Making Your Stagea A Fuel Miser

[groonsnout]

Hey hey People,

So now having been a stagea owner for a month or so now I'm a big fan! but.. (and there is always a but) as we all know, it does go through the juice! Infact, it uses more than my twin turbo 300zx with 260kw at the wheels, but that is a manual and weighs 300kgs less.. but anyway!

My Series 1 is dead rock stock standard. The only mod I have done is the boost solenoid, which did help slightly with highway consumption - around town, no real difference.

Would any of the following mods make any positive difference to fuel consumption? (currently get 400km from 58L around town or 14.5L/100km)

• High boost mode (helped a little on highway)

• Good quality panel filter or pod filter replacement (uni filter or similar)

• Exhaust - freer flowing, is there anything in the system that is particularly restrictive?

• AFC or similar - I know they run rich - but is buying an AFC and leaning it out going to make a difference?

• Plugs & Leads - is the stock gear any good?

• Power mode - does moving the shift points up let the engine breathe more efficiently?

• EGR gear - anything I can remove/plug up to help?

Thoughts?

Edited March 20, 2007 by groonsnout

[rpms]

i have the same problem..... but i think my power mode on the auto is stuck on!!!?!?!? asking the same questions as + one does anyone know how to fix a stagea that doesent engage in 4wd....right now mines is only in 2wd!!!!!!

[stasis]

over the years one of the first mod i will do to a car is to replace the panel filter with K&N drop in replacement filter. Only recently i have proven to myself it save on the fuel on HWY by up to 15% on cruise control.

My dad bought a BMW 740IL about a year ago and i replaced the panel filter with a drop in replacement (K&N) by using the onboard computer to tell me how much fuel its using. By changin the panel filter the fuel comsumption actually drop by 14.7%. I took a reading before and after i changed the fileter travelling on the same road, same speed, same weight load and same type of fuel (mobil 98).

I have heard people saying that more air into the engine means it will burn more fuel. But as far as i know the way K&N filter works is it straightened the air flow out before it gets to the combustion chamber and the filter let the engine suck in the air easier. Its like OEM filter is like a tissue folded in two twice therefore its thick and harder for the engine to suck the air in. But the K&N panel filter its like a tissue folded into only therefore it makes the engine easier to suck. Less energy wasted.

Perhaps SK might be able to explain better.

Anpther thing i find that by changing the ECU to Power FC although it produces more power the fuel consumption actually almost stayed the same as before. It also largely depends on your driving style i guess.

Edited March 20, 2007 by stasis

[leetom]

Hey hey People,

So now having been a stagea owner for a month or so now I'm a big fan! but.. (and there is always a but) as we all know, it does go through the juice! Infact, it uses more than my twin turbo 300zx with 260kw at the wheels, but that is a manual and weighs 300kgs less.. but anyway!

My Series 1 is dead rock stock standard. The only mod I have done is the boost solenoid, which did help slightly with highway consumption - around town, no real difference.

Would any of the following mods make any positive difference to fuel consumption? (currently get 400km from 58L around town or 14.5L/100km)

• High boost mode (helped a little on highway)

• Good quality panel filter or pod filter replacement (uni filter or similar)

• Exhaust - freer flowing, is there anything in the system that is particularly restrictive?

• AFC or similar - I know they run rich - but is buying an AFC and leaning it out going to make a difference?

• Plugs & Leads - is the stock gear any good?

• Power mode - does moving the shift points up let the engine breathe more efficiently?

• EGR gear - anything I can remove/plug up to help?

Thoughts?

you will go along way to improving fuel issues with a quialty turbo back system[split front dump] & good cat plus above mentioned k&n filter

[Mr_RS4]

Although there have been so many threads on this already I have to say if your getting 400km per tank around town then I wouldn't be complaining. If you do a search on this topic you'll come across a thread which shows a lot pf peoples different fuel comsumptions and most are worse than that.

But that said if thats what your getting now then you can probably improve on that a bit:

-K&N Panel filter

-Full 3" Turbo back exhaust (with new dump pipe)

-New Spark Plugs gapped to .8 (Normal coppers are fine)

-Apexi SAFC and SITC (for fuel mixtures and timming adjustments) !This is ones of the best places to start!

-Replace the Oxygen Sensor

-Also I've heard that fitting a shift kit (such as the MV Automatics kit for eg.) helps with fuel consumption as it stops a lot of the wasted power through slipping and flaring between gears and throttle changes and also keeps the torque converter locked up more.

-And last but not least watch the way you drive, keep off boost as much as you can and keep the torque converter locked as much as you can (espically on the High Way) this will save a fair bit too.

My goal is to get over 500kms per tank on the high way and at least 450kms normal driving. Got a little way to go yet, record so far is 420kms with the fuel light on

[stasis]

opps soz i didnt include mine. i can get about 430km/tank. Err im using Boost 98

[Sydneykid]

I have heard people saying that more air into the engine means it will burn more fuel. But as far as i know the way K&N filter works is it straightened the air flow out before it gets to the combustion chamber and the filter let the engine suck in the air easier. Its like OEM filter is like a tissue folded in two twice therefore its thick and harder for the engine to suck the air in. But the K&N panel filter its like a tissue folded into only therefore it makes the engine easier to suck. Less energy wasted.

Perhaps SK might be able to explain better.

Well........I doubt that the airfilter is going to do much straightening in a Stagea after the compressor has spun it around at 100,00 rpm or so, then the intercooler has carved it up in 2 mm slices etc etc.

What actually happens.......the filter acts as a restriction and creates a partial vacuum in the inlet system, which results in the engine not running as efficiently as it should. Remove the restriction and you get freer flowing air into the engine. Simply put, an N/A engine (or a turbo engine off boost) doesn't have to suck as hard.

But (there is always a but) this would only improve fuel economy on an engine with a MAP sensor driven ECU. An AFM driven ECU has the AFM after the airfilter, so the ECU knows the correct airflow (restricted or not) and so squirts the correct amount of fuel for that amount of air.

There is another but (yes two buts), at cruise and idle (closed loop) the lambda sensor readings determine how much fuel is injected, just enough to meet A/F ratio aim. So changing air filters would have zero effect during closed loop running.

The bottom line, I don't think changing air filters would make 1 poofteenth of a difference to fuel economy in a Stagea.

cheers

PS; I prefer Pipercross filters to K&N.

[stasis]

PS; I prefer Pipercross filters to K&N.

Why is it?

Edited March 21, 2007 by stasis

[Sydneykid]

Why is it?

The pipercross filters have 3 layers of different density foam. So the large lumps get caught in the more open density, then the next smaller in the middle density and the really fine stuff in the smallest density foam. This means they work better for longer than the single density K&N.

A real world example, we had to clean the K&N filters after every race, otherwise the power dropped off. With the Pipercross filters we can run the whole weekend without cleaning the filters and not loose 1 single horsepower. Transfer that to a road car and it means not having to clean you K&N filter every 2,000k's or so. You can do the Pipercross one whenever you change the oil, safe in the knoweldge that you aren't loosing horsepower by doing that. Obviously the less frequent intervals means that the cost of cleaning kits is less than half as well.

cheers

[Stinky Rooster]

Isn't losing power through a dirty air filter element evidence that replacing the standard filter with an aftermarket jobbie proof that it makes the engine more efficient?

I'm not saying that it will cause the engine to use less fuel, rather it will be able to make more power with the same amount of fuel due to less vacuum before the turbo compressor, therefore a new air filter will make more than a "poofteenth" difference

[Sydneykid]

Isn't losing power through a dirty air filter element evidence that replacing the standard filter with an aftermarket jobbie proof that it makes the engine more efficient?

I'm not saying that it will cause the engine to use less fuel, rather it will be able to make more power with the same amount of fuel due to less vacuum before the turbo compressor, therefore a new air filter will make more than a "poofteenth" difference

Improving fuel ecomomy (in the usual meaning) is related to very small throttle opening, whereas lowering maximum power happens at WOT. An inefficient (dirty in my example) air cleaner will have very little (in fact zero) effect on the airflow at small throttle openings, hence it will have no effect on fuel ecomomy. Because at such low airflows it would not prove to be a restriction, not unless it was unbelievably dirty. This may not be the case at WOT, where the (dirty) innefficient air filter may well be a rerstrcition and as such cause a power loss.

If you were talking about efficient fuel usage at WOT (maximum power) then it could be argued that the restrictive air filter would cause the engine to use more fuel to make less power. But that's hardly "fuel ecomomy".

cheers

[pixel8r]

Ok, I could possibly be among the luckiest stagea owners with regards to my current fuel economy!!

I usually measure my fuel economy every time I fuel up, by dividing the Litres that went in with the km's travelled since last fuel-up. This is the most reliable method of calculating fuel economy.

When I bought the car it was averaging 13.5-14.5L/100km (note that its a S2).

I'm now getting around 11.5L/100km in Adelaide suburbs traffic, although most of that is off-peak.

This is including the use of air-con about 20-30% of the time.

Before that I got a figure of 12.9L/100km where I was using air-con about 70-80% of the time and in more peak-hour conditions.

Last good country run (interstate to Brisbane and back to Adelaide) I averaged 10.2L/100km and with air-con off I managed 9L/100km - no kidding!!

The mods I have that help fuel economy are:

- 3" turbo back exhaust. My opinion is that an exhaust will help a bit but without an SAFC or similar computer you will not see the best from it. In my case whilst it frees up the engine it also made it run richer so thats why you need some way of tuning it to clean it up (and keep away from R&R).

- GT30 turbo - more lag means for city driving I spend most of my time off-boost. not an ideal setup for most people but the fuel savings makes it sort of worthwhile. Anyone with a GT28 highflow would have similar results I imagine - less initial response (lag) yet better fuel economy.

- Apexi panel air filter - I've tried K&N before but they are oiled and I've had so much trouble with oil stuffing up the AFM (at one point causing the car to stall), that I ditched it for a cheapie bosch one and had no more trouble. The apexi one I bought 2nd hand - its a cloth type filter (like K&N) but is dry-type so no problems at all. I still get plenty of induction noise so its obviously giving more airflow than stock.

- MV Auto shift kit - not sure if this improves economy at all - I dont think I noticed a difference - it was my first mod since I bought the car stock.

- SAFC + GOOD tune. When I first had it installed the tune wasn't that good so I didn't notice much difference other than more performance. Fuel economy stayed much the same since not much was altered with the tune. I recently had it retuned, including advancing the ignition timing - picked up 10awkw extra and with the more efficient tune using the SAFC, I'm using almost 1L/100km less on average than before the tune.

- I always use full synthetic oil - not sure how much difference that would make.

Thats about all I can think of. I do have a manual boost controller set to 12psi but thats not helping my fuel economy. If you set your boost setting lower I imagine you could gain fuel economy at the expense of max power - depending on your driving style.

I generally do not try to drive slow everywhere - I just try to be smart if I'm not in a "go fast" mood. Things like letting the revs coast down instead of early braking and keeping the throttle/revs constant when practical. But like I said its more a habit than me constantly trying to be "good". Any good opportunity to hit boost and I will take it

apologies for the long post but hope it helps...

Edited March 21, 2007 by pixel8r

[Sydneykid]

Ok, I could possibly be among the luckiest stagea owners with regards to my current fuel economy!!

I usually measure my fuel economy every time I fuel up, by dividing the Litres that went in with the km's travelled since last fuel-up. This is the most reliable method of calculating fuel economy.

When I bought the car it was averaging 13.5-14.5L/100km (note that its a S2).

I'm now getting around 11.5L/100km in Adelaide suburbs traffic, although most of that is off-peak.

This is including the use of air-con about 20-30% of the time.

Before that I got a figure of 12.9L/100km where I was using air-con about 70-80% of the time and in more peak-hour conditions.

Last good country run (interstate to Brisbane and back to Adelaide) I averaged 10.2L/100km and with air-con off I managed 9L/100km - no kidding!!

The mods I have that help fuel economy are:

- 3" turbo back exhaust. My opinion is that an exhaust will help a bit but without an SAFC or similar computer you will not see the best from it. In my case whilst it frees up the engine it also made it run richer so thats why you need some way of tuning it to clean it up (and keep away from R&R).

- GT30 turbo - more lag means for city driving I spend most of my time off-boost. not an ideal setup for most people but the fuel savings makes it sort of worthwhile. Anyone with a GT28 highflow would have similar results I imagine - less initial response (lag) yet better fuel economy.

- Apexi panel air filter - I've tried K&N before but they are oiled and I've had so much trouble with oil stuffing up the AFM (at one point causing the car to stall), that I ditched it for a cheapie bosch one and had no more trouble. The apexi one I bought 2nd hand - its a cloth type filter (like K&N) but is dry-type so no problems at all. I still get plenty of induction noise so its obviously giving more airflow than stock.

- MV Auto shift kit - not sure if this improves economy at all - I dont think I noticed a difference - it was my first mod since I bought the car stock.

- SAFC + GOOD tune. When I first had it installed the tune wasn't that good so I didn't notice much difference other than more performance. Fuel economy stayed much the same since not much was altered with the tune. I recently had it retuned, including advancing the ignition timing - picked up 10awkw extra and with the more efficient tune using the SAFC, I'm using almost 1L/100km less on average than before the tune.

- I always use full synthetic oil - not sure how much difference that would make.

Thats about all I can think of. I do have a manual boost controller set to 12psi but thats not helping my fuel economy. If you set your boost setting lower I imagine you could gain fuel economy at the expense of max power - depending on your driving style.

I generally do not try to drive slow everywhere - I just try to be smart if I'm not in a "go fast" mood. Things like letting the revs coast down instead of early braking and keeping the throttle/revs constant when practical. But like I said its more a habit than me constantly trying to be "good". Any good opportunity to hit boost and I will take it

apologies for the long post but hope it helps...

Good post, unfortunately Adelaide traffic + 3 L/100k = Sydney traffic.

If the air filter oil is contaminating the AFM, then you are over oiling the airfilter.

cheers

[stasis]

i never had any problems with the K&N. As SK said over oiling. As long the elements looks abit pinkish thats ok as long its not like whie color.

[pixel8r]

I may be wrong on the cause of AFM failure there. I've heard that K&N oiled filters can cause problems with AFM's (which sounds like it may be false anyway) and kind of linked this "rumour" to my problem at the time. This was in the silvia anyway. I cleaned the AFM contacts (using metho and leaving it out for 30 mins to dry) and this almost always gave a noticeable improvement.

Its also quite possible my K&N filter had been re-oiled by a workshop when the car was in for a service somewhere.

I also realise the difference in city L/100km figures between cities, which is why I mentioned Adelaide. I feel sorry for those who need to drive into the city for work in almost every other capital city

As a side note, driving around Brisbane mostly off-peak and using the motorways to avoid the city, I acheived almost as good fuel economy as in the country.

And something I forgot to mention, is to make sure you take it easy when the engine is running cold!!

This is common sense and applies to any car but it can make a big difference to fuel economy (not to mention reliability).

[Topkart R33]

Just recently did a trip in mine down to Sydney/Wollongong from Brisbane and could easily get 600-630 km's per tank with fuel light just popping on. This is using a/c and overtaking lanes where appropriate. Fuel economy is only going to be as good as your right foot is letting it be. High boost and stop start traffic always going to lower the effiency. Round town can get approx 500-520 km's per tank.

This in a 1999 S2 RS tiptronic, only mod is the 3" cat back system that came with the car.

[Mr_RS4]

Damn all you S2 drivers and your better fuel economy. It would seem that S2 on average have much bettter economy than the series 1's. I still haven't had my SAFC tuned and am still madly trying to find an SITC. Buggers me why Apexi never made a replacement and yet they keep making new versions of the SAFC

[groonsnout]

Hmmn... so it seems overall that a mild exhaust could be the key to getting a bit more per tank on a stock car... ? I do like the idea of the SAFC but just a bit reserved about anyone here in Canberra really knowing what they are doing when it comes to tuning.. heard a lot of bad stories.

Any recommendations here in ACT for a SAFC fit and tune?

[MRO]

I am going to get the exhaust and SAFC as well.

I just did a run to Kalgoorlie and back (600km) and sitting around the 110km speed limit i averaged 350km per tank! This makes my old 5.8L Ford Falcon seems like a fuel miser. This is definately the most dissapointing part about my Stagea. If i cannot get more economy i might consider selling!

[Sydneykid]

I should mention that the compliance cat was really crap on mine, necked down to 2" ID and killed noticeable power. When I chenged it (to a Catco 3") the fuel economy improved a bit as well.

Plus tyres shouldn't be ignored, I have been testing multiople heat cycles on some "R" tyres for a few months (compared to my usual Michelins) and they knock the fuel ecomomy around something fierce. Handling is unbelievable of course, but I have worn them out now, so it will be interesting to see what happens when I stick the Michelins back on.

cheers