| Purposefully Misfiring Engine - Click HERE for Original Thread |
| Buddyworm |
What does a misfiring engine, like they use in rally cars, accomplish? Other then spit flame out the tail I can't figure out for the life of me what it does. And yes, I'm not afraid to say I had no idea engines like that actually served a purpose until I watched Initial D.
B-Wurm :lol: |
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| Mustard |
thats not misfiring... thats backfiring...
and theres a lots of reasons...
sometimes its cause is timing advanced and it happens during deceleration, othertimes it's running with too much fuel during idle, aka "rich"
but there are other reasons too....
like dumbasses putting spark plugs in there tail pipes :p |
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| dmak_el |
| i think it keeps the boost up or keep spool up the turbo. something like that. But it's not good for the engine, as far as i know. |
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| DeathBy240 |
| It also happens in turbo cars when the MAF is placed before a Blow off valve that vents into the atmosphere. When the air is blown into the atmosphere it has already been metered so by the time it gets to the cumbustion chamber there is not enough air and too much fuel causing a backfire. At least thats how it was explained to me. |
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| -=MJ=- |
quote:
Originally posted by DeathBy240
It also happens in turbo cars when the MAF is placed before a Blow off valve that vents into the atmosphere. When the air is blown into the atmosphere it has already been metered so by the time it gets to the cumbustion chamber there is not enough air and too much fuel causing a backfire. At least thats how it was explained to me.
exactly and they have no cat and HUGE pipes |
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| Wheelhop |
| Dmak_el is correct. Rally cars engine management Feeds fuel into the odd cylinder under deceleration to keep the turbo in boost to reduce spool up when they switch to acceleration again. Then they dont have to left foot brake like you do in a turbo'd street car to get the same effect. |
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| Buddyworm |
Alright. I getcha. Thanks.
B-Wurm :lol: |
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| Pro Drag |
quote:
Originally posted by DeathBy240
It also happens in turbo cars when the MAF is placed before a Blow off valve that vents into the atmosphere. When the air is blown into the atmosphere it has already been metered so by the time it gets to the cumbustion chamber there is not enough air and too much fuel causing a backfire. At least thats how it was explained to me.
That is correct sir. |
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| GTS Jeff |
haha everyone is off in their explanations at least in some way. whats even funnier is that i know very little about turbo cars.
mustards post is mostly correct, except that retarded timing causes a rich condition, not advanced timing. the problem with this post is that it doesnt answer the question at all. it just describes a couple ways that cars can run rich.
dmak_el is correct. :p
deathby240 is explaining why u cant just put a atmospheric venting bov on a car that uses a maf. what he says is correct, but has no relevance to the topic at hand.
mj is also not answering any questions, altho yes a cat does eat up some of that flame firing jazz.
wheelhop is on the right track. rally cars use engine management to massively retard ignition timing while cranking the af super rich to shove a bunch of unburnt fuel into the exhaust manifold upon deceleration. when the unburnt mixture hits the super hot exhaust manifold, it combusts in the manifold and keeps the turbo spooled between shifts.
edit: ill also point out that it IS referred to as a misfiring system, not "backfiring system" haha. the technical term is antilag system. |
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| DeathBy240 |
| Very interesting. Thanks for clearing it up. :bthumbup: |
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| GTS Jeff |
quote:
Originally posted by DeathBy240
Very interesting. Thanks for clearing it up. :bthumbup:
:bthumbup: |
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| dc2696 |
quote:
Originally posted by GTS Jeff
haha everyone is off in their explanations at least in some way. whats even funnier is that i know very little about turbo cars.
mustards post is mostly correct, except that retarded timing causes a rich condition, not advanced timing. the problem with this post is that it doesnt answer the question at all. it just describes a couple ways that cars can run rich.
dmak_el is correct. :p
deathby240 is explaining why u cant just put a atmospheric venting bov on a car that uses a maf. what he says is correct, but has no relevance to the topic at hand.
mj is also not answering any questions, altho yes a cat does eat up some of that flame firing jazz.
wheelhop is on the right track. rally cars use engine management to massively retard ignition timing while cranking the af super rich to shove a bunch of unburnt fuel into the exhaust manifold upon deceleration. when the unburnt mixture hits the super hot exhaust manifold, it combusts in the manifold and keeps the turbo spooled between shifts.
edit: ill also point out that it IS referred to as a misfiring system, not "backfiring system" haha. the technical term is antilag system.
just thought i should add something, this system sends egt's through the roof, and doesn't like exhaust systems (ie mufflers and cats),but some mild-race set ups can provide FULL boost at idle!(about 22psi) |
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| Talontsi96 |
| I got that system on my car and lets say that it works like a charm. Antilag is awsome. I can get as much boost as I want sitting at the line or while shifting (no lift to shift). The no load boost is set using the fuel enrichment and timing retard settings of the system. |
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| REFLUX |
quote:
Originally posted by Talontsi96
I got that system on my car and lets say that it works like a charm. Antilag is awsome. I can get as much boost as I want sitting at the line or while shifting (no lift to shift). The no load boost is set using the fuel enrichment and timing retard settings of the system.
????
:confused:
I'd like to believe you but I must see it first
though you can add to your credit if you show us some pics or info you've gained through experience about such a system on your car... |
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| Talontsi96 |
No problem...Check out...Version 2.. or V2 of DsmLink. Antilag feature.
at
www.dsmlink.com
Enjoy!!!!
I was getting 15 to 18 psi sitting at the line at bud park last year.
And the looks that you get doing the antilag launch on the street are priceless. Specially when all four tires light up through all of first and half of second gear. :)
The system allows you to specify the RPM that you want your antilag and stutterbox to be set at, also it allows you to richen the mixture and retard timing of the antilag. This applies also during no lift to shift option which allows you to set the desired RPM for antilag during shifts.
What you do is shift and not let off the gas when you shift, the system goes into antilag, defaults to the set RPM point and antilag settings for timingretard/fuel enrichment during the shift. There is a switch installed in the clutch pedal so as soon as the clutch gets depressed and throttle is at 100% the system goes into antilag. It works awsome and you do get a really weird stutteing type sound out of the exhaust.
I'll tell ya NLTS is really hard to get used to, I didnt get one good run last year because of my old habbits. |
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| mitsuman |
I've seen this. It’s an enhanced stage rev limiter with ignition timing control. In a nut shell, at open throttle fuel is sprayed in, and timing is retarded to the point such that when the fuel is ignited, it’s almost at the time when the exhaust valves open... Instead of loading the piston, you are pushing the gases through the turbo.... Thus achieving high boost. It works great for drag racing, however I would not use this all the time as it’s hard on exhaust valves, turbo and other exhaust components.
In rally cars, this system operates in a similar fashion, however those cars have an independent throttle by pass valve + all other controls for fuel and timing which we all know are cutting edge. In this case, every time you lift on the throttle the system activates and keeps the turbo spoolin'
quote:
Originally posted by REFLUX
????
:confused:
I'd like to believe you but I must see it first
though you can add to your credit if you show us some pics or info you've gained through experience about such a system on your car...
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| Talontsi96 |
Marcin did you ever get a chance to check the antilag on my V2 of DSMLink? or did I deprive you last year? lol.
Marcin is completely right about how the antilag system works. Its true that mine is slightly different than the rally car antilag although it uses the same principles it was built for a differnet style of racing (drag race applications). So mine doesn't engage everytime you lift the throttle (like the rally type) mine engages when the clutch is depressed and throttle is above 80 or so percent (configurable).
Paul
As far as using it all the time? Yest it will wear out things quicker, but in drag race applications the duration of shifts is very small and people that are using this sytem have not reported failures or noticable increase in wear because of the system. You would not use this system in normal driving just when racing. |
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| REFLUX |
| damn I'd really like to see it in person!!! |
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| Talontsi96 |
Reflux
When I come out to one of the meets, I'll show you in person how the system works and sounds. I first have to get the car put back together and out of the garage. |
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| dc2696 |
quote:
Originally posted by Talontsi96
Reflux
When I come out to one of the meets, I'll show you in person how the system works and sounds. I first have to get the car put back together and out of the garage.
I wouldn't mind checkin that out myself |
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| Talontsi96 |
No problem the more the merrier.
:bthumbup: |
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| DeathBy240 |
I was reading about another type of anti-lag system that was kind of interesting.
quote:
In the 2001 WRC cars, the engineers had welded large tanks in the back of the car, which they attached to the compressor outlet. When the turbo was making boost (which is 98% of the time the car is driving), the boost was limited by the wastegate, as with normal cars. But the WRC engineers decided to run HIGHER boost than normal, then bled some of that excess boost into the storage tanks, so the end boost going into the engine was still the same as the original, and the tank would build up a good 10-15 psi charge.
Then when the RPMS got too low to make full boost or the turbo was not spooled, the computer would trigger the pressurized tank to dump some of that pressurized air back into the engine to make the car think it was at full boost, up until the turbo was fully spooling. its kind of a neat system, but it was banned that same year because it was a potential "hazard" to have a pressurized tank essentially in the driver compartment.
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| dc2696 |
quote:
Originally posted by DeathBy240
I was reading about another type of anti-lag system that was kind of interesting.
I've also heard of that system, good idea but the tank adds some unwanted weight as well as the whole hazard thing:D |
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