anti lag

[jonnyc]

im sure this has been asked before, is there anyway to use a syves s6 to run a system like the 'zerolag' system, i dont see a reason not to (i am more than likly missing something!) but it can already do antilag by jacking the throttle is there a way it could just controll the solonoid on the compressor side to the exhaust header as this would be great, and no need to change my break system too
http://www.youtube.com/watch?v=n_qCd6Lx7pE

just wondering......

jonny

[pat]

Johnny,

There presently isn't a mechnism in the strategy code that would allow fuel delivery to a configuration such as featured in the video. It is a bypass type ALS system which runs the turbocharger as a gas turbine when the engine is unable to provide sufficient drive to the turbine. It is a mass flow balancing system, with two gas producers, the internal combustion engine and a secondary combustor in the exhaust system, with a valve that allows compressed air to bypass the engine and go directly into the exhaust. Of course the turbo won't keep going indefinitely if you just push air into the exhaust, there must be at least unity power balance between the compressor and turbine stages; that is to say if you take the mass flow rate of the compressor, work out the power required to isentropically compress that and factor in the efficiency (power requirement being greater in reality than in theory), add the losses in the core, then the turbine must be able to extract at least that much power from the gas flowing through it (and it also isn't 100% efficient). Since the mass flow rate is (mostly) constant (ie we don't magically introduce mass flow somewhere between the compressor and turbine) then the only solution is to add heat. Heat comes from fuel, but we haven't added any yet. The system featured in the video introduces fuel via the fuel injectors in the engine, and "forgets" to light it up in the cylinders for some strokes, making it available to mix with the fresh charge air, to burn in the exhaust, raising the gas temperature, thus balancing the power across the turbocharger and maintaining operation at the desired shaft RPM.

If you observe the engine RPM never falls below about 1800 with the system running. This appears to be about the lower limit to getting sufficient fuel to the turbo to keep it going. I suspect that with a larger turbocharger it would require more RPM. Ultimately, I suspect it may become impossible to add sufficient fuel without bore washing the engine (the fuel requirements to make a GT4202R run under its own steam are somewhat greater than those for an IHI RX6 turbo designed to work with a 34mm restrictor). Whilst it would be possible to add a strategy to make this work, there are other solutions to the problem that don't require anything abnormal from the internal combustion engine and could continue to run the turbo even with the engine stopped. Such solutions are of greater interest to Syvecs since they are more universal and more flexible, and any implementation that we may offer in the future are more likely to be based round such approaches. Mechanically they may be a little more "interesting" to implement (like injecting fuel into a pipe that's at 900 degrees C without melting the fuel injector, for example) but I believe I've found solutions to all of the "gotchas" with that approach. Watch this space, as they say [but don't hold your breath, it is only one of many things we're working on]

Cheers,

Pat.

[Andrearally]

all the wrc cars since time use fresh air system to feed air and in some case with an extra injector fuel to the exhaust pipe.

Like: http://www.racedandrallied.com/technica ... lag-system
Also if the article isn't fully correct.

This is a Subaru manifold with dummy rocket. Inside of the manifold there is a kind of diffuser with mix air and fuel:

[pat]

Andrea,

bypass type ALS is certainly not new, and we can support the use of an EGR valve for conventional bypass type ALS. I suppose one could fit a fuel injector sufficiently far upstream that it doesn't suffer with the heat but then you have the transport time to worry about which won't help in trying to maintain a stable shaft speed....

Inside of the manifold there is a kind of diffuser with mix air and fuel:

Ah, you mean a bit like this.... (knew there was a good use for that S8 on my desk, it props up the manifold nicely )



There does not appear to be a fuel admission orifice on this, ergo the fuel would have to come from the engine. Compressed air is mixed with it inside the "rocket". It serves a few purposes; the flammability limits for petrol as f(AFR) are much narrower than for propane so it must maintain a suitable AFR; the flame speed of petrol in a mixture without turbulence is slower than the gas speed in the exhaust so it must act both as an agitator and as a flame holder; the flame temperature of petrol exceeds the melting point of the exhaust material so it must provide both a buffer layer of air near the surface and also dilute the combustion products to ensure that the turbine inlet temperature does not exceed safe limits. It is, for want of a better description, a cross between a combustor and an afterburner. Whilst there is no question that it works on the Subaru WRC engine, it does have the limitations that it cannot provide full boost with the engine stopped or idling (ignoring for a moment that oil pressure would be lost when the engine stops, but that is no great problem to overcome), and it is not scalable beyond the original design spec; that is to say that if we suddenly decided that we wanted to run a turbo which has four times the mass flow potential then it may not be possible to provide fuel via the engine without either risking bore wash due to massively rich mixture (just to get enough fuel through) or having the "idle" even higher (an engine that "idles" at 4500 RPM just to keep the turbo going is not hugely useful). Furthermore the geometry of the rocket is designed to be able to maintain shaft speed on the WRC turbo, and as such it will be able to cope with sufficient mass flow to keep that turbo in a "fast idle". If it needed to produce four times as much gas then it may well just flame out due to excessive gas speed. That is not to say that you couldn't build a larger version, of course.

Hope this helps,

Pat.

[Andrearally]

In another engine management system I've Fuel injected during ALS versus Turbo speed and with EGT limit due to keep turbo running without destroy the turbo

[Laci]

Could ecu control another one throttle bypass valve (posteriorly built) in ALS mode by ALS setting: Bypass Duty Effect / Idle Stepper Control)?
For example: through EGR output (EGR Mode: During Antilag).
I need this because there is only in that case enough air for ALS operation when both valves are open (Stock idle stepper control + throttle bypass valve).

Thank you for your helping in advanced.

Laci.

[Benkku]

KISS... Keep it simple stupid. No diffucer, just plain pipes from auxiliary air valve. Air entrance from cold side of IC and some ecu control strategy. Picture from 2002 Peugeot 206 WRC. Cold side feed, helps to prolong ALS - at least few milliseconds longer, before melt down.

[Laci]

KISS... Keep it simple stupid. No diffucer, just plain pipes from auxiliary air valve. Air entrance from cold side of IC and some ecu control strategy. Picture from 2002 Peugeot 206 WRC. Cold side feed, helps to prolong ALS - at least few milliseconds longer, before melt down.

I DON'T want to make als with EGR system. I would like to use one of output of ecu (EGR output) to control auxiliary throttle bypass valve, while the base settings of als contols the stock idle stepper control.

[Benkku]

Those (Subaru and Peugeot) systems definitely, are NOT EGR system's in any way. But effective auxiliary air systems - you can't get enough air (air/fuel mixture) using idle speed air valve to keep up turbo revolutions.