fuel economy

[Sydneykid]

Well done SK, 11lt per 100km is pretty respectable.  I'm still hovering around the 13lt per 100km with about 60% city driving, 40% highway.

Going down to Sandown this weekend, I reckon there is a 10 in there somewhere. Otherwise I am going to have to stop for petrol twice, only do that when there is a trailer on the back. Wish I had time to put the R34GTT intercooler on before we go.

[Jay95R33]

For us that have a standard EBC setup, is it best to switch to low boost when trying to keep the fuel usage down ? It doesn't take much throttle movement to get her on boost.

I suppose that's where the Jaycar EBC is good, you could tune it so it takes, say, 15% duty until it lets it hit high boost..

J

[Terminal]

Far out, i think i have something wrong then, i'm getting about 350 - 380km to a tank comined city/highway driving. might have to check out a few of the bits that cause that. thanks for the tips guys

[Jay95R33]

OMFG........ I just paid 126.9 cents per litre for Optimax !!! I looked at the price and only put 10 bucks in the tank to get me by until Sunday/Monday. That is a joke

BUT, I was very happy on the way home cause I had my very first run (on a private road) with any car. It was with a WRX too ! Neither of us launched, but I was ready for him to put his foot down. Up to 90km/h his rear bumper was level with my front bumper. I think that's pretty damn good if you ask me !! I was that excited that I almost ran up the gutter LOL, thank god it was one of those slopey gutters..LOL

Anyway, the thing that made the big difference with mine is a piggyback. You gotta get the a/f down.

The Unichip made a big difference on mine and the way it's going it'll pay itself off pretty fast.

J

[Sydneykid]

Took the Stagea down to Sandown for the Vic State Championship round last weekend. We had 2 people on board plus luggage and around 180 kgs of spare parts, including a forged RB31 bottom end on the way down and a stuffed RB25 bottom end on the way back. On the drive from Gundagai to Port Melbourne we managed the 494 k's on 58 litres, that's 11.7L/100k's. And we weren't hanging around either, we completed the whole 1,900K round trip in under 18.5 hours of driving time.

The average for the weekend, including numerous short trips into the city etc (120 k's worth), was 12.6L/100K. Not a bad effort for over 2.1 tonnes of fast moving waggon.

[sy300]

Our Stagea S1 (1997) RSFour (4wd) Auto RB25DET (non Neo) weighs 1694 kgs with a full tank of petrol and no one in it.  It is a waggon, so it is about as aerodynamic as a house brick.

1694 kgs! On the ownership papers for my '98 RS4 the weight is quoted at 1925 kgs (weighed in NZ during compliance). How did you loose almost 300 kg.

Around town I get about 14l/100kms.

[Sydneykid]

1694 kgs! On the ownership papers for my '98 RS4 the weight is quoted at 1925 kgs (weighed in NZ during compliance). How did you loose almost 300 kg.

Around town I get about 14l/100kms.

That's laden weight, with passengers isn't it? Mine has had no weight reduction and it weighed 1,658 kgs (almost zero fuel) for Compliance. The Bill of Lading says 1,650 kgs when it was loaded onto the car carrier in Japan. The Nissan data sheet for a 1997 model says 1,640 kgs to 1,695 kgs depending on options. It weighed 1,682 kgs with almost a full tank of fuel on my corner weight scales.

[sy300]

That's laden weight, with passengers isn't it?  Mine has had no weight reduction and it weighed 1,658 kgs (almost zero fuel)  for Compliance.  The Bill of Lading says 1,650 kgs when it was loaded onto the car carrier in Japan.  The Nissan data sheet for a 1997 model says 1,640 kgs to 1,695 kgs depending on options.  It weighed 1,682 kgs with almost a full tank of fuel on my corner weight scales.

On the papers it's GVM, which I assume is Gross Vehicle Mass.

[Sydneykid]

On the papers it's GVM, which I assume is Gross Vehicle Mass.

Over this side of the ditch, that includes passengers.

[Brazen]

Anyway, the thing that made the big difference with mine is a piggyback.  You gotta get the a/f down.

The Unichip made a big difference on mine and the way it's going it'll pay itself off pretty fast.

J

OK hate being so dumb about all this stuff - can a few of you please give me your opinions on Unichip vs SAFCII... I dunno which way I should be leaning towards - and what the difference in price is (supply fit and tune)... (and I know the Jaycar should be the way I am heading but I am useless at that sort of stuff - so just after the Unichip vs SAFCII comments please)... which should I look at?? And also is anyone looking at the new Japanese Neo6 daughterboard group buy thread??

[Sydneykid]

OK hate being so dumb about all this stuff - can a few of you please give me your opinions on Unichip vs SAFCII... I dunno which way I should be leaning towards - and what the difference in price is (supply fit and tune)... (and I know the Jaycar should be the way I am heading but I am useless at that sort of stuff - so just after the Unichip vs SAFCII comments please)... which should I look at??  And also is anyone looking at the new Japanese Neo6 daughterboard group buy thread??

I don't think you can "Unichip" the R34 generation of ECU's.

The SAFC will adjust the A/F ratios OK, but there are compromises with A/F ratios and optimising the ignition timing, as previously discussed.

The daughter board sounds like the go, but do you know anyone near you that can tune it? What tuning software does it use? What parameters and maps have they opened up with the daughter board? Does it work Ok for auto's? Stagea 4wd?

[Brazen]

Thanks SK

Ken from Hyperdrive can do it - but he is still waiting and watching for the group buy to sort its sh*t out - they are still trying to piece together maps and all the other technical mumbojumbo I know nothing about... basically they started the group buy thread way to early before they had sorted all the details... but hopefully something will come of it soon - otherwise it looks like it'll have to be the SAFCII... but Ive got a bit of time coz gotta do split dump pipe and FMIC first.

In the group buy thread it says the daughterboard states compatibility for R34GTT and Neo6 Stageas and works for tiptronic autos as well - so I hope it gets sorted soon coz that daughterboard would be sweet!

But yeah - not sure about how much progress they've made SK... maybe if u get a minute you could read through the thread in group buy section and summarise it for me... there's lots of individual posts saying "Ive mapped the..." Ive worked out the...." "I just need to..." - but I dont know what they all add up to - dunno how far from completion they are - any interpretation of that messed up thread would be a massive help lol!!

[Jay95R33]

If you've got yourself a good tuner I'd lean towards the daughterboard and a remap. That way you don't have anything trying to 'fool' the signals. The tuner will have full control over what he wants the ECU to do.

The Unichip works fine on the Stagea's and one fella in Canberra is running one on his automatic R34 Gtt with good results (195rwkw with simple mods).

The Unichip can do both fuel and ignition while the SAFC only does fuel. The Unichip has more load points than the SAFC too, but again, it comes down to the tuner and how well he knows the Unichip and the car's ECU. I still have a dip in my power curve but am pulling a strong figure at save a/f's and low boost. If my tuner knew the Stagea's ECU's better he could probably tune the dip out.

Unichip also has features like voltage clamping on signals (if you need it), a electronic boost control option and also can get rid of the speed cut at 180km/h if your into taking the car to the track.

But bang for buck you can't go past the Jaycar unit. If the daughter board doesn't work out then I'd try our best to get someone to make the Jaycar kit up for you.

J

[BensDR30]

Remove it from the dump pipe and then shake it, if it rattles inside then its obviously stuffed. The O2 sensor on my mates stagea 4cefed @ 64,000k rattled inside and I replaced it.. I replaced one before and economy improved by about 100k per tank.

 

I got the 02 sensor from Automotive Service Solutions in Brisbane.. ph 07 3857 9500.... part number 23009 3 wire uni fit. @ $130 total includes freight. Has two whites and a black wire which u connect to the original 2 browns and 1 white... so two white wires connect to two brown wires and the black wire to the singular white wire.

 

 Use a 22mm ring or open ender... short open ender is easier. Not hard to remove..

I'm just re-visiting this thread after putting my car on the rollers yesterday....

In stock form, it turned the dyno with 127kW at full noise. BUT on a light-throttle run at 70km/h the AFR's were in the LOW 11's (sometimes dipping into the 10's!). It's running extremely rich at all throttle loads & I'm getting less than 400km from a tank of fuel. The current suspect is a faulty O2 sensor, so I'm picking up a new one from my local Nissan dealer on Tuesday....

It's not fouling the plugs - yet.

I probably won't be taking the car onto the dyno again until I get my new R34GTT intercooler fitted (~$110 from Yahoo! Japan). The individuals responsible for discovering this little upgrade gem know who they are!

However I will keep an eye on the economy post-replacement & report in.

[ian]

... I'm getting less than 400km from a tank of fuel. The current suspect is a faulty O2 sensor, so I'm picking up a new one from my local Nissan dealer on Tuesday....

 

However I will keep an eye on the economy post-replacement & report in.

Don't forget to do that! I think a lot of people want to know how you go..

I just improved the fuel economy of my R34 GTT by changing the plugs and redoing the timing... Made a big difference... :-)

Ian

[BensDR30]

***Update***

Just about finished my first tank of fuel with the new sensor. City driving, with the odd bit of 80/100km for a few km, a few hard launches - the usual stuff really. The trip meter has just ticked over 400km & the low fuel light has just started to come on. I'll fill it up tonight & do the sums.

I've also removed the tank nozzle restrictor, as it wasn't sealing properly. BUT in order to fit it originally, the compliance workshop had to remove the OEM threaded section of the filler neck... So right now my tank isn't sealed 100% until my new filler neck arrives (or I fit a restrictor PROPERLY). Once this is sorted, then there will be a little less evaporative losses (the car always smelt of vapour adjacent the filler).

Reading up on the thread 'into the 10's' puts even more weight behind the installation of a DFA. But I want to get a baseline economy reading of a well-tuned standard setup first. Then the R34GTT cooler goes in & I'll get another set of dyno measured AFR, power & boost curves.

More Updates:

Here are the figures from the last 4 tanks of fuel, as you can see there is a bit of variance (as expected), but the last one is substantially better. I believe this to be the result of replacing the O2 sensor. 13-14L/100 around town would be what I'd expect from a car this size, not 17-18!

13/05/2005 15.8L/100km (340km)

20/05/2005 17.8L/100km (331km)

24/05/2005 16.1L/100km (340km)

01/06/2005 13.8L/100km (413km)

[ICE12]

Part number for O2 sensor and just from your local Nissan dealer.

Cheers ICE

[BensDR30]

As mentioned earlier - you can get generic aftermarket sensors for around $100, bearing in mind that you'll have to check the factory pinouts & re-terminate the connector (no big deal, but worth mentioning as there are people who are not comfortable with fiddling with electrics)

The Nissan number is: 22690-83T13

and was ex-Melb (plenty in stock).

An interesting point was that the dyno workshop metioned that it was quite common for them to replace sensors in the CA/SR/RB engines, as a large % of them appeared to be faulty by the time the cars were complied & on the road here in Aus.

[ICE12]

Thank you may just change it anyway for a new one.

Cheers ICE

[ryMan]

sorry to grave dig, but i am an extremely new person to skylines and am in search of some info... i have read this whole post and most of it seems mumbo jumbo to me...

in simpler terms, is someone able to list mods, parts and prices to get the fuel economy as low as possible on a 96 r33 gtst... and how many L/100k or k's per tank i should approximately be expecting...

what is the stock rating on this car?

edit: crap right topic, wrong cars...sorry fellas

Edited August 29, 2005 by ryMan