Ignition cut = damage?

civic4g · Post by **civic4g** » Sun Jun 20, 2010 8:32 am

Hi guys Can ignition cut damage the ignitor or any other component of the ignition system?

JaredKaragen · Post by **JaredKaragen** » Mon Jun 21, 2010 2:30 pm

Ign cut: no, it just cuts the spark.... The fuel can. Be mindful of that.

9400RPMS · Post by **9400RPMS** » Mon Jun 21, 2010 4:41 pm

JaredKaragen wrote:Ign cut: no, it just cuts the spark.... The fuel can. Be mindful of that.

so which is actually better for the motor, considering, fuel cut is a stock setting..

TopMountGSR · Post by **TopMountGSR** » Tue Jun 22, 2010 1:41 am

Every car I tune with ectune is setup using an ignition cut. Ignition cut is to prevent damage, not cause it Plus it sounds bad ass!

cyanide · Post by **cyanide** » Thu Jul 22, 2010 5:13 am

Wouldn't ignition cut cause flames out the back when the ignition resumes, but with lots of fuel in the exhaust?

JaredKaragen · Post by **JaredKaragen** » Thu Jul 22, 2010 8:17 pm

Depends on col1 values... And richness when ign-cut trips. This is a double edged sword trying to get those pops completely away upon decel... Ign cut is great for antilag, but for daily driving, not my recommendation. I know fcut creates a lean spike, but in theory it shouldn't be in the middle of an ignition cycle so it is not a worry about the injector firing half way. Plus you don't wash your cylinder walls clean while under fcut.

Post by **Bugermass** » Thu Jul 22, 2010 11:27 pm

you know, I really don't think fuel cut will damage anything either. I'd imagine that if fuel cut were so bad that it wouldn't be on every EMS there is. Also alot of the factory computers use fuelcut limiters. I understand the idea by which its thought to be dangerous, but I've never seen it actually happen and I use a mix of fuelcut and ignition cut in different situations to get different affects (mainly on standalones)..

JaredKaragen · Post by **JaredKaragen** » Fri Jul 23, 2010 1:44 am

From an emissions standpoint they were forced into fcut, and the extra ignition pulses help burn any left over fuel to even more reduce emissions when firing in the exhaust stroke as well as when it's under a decel/limiter condition. Tis how I see it

Pandor · Post by **Pandor** » Tue Jan 25, 2011 6:21 am

civic4g wrote:Hi guys Can ignition cut damage the ignitor or any other component of the ignition system?

JaredKaragen wrote:Ign cut: no, it just cuts the spark.... ...

JaredKaragen wrote:... Plus you don't wash your cylinder walls clean while under fcut.

seem contradictory to me... I Would believe bore wash to be rather unhealthy for the engine... Whereas with fuelcut there is nothing to burn, so its not a lean spike. It's just 'air' passing through. is it not?

JaredKaragen · Post by **JaredKaragen** » Tue Jan 25, 2011 4:36 pm

constant bore wash (boosted for example) is way less fuel than a fuel cut scenario.... load, vs. unloaded. I dont think it would be a problem either way. fuel cut is a lean spike... great; but the ECU doesn't cut fuel mid injector pulse... that would be retarded and be a way that it could potentially cause damage. I wouldn't worry about it. Besides; OEM ecu's use fcut and its fine.... whereas people that are worried use ign cut to prevent \"lean\" limiters.

Pandor · Post by **Pandor** » Tue Jan 25, 2011 8:48 pm

here's my take on the subject. These are my assumptions from reading from different sources. So most is based on 'hearsay' Fuel cut: pros:

No fuel to ignite outside of combustion chamber (safer)
No unburnt fuel, no bore wash

cons:

No fuel to cool combustion chamber (but intake air does cool it?)
Does not sound as impressive as Ign cut (personal opinion)

Ign cut: pros:

fuel cools down combustion chamber
popping/flames coolness (personal opinion)

cons:

Unburnt fuel washes cilinder wall. piston rings lose seal and lubrication. (damage to rings and cilinder wall due to metal to metal scraping)
unburnt fuel might detonate in the header, which can potentially damage valves,etc... (how does the o2 sensor cope with detonation?)

I've been steering away from ign cut for launchcontrol use on my N/A build due to the above cons. But is my fear justified? I mean, does bore wash happen on the first instance, or is it worst case (say 10min straight on the throttle, constantly flooding the combustion chamber). How does ectune deal with a fuel/ign cut combination? Does it alternate between them?

Gruelius · Post by **Gruelius** » Tue Mar 01, 2011 12:50 pm

Although its a bump by a random i found this googling and thought i might add my 2 cents For your CONS list of IGN cut you say that the fuel will strip the walls of oil, during the 4 stroke cycle for 2 cycles there is just fuel in the cylinder (granted intake has no fuel for a portion of it). Would an additional 2 strokes be that bad for the cylinder walls? im assuming that pure fuel isnt drastically worse than the combustion for removing the lubrication. And for dedonation damaging sensors, my idea is speculative (then again most of this stuff is as i dont think anyone has destroyed motors on purpose to prove theory!) but the oxygen sensor in my exhaust has the following ratings Exhaust gas pressure < 4 bar Exhaust gas temperature range (operating) < 930 Â°C Exhaust gas temperature range (max.) < 1,030 Â°C im happy to be proven wrong but i dont think any combustion in exhaust would have instantaneous temps anywhere near 900 degrees celcius and it would be unlikely to boost the exhaust to 4 bar.

RoadXY · Post by **RoadXY** » Wed Mar 23, 2011 2:30 am

And would ign. cut damage turbo's if burnt in the exhaust?

ckretvix · Post by **ckretvix** » Mon Mar 28, 2011 9:21 pm

I doubt it. Turbine wheels are designed to take alot of heat and pressure. Antilag all the time is another story

Post by **Bugermass** » Wed Mar 30, 2011 12:06 am

ignition cut will not damage your engine.. Antilag by nature can damage turbos and manifolds, but if used sainly and not for long durations at a time you'll be fine.