anyone using spark cut option on RLTC?

[eyefi]

anyone using spark cut option on RLTC?

 

cheers,

[imi]

isnt that how they are all supposed to be set....in addition to the ABS sensors..

[Gamer]

RLTC uses fuel cut and spark cut:

 

Race Traction Control Systems rely on much more precise, and faster acting ways of reducing power. The first method is shutting off fuel to the engine, and the other is cutting out the spark. Both methods have exactly the same high speed modulation ability, but the spark cutting system will happen potentially one cycle earlier. The magnitude of difference in reaction times between spark cut and fuel cut is negligible compared with the difference between throttle actuation and spark/fuel cut. (See fuel cut and spark cut below)

 

http://www.racelogic.co.uk/?show=Traction_Control-Technical-How_it_Works#fuelcut

[eyefi]

the standard unit is a fuel cut

[Branners]

not sure you would want to do spark cut as then you have unburnt fuel in the cylinders which I have been told could cause bore wash...but I could be wrong.

 

JB

[damouk]

if u use fuel cut then you can lean out to

 

swings and roundabouts i guess

[SimonB]

if u use fuel cut then you can lean out to

 

swings and roundabouts i guess

 

No you can't, it stops individual injectors from firing, so you get no fuel at all - the spark fires but there's nothing to burn. The only reason I can think of why you'd want spark cut is if you were using nitrous. You can't use it with fuel cut because you still get the extra fuel injected with the nitrous even when it cuts the rest which would make you run very lean.

[Gamer]

not sure you would want to do spark cut as then you have unburnt fuel in the cylinders which I have been told could cause bore wash...but I could be wrong.

 

JB

 

Correct.

 

Spark Cut

Cutting the spark to an engine will stop any chances of a weak mixture occurring, but it carries it's own potential problems due to a large quantity of unburned fuel travelling through the cylinder and out of the exhaust. This petrol can remove some of the oil lining the inside of the cylinder, and pass it thorough the exhaust, again this only becomes a problem if the fuel to one particular cylinder is cut for an extended time. The best way to overcome this is to rotate the order in which the cylinders are cut.

 

The unburned fuel in the exhaust will have a catastrophic affect if there is a catalytic converter in the exhaust, as it will try to convert the unburned fuel to harmless elements, effectively burning the mixture. This causes the catalytic converter to heat up very rapidly, reaching temperatures in excess of 1000°C, and possibly melting down completely. Thus prolonged spark cut is not recommended for catalytic equipped cars

[Gamer]

I will take a wild stab as to why someone would want to use spark cut.

 

Could it be for cars without electronic fuel injection maybe ?

 

 

*Edit: Yup it seems that is the case...

 

Q:- Will it fit my car?

A:- The easiest car to fit Racelogic Traction Control is an electronically fuel injected car with ABS. If the car does not have ABS then special wheel speed sensors sensors have to be fitted. If the car is not electronically fuel injected, then the system requires a coil interface unit.You can find more information on the Spark Interface under the 'Misc' link.

 

Spark Cut

 

The Spark interface unit allows Racelogic Traction Control to be fitted to a car without electronic fuel injection. The system can drive up to two separate coils, and interrupts the original signal going to the coil, and allows the Traction Control system to selectively miss-fire set cylinders.

 

The unit will automatically cycle the cylinder cut so the plugs do not foul. The more reduction in power that is requested from the Traction Control unit, the more cylinders are cut. The effect is from a mild miss-fire, through a soft-cut rev-limit to a total cut.

[Bob]

I dread to think how the fuel cut would affect the engine under nitrous use . . .

[eyefi]

I dread to think how the fuel cut would affect the engine under nitrous use . . .

 

depends if it's wet or dry (the nitrous and the road)

[eyefi]

No you can't, it stops individual injectors from firing, so you get no fuel at all - the spark fires but there's nothing to burn. The only reason I can think of why you'd want spark cut is if you were using nitrous. You can't use it with fuel cut because you still get the extra fuel injected with the nitrous even when it cuts the rest which would make you run very lean.

 

i think even with spark cut the fuel/nitrous mix will ignite in the exhaust manifold, major antilag, for a few seconds anyway

[eyefi]

not sure you would want to do spark cut as then you have unburnt fuel in the cylinders which I have been told could cause bore wash...but I could be wrong.

 

JB

 

thanks for the headup but like someone quoted earlier only really a concern if traction is abysmal and igniting my cylinder content without fuel may be alot worse.

 

still fuel cut is alot better for genaral road car use.

[eyefi]

so, no-one is using it? knows anyone else using it?

[Terminator]

I am pretty sure it is only used on cars with carbs. We were considering it when we were tuning( Dont knock it till youve tried it) Nova's, to help us get power down on launches. But some miss time our last engine when the unit was loaned, and wrote off all the custom work, never again. Unless you have an injector not shutting off properly there should be nothing to ignite in the cylinder in the injector cut system. From my knowledge there are settings that you could tweek that can tighten up the injector cut even further, but we are talking fractions of a second and only a few cm's of difference in front and rear wheel speeds not really woth doing.

 

There are cheaper ways to produce flames;)