Winter fuel economy/power

NoDOHC · 01-01-2009, 12:26 AM

Engine Statistics:

'86 (Stock ECU)
ECU: Original N326 built in October 1985
Fuel mix: Running closed loop at 14.7:1 AFR (when it was actually closed loop)
Timing: 12 degrees BTDC Leading 3 degrees ATDC trailing at idle (+17 degrees from stock)
Mileage: 178,000-192,000 miles
Compression: 104-110 psi on all faces
Block: Never touched, never had intake or exhaust manifold off, completely stock.
Coolant Seals: One may have been leaking slightly
Oil Seals: Blew clouds of oil smoke above 7,000rpm
OMP: Adjusted to the max
Premix: 4 ounces/tank
Auxiliary Ports: Functional in stock form (open at 3500 at WOT).
Air pump: Functional
Power Steering: Belt Removed
Air Conditioning: Belt Removed
Intake manifold: Stock and untouched
Exhaust: Stock 3 cats (functional) Dyna-Flow Mufflers, stock Y pipe.

'86 (Haltech)
ECU: Haltech E6X controlling ignition and Fuel.
Fuel mix: Running closed loop at 16:1 AFR (Wide band input)
Timing: 0 degrees BTDC Leading 12 degrees ATDC trailing at idle (advanced until ping elsewhere, 0 degree timing split above 2,000rpm)
Mileage: 192,000-199,000 miles
Compression: 104-110 psi on all faces
Block: Never torn down, completely stock.
Coolant Seals: One leaking slightly at first, both leaking toward the end
Oil Seals: Blew clouds of oil smoke above 7,000rpm
OMP: Adjusted to the max
Premix: 4 ounces/tank
Auxiliary Ports: Modified but functional (open at 4500 at WOT).
Air pump: Removed
Power Steering: Removed
Air Conditioning: Removed
Intake manifold: UIM deburred and polished, LIM deburred
Exhaust: Racing Beat Headers, Dyna-Flow Mufflers, stock Y pipe.

'91
ECU: Original
Fuel mix: Running closed loop at 14.7:1 AFR (when it is actually closed loop)
Timing: 17 degrees BTDC Leading 2 degrees BTDC trailing at idle (+22 degrees from stock)
Mileage: 146,000-154,000 miles
Compression: 80-100 psi on all faces (cold)
Block: in-car porting of irons to maintain runner cross-sectional area (Minimal port timing changes).
Coolant Seals: Good
Oil Seals: Good
OMP: Not adjustable
Premix: 6 ounces/tank
Auxiliary Ports: Fully Functional
VDI: Fully Functional
Air pump: Functional
Power Steering: Functional
Air Conditioning: Functional
Intake manifold: Port matched LIM and UIM
Exhaust: Racing Beat headers, ???(Stainless steel, unknown manufacturer) presilencer Y-pipe and mufflers.

I would guess that your street ported engine will not get stock port mileage. (Although I have heard some say that a street port makes little to no difference).

01-01-2009, 12:26 AM	#1
NoDOHC The quest for more torque Join Date: Sep 2008 Location: Sheboygan, Wisconsin Posts: 855 Rep Power: 17	Engine Statistics: '86 (Stock ECU) ECU: Original N326 built in October 1985 Fuel mix: Running closed loop at 14.7:1 AFR (when it was actually closed loop) Timing: 12 degrees BTDC Leading 3 degrees ATDC trailing at idle (+17 degrees from stock) Mileage: 178,000-192,000 miles Compression: 104-110 psi on all faces Block: Never touched, never had intake or exhaust manifold off, completely stock. Coolant Seals: One may have been leaking slightly Oil Seals: Blew clouds of oil smoke above 7,000rpm OMP: Adjusted to the max Premix: 4 ounces/tank Auxiliary Ports: Functional in stock form (open at 3500 at WOT). Air pump: Functional Power Steering: Belt Removed Air Conditioning: Belt Removed Intake manifold: Stock and untouched Exhaust: Stock 3 cats (functional) Dyna-Flow Mufflers, stock Y pipe. '86 (Haltech) ECU: Haltech E6X controlling ignition and Fuel. Fuel mix: Running closed loop at 16:1 AFR (Wide band input) Timing: 0 degrees BTDC Leading 12 degrees ATDC trailing at idle (advanced until ping elsewhere, 0 degree timing split above 2,000rpm) Mileage: 192,000-199,000 miles Compression: 104-110 psi on all faces Block: Never torn down, completely stock. Coolant Seals: One leaking slightly at first, both leaking toward the end Oil Seals: Blew clouds of oil smoke above 7,000rpm OMP: Adjusted to the max Premix: 4 ounces/tank Auxiliary Ports: Modified but functional (open at 4500 at WOT). Air pump: Removed Power Steering: Removed Air Conditioning: Removed Intake manifold: UIM deburred and polished, LIM deburred Exhaust: Racing Beat Headers, Dyna-Flow Mufflers, stock Y pipe. '91 ECU: Original Fuel mix: Running closed loop at 14.7:1 AFR (when it is actually closed loop) Timing: 17 degrees BTDC Leading 2 degrees BTDC trailing at idle (+22 degrees from stock) Mileage: 146,000-154,000 miles Compression: 80-100 psi on all faces (cold) Block: in-car porting of irons to maintain runner cross-sectional area (Minimal port timing changes). Coolant Seals: Good Oil Seals: Good OMP: Not adjustable Premix: 6 ounces/tank Auxiliary Ports: Fully Functional VDI: Fully Functional Air pump: Functional Power Steering: Functional Air Conditioning: Functional Intake manifold: Port matched LIM and UIM Exhaust: Racing Beat headers, ???(Stainless steel, unknown manufacturer) presilencer Y-pipe and mufflers. I would guess that your street ported engine will not get stock port mileage. (Although I have heard some say that a street port makes little to no difference). __________________ 1986 GXL ('87 4-port NA - Haltech E8, LS2 Coils. Defined Autoworks Headers, Dual 2.5" Exhaust (Dual Superflow, dBX mufflers) 1991 Coupe (KYB AGX Shocks, Eibach lowering springs, RB exhaust, Stock and Automatic) Last edited by NoDOHC; 01-01-2009 at 12:30 AM.