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Old 08-20-2008, 08:51 PM   #21
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That last table looks about right. I didn't know the cam timing pulled back either, from the graphs I thought I'd remembered things just getting worse after the crossover if left in one position.

Only, I think I'm going to try to save the head I've got. Sure wish I could make up my mind. Certainly if I get one the valve cover will meet with a cutting wheel.

This is pretty tempting... I'll have to think about it - or test it on my buddys 2001.

The real question is: Is all the headwork I did worth spending $500 on valves and springs to save the head I've got? Uhg! Indecision!
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Old 08-21-2008, 12:06 AM   #22
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joe, i wouldn't leave the "for now" map any room for interpolation. set your RPM points 1 rpm apart at switchover.

the reason you want to retard-advance-retard is because the car doesn't run right with too much overlap at low RPM (idle) and has more power in the low-midrange with advance and then performance on the top end is best with full retard.
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Old 08-21-2008, 01:09 AM   #23
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I guess, but the very first thing you're going to do is tweak those. And, with an instant switch, you'd need to know where to switch it.
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Old 08-21-2008, 01:29 AM   #24
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How Are You Gentlemen. All Your VVT Frequencies Are Belong To Us.
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Old 08-21-2008, 01:43 AM   #25
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reverent set us up the bomb!
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Old 08-21-2008, 11:24 AM   #26
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We get signal!!
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Old 08-21-2008, 01:55 PM   #27
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Italic exclamation points? Geeze, talk about attention to detail.

I need to figure out this head thing, asap, since the VVT thing sounds fun.
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Old 08-22-2008, 04:32 PM   #28
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Since I've rarely used an O-scope, could someone please explain what we're actually learning from the graph above? I assume it has something to do with the PWM frequency.

Please excuse my dumbassedness, I'm running an AEM, so I don't usually get really in depth with the electronics side.
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Old 08-22-2008, 05:15 PM   #29
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Quote:
Originally Posted by JasonC SBB View Post
BMW VANOS (at least on the 92-00 cars) is DISCRETE. Full retard, or full advance. No in between. Unlike VVT.
They brought out a continuously variable version called Double VANOS around 2000, however.
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Old 08-22-2008, 05:27 PM   #30
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Quote:
Originally Posted by mistersolo View Post
Since I've rarely used an O-scope, could someone please explain what we're actually learning from the graph above? I assume it has something to do with the PWM frequency.
The verticle access is voltage, the horizontal is time. 500 us -> 0. 000 500 seconds per division. The leading edges on the pulses are ~7 squares apart, 7 * .0005 = 0.0035, or 3.5 ms per pulse. 1/0.0035 = ~285 pulses per second.



Quote:
Originally Posted by Matt Cramer View Post
They brought out a continuously variable version called Double VANOS around 2000, however.
Double VANOS just means it's on both cams, though it might have appeared at the same time as the continuously variable sort, there's no inherent implication.
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Old 08-22-2008, 06:03 PM   #31
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Thanks for the explanation. The AEM has a 300 Hz setting, so if I can get it to read the cam signals, I may get it to control the cam better than the full advance/retard that I'm currently doing.

BTW, a cam cover with exposed cam gears won't do any good as far as monitoring how the timing is changing. The only thing that would be rotating relative to the cam advance would be the cam gear bolt. Everything else is hidden in the VVT mechanism which is attached to the cam pully teeth.
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Old 08-22-2008, 06:11 PM   #32
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mrsolo: can the AEM calculate the phase of the cam relative to the crank?
or if not, can you add an NA cam sensor to the ehx cam?
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Old 08-22-2008, 06:26 PM   #33
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I took JasonC SBB's 99 AEM Settings and made a poor effort to get the car to run on the 2001's cam and crank sensors, it barely ran. I'm using the CAS from my 94 to currently make it run.

I'm planning to give it another shot on the 2001 stuff soon.

In theory the AEM should be able to calc the phase angle between the cam and crank signals. I believe it does it on the S2000's program. The AEM does have specific maps for VVT.

I've actually got to get it running on the 2001 stuff before I start worrying about the VVT. But for right now the 94 CAS and the off/on/off for the VVT is working pretty good.


An independant cam sensor on the exhaust cam won't do any good, since it's still running at the same phase difference as the crankshaft at all times. I'm just not sure if the 3 tangs on the intake cam are causing any trouble with the AEM. I'm going to double check Jason's settings to see if I did something wrong.

Last edited by mistersolo; 08-22-2008 at 08:31 PM.
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Old 08-22-2008, 08:36 PM   #34
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I'm positive you could use a cam sensor on the ex cam to run it like a stock '99, let the intake cam timing do what it wants.

As for watching the cam advance, yeah, you should be able to see it with the cover off, which I don't think is pressurized. Not the valve cover, but the little VVT gear cover. But you're right, the outside of the gear wouldn't tell you anything, and I don't knwo what parts of the inside you could see.

Watching it on a 'scope would be the best, adding a cam sensor to the other cam would be an easy way tell tell.
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Old 08-22-2008, 09:25 PM   #35
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I have a cam sensor on my exhaust cam. just dont got no o-scope.
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Old 08-23-2008, 02:23 AM   #36
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I attached a picture of the intake vvt. I think the center bolt is the only thing that rotates relative to the camshaft and not the pulley.

Isn't the 99 timing sensor on the intake camshaft? (it reads the pulley and is mounted on the front of the valve cover) Or are you using the a sensor on the back of the head that reads the rear of the exhaust cam?
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Old 08-23-2008, 12:16 PM   #37
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I have an 01.. but added the early cam sensor to the exh cam to run sequential ignition on my Tec 3. The Tec is gone but the sensor is still hanging around.
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Old 08-23-2008, 01:40 PM   #38
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oh god, why is that oiley? Oil doesn't come out of the bolt does it?!?!

I'll assume not. Anyway, that would make a fine degree wheel, marks on the cam and a divet in the bolt head. You could even put some sort of plate.

Do the '01's get a different cam tensioner? At least they (99+, probably all years) aren't prone to failure even if they seem lame.

Anyway, the cam drive gear is the same as the intake gear on the '99, meaning you could read it easily.

You could read that or the crank signal to get a good idea for what's going on.
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Old 08-23-2008, 11:10 PM   #39
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VICS doesn't open a second set of runners, it opens to a resonance chamber. This info probably has nothing to do with this thread. If so, sorry.
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Old 08-23-2008, 11:35 PM   #40
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Quote:
Originally Posted by TurboTim View Post
VICS doesn't open a second set of runners, it opens to a resonance chamber. This info probably has nothing to do with this thread. If so, sorry.
That's ok. I haven't actually seen the other half of the intake mani for a 99-00 so I didn't know what it looked like.
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