Fuel Consumption - help

[nedb]

With my R32 I get about 300 km per fuel tank - 55L. Rarely I would get over 300 km.

It seams like it doesn't really matter much if I gun it quite a bit or not, it's always within 20kms. I'm still using stock computer and stock injectors. A/F ratio is on the ritcher side, low 11s.

Even the boost I run doesn't play major role when it comes to the fuel consumption. Is it the O2 sensor or something else?

[DivHunter]

I have consistently got 500km out of each tank with my R33 since I got it. Love it, it has saved me on fuel compared to the '99 Ghia V8. Although I have had to baby it a bit in the wet, the simex tyres on it are pure shit, like driving with bald tyres.

[ferni]

I get around 300km per 48ish litres in my stockish GTR

Mrs gets around 370km per 48ish litres in her stock GTS

Go figure.

[firefox]

Thanks for all the help guys.

I have taken out the new O2 sensor and replaced it with the old one as my microtech ltx-12 does not use the O2 sensor.

I am selling the new O2 sensor on www.firesport.com, so if anyone with a stock ecu or one that needs the O2 sensor want to try imporve fuel economy the sensor.

Am getting more tunning done soon to try increase my fuel economy.

Ps. after the last time my car went on the dyno managed to squeze 330km out of a tank.

[Roy]

Get rid of the Microtech, they are essentially an electronic carbie, and save having to re-jet the carbs:)

I sue to get shocking fuel economy with my old LT8 runnning on a lightly modded RB20. It took a lot of work to get the eeconomy acceptable... and it took an Autronic dealer to get it right...all the Microtech tuners seemed to be wide open throttle jockeys who expected you to live with poor throttle response, poor economy albeit with good WOT power.

Now with my current car i am getting 400-450kms of city driving with a PFC and 235rwkws. (Thats not boosting it very much and 50 of my 120 daily kms are on the highway.

Ditch the Microtech or go to a tuner who is willing to work on the light load maps

[nismo33]

damn...and i thought mine was bad... i'm getting no more than 360km per tank on my r33 gtst and that's on high way driving..everyday use on traffics i'd say i get around 320km per tank... but my wolf 3d is coming in next week...we will see some changes.

[JaFF]

I'm having the same issues. standard ecu with new o2 sensor and still getting barely over 320kms.

I have a SAFCII. SHould I ask my mechanic to lean it out?

What is a safe AFR to run at for a stockish (SAFCII, FMIC, 11.5PSI Boost, 3" exhaust) R33? Please note that i'm from tas and we only have 95RON premium down here.

Oh yeah. The car seems to run really rich too. always popin/backfire noise when I change gear. I'm not getting any soot though.

[Cubes]

Mine has always got good fuel consumption, even when it had the stock ecu and running in to the 10's at full throttle.

However I did notice at WOT around 3000-3500rpm it would hover around the low 13's. I was told it was normal as the Nissans run a little leaner in the mid to help fuel consumption.

On the dyno afr's were spot on 14.7:1 and would hang in there until 2psi of boost was being made. That was with the stock ecu and the rb20det.

It has never really backfired or popped. Only if I were to ever so slightly have my foot on the throttle.

A few things I would be looking at.

Fuel injectors, AFR's, O2, ECU's Water Temp sensor (one for the dash, one for the ecu), cam timing, compression.

[JaFF]

http://www.skylinesaustralia.com/forums/at...achmentid=27315

this is my current tune. I've been told the AFRs look good.

From what i understand though an R33 should be able to produce a fair bit more power than what I'm running so should it be leaner?

[JaFF]

I am always the thread killer!

[Cubes]

Jaff, Its not a Dynamic Dyno in shoot out mode.

[JaFF]

meaning?

[WetGTR]

I think he means that there is no AFR readings on you Dyno report.

The Lamba readings are only what the sensor registered back to the Dyno Computer but there is no graph on AFR

[JaFF]

oh i thought the lambda was the afr.

in these 2: http://www.skylinesaustralia.com/forums/at...achmentid=27316

http://www.skylinesaustralia.com/forums/at...achmentid=27317

which are the same run it calls them AFR LMDA

[WetGTR]

The Lambda sensor sends the results to the Dyno Computer. With this reading they can work out the AFR.

Here is a picture of a Dyno read out with the AFR on them.

BTW I hate my fuel economy, only @250km per tank, really sucks!! Wish I could get @350 per tank.......mmmmmm 350 per tank :wassup:

[JaFF]

lol I wish I had 417awkw though then i'd be happy enough to pay for 250-300kms per tank.

[rob82]

Get rid of the Microtech, they are essentially an electronic carbie, and save having to re-jet the carbs:)

I sue to get shocking fuel economy with my old LT8 runnning on a lightly modded RB20. It took a lot of work to get the eeconomy acceptable... and it took an Autronic dealer to get it right...all the Microtech tuners seemed to be wide open throttle jockeys who expected you to live with poor throttle response, poor economy albeit with good WOT power.

Now with my current car i am getting 400-450kms of city driving with a PFC and 235rwkws. (Thats not boosting it very much and 50 of my 120 daily kms are on the highway.

Ditch the Microtech or go to a tuner who is willing to work on the light load maps

Finally somebody who know something about engine managment. Best piece of advice I could offer you firefox is to ditch the electronic carby and revert back to you standard ECU and have it chipped.

[Cubes]

Sorry.. I was meaning that ~170kw could very well be 190kw on a Dynamic Dyno.

EDIT: I find it interestering how Racepace ran slightly richer afr's as torque hits then slightly richer once again once peak power is made.

I've seen a few cars now that have been tuned by RacePace.

One being an RB30DET.

They sure do know what they are doing.

[WetGTR]

Sorry.. I was meaning that ~170kw could very well be 190kw on a Dynamic Dyno.

 

EDIT: I find it interestering how Racepace ran slightly richer afr's as torque hits then slightly richer once again once peak power is made.

I've seen a few cars now that have been tuned by RacePace.

One being an RB30DET.

They sure do know what they are doing.

Hi there Cubes,

Would my AFR be contributing to what I believe is bad fuel economy?

Spoke to Ben at Racepace today about my fuel economy, he said Big Cams (Step 2 280)on my engine means that its out of its efficiency range on the freeway.

Couldn't I have a setting where it could lean out or something on the Autronics when it sensors highway use to go into an economy mode on light loads or something?

[Cubes]

It very well could be the cams are not working well on the freeway.

With such large lobes it would require a bit of playing to improve fuel economy.

No doubt you will also loose a little top end to in order to improve bottom end torque, VE and fuel economy.

Everything has its trade off's.

It may be worth dropping 20kw at the top end to pick up decent fuel economy.

250km's per tank is unbelievable. What injectors are you running?