bare from a place in BC Canada. Then I assemble them myself. I would have liked to have use the Holley intake and TB, but with the Canadian dollar down, cost was an issue. I have the Sniper TB on the current engine and I am very happy with it. I modified a factory coil bracket to accept the Holley Smart coils I already have. I am also going to reuse the Holley 36lb injectors I currently have. I still need to purchase the Holley oil pan, Holley accessory drive brackets and Holley EGT kit for my F-body. Then when all this is done my wife will probably ask "is it done yet" and I'll probably so no.

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    Comments

    • Ry

      04/22/2021
      Awesome!