When i worked it out it was all freeway driving when i first got the trol and its timing and tps adjustment was at the factory presets, from memory 91 i was getting 4km/l, 95 was 5km/l and 98 was 6km/l after i adjusted the timing and tps ( the tps was more for changing the shift points in the auto to compliment my driving style) i now get on 98 6.5-7.5km/l around town. Same driving style but less fuel consumption and a slight increase in power. All this was calculated on my 265's, with the 285's it works out on paper to use more fuel but i still travel the same distance for example with the 265's on 687km to 109.58ltrs and on the 285's 576 to 108.33ltrs but i still did my weekly drive and filled up after 6 days both times.
Only way for you to calculate it is you need to run each fuel thru 2 tank fills and record your data on the third tank, after the third tank adjust your timing a record another tank full of fuel and see what results you get
In our turbo diesel application with a much denser air charge due to the water injection we actually use less fuel. When you add methanol you can get it cooler again plus get the added power of a highly oxygenated fuel. You don't need a huge amount for good gains and can use boost and egt set points to switch it on and off. In a wagon you could get away with a 30-40l tank no worries.
Water/meth injection is the best way to lower intake air temps especially if using pre and post turbo injection. When used with a good intercooler you get a very stable intake air temp.
Sherro (17th May 2014)
And methanol is a good carbon remover, so you get a cleaner engine
Cheers
Kallen Westbrook
Sherro (17th May 2014)
Why is it not a more common engine mod? Price?
Nissannewby and others
Years ago I fitted water injection to a V8 and got big benefits
Cost was negligible but it was a carby engine. Two small copper tubes inserted thru the carby wall into the venturi tubes with a 45 degree angle cut on the end. No pump just vacuum with water intake 4.5 to 5 cc per mile (1.6km for the non GOMs) Also lifted carby 50mm with a balance tube setup between the twin barrels on the carby (WW2)
Benefits came from changing timing from 6 degree advance to about 12 degrees. Torque curve flattened but kept rising instead of the previous 2600 rpm peak some it went really well if you were of a mind to floor it.
Fuel consumption improved from 12 to 18 mpg around town and 18 up to 30 on the open road.
Most people never got the benefit they could have from water injection because they didn't fit it as well as they should and they didn't alter timing and fuel mixing by things like lifting the carby and balancing the in flow of fuel.
Mind you this was with a V8 carby so not sure how it would go with the new injected gear.
Cheers
Chimo
BigRAWesty (12th May 2014)
I see a pattern forming lol, so with your td mods you add fuel and try and lower intake and egt's to get better economy and performance yeah!? And adding a water methanol injection kit should help get you better economy. As a rough guesstimation with this lower fuel consumption how long would it take to pay for it self with the money you save on fuel ?? Say for argument sakes all up it costs you $2000 to buy, fit and tune