[Thumper]

You heard me correctly, you can achieve better fuel economy than what Hyundai did with their economy challenge from Darwin to Adelaide.

You can have a vehicle that is more economical than any other fuel driven vehicle on todays market.

You can do this with the current i30 diesel manual.

You can do this with NO ADDED MODIFICATIONS!

You can do this without spending a cent.

I have achieved this economy for over 200km, driving at normal road speeds in my own i30 diesel.

All you need to do is pull one little tube from the engine, then plugging that tube with a bolt/screw.



This is the vacumm tube controlling the variable vanes inside the turbo. No vacumm, vanes open up fully, allowing exhaust gas to bypass the turbo.

Result, no boost below 3,000rpm

Above 3,000rpm, there is enough exhaust gas flow to now start spooling up the turbo, creating boost all the way to the top end.

Since there is no boost down low, the engine is not injecting extra fuel to compensate for the extra air entering the engine.

There is more than enough torque down low to take off, sustain normal highway speeds, keep up with traffic on a small to moderate hills. (Larger hills require more throttle to climb)

Driving very sedately, I am achieving 3lt/100km.

I am sure most of you can keep it below 4lt/100km.

(The VGT on the newer diesels run vacuum to close the variable vanes, to create boost. Unlike older petrol turbos that require boost to open a wastegate to control boost.)

Side affect, I now have a very grumpy sounding exhaust. (It sounds like a dead ringer for a WRX now)  

[EymaTeapot]

Sorry Thumper,

That sounds like taking fuel economy to the extreme. I am not sure hyundai would recommend such measures. I imagine it could effect warranty claims as well.
Are you suggesting we should make these alterations, or are you just trying to demonstrate how Hyundai got such wonderful fuel economy figures in the many well heralded fuel econ runs they've performed.
I am pretty happy with the economy i am getting, not sure i want to make such drastic alterations, particuly if they will reduce the performance of the vehicle.

[Thumper]

Yes, I am taking fuel economy to the extreme. (Just put $100 worth of fuel in mine, tonight)  8-)

As for what Hyundai did for their economy run, well......... Proof is in the pudding, so to speak.  

[echocae]

what thumper did is blocking the boost vaccum hose to the wastegate of the turbo, this techniques is use for reducing boost if u have a boost controller, by blocking the vacuum u will automatically reduce the boost/make it spool later, and there for it will reduce fuel comsumption, this alteration wont damage any of the engine parts , but its will eventually damage the ECU , it because the ECU just assume how much fuel need to be inject

[Thumper]

but its will eventually damage the ECU , it because the ECU just assume how much fuel need to be inject

Care to explain this part, please ?

(Or are you talking about closed loop/open loop systems ?)

Either way, how can it damage the ECU ?

Thumper,

I think it is going a bit far to suggest (or claim) Hyundai used this method of tampering with the boost to achieve the fuel economy they achieved in economy runs.

Bob

[echocae]

what I'm saying that whether u increase or decrease performance of the car, the ecu need to be tune properly

[awj2005]

congrats on reaching 3.0 litres per hundred km but for my i prob wont be able to reach 3.0 litres as i have the petrol version, the lowerst i'll prob be able to get is around 5.0 but if i can that'll still be gd fro the petrol model.

congrats again

ash

[Thumper]

Ok, I may have gone too far in suggesting that Hyundai 'may' have used this method to achieve their economy figures.  8-)

(Oh yes, I do get carried away in what I like and what I love. It's a passion.   )

[echocae]

By doing this we can try a CRDI N/A i30, LOL,  
Also these technique is not recommended for auto user , due to special parameter/condition needed in running auto gearbox properly.

[Dazzler]

Good on ya Thumper...

You're a constant source of interesting info..so...

Be careful crossing the road today (it's Friday 13th!)  

Cheers,

Dazz

[Thumper]

Well, I put the pipe back on, partly because the ambient temperature is 6 degrees C (Causing my fuel use to go up) and partly because it's Friday the 13th!  

[echocae]

..

[EymaTeapot]

Yes snow, it does happen here from tomt ot time.
Nothing like our uk members would be used to though.

[Hemmi]

but i thought that winter in aus was like summer here in iceland, 15 - 20 °C ?
 

[EymaTeapot]

but i thought that winter in aus was like summer here in iceland, 15 - 20 °C ?
 

Hemmi, Depends what part of Australia. In the lower aeras of NSW and Victoria, we see a fair bit of snow.

[Thumper]

but i thought that winter in aus was like summer here in iceland, 15 - 20 °C ?
 

[jamiec]

Hey Thumper great work on the 3l/100km was that with the new exhaust and intercooler blocked
as well? I have been thinking if running a higher temp engine thermostat say 5-10 degree higher would help with the thermal efficiency of the motor as it can in petrol engines it may be worth a try.

[Dazzler]

Hi Jamie..

Nice to see you back visiting... club is growing well (see members tab)

Your suggestion sounds feasible will be interested in Thumper's answer...

Cheers,

Dazz

[jamiec]

Thanks Dazz i just got back from QLD with my old morris 850 mini now just need to fix it up
and get it regested  have done things like aerodynamic mods,higher tyre pressure,higher compression ratios,hotter thermostats,leaning out fuel,high flow exhaust,combustion chamber mods, but all done on petrol motors so some may not work on diesel.

[Bluei30Crdi]

Hi Thumper,
Be very carefull disconnecting the Variable nozzle control on the Turbo.
Reason being, by reducing boost at low revs, you can expect your combustion temps to skyrocket and similarly your EGT's (exhaust gas temps) will skyrocket as well.

Most diesels will tolerate around 600 deg Celcius POST turbo, over that and you will start thermally stressing things, such as piston crowns etc.

My other drive is a 2003 3.0 ltr Di patrol, and as many others have on the Patrol forum (www.patrol4x4/forum) I have taken turbo control away from the ECU, due to uncontrolled spiking of boost pressures and deactivating of the EGR. (done to extend engine life due to the patrols propencity to crack pistons)
When the patrol opened the EGR it woulddrop the boost and at a light load cruise the EGT's would go through the roof, (yes I have Boost and EGT guages in the Patrol)
I now have a manual boost control & Dawes valve and when cruising can play around with the boost and as a result watch EGT's fluctuate accordingly.

Be very carefull playing with boost control on Variable Geometry turbos

Cheers
Bruce

[Thumper]

Bluei30Crdi, interesting.

I do not have a EGT probe hooked up to the i30, yet, but had one on my 2003 ZD30 Patrol. (3lt 4cyl turbo diesel) The only time I noticed EGT's rising was when towing very large loads going up long hills.

Not once during my entire time with this vehicle did I have EGT rise above 650 degrees C when the VGT vacuum pipe was disconnected. (I covered over 280,000km in the beast. Didn't suffer from the dreaded dead turbo problem) The vanes on most VGT's can handle around 700-750 degrees C these days. (Unfortunately this is why VGT are not suitable for petrol engine vehicles, due to their higher exhaust temps)

Yes, EGT's will climb when the EGR valve opens, this I know and understand. (Simple physics, really) Yet they should not go any higher than what has been set at the factory.

Ok, think about it, I am running lower boost (Almost zero) at lower RPM. When the revs climb, so does boost, now. At the top end, I have the same amount of boost as if the VGT vacuum pipe was still connected.

The engine has a MAP sensor, if there is no boost down low, it will not inject more fuel. So it runs like you have a VERY light throttle. Little bit of fuel for a given RPM.

What is the difference between this kind of running (Sans VGT vacuum pipe) and when you would normally be coasting down a long hill, with a very light throttle?

When a diesel runs lean, it actually runs cooler. (Unlike a petrol engine vehicle that runs slightly hotter when it leans out) A Diesel is designed to run lean, that is it's basic function. (Anywhere up to 100:1)

Forcing more fuel into it creates a hotter combustion.

Ever notice how it takes a diesel ages to warm up, if it just idles? Yet if you go for a drive, increasing the amount of fuel into the engine, it warms up quicker.

A diesel runs WOT all the time. At idle, it is running WOT. HEAPS of cold air is entering the engine. Only a fraction of fuel is going in.

Cold air + little fuel = cooler flame

Now, get out onto the road, half throttle:

Cold air + moderate fuel = hotter flame

Now, as you said before, EGT do climb when a EGR valve opens. It is designed to do this. (One, to help burn everything in the exhaust completely the second time around in the engine. Two, to help burn any soot on the valves and before the turbo)

They are designed to withstand elevated EGT's for short periods of time.

I would not run my vehicles without the vacuum pipe under load for extended periods of time. That is just silly.

What I am doing is simulating very light running, very low loads and low RPM.

With the sensors in place, I have noticed anywhere down to -10 degrees C entering the inlet manifold at 110km/h on the highway. With boost or without boost, it doesn't matter, it's still bloody cold air entering the engine. (Most of the time, on the highway, you are not boosting significantly enough to create heat in the intake manifold)

I have found the i30 diesel has a post intercooler air temp of between -10 to 70 degrees C, normally. Any temp that is outside the window of 10-50 degrees C, hurts economy.

Light running on the highway (99% of my driving) I find the post intercooler temps never get above ambient temp. (On most cold moist nights, it drops below ambient temp. Due to wind chill. This can be on average 5 degrees C lower than ambient in winter.)

Even my Patrol hated winter weather when I was working around Thredbo. Started no problem, just used significantly more fuel when the temp dropped below freezing. Driving up to Darwin during summer, the Patrol returned the best economy. Driving around Darwin on 40+ days, the best economy for town.

I know and fully understand the issues regarding modifying engines. I take full responsibility if anything goes wrong.

I am yet to see one instance of a turbo diesel engine suffering any form of stress due to running LESS boost down low.

(I have seen plenty of turbo diesels being destroyed from running too much boost and too much fuel)

Not having a go at you Bluei30Crdi, not at all, just wish to let everyone know that I have been around this game for a very long time, and have built many engines and several race/rally vehicles. I do have 'some' knowledge in this area.  

[Dazzler]

You enjoyed that didn't you Thumper..

[Thumper]

Lol. Opps, I typed all of that before my morning coffee.  8-)

[Dazzler]

You'll hit about 10000 km won't you by the time you get home?

[Shambles]

You lost Shambles after the second line...

During the second line actually, when I saw the word EGT

[davet]

Hii Thumper,

Is this an "on off" change?  i.e. if the tube is restricted rather than blocked, would there be a midway effect in the tradeoff between  boost/power and economy?

(visions of a power/economy dial that variably controls the turbo boost on the fly...)

Dave (lived in Canberra for most of the last 35 years - can't say I'm unhappy with 19 degree mid winter temps in Coffs..)

[Thumper]

There is a huge trade off with power. There is no boost below 3,000rpm thus it drives like an old diesel Hilux 2.4 4x4

Once you go over 3,000rpm there is a linear increase of boost and power all the way to the top end. (Just like a small capacity petrol engine)

In all honesty, it's not worth the highly reduced power output.

This morning, I drove from Canberra to Cambletown, then back to Canberra. Only mods, the exhaust and intercooler cover. For the entire trip I averaged 3.7lt/100km traveling at 90km/h (Yeah, had all day to do what I needed, so tried an economy run) Outside air temp was 5 degrees C on the way up, 8 degrees C on the way back.

I am noticing that my economy is getting better as the engine frees up.  

[echocae]

i try this "THUMPER TECHNIQUE" on AUTO crdi.. its give around 4.5-5.2l/100km but the engine is produce more noise... (like WRX engine...same like what thumper said), but I still wouldn't recommended this technique on AUTO if u using on for city drive(Start and Stop), its great when AUTO CRDI do a long distance .

[sopel]

i'm gonna try that on my manual 1.6 crdi.
can you do a more detailed photo from larger distance, where exactly that tube is  , and with what should i replace it ? can it be any bolt that fits in ?