Quote:
Originally Posted by bazman
Both my 4100lb sedan (with me in it) and the Viper have the same 3.07 final drive. However my 4th gear is 07:1 giving an effective final ratio of 2.149:1. The Viper however has a 0.5:1 rato in 6th gear giving a final drive in 6th of 1.535:1. In other words it is idling along at 60mph.
A Viper from the factory in good tune can easily get 25-28mpg if driven very carefully on the highway/interstate. To get the extra 2mpg simply requires a tune that injects less fuel per cycle yet maintains power to maintain cruise speed. In the case of the 1000hp turbo Viper that improvement was a simple combination enabled by custom tuning and after market low impedance injectors that tolerated a more accurate map than stock injectors could. Sorry I don't know the injector make. The custom tune would have been leaner at cruise with as much spark advance as was useful. Factory tunes are conservative and never run as lean or as much spark advance as the engine might like.
My LS3 runs the latest state of art Bosch EV14 injectors and they are worth a little mpg over stock OEM older style injectors. Their main value however is they are available in far higher flow rates so can support more power. LS engines are easy to get great power and economy out of. Mine has 300hp at the wheels as low as 2600rpm, which is phenomenal torque for a 6.2.
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Quote:
Originally Posted by bazman
Well, I got 31.24mpg from the 550hp LS1 on a trip under perfect conditions but no hyper milling. Averaged 100kph (62mph).
Sadly that is imperial mpg, so that translates to 26mpg US or 9.09L/100km. Still not as good as the stock cam but I am yet to install the new state of art Bosch EV14 injectors which should gain another 3-4% over the bored out crappy injectors I am now using as there are several areas where the tune can be improved with better injectors.
We are getting there :-)
It's not bad for a 4000lb 4 door sedan with auto. Figures are no BS dash reading, these are actual kms and actual fuel used topping up by sight to ensure same level at each fill up.
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606 foot pounds of torque is pretty crazy. Is it normal for the engine to only rev to 4.7k? I know a lot of v8s will only go into mid 5s, but I thought the LS series was usually good to 6k or so.