Diesel Tuning - Ignition Advance.....
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Soldato
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1. Advancing the ignition does not give you more power unless you are doing it to use a higher octane fuel in a petrol car.
2. Diesels until recently use auto ignition, which cannot be re-timed. Some of the high pressure injection engines inject the fuel at the point of firing/s, this could be altered, but there would be no advantage to pre-ignition.
2. Diesels until recently use auto ignition, which cannot be re-timed. Some of the high pressure injection engines inject the fuel at the point of firing/s, this could be altered, but there would be no advantage to pre-ignition.
Cool
But squirting the injectors that little bit earlier - Would that give you more power?
But that will be down to higher flow-rate at the correct point of injection/compression, rather than squirting early which in theory will do nothing, as the compression won't be high enough.
How? and what car?
In Diesels - The fuel is what gives power - So if you chuck in more, it will give you more power.
rover L-series, it's quite an easy engine to tune. Stock 100bhp can be taken to 155bhp/250ftlb for about £500.
The engine can only burn so much fuel, if I boot it, I will get some black smoke aka unburnt fuel.
Caporegime
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do diesel have VVT?
on most modern petrol cars you can adjust (independantly)
IGN Timing
VVT
Cams (switchoverpoint)
i take it diesels lack the first option here but what about the other 2?
on most modern petrol cars you can adjust (independantly)
IGN Timing
VVT
Cams (switchoverpoint)
i take it diesels lack the first option here but what about the other 2?
Soldato
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No...as Rover416i found out when he 'tuned' his diesel Rover, it belched black smoke and gained about 5bhp...he'd also cranked up his turbo...and then blew a turbo hose ~30mins later.
Fuel is what gives all car their power. :/
Suspended
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Soldato
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Same with a diesel, still needs air mixed in, my point was 'In Diesels - The fuel is what gives power' also applies to petrol engines.
The key difference is that if you overfuel a diesel it'll have crap fuel ecomony and spew black smoke out of the back but it'll still make good power. If you overfuel a petrol you will produce less power than if you fuel it properly. On this basis tuning a diesel for power is all about improving airflow then just chuck in 'plenty' of fuel.
Soldato
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30bhp for £50 actually!
Boost increased to 20psi and TU1 tuning box - adjusts the fuel quantity. Shifted well for an old derv!
All diesels have the equivalent of ignition timing (even the old mechanically injected engines), it's called injection timing. And just like a petrol randomly advancing the timing is likely to reduce power and eventually cause damage. The cylinder pressures are so much higher in a diesel that timing is even more critical than a petrol.
Many people mistakenly believe that the object of ignition timing is to get as much advance as possible, this simply isn't the case. Ignition advance is necessary evil due to the finite speed at which the fuel burns; the objective is to get highest cylinder pressures throughout the power stroke (hence highest torque and greatest power output). Do do this the peak cylinder pressure needs to be acehieved at a point somewhere past TDC (~15 degrees), and the ignition is timed to achieve this. More advance than this will not achieve more power.
The only time more advance will give more power is when the engine is running artificially retarded to start with, either to suppress detonation or because a higher octane (slower burning) fuel has been used.
Many people mistakenly believe that the object of ignition timing is to get as much advance as possible, this simply isn't the case. Ignition advance is necessary evil due to the finite speed at which the fuel burns; the objective is to get highest cylinder pressures throughout the power stroke (hence highest torque and greatest power output). Do do this the peak cylinder pressure needs to be acehieved at a point somewhere past TDC (~15 degrees), and the ignition is timed to achieve this. More advance than this will not achieve more power.
The only time more advance will give more power is when the engine is running artificially retarded to start with, either to suppress detonation or because a higher octane (slower burning) fuel has been used.