1227165 with 12P on a LQ1 (3.4 DOHC)
Posted: Tue Mar 28, 2017 12:28 am
I am starting this to document my attempt to control my motor for my budget endurance race car. The car is built against the Chump Car series rules, with plans to compete in 24 Hours of LeMons and World Racing League events as well. The Car is a 1987 Fiero GT, 100% gutted, seam welded/reinforced and repaired from rust and previous crash damage. The engine, is a 1996 3.4L DOHC LQ1 from a US Chevrolet Lumina LS.
The engine has reground camshafts, lightweight lifter buckets, a shortened runner intake with an extra large large plenum (above 10L), a 75mm throttle body from a later OBDII spec Northstar V8. These engines are the bastard spawn of the GM 60 degree V6, adopted to DOHC by removing guts in the lifter valley, running a belt pulley of the blanked shaft where a standard pushrod camshaft would live. The camshafts ride in heavy aluminum carriers, machined like cam-in-block tunnels. They hold the 35mm lifter buckets and camshafts. Its an inefficient design that's heavy, but I'm sure GM did this to allow common tooling in their V6 plant. they have a 7x crank wheel, a 1x cam sensor, and run waste spark DIS. The heads are 24V units, with square intake ports, obround exhaust ports. No headwork has been done at this point beside a 3 angle valve job (if they the machine shop even did that) and spring shims to bring the effective rate up. the design of the timing belt setup allows for infinite adjustment of the camshafts, so I might play with that a bit.
Current timing is: 236 Degree duration (.05") with 10mm of lift on intake and exhaust . Timing is 108 Intake Centerline and 112 Exhaust Centerline.
This engine used to run a 16196401 from a 1994 Monte Carlo Z34 with a custom tune from gmtuners.com when it was stock. I attempted to retune with my AutoProm from Moates, but never had much success getting tuner pro to read the ALDL data, and the .bin from the chip with that ECU. I am ditching that ECU so that I can run a MAP sensor instead of MAF, and have better ignition and fuel control at high RPMs. The old ECU used to stall when disengaging the clutch at times. and if it didn't the idle would be around 1100rpm and slowly settle, (tricks with the IAC to raise idle after cruising and prevent the stalling)
I have a 1227165 ECU and harness from a mid 80's 5.0L Firebird, the Old harness and ECU from the 16196401 days, my autoprom, and I am trying to buy the NVRAM module from Antus currently to make tuning easier than running through the autoprom emulation. The good news for me is, I work at a Dynamometer manufacturer, http://powertestdyno.com/ and http://www.stuskadyno.com/. On weekends I can run the engine on our XS211 test dyno to work on the tune outside of a car.
Right now I still need to wire the harness to the 12P spec, make mounts for the engine stand at work, and have the driveshaft adapter cut for the crank pattern so I can run on the dyno.
Ill keep this thread update as I go through making this setup work.
The engine has reground camshafts, lightweight lifter buckets, a shortened runner intake with an extra large large plenum (above 10L), a 75mm throttle body from a later OBDII spec Northstar V8. These engines are the bastard spawn of the GM 60 degree V6, adopted to DOHC by removing guts in the lifter valley, running a belt pulley of the blanked shaft where a standard pushrod camshaft would live. The camshafts ride in heavy aluminum carriers, machined like cam-in-block tunnels. They hold the 35mm lifter buckets and camshafts. Its an inefficient design that's heavy, but I'm sure GM did this to allow common tooling in their V6 plant. they have a 7x crank wheel, a 1x cam sensor, and run waste spark DIS. The heads are 24V units, with square intake ports, obround exhaust ports. No headwork has been done at this point beside a 3 angle valve job (if they the machine shop even did that) and spring shims to bring the effective rate up. the design of the timing belt setup allows for infinite adjustment of the camshafts, so I might play with that a bit.
Current timing is: 236 Degree duration (.05") with 10mm of lift on intake and exhaust . Timing is 108 Intake Centerline and 112 Exhaust Centerline.
This engine used to run a 16196401 from a 1994 Monte Carlo Z34 with a custom tune from gmtuners.com when it was stock. I attempted to retune with my AutoProm from Moates, but never had much success getting tuner pro to read the ALDL data, and the .bin from the chip with that ECU. I am ditching that ECU so that I can run a MAP sensor instead of MAF, and have better ignition and fuel control at high RPMs. The old ECU used to stall when disengaging the clutch at times. and if it didn't the idle would be around 1100rpm and slowly settle, (tricks with the IAC to raise idle after cruising and prevent the stalling)
I have a 1227165 ECU and harness from a mid 80's 5.0L Firebird, the Old harness and ECU from the 16196401 days, my autoprom, and I am trying to buy the NVRAM module from Antus currently to make tuning easier than running through the autoprom emulation. The good news for me is, I work at a Dynamometer manufacturer, http://powertestdyno.com/ and http://www.stuskadyno.com/. On weekends I can run the engine on our XS211 test dyno to work on the tune outside of a car.
Right now I still need to wire the harness to the 12P spec, make mounts for the engine stand at work, and have the driveshaft adapter cut for the crank pattern so I can run on the dyno.
Ill keep this thread update as I go through making this setup work.