Reluctor Wheel Adjustment
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Okay maybe I said this wrong but the balancer has the trigger wheel behind it,and mine is off by 13* according to the tables on the FAST. So is there a diagram that will show how to postion it correctly? I read other threads that the trigger wheels are off by 3* to 4* stock.
northerngn
Master Monkeywrench
- Joined
- Oct 8, 2006
- Messages
- 770
sounds like you have it's out of adjustment corrected with fast
why do yo fell you need to change it?
btw i have xfi and im at 12 deg on my car
this was on a stcok motor with a stock balancer
-dan
why do yo fell you need to change it?
btw i have xfi and im at 12 deg on my car
this was on a stcok motor with a stock balancer
-dan
If you have a FAST setup and the timing is off, can't you just change the reference angle so the timing as commanded by the FAST = timing as measured by a timing light? I didn't think there was a need to physically move the timing ring on the balancer.
John
John
- Joined
- May 28, 2001
- Messages
- 16,575
That's
correct, John.
The BMS balancer on my stage 2 was off 7*. Corrected w/ the FAST.
correct, John.
The BMS balancer on my stage 2 was off 7*. Corrected w/ the FAST.
it is true that there is sometimes a variation in the placement of the reluctor wheel on the balancer assembly---------with a F.A.S.T. this seems to be of little bother since you can use a timing light and set it to where you want it to be but it can be useful to know where true "0" is--------as for moving the wheel to make it correct i did an interesting test a few weeks ago-------checked a lot of good condition undamaged stock balancers and found them within a few degrees--------here's the real surprise--------we selected a single stock balancer and took several of the sensors---------we found that the timing of the sensors varied MORE than the balancers--------the sensors were all GM replacements and appeared to be in good shape--------most were within 3 to 4 degrees but worst in the batch was 11 degrees out-------can't remember if it was advanced or retarded---------makes you wonder what kind of total variation could actually occur between two stock cars if one had a worst case reluctor AND sensor and the other had a BEST case pair...............RC
Great information right there.
sorry for the slow reply. Here is some information that I've posted before, hope it helps:
If the timing ring that is pressed on the balancer and passes through the crank sensor is not positioned accurately it will throw off the ignition timing, because the ECM will think the #1 piston is in a different spot than it really is. If the ring is 5 deg off for example, when the the engine is actually at 20 deg BTDC, the ECM will think it is either at 15 deg BTDC or 25 deg BTDC, depending on which direction the ring is off. At WOT this would make a huge difference in the cars performance. What is the timing difference between a race chip and a street chip at WOT? 24 deg vs 18 deg? 6 deg difference then? Something like this would explain why one guy can run 20 psi on his street chip with 93 octane, while another guy can only get to 16 psi.
Several years ago one of Conley's mechanics (pudd'n) posted that "The edge of the ring should be lined up perfectly with tdc mark on the harmonic balancer. With age they seem to move. They are only pressed on." Mine didn't look like that. See the attached picture. The string is in the balancer 0 deg mark.
I pulled the ring off, moved it to the appropriate spot, and pressed it back down, with a little loctite to hopefully keep it in place forever.
You can check the position of the ring with a timing light using this procedure:
1. If you look at the timing tab on the timing chain cover, most of the marks and numbers run down the outside edge. There is one mark and number on the inside edge; it is at 15 deg.
2. Start the car and put the ECM in "diagnostic" mode. You put the car in diagnostic mode by jumpering the ALDL pins A and B (same as pulling codes via the service engine light).
3. In diagnostic mode the ECM fixes the timing at 15 deg. So once the car is idling in diagnostic mode, take your timing light and make sure the timing mark on the balancer lines up with the single mark on the inside edge of the timing tab. If they are not aligned, the mismatch is how much your timing ring is off.
Note that diagnostic mode is different than ALDL mode. ALDL mode doesn't fix the timing, it just adds 8 deg to the normally calculated advance, so that doesn't help. So if you have a scan tool that can put the ECM in ALDL mode, don't bother trying to do that with this procedure.
When I moved my ring (the picture shows the Before position, I don't have an After picture) and then went through the above test, my timing marks lined up exactly. So the picture shows a ring that is probably 2 or 3 degs off.
John Estill
If the timing ring that is pressed on the balancer and passes through the crank sensor is not positioned accurately it will throw off the ignition timing, because the ECM will think the #1 piston is in a different spot than it really is. If the ring is 5 deg off for example, when the the engine is actually at 20 deg BTDC, the ECM will think it is either at 15 deg BTDC or 25 deg BTDC, depending on which direction the ring is off. At WOT this would make a huge difference in the cars performance. What is the timing difference between a race chip and a street chip at WOT? 24 deg vs 18 deg? 6 deg difference then? Something like this would explain why one guy can run 20 psi on his street chip with 93 octane, while another guy can only get to 16 psi.
Several years ago one of Conley's mechanics (pudd'n) posted that "The edge of the ring should be lined up perfectly with tdc mark on the harmonic balancer. With age they seem to move. They are only pressed on." Mine didn't look like that. See the attached picture. The string is in the balancer 0 deg mark.
I pulled the ring off, moved it to the appropriate spot, and pressed it back down, with a little loctite to hopefully keep it in place forever.
You can check the position of the ring with a timing light using this procedure:
1. If you look at the timing tab on the timing chain cover, most of the marks and numbers run down the outside edge. There is one mark and number on the inside edge; it is at 15 deg.
2. Start the car and put the ECM in "diagnostic" mode. You put the car in diagnostic mode by jumpering the ALDL pins A and B (same as pulling codes via the service engine light).
3. In diagnostic mode the ECM fixes the timing at 15 deg. So once the car is idling in diagnostic mode, take your timing light and make sure the timing mark on the balancer lines up with the single mark on the inside edge of the timing tab. If they are not aligned, the mismatch is how much your timing ring is off.
Note that diagnostic mode is different than ALDL mode. ALDL mode doesn't fix the timing, it just adds 8 deg to the normally calculated advance, so that doesn't help. So if you have a scan tool that can put the ECM in ALDL mode, don't bother trying to do that with this procedure.
When I moved my ring (the picture shows the Before position, I don't have an After picture) and then went through the above test, my timing marks lined up exactly. So the picture shows a ring that is probably 2 or 3 degs off.
John Estill
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Eric Stage I
TurboTweak Guy
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- May 25, 2001
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Just for reference, the stock ECM has the same adjustment as a FAST system for the reference angle. It can be changed in the chip.
Eric
Eric
I have seen the timing all over the place even with the stock setup. In my presentation at Richard's I tried to emphasize that the timing MUST be checked even on a 100% stock vehicle. I blamed it on too many tolerances stacking up. I am now thinking that Richard found the true culprit. While in NC I helped two guys who had been running their cars for years WITH THE WRONG TIMING 
Since you have a FAST, I would normally adjust the crank referance angle and call it a day. If it is off a lot then I would recommend moving it, epecially on a street car with a knock sensor. You really don't want your timing getting too close to your crank referance angle. In other words, I wouldn't recommend running a street car with 18 degrees timing and a 13 degree crank referance angle. The reason I say "street car" is because of the additional timing that can get pulled out by the ESC.
Sorry for the long winded response
Since you have a FAST, I would normally adjust the crank referance angle and call it a day. If it is off a lot then I would recommend moving it, epecially on a street car with a knock sensor. You really don't want your timing getting too close to your crank referance angle. In other words, I wouldn't recommend running a street car with 18 degrees timing and a 13 degree crank referance angle. The reason I say "street car" is because of the additional timing that can get pulled out by the ESC.
Sorry for the long winded response
Just went through this on one of my cars. The ring was off 2*. Most seem to be off 2-4*. The mechanical portion of this relative to the crank keyway can be verified with a piston stop and degree wheel. This can eliminate variables with the timing tab or key location.
