Engine Timming Gear and ECU Random?
06-28-2002, 03:37 AM
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Engine Timming Gear and ECU Random?
Ok I have been doing a bunch OH reserch on engine timming and the like. (I hope to get an accent and turbo the hell out of it)
Now we all know timming retard is used to avoid Predet. And on race day you want to run as close to that point as possible.
This is done (in most cases on our cars) by using either a MSD retard box or An after market ECU (haltek for example) YOu adjust your spark timming to reflect a point past TDC but not so far as to kill all your power.
Paeople have talking about the "Timing gears" and Adjusting the timming on the cams.
This is what confused me.. Is this simply an adjustment to try and get as much Air/fuel mixed as possible and change the escape gas profile or is this used in conjuction with spark timming to avoid predet (or in NA) the oppisite. Advancing the timming to try and get as much power as possible. So even though the Piston is not yet to TDC the ignigtion of the fuel is started and by the time it goes past TDC you reach the max power given off by the combustion.
Thanx and IF this is a dumb question.. Answear first then Flame..
Now we all know timming retard is used to avoid Predet. And on race day you want to run as close to that point as possible.
This is done (in most cases on our cars) by using either a MSD retard box or An after market ECU (haltek for example) YOu adjust your spark timming to reflect a point past TDC but not so far as to kill all your power.
Paeople have talking about the "Timing gears" and Adjusting the timming on the cams.
This is what confused me.. Is this simply an adjustment to try and get as much Air/fuel mixed as possible and change the escape gas profile or is this used in conjuction with spark timming to avoid predet (or in NA) the oppisite. Advancing the timming to try and get as much power as possible. So even though the Piston is not yet to TDC the ignigtion of the fuel is started and by the time it goes past TDC you reach the max power given off by the combustion.
Thanx and IF this is a dumb question.. Answear first then Flame..
06-28-2002, 04:12 AM
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another way to avoid detonation,... lower compression
Low compression pistons or a spacer can reduce the compression in your little accent
as for timing
ill let the big shots handle that
Low compression pistons or a spacer can reduce the compression in your little accent
as for timing
ill let the big shots handle that
06-28-2002, 05:41 AM
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Dude, check your spelling:
EDIT> he fixed it, I won't maintain a record of past sins wink
And I'm going to bite my tongue on this one, I think I may know but could very easily be way off-base. If nobody answers I may do my reading when I get home to confirm my thoughts and post back. wink
EDIT> he fixed it, I won't maintain a record of past sins wink
And I'm going to bite my tongue on this one, I think I may know but could very easily be way off-base. If nobody answers I may do my reading when I get home to confirm my thoughts and post back. wink
06-28-2002, 06:02 AM
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DUH MY bad.. Should be all fixed now.. (OK OK SO SPELLING WAS NEVER A STONG POINT FOR ME) rolleyes.gif
But YEa that timming thing.. IM thinking of picking up a modern tunning book but havent had the time.. Just tring to wrap my brain around it..
But YEa that timming thing.. IM thinking of picking up a modern tunning book but havent had the time.. Just tring to wrap my brain around it..
06-28-2002, 09:10 PM
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Try this; you can use a higher-octane fuel if you don't wanna go PING! A higher compression ratio requires either several degrees retarded timing(ATDC)depending on the fuel type and the compression ratio.
06-29-2002, 12:34 AM
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Right well I know the theory about not going Ping knock knock boom...
What confuese me is adjusting the cam timming. DOes this effect spark timming? Why do this..
I mean I plan on dropping the compression ratio to 7:1 (yes mad amounts of boost) but whern Im doing this besides the spark. should I be adjusting the cam timming as well?
What confuese me is adjusting the cam timming. DOes this effect spark timming? Why do this..
I mean I plan on dropping the compression ratio to 7:1 (yes mad amounts of boost) but whern Im doing this besides the spark. should I be adjusting the cam timming as well?
06-29-2002, 12:45 AM
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I'm not sure what you are refering to here, so I'm just going to ramble for a bit, and hope I hit the area you're interested in somewhere in here.
There are 2 types of timing in an engine. Spark timing, and valve timing.
The two are loosely related, but not tied together. I say loosely related, because you don't want your spark plug going off while your intake/exhaust valves are open, but that's about the extent that the two are related.
Spark timing and Valve timing are actually tied to Crank Rotation. You want your intake valves to open BEFORE top dead center, and you want them to close AFTER Bottom Dead Center. You want your exhaust valves to open BEFORE bottom dead center, and close AFTER Top Dead Center.
Timing gears for CAMS allow you to alter the timing of the intake and exhaust cams, which alters when the intake and exhaust valves open. Usually the intake cam is ADVANCED a few degrees (opens earlier) and the exhaust cam is retarded a few degrees (opens later).
For the Beta motor, with it's ecentric Intake Cam driven CHAIN on one side, and the timing belt driving the exhaust cam, timing gears are a Serious Major PITA.
For the 1.5L SOHC Alpha, since there is only one cam, any adjustments made to the cam affect both intake and exhaust. As you usually want to advance intake and retard exhaust, it is usually fairly pointless to install an adjustable timing gear on a SOHC engine.
For the 1.6L DOHC, it uses the same damn goofy system as the Beta. Chain driven on one side, and Belt driven on the other. Making Cam timing adjustments a MAJOR PITA.
If you are refering to Gear Driving Timing devices, those are specific to distributor ignition systems. Both the Alpha and Beta motors use a distributorless Igniton system, so they do not apply to our motors.
There are 2 types of timing in an engine. Spark timing, and valve timing.
The two are loosely related, but not tied together. I say loosely related, because you don't want your spark plug going off while your intake/exhaust valves are open, but that's about the extent that the two are related.
Spark timing and Valve timing are actually tied to Crank Rotation. You want your intake valves to open BEFORE top dead center, and you want them to close AFTER Bottom Dead Center. You want your exhaust valves to open BEFORE bottom dead center, and close AFTER Top Dead Center.
Timing gears for CAMS allow you to alter the timing of the intake and exhaust cams, which alters when the intake and exhaust valves open. Usually the intake cam is ADVANCED a few degrees (opens earlier) and the exhaust cam is retarded a few degrees (opens later).
For the Beta motor, with it's ecentric Intake Cam driven CHAIN on one side, and the timing belt driving the exhaust cam, timing gears are a Serious Major PITA.
For the 1.5L SOHC Alpha, since there is only one cam, any adjustments made to the cam affect both intake and exhaust. As you usually want to advance intake and retard exhaust, it is usually fairly pointless to install an adjustable timing gear on a SOHC engine.
For the 1.6L DOHC, it uses the same damn goofy system as the Beta. Chain driven on one side, and Belt driven on the other. Making Cam timing adjustments a MAJOR PITA.
If you are refering to Gear Driving Timing devices, those are specific to distributor ignition systems. Both the Alpha and Beta motors use a distributorless Igniton system, so they do not apply to our motors.
06-29-2002, 12:02 PM
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Random, so if we wanna use large amounts of boost, then we should also an ECU that would be able to retard ignition timing, is this correct?
On the Beta, CPS has no provision for adjustment, so is this the only option? Sory man, still learning lots about turbocharging.
On the Beta, CPS has no provision for adjustment, so is this the only option? Sory man, still learning lots about turbocharging.
06-29-2002, 04:45 PM
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Random YA hit.. thanx for rambaling..
It makes alot more sense now.. So I wont even have to touch cam timming. And If I do it "RIGHT" I may not have to touch spark but At least I now know that IF I retard the spark I wont have to Well ya get the idea..
Thanx
thanx for rambaling.. It makes alot more sense now.. So I wont even have to touch cam timming. And If I do it "RIGHT" I may not have to touch spark but At least I now know that IF I retard the spark I wont have to Well ya get the idea..
Thanx
06-29-2002, 05:32 PM
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Okay, regarding our spark timing. It is set by the ECU. No "adjustments" can be made unless you know how to speak "ECU"ese. (I've tried pleading and whining, it doesn't work). The ECU has internal "maps" based of throttle position, engine load, and RPM as to when it should trigger a spark. The only thing that can change that is the Knock sensor. If the Knock sensor senses detonation, then the ECU will retard the timing about 10-15 degrees (based on my experience). It keeps retarding the timing until the Knock sensor goes quiet.
There are various different aftermarket solutions.
The most common "simple fix" is either the Apex-i ITC, or the MSD Programmable DIS-2.
I cannot find any info on the Apex-i ITC, but if memory serves me correct, it does not compensate for boost, it simply allows you to adjust ignition spark timing based off TPS and RPM. It runs about $250-$300 if it is still available
The MSD Programmable DIS-2 is basically a stand alone ignition system. It offers complete programability including retarding ignition timing based off boost. It runs about $400 to $500. You can read more about it at http://www.msdignition.com/n2000j.htm
The "of course" solution are a stand along engine management system, such as a Haltec, Motec, or SDS Tec-2 or Tec-3. Sure, they cost $1200 to $3000. But for that kind of money, you get a lot of tuning ability.
If you think about it. $300 for a S-AFC, and $400/$500 for the programmable DIS-2, you're 80% of the way to the cost of a Haltec EK6 ($1200).
Oh..one last Caveat. By changing your ignition timing....you've got the ability to really screw up your engine. It's not something I reccomend that ANYONE try to "tune" themself. Let the pro's do it on a dyno, the right way.
Pistions and blocks with holes in them just don't work right.
There are various different aftermarket solutions.
The most common "simple fix" is either the Apex-i ITC, or the MSD Programmable DIS-2.
I cannot find any info on the Apex-i ITC, but if memory serves me correct, it does not compensate for boost, it simply allows you to adjust ignition spark timing based off TPS and RPM. It runs about $250-$300 if it is still available
The MSD Programmable DIS-2 is basically a stand alone ignition system. It offers complete programability including retarding ignition timing based off boost. It runs about $400 to $500. You can read more about it at http://www.msdignition.com/n2000j.htm
The "of course" solution are a stand along engine management system, such as a Haltec, Motec, or SDS Tec-2 or Tec-3. Sure, they cost $1200 to $3000. But for that kind of money, you get a lot of tuning ability.
If you think about it. $300 for a S-AFC, and $400/$500 for the programmable DIS-2, you're 80% of the way to the cost of a Haltec EK6 ($1200).
Oh..one last Caveat. By changing your ignition timing....you've got the ability to really screw up your engine. It's not something I reccomend that ANYONE try to "tune" themself. Let the pro's do it on a dyno, the right way.
Pistions and blocks with holes in them just don't work right.