TPITuned Port Injection discussion and questions. LB9 and L98 tech, porting, tuning, and bolt-on aftermarket products.
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Tomorrow morning I am going on vacation. I will be driving (proudly), my 1991 z28 camaro. The car has a 5.7 litre TPI engine with 137,938 original miles, edelbrock TES headers, Dynomax exhaust, TPIS airfoil, Jeg's red hot Ignition coil,Accel 300+ plug wires, Summit boot protectors, new (rebuilt) 22lbs. injectors from south bay fuel injectors, new KYB shocks and struts, and new Cooper Xeon tires. The trip will be between 700 and 1000 miles, freeway and mountain miles. I do not baby this car. I will represent all third gen owners with pride. What are your guesses on fuel mileage? I will report back when we get home. Thank's Randy
When I drove my car on long trips (1000 miles +) I would get between 23/26 MPG. Using 93 Prem. and driving at least a average speed of 75MPH from Ohio to Florida. When I had the 305 TPI motor the avg was 25/28 for the same trips.
just did a trip myself from florida to north carolina and back. i got 16.6 mpg highway running 75-85mph. i have 24lb injectors and a big cam though. premium fuel the whole way.
OK, I'm back from my road trip. I am disappointed with my mileage. I used 51 gallons of 91 octane fuel on a 1071 mile trip. 21 mpg. Long ago I reported 25 mpg on a longer trip. I think that I know what happened. In my original post I neglected to say that I had also replaced the radiator with a Summit direct fit (LOL) aluminum radiator. Annd a 160 degree thermostat. Wow, what a difference in temperature. I am not familiar with the gauges in other third gen vehicles, but, during the whole trip my temp gauge never went past the mark between 100 and 220 degrees. I was running too cool, what do you all think? The car ran good, but I think it smelled rich. Thank you for your input, and I CORRECTED MY PROFILE. I do have a 700 r4. Thanks, Randy
Sounds like you were running right around the 180 mark. On my car (Pontiac gauges) the 1/4 mark is exactly 180. I have a 180 stat and that's exactly where it runs on the highway.
I don't know how you ever got 25 mpg before with the L98. People generally need the 2.77 gears with a lightweight setup (Z28 or Formula, skinny person, no spare tire)
