Turbo Diesel instant boost 3

[gizmag1]

Just an idea I conjured up recently. Naturally aspirated Diesels draw basically the same amount of air at idle as they do at full revs, They only vary the amount of fuel injected into the cylinder to vary their output, add more air (i.e turbo) and you're able to burn more fuel - more power...But with turbo lag still posing an engineer's nightmare. Variable vane turbo's, while better, still aren't perfect. What aboutfitting an injector situated between the exhaust manifold and the turbocharger. This would allow full boost to be achieved from idle - actuated with application of full throttle. NO turbo lag, Super charger style boost without the parasitic drag... Just a thought?

 

[r2800]

Toyoytas use throttle butterflies to this date

 

[SomptingGuy]

I seem to remember throttling a diesel being a potential solution to something related to NVH or emissions a few years back, but my searches (internally and externally) have left me empty-handed. Would be interested to know what the story was... and what Toyota use throttling for.

 

[globi5]

Apart from the electric supercharger or electrically assisted turbo, there are additional options to reduce lag:

A 'Dual-Turbo' (sequential-turbo):

http://www.greencarcongress.com/2006/06/peugeot_applies.html

(The porsche 959 originally introduced this concept).

Or a mechanical supercharger that is engaged at low rpms:

http://www.greencarcongress.com/2005/08/vw_introducing_.html

Or a pressure wave supercharger:

http://www.egr.msu.edu/mueller/projects_waverotor.htm

http://www.wenko.ch/e/news.e/techinfocontent.e.jsp

Mazda 626 was running it.

 

[WGJ]

r2800 - Like SomptingGuy, I'd be very interested to have any links you may have for the Toyota application.


Bill

 

[patprimmer]

globi5

See my post of a few days ago.

gizmag1

There is an extensive previous thread on compound supercharging or twin-charging. The on site google feature works best.

Regards

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[turbomotor]

Hello gizmag1 -

Relative to your original post (this thread has really meandered), and to GregLocock's answer, please do a search for the French built SACM Hyperbar diesel engine that is used in the Leclerc main battle tank.

Dick Vincent

 

[gizmag1]

Turbomotor - Thanks for the lead - wikipedia will be hit hard! You do realise than you've made it increasingly difficult to explain the need to experiment with this technology on my own hilux!!! I can hear the missus now - TANK your not bolting a tank to you car!!!

 

[r2800]

The toyota system uses a butterfly controlled by a stepper motor controlled by ecu,designed for emissions rather than throttling in the conventional sense.
In my earlier life I worked extensively on trucks & coaches and pnuematic governors were common as indeed was a throttle set up to allow manifold vacuum to be built up for servo brake operation, I'm thinking of old landrover diesels here.

 

[WGJ]

r2800

The toyota system uses a butterfly controlled by a stepper motor controlled by ecu,designed for emissions rather than throttling in the conventional sense

Exactly what has been said. The 'throttle' is used so that, under certain speed/load conditions, EGR and crank case gas is consumed in preference to clean air to help control emissions. The valve is often shut at key-off to help reduce engine shake as it stops.

In my earlier life I worked extensively on trucks & coaches and pnuematic governors were common as indeed was a throttle set up to allow manifold vacuum to be built up for servo brake operation, I'm thinking of old landrover diesels here.

Well, I suppose the adoption of vacuum pumps to power the brakes and the efficiency loss due to throttled operation killed off the old pneumatic type governeors. I certainly never saw one on the 30 years I've been associated with truck and car diesels.


Bill

 

[r2800]

Leyland 350,600 & some versions of 680, Bedford 300/330
Ford Trader 4 & 6 cyl models, Some Perkins models too.
Admittedly these are late 50's early 60s.

 

[LadaTrouble]

The later Toyota (and other brands too) with electronic pumps use the throttle body for TPS and ECU control of the pump....and vacuum control of EGR etc.

I've seen throttle bodies on the old British diesels as others have mentioned,and diaphram govenors.The last vacuum govenors I worked on were in the Nissan 220D,a common vehicle for taxi's.

 

[jblaine]

Pre-turbine combustion anti-lag strategies have been used for quite some time in racing with excellent results (most commonly found in rally cars).

http://www.rallycars.com/Cars/bangbang.html

It's incredibly loud and will never make it to production vehicles in that form.

 

[NickE]

jblaine -- Rally fan? I was wondering if anyone would put that link up....

(TSD Rally driver, RA Worker, Service crew chief #734, KD8EUT)

 

[jblaine]

NickE - Well well, if it isn't LyveWRX Hello from a fellow NASIOC member with Google skills.

 

[NickE]

yea, I inhabit this place too... The questions are harder and the answers way more involved than most delivered to NASIOC.

Of course we have our share of disagreements here, though they usually can be solved with a small application of math and science, something that normally doesnt help at NABISCO.

 

[dicer]

I worked on a 60's something Mercedes Diesel that throttled the inlet air.