[NA18CamaroSS]

Quick question for experienced tuners: Have you seen less than advertised retard with phase limiters?
I am logging 2.5 degrees of max retard with my BTR 4 degree phase limiter. Noticed this when I was going over my full throttle logs. I did a little experiment and set all of the cam tables to 5 degrees at idle and slightly above. Data logged intake cam angle, intake cam angle command, and intake cam error. Sure enough, the PCM was commanding 5 degrees, but I was only getting 2.5, showing a 2.5 degree error.
I can live with it, but it's a little disappointing.

[KingLT1]

I believe this is why many lock out or delete the phaser all together. I know BTR likes to keep the stock phaser, but it seems to be unstable with aftermarket cams combined with high rpm. If this was a 5.3 truck, I would keep it because you will want the torque, and you are not going to rev it past 6-6200rpm. In a car, not sure it's worth the headache from the phaser fluctuating at high rpm.

[GreyGhost702]

I talked to BTR about the same thing pretty much. They didn't have any inspiring input for me, other than finger shaking for running the 220 cam on a FI setup. They claim the boost is my issue, which just makes my eyes roll back. I'm only pushing 9-10psi. Somehow that extra cylinder pressure plus the cam profile is too much for the GM Phaser to control. For sure, I can see overall stability being a problem but the Phaser was not doing as commanded even while not under boosted load.

When I was doing the break-in session on my build, we noticed in the logs VVT wasn't matching what we had asked for (using BTR's recommend VVT table for the 220 cam). We even tried zeroing the cam tables, and to some degree that worked but at higher RPM it still seemed to bounce in/out. I used Driven GP1 30 Grade Break-in oil. When I dumped the break-in oil and put in 5w50, it seemed to help the Phaser behave better. We put the BTR VVT table back in and it's pretty close in the logs. 5w50 has bumped my oil pressure up compared to the 30 grade break-in oil. I never logged the car with 0w40, and 5w50 was what Katech and Total Seal recommended for my setup. Pretty happy with the UOA's so far.

My tune is pretty much finished, I just haven't had the time to bring it in for a dyno session to get it finalized and lay down a number. It's nice and hot now, so if there's ever a time to do it's the most adverse, nothing worse than perfect condition power numbers you'll never see on the street lol. Would like to see ~680whp+ in the summer heat. Cam angle is one we will be dialing in on in that session. It's rough to remote tune. I have a spot in the desert on a lonely road where I do my WOT pulls, but I only go to the top of 3rd out there. Lonely roads aren't the smoothest and I get some wheel spin at the top which is more road issue than tire issue. Some day when I do my build thread, post-dyno session, VVT will be one of things I harp on.

As King said, sometimes that extra potential isn't worth the headache. I don't know what a few degrees of retard is worth NA, undoubtedly it would vary from build to build, I'd guess just a handful of ponies. Just be careful trying to do a Phaser Delete on a VVT Cam. There is a difference between a Phaser Delete and Phaser Lockout. There is advance built into the cam grind for the BTR220 cam, as it was intended to run with a Phaser and not a standard cam gear. You'll want to talk to your cam's manufacturer to clear what you should do if you want to lock out or delete. At least, that's what BTR says for their cams. May be worth trying stepping up in viscosity, see if your Phaser behaves better. Mine didn't have a problem swinging full range of the limiter, but it had a hard time staying aligned with commanded. Still does, but the higher range looks a lot better and fewer blips throughout the log.

[KingLT1]

I agree even though I would think a 220 cam would have enough PTV locked out with unmilled heads and stock gaskets. Not uncommon for cam shafts to have advance ground in. A lot of gen 3 and 4 LS cams have 4-5 degrees advance ground in them. Either way check first as mentioned above.

[GreyGhost702]

Originally Posted by KingLT1

I agree even though I would think a 220 cam would have enough PTV locked out with unmilled heads and stock gaskets. Not uncommon for cam shafts to have advance ground in. A lot of gen 3 and 4 LS cams have 4-5 degrees advance ground in them. Either way check first as mentioned above.

Locked out for sure. Deleted, I don't know. I think BTR said a delete would send them 8.5 degrees advance. That's kind of a lot, and a lot of top end range to give up. People refer to the 220 as the "baby" cam but it's got a lot of lift and fair amount of duration for a baby. I don't know enough about the G5 LT1 to know how much slack there is in PTV before enough is enough. At least the LT's have reliefs, I think previous Gens were dished?

[KingLT1]

NA LS car engines were flat tops. Would be curious to know how deleting would increase advance that far over a 0 degree lockout. I thought delete is a solid gear set for 0 degrees?

[6spdhyperblue]

Did you buy the revised phaser when you did the install?

But I thought less oil pressure is retarded and more oil pressure is advanced, so any “weakness” would let it ride on the btr limiter at 4*

Does it go to 0 when commanding 0?

[6spdhyperblue]

Originally Posted by KingLT1

NA LS car engines were flat tops. Would be curious to know how deleting would increase advance that far over a 0 degree lockout. I thought delete is a solid gear set for 0 degrees?

This is my understanding as well.

There is no advance the stock cam 0 to 30 or more retarded


The only way it was advanced is if it was ground in. Showing a “+8.5” after the lsa on the cam card. So 8.5 advanced when installed at “0”

[NA18CamaroSS]

Thanks for responding. Now I don't feel like the Lone Ranger. It is annoying that the limiter is not behaving as advertised, but at least it's not retarding past 4* and causing P-to-V issues. I guess that I could get a cam gear and another VVT limiter and haver my machinist buddy work his magic on the phase limiter and get the full 4*, but it seems like a lot of trouble for minimal gains.

[GreyGhost702]

Originally Posted by KingLT1

NA LS car engines were flat tops. Would be curious to know how deleting would increase advance that far over a 0 degree lockout. I thought delete is a solid gear set for 0 degrees?

I argued the same with BTR, I didn't understand where he was coming up with 8 degrees if the cam rests at 0 and can only retard 4 degrees. He fed me some non-car guy language about the difference between Valve Timing in the grind vs gear timing. My eyes glazed and I asked if I could just 0 the tables to get by until I decided on a different cam to run and he said that would be fine but I'd lose out on some top end.

Originally Posted by 6spdhyperblue

Did you buy the revised phaser when you did the install?

But I thought less oil pressure is retarded and more oil pressure is advanced, so any “weakness” would let it ride on the btr limiter at 4*

Does it go to 0 when commanding 0?

To your last question, yes and no. Under normal driving conditions, it held 0 degrees. With all the tables 0 we were still seeing + numbers under WOT conditions beyond ~3500rpm, it would bounce. Not like it was flopping around but it wasn't going where it was told.

As for what Phaser design, I didn't buy a new phaser. Because the cam came out of a '22+ car, I used a '22+ Phaser and new Cam bolt. I did lock the spring and check the Phaser to make sure the limiter block was installed in the correct pocket, just verifying the previous installers work. It was different from my '19 Phaser for sure. Wish I had documented it better. Since it came out of a '22, it's likely the "new design."

As far as how the phaser works, the phaser parks at 0 degrees in terms of cam gear timing. One can't say what 0 degrees is without knowing what the cam profile is in relation to valve timing in that position. Cam gear timing is timed to the crank. Valve Timing is different. Part of the advantage to being able to manipulate valve timing in relation to the crank.

In the case of the stock cam, we know what 0 is. I can only repeat what BTR told me when I asked about deleting the Cam Phaser completely with the 220 cam. I was told deleting the Phaser and using a standard cam gear would set the cam 8 degrees advanced. The dude on the phone was their Cam Engineer, not the sales guy, so I took his word for it. Though, I really don't comprehend it. Not sure why a standard cam gear would set a different timing event than a phaser locked out? Unless the cam gear's cam lock is a different degree than the Phaser's? I've degreed cams on a couple 4.6 Ford's running custom grinds. That was easier to understand than this, lol. I'd honestly like to have another conversation with BTR about it, because there's only 4 degrees of possible swing with the limiter installed, so I'm wondering if the cam has 8 degrees of advance in the grind, where does that put valve timing in relation to the crank with the phaser at 0 through 4 degrees? What kind of lies are we feeding the ECM? lol

In terms of oil pressure, it was more of a cause and effect. I went from having a lack of Phaser control with it bouncing around the full range, did an oil change, and then not having as much of a problem. It still jitters ~1 degree or so, but at least when we're asking for cam retard it's going that direction lol. Stays 0 where desired.

I know Phasers are actuated via oil flow control by the VVT Solenoid. To me, it makes sense that Oil Pressure is the strong arm behind the fluid. Hydraulic operation. With the more aggressive lift and duration working against the camshaft, including higher cylinder pressures when under boosted conditions, the higher viscosity oil and associated pressure give the VVT system a stronger control over the cam. Again, makes sense to me. Without being able to bench test or go through a series of oil changes decreasing and increasing viscosity, I couldn't come up with any other reason for the change in behavior. And I'd rather not subject the engine to lower viscosities Can't really bench test either, cause I'm just not independently wealthy lol.

[6spdhyperblue]

Yeah thinking about it again i made a big assumption increase in oil pressure in the solenoid brings it makes it retard but it could easily be the opposite

[7speed]

You need this

https://youtu.be/oTyq_Fdc5bY?si=xY3FqB_U6dHy_Osk

[Katech_Mike]

Originally Posted by KingLT1

I thought delete is a solid gear set for 0 degrees?

With the proper cover and modified gear it is. If you try to slap on a stock LS3 cam gear the timing will be off.

[GreyGhost702]

Originally Posted by Katech_Mike

With the proper cover and modified gear it is. If you try to slap on a stock LS3 cam gear the timing will be off.

That's what the BTR was talking about. Trying to recall a phone conversation from a year ago lol. BTR doesn't make a custom gear to delete the phaser for the 220 cam and a LS3 timing set would set the cam ~8.5 degrees advanced, and I swear he said there is advance already in the cam grind, so you'd have to do the math on valve timing. Either way, you'd be chopping off a nice chunk of top end range just to delete the phaser. Better to just run a cam spec designed for a phaser delete than try to force the 220 to bend to your will, LOL.

I still think OP should try to juice up the oil pressure a bit and see if the Phaser behaves better. Should be able to swap in some 15w50 if you can't get 5w50 locally. 15w50 is track spec. If it helps stabilize, then it's a good fix. If not, it could be a bad phaser perhaps. The spring should have enough tension to keep the phaser at rest, and the cam spins in favor of the direction of rest, if the cam is coming off "0" it's getting fed oil and/or the spring doesn't have enough tension to keep it at rest. Would have to compare datalogs with someone who has the BTR cam w/limiter and "not" having issues. See desired cam angle and actual cam angle on that log, in both normal driving and WOT conditions. I have a feeling most that are running the limiter see similar conditions with cam angle doing its best to maintain desired but it's not perfect. If someone can post a log showing desired and actual cam angle in lock-step with each other, then I guess I have a problem, too. LOL