diesel antilag?
diesel antilag?
Hi, I am new to this forum and I have an idea for my own diesel track car.
I want to fit a bigger turbo but I would also like less turbo lag. I have been looking at what some WRC cars did in the past and got thinking.
http://www.motoiq.com/MagazineArticles/I...easer.aspx
This system works by using an engine bypass straight into the exhaust manifold pre turbine. This air is mixed with more fuel and exhaust gas in a combustor very similar to a gas turbine.
I was thinking that maybe with a diesel engine you may not even need a bypass at all because most of the air could be passed straight through the engine as it has no air throttle.
Has anyone tried similar before I get fabricating?
Thanks
Phil
What anti lag does is basically raise the exhaust energy (temperature and volume) when the engine is unloaded.
Rally style anti lag can surely be had on a diesel by injecting fuel into the exhaust manifold (and some modern diesels do exactly that to get some heat into the diesel particle filter).
No air bypass would be necessary, the air bypass on the petrol engine is done to move the combustion out of the combustion chamber and into the exhaust manifold while the throttle is closed.
(12-09-2013, 04:56 PM)baldur What anti lag does is basically raise the exhaust energy (temperature and volume) when the engine is unloaded.
Rally style anti lag can surely be had on a diesel by injecting fuel into the exhaust manifold (and some modern diesels do exactly that to get some heat into the diesel particle filter).
No air bypass would be necessary, the air bypass on the petrol engine is done to move the combustion out of the combustion chamber and into the exhaust manifold while the throttle is closed.
Hi, thanks Baldur
yes I was thinking there would be no need for a controlled bypass and therefore the system could be simpler. It could maybe even use propane to fuel the combustor from a small controlled injector. Maybe the turbo speed would not need to be measured but maybe just the intake manifold pressure to monitor its performance..
Phil
(12-09-2013, 04:56 PM)baldur What anti lag does is basically raise the exhaust energy (temperature and volume) when the engine is unloaded.
Rally style anti lag can surely be had on a diesel by injecting fuel into the exhaust manifold (and some modern diesels do exactly that to get some heat into the diesel particle filter).
No air bypass would be necessary, the air bypass on the petrol engine is done to move the combustion out of the combustion chamber and into the exhaust manifold while the throttle is closed.
Yes, intake manifold pressure is a good indicator of turbo speed when the engine is your air restrictor. If you run an air bypass from the compressor to the exhaust manifold, you would be advised to monitor turbo speed as in that case the speed can easily go out of control with too much bypass.
Whatever you do inject into the exhaust manifold, there must be enough heat to ignite it or you need to have some kind of ignition source (glow plug?).
I'm afraid the spark plug would foul up with soot real quick, but you know, maybe the hottest plug you can find will stay clean. You could also just use a furnace injector and pump diesel into the manifold, the heat of the manifold should be enough to ignite that.
From some surface discharge jet engine ignitors I have played with they are so strong that I think they would ignite through anything. But they need some serious capacitor discharge ignition system.
I will have to think about this one..
The electronic control of this thing would be pretty easy.
This is me in my little track car that I want to tune up some more > http://www.youtube.com/watch?v=_t1jhFoUyyI
I just wish I could fit a big Mercedes engine!
Phil
I was just thinking about antilag on a Mercedes diesel last night...
larsalan I guess I need to look at this stupid ass drip shit. What you have to like mess with those elements on the pump? What a fucking hassle. then use some wire to hold the throttle open or some shit?
Put a 6cyl IP on a 5cyl and route the 6th injector to the exhaust manifold.
Get a custom cam cut for the new timing (60* vs 72*)
larsalan I guess I need to look at this stupid ass drip shit. What you have to like mess with those elements on the pump? What a fucking hassle. then use some wire to hold the throttle open or some shit?
(12-09-2013, 03:10 PM)pemtek This system works by using an engine bypass straight into the exhaust manifold pre turbine. This air is mixed with more fuel and exhaust gas in a combustor very similar to a gas turbine.
(12-09-2013, 03:10 PM)pemtek This system works by using an engine bypass straight into the exhaust manifold pre turbine. This air is mixed with more fuel and exhaust gas in a combustor very similar to a gas turbine.
(12-10-2013, 03:54 AM)DiseaselWeasel It's a tad more complicated than that... It's more like a rocket engine, thus requires (lots of) oxygen. Supplied by the turbo via the air-bypass - I guess this is also required to take stress of the egngine. And fuel to generate a high amount of hot gas (rocket fumes ) which keeps the turbine loaded. I'm not sure the remaining oxygen in the exhaust gas volume is sufficient, plus it would all need to go through the rocket booster.
It will also require monitoring turbine speeds to not over-spin the turbo when the engine RPM and thus gas volume supplied by the cylinders rises. The theory is simple, the realisation is not. Another factor worth considering is heat.
Simply pouring fuel in the exhaust and igniting it with a spark - that sounds a bit crude, but will probably work for some minutes The key is to make it controllable and tunable to make a transition between booster supplied gas volume and engine suplied gas volume possible without over-stressing the turbine. I can't see this happening with a redneck-approach like a injector 6 spark plug in the exhaust, sorry... But try it, I'm eager to read you report on it. But my bet is - it will not happen.
(12-10-2013, 03:54 AM)DiseaselWeasel It's a tad more complicated than that... It's more like a rocket engine, thus requires (lots of) oxygen. Supplied by the turbo via the air-bypass - I guess this is also required to take stress of the egngine. And fuel to generate a high amount of hot gas (rocket fumes ) which keeps the turbine loaded. I'm not sure the remaining oxygen in the exhaust gas volume is sufficient, plus it would all need to go through the rocket booster.
It will also require monitoring turbine speeds to not over-spin the turbo when the engine RPM and thus gas volume supplied by the cylinders rises. The theory is simple, the realisation is not. Another factor worth considering is heat.
Simply pouring fuel in the exhaust and igniting it with a spark - that sounds a bit crude, but will probably work for some minutes The key is to make it controllable and tunable to make a transition between booster supplied gas volume and engine suplied gas volume possible without over-stressing the turbine. I can't see this happening with a redneck-approach like a injector 6 spark plug in the exhaust, sorry... But try it, I'm eager to read you report on it. But my bet is - it will not happen.
How about injecting washer fluid 50/50 water/methanol it should ignite at a lower temperature. or pure methanol in to the exhaust preturbo with the nozzle in thew bypass from the turbo.
Heat, turbine-RPM, controllability. Same story.
@baldur: yes. And type 3; the auxilliary gas generator as per Subaru WRC rocket booster system Independent from engine.
You could use a turbine rpm gauge or optical sensor on the compressor nut with arduino to control fuel/air flow to shaft RPM. And make the air by pass out of an old idle air control valve to control air flow and a fuel injector to control fuel flow
50/50 I think would only give your turbo a steam clean. Pure methanol would work if you can inject it with a good spray so would need a heat proof injector of some sort. Same would go for petrol. Diesel would also need to be properly injected but I think it would still be difficult to ignite fully but at least an injector wouldn't be so hard to come by although the pump might be. I think propane would be the easiest, its already a gas so should ignite easily. Its also what they use for the homemade turbo jet engines.
Another option instead of an air bypass might be to inject nitrous into the exhaust manifold along with your fuel. Sounds like a cool idea but its probably getting a bit silly and race only if it worked. Course if you really want to get silly you could inject nitromethane. Fuel and oxygen in one hit!
Yes I know, I have taken it too far :-)
I will try to make it work using propane as that is easiest to control and mixes well so will ignite easier even though it has a relatively high flash point. Fitting a supercharger on my Elise is just not straight forward due to space constraints so a twin turbo or a single and some mad anti lag setup it will have to be..
I am on with building an engine dyno at the moment including my own controller using a water cooled eddy current brake so I can experiment with it a lot better than driving along trying to adjust things.
I will probably get totally sick of it and wish I never started!
Cool, I have an engine dyno myself, a Superflow waterbrake absorber with my own data acquisition and control electronics. It's a wonderful tool for experimenting with engine tweaks. The only instrumented engine dyno in the country.
https://www.youtube.com/watch?v=KIGKFZD8NBA
Oh very nice! What can your brake hold?
My water cooled brake is rated for 130kw continuous and max 8000rpm but I am expecting it to be able to take quite a lot more power for short bursts. I have a large Telma retarder that is rated a lot higher but rpm limited to 4000rpm I just thought messing with a gearbox was too much hassle. I am just sourcing a few parts at the moment and designing the eddy current brake electronics for the 190v coils.
Phil
The brake can supposedly hold 1000lb-ft at 3000rpm and 2000ft-lb at 5000rpm, in my experience 2000RPM is the lower operating limit where it will hold about 400lbs. Max RPM 10000 continuous with bursts to 12000 permitted with reduced bearing life. People have measured as much as 3000hp on these while the manufacturer has varied their rating from anywhere between 1000hp and 2500hp (seemingly, just by altering the brochure!), the big limiting factor is water supply, it needs a lot. The load cell I have on it now measures up to 1000lb-ft.
I was thinking the bypass could direct air from the pressure side of the turbo directly in to the exhaust bypassing the engine basically turning the turbo in to a mini jet engine. except started by the engine used at idle until it's needed for the engine then the bypass would close and turn fuel off and off she goes at 20psi at 1500 rpm. If the injection was controlled electronically it could be started and stopped based off engine rpm turbo shaft rpm or a master switch in the car to turn the whole system on or off. It could maintain turbo shaft rpm at a preset RPM ie 150,000 RPM . Nitrous could also work if you can meter the injection amounts. I think the optical sensor on the turbo is a must very easy to do they make them on the home made turbocharger jet engines to measure turbo shaft speed. I have an exhaust impeller that shared off the shaft on an eclipse that was injecting to much nitrous in to the exhaust preturbo for drag racing basically the same idea to spool up the turbo.
I just sold my 05 Elise with a turbo kit.
hello fine people,
have u ever heard about hypercharging? whell i think is what u want , no lag upon delivering power? whell u can find some more info in the french/german tank manufacturer Krauss-Maffei "leopard" where they can achive the same performance as a "abrahams" with a diesel engine instead of a turbine engine.
regards
(12-11-2013, 03:02 PM)barrote hello fine people,wow,
have u ever heard about hypercharging? whell i think is what u want , no lag upon delivering power? whell u can find some more info in the french/german tank manufacturer Krauss-Maffei "leopard" where they can achive the same performance as a "abrahams" with a diesel engine instead of a turbine engine.
regards
(12-11-2013, 03:02 PM)barrote hello fine people,wow,
have u ever heard about hypercharging? whell i think is what u want , no lag upon delivering power? whell u can find some more info in the french/german tank manufacturer Krauss-Maffei "leopard" where they can achive the same performance as a "abrahams" with a diesel engine instead of a turbine engine.
regards
(12-11-2013, 03:02 PM)barrote hello fine people,
have u ever heard about hypercharging? whell i think is what u want , no lag upon delivering power? whell u can find some more info in the french/german tank manufacturer Krauss-Maffei "leopard" where they can achive the same performance as a "abrahams" with a diesel engine instead of a turbine engine.
regards
(12-11-2013, 03:02 PM)barrote hello fine people,
have u ever heard about hypercharging? whell i think is what u want , no lag upon delivering power? whell u can find some more info in the french/german tank manufacturer Krauss-Maffei "leopard" where they can achive the same performance as a "abrahams" with a diesel engine instead of a turbine engine.
regards
hello people, well i dont know much about that hypercharging issue, but is something like using a small gas turbine blowing into the intake, or powering a compressor , or maybe blowing everithing inside the diesel. u wont find much info on that its military and as i said they can achive the same performance with a diesel engine , as others with huge turbines.
what i recomend is if u really want to go 3,4,5 BAR and assuming the engine head/pistons rods can cope with that, study the works on the turboshaft engine and maybe u can fx a way of after exaust burning with the consequent density increase in such a way u can have the turbocharger full load all the time.
regards