Fuel Economy ,with Big Turbo

[R31Nismoid]

stuck up it

check the sticky @ the top of this section if your worried about fuel usage, i think there is a link for it

[discopotato03]

I think Sydneykid said if your engine is into boost at freeway cruise speeds , like every time you breath on the pedal for a hill , the consumption will be poor .

Cubes may have found by using the larger turbine housing the boost threshold is higher and exhaust restriction lower . If the final drive was raised to 3.7/3.9 the car could use the extra torque it makes at lower revs to get better mileage .

O/T but notice how the R34 GTt uses propper variable cam timing and makes good torque even with the larger turbine housing . The effective or dynamic CR is probably better that the GTS25T at the low end so does not need the early onset of boost to get it going . Has anyone compared consumption on a 33 and a 34 ?

I'd like to know what the aftermarket VCT does to a GTR from a power and consumption point of view .

Cheers A .

[gtst25]

bloody hell, im running a stock r33 s2 with just 4" exhaust (from 3"cat) 10psi boost and power fc and i can only get 360 k's out of it max even driving like a ganny most the time

you guys reckon the big exhaust has somehtnig to do with this or not?

<{POST_SNAPBACK}>

Hi there,

No don't think the exhaust has anything to do with it.

More than likely that your tune isn't the best - I doubt it would be the oxygen sensor (please correct me if I'm wrong!) as with mine turned off at light to moderate loads the AFR's are pretty much the same as with it on. It would be interesting if you could go for a drive with a lambda sensor to see what's going on - getting that done at a shop would probably end up paying for itself with the fuel you may save.

Something I did notice about the other guys I went on the cruise with is that they are always in a low gear giving it a rev.

No good for economy.

Strange that you get such bad economy with a 10 psi tune though - who ever tuned it wouldn't have had to change the maps too much and mine got excellent fuel economy with the factory apexi maps!

Cheers

[shanef]

Hi there,

No don't think the exhaust has anything to do with it.

More than likely that your tune isn't the best - I doubt it would be the oxygen sensor (please correct me if I'm wrong!) as with mine turned off at light to moderate loads the AFR's are pretty much the same as with it on. It would be interesting if you could go for a drive with a lambda sensor to see what's going on - getting that done at a shop would probably end up paying for itself with the fuel you may save.

Something I did notice about the other guys I went on the cruise with is that they are always in a low gear giving it a rev.

No good for economy.

Strange that you get such bad economy with a 10 psi tune though - who ever tuned it wouldn't have had to change the maps too much and mine got excellent fuel economy with the factory apexi maps!

Cheers

<{POST_SNAPBACK}>

Mercury tuned it, twice actually lol, wasnt all that happy with the first but they werent able to do a road test/tune, n still not fully satisfied, but will wait til i get the fmic on n go back.

Also we had huge problems with it running heaps rich, but it should be fixed now, also when i put the new dump pipe on the 02 sensor was chalked up with heaps of carbon, but i cleaned it all up n looks ok

lambda sensor what is it n what does it do?

P.S. sorry for highjacking the thread :lol:

[shanef]

forgot to ask, how much u sellin them stocko rims for???

i need a set of burnout rims hehehe

[GKTECH]

Rb25 with TD06, 251rwkw's. Get around 200 - 250km's out of a full tank in an R32.

Greg

[gtst25]

Mercury tuned it, twice actually lol, wasnt all that happy with the first but they werent able to do a road test/tune, n still not fully satisfied, but will wait til i get the fmic on n go back.

Also we had huge problems with it running heaps rich, but it should be fixed now, also when i put the new dump pipe on the 02 sensor was chalked up with heaps of carbon, but i cleaned it all up n looks ok

lambda sensor what is it n what does it do?

P.S. sorry for highjacking the thread  :lol:

<{POST_SNAPBACK}>

Lambda sensor is one of those sniffer things the dyno guys put up the exhaust so they can check what the air/fuel ratios are.

Id say you'll get better economy with an intercooler and dump.

If it was running heaps rich then maybe your O2 sensor is buggered.

[r33_racer]

getting about 1.2ltrs per 1.1kms at morgan park on the weekend. rb25det with about 350hp @ rears...almost always on boost...martini 110 race fuel...expensive shit..and we went through it like no tomorrow..used about 80-90 litres for about 79 laps. lol 150 bux per 20ltr drum.