Surging at WOT, the saga continues

[Fopar]

In my experience a loose reluctor wheel won't cause surging. It will however leave a bunch of marks in the tops of your pistons.

I've heard the alternator shutting off thing before, but it doesn't make sense to me. Nothing is controlling the alternator to shut it off. And why would anyone want dropping voltage at the time its most important? Not too mention those running upgraded alternators seeing 13.5+vdc at WOT in logs.

@Fopar, can you record the boost gauge during a hit? Maybe angle it to get the tach in the view?

Reeee it’s in the dyno graph pic!

 

[01yellercobra]

Reeee it’s in the dyno graph pic!

I looked at your graph. But I doubt it's actually as smooth as the graph shows.

 

[Fopar]

I looked at your graph. But I doubt it's actually as smooth as the graph shows.

I mean the gauge is about that smooth... logging the TMAP won't tell you anything as it's just 1 bar.

 

[Fopar]

Motor is healthy, has about 3k miles on it. Compression test on the the list of things to check. Car still made 744 on 19 psi, Problem is it was pullied for 26 psi. Both pulley sets were 6 psi low, so it's not belt slip.

I wish I had accurate degree's from before to now. But now they are degree'd to within 1/4° of the cam card. 110° intake and 114° exhaust.

Sorry to hijack your thread too btw.



I was told during WOT, the alternator is supposed to shut off and the car is running strictly from the battery. My battery is in the trunk, I am running 4 ga wire to feed the relay and the pumps. I have 1/0 ga power and ground wires running to the alternator and starter. During normal idling or driving, I'm reading 13.3-14.2 on my gauge.

I am running 2 465 pumps full time.

4 things I changed between last dyno session and this time.

1.) Degree'd the cams. I am 99% confident they are set correctly.
Last time, not so much, I was not using a crank socket with the degree wheel, so not actually sure what how accurate the measurements were.
2.) Ported the Lower Intake. Had it done, did not do this myself.
3.) 0.010 thinner head gaskets.
4.) I installed a new blower gasket, but I did not RTV it to the blower. Not sure if this is where I am loosing the boost or not. I need to smoke the intake and check for leaks.

Well don't be so sure if the evidence says otherwise. A good sanity check is to know how far you have to move the cams... if it's a couple degrees then whatever, if it's like 10 then you probably didn't measure something correctly. Assuming your car is still a MAF setup the thing I would look at is airflow now compared to what it was before. If your airflow is the same and ur A/Fs are the same , but boost is less then it's a cam timing issue and ur just blowing intake air out the exhaust... if your airflow decreased in accordance with boost then it's a SC or belt issue.

 

[Fopar]

Anyone think a diff issue or u-joint could cause this? It's a big stretch considering both don't make any noise or any other symptoms but I'm starting to reach here

 

[Fopar]

Ok, I came up with something when I woke up this morning.....

What if... the reluctor wheel got bowed when I pressed the new balancer on... I have a decent pressing tool and I don't go easy on it so I may have pressed it a bit too hard. So maybe the teeth are now forward of where they should be and the crank sensor square wave is a bit funky and the ECU is computing it off and I've lost a bunch of timing. This would explain both the idle and WOT performance issues... Does anyone have an engine on the stand that they can take a pic of their reluctor wheel through the crank sensor hole on? Compare to what I have in this vid and tell me how much room between the front cover they have to the teeth?

 

[03' White Snake]

Well don't be so sure if the evidence says otherwise. A good sanity check is to know how far you have to move the cams... if it's a couple degrees then whatever, if it's like 10 then you probably didn't measure something correctly. Assuming your car is still a MAF setup the thing I would look at is airflow now compared to what it was before. If your airflow is the same and ur A/Fs are the same , but boost is less then it's a cam timing issue and ur just blowing intake air out the exhaust... if your airflow decreased in accordance with boost then it's a SC or belt issue.

When I brought the car to the dyno, the new setup was way lean. I even bumped fuel pressure 10 up to 50 to help compensate a little bit. Also the IAC was way out the tuner said. After he started tuning it, We lowered the base pressure down to 40 where it should be.

 

[Fopar]

Related question, has anyone pulled a front cover with the valve covers still in place?

 

[03' White Snake]

I've lifted the VC's but leaving them in there and pulled the timing cover out before. Need to be careful not to tear the oil pan gasket. Made that mistake, I repaired it with RTV until I swapped the pan gasket out later. So it can be done.

 

[Fopar]

When I brought the car to the dyno, the new setup was way lean. I even bumped fuel pressure 10 up to 50 to help compensate a little bit. Also the IAC was way out the tuner said. After he started tuning it, We lowered the base pressure down to 40 where it should be.

My cam card

View attachment 1757032

Final numbers…

View attachment 1757033

My calc’s…

View attachment 1757034

Well I wanna help more but at this point I think you should start your own thread as it’s getting a bit cluttered in here

 

[Fopar]

Does anyone have a motor on a stand right now that they can take a pic of the trigger wheel through the hole for the crank position sensor?

 

[01yellercobra]

Do you have access to an o-scope? You can tap into the crank sensor output and check the square wave.

That being said if the reluctor was the problem I'd think you'd have issues every where. And if you bent it putting the engine together I'd think it would be a problem from day one.

Have you vacuum checked the bypass?

 

[Fopar]

Do you have access to an o-scope? You can tap into the crank sensor output and check the square wave.

That being said if the reluctor was the problem I'd think you'd have issues every where. And if you bent it putting the engine together I'd think it would be a problem from day one.

Have you vacuum checked the bypass?

I only thought of it after taking the rad etc out so o-scope later.

I'm not saying it happened putting the motor together, I'm saying it happened swapping the balancers. It's possible it's retarding the timing and it's just not as noticeable at low loads/RPMs... could also be retarding more the higher the RPM is.

Vacuum bypass is fine

 

[Fopar]

So maybe not tight but chain pushed sprocket foward? Not sure... going to see if I can push the balancer on anymore and it straightens out

 

[03' White Snake]

Your balancer should be tight against the timing wheel inside the timing cover. Should press on the pulley as far as it will go and tq the bolt. With my upgraded crank bolt, it is torqued to 236 ft-lbs. that thing isn’t going anywhere.

Check your bypass is fully operational and not getting stuck on anything.

Found part of my issue anyway, the ball joint on the bypass is coming out and my bypass was getting stuck on the fuel rail fitting. Hence why I was down 6 psi of boost. It wasn’t fully closing.

 

[Crimson2v]

So maybe not tight but chain pushed sprocket foward? Not sure... going to see if I can push the balancer on anymore and it straightens out

At 12-13 seconds it looks like the reluctor wheel moves out of sync with the crank. I wonder if the key way in the wheel is wallowed out.

 

[Fopar]

Your balancer should be tight against the timing wheel inside the timing cover. Should press on the pulley as far as it will go and tq the bolt. With my upgraded crank bolt, it is torqued to 236 ft-lbs. that thing isn’t going anywhere.

Check your bypass is fully operational and not getting stuck on anything.

Found part of my issue anyway, the ball joint on the bypass is coming out and my bypass was getting stuck on the fuel rail fitting. Hence why I was down 6 psi of boost. It wasn’t fully closing.

View attachment 1757261

View attachment 1757262

Eggcellent sounds like good news for both of us (well more for you)

 

[Fopar]

"Solved": sorta..

Went to press the balancer on more, pryed the crank forward so I could measure if it moved at all, then I went to bias the reluctor towards the advanced direction (assuming the play was minimal) and it looks like I took the pressure of the chain sprocket off the reluctor, was shocked at how much play there was in the the keyway on the trigger wheel , clearly is horribly wallowed. That balancer was tight as **** tho, so ****ing ATI makes their hub too small, going to have a local machinist hone it to get it closer to the factory press.

 

[03' White Snake]

Wow, that’s not good. That is definitely your problem. I had the machine shop check the press on my IW dampener, smart thing to do.

Check your keyway is straight too when in there. That much movement might have started to damage the key.

 

[badcobra]

This is what it will look like