COUPLE ISSUES- LOCKED CAM ESS SETUP

[BreckinHardin]

Hey gents, I got a bit of stuff going on. Finally got the car wrapped up and tested today, not happy with results.
2020 5.0 MT82D4 ESS G3x, 105MM, saw peak 16.7 lbs of boost consistent 16.2/Veng stage 3/MGW x/braided line/trans mount/4.11 gear/WOT box/Hoosier QTP & skinnies.

I listed several mods, gonna talk about a few things.
The big thing that’s killing me was the lockout. Not sure why I’m getting locked unless I got a bad clutch/trans.. but doesn’t seem to be likely. I should have a proper setup to be banging gears but it just won’t let me. I had some luck on the street, I’m wondering if it’s high RPM related (trying to NLS at about 8-8200) clutch has 4K miles.. these clutches get a lot of praise so I don’t want to think it’s the clutch.

Brakes. So my line lock wouldn’t work today, we absolutely could not press the brake firm enough. We also got a couple brake error warnings at idle, cleared up when driving down the road. Leads us to believe it’s brake booster/vacuum issue. Due to the cams. Stock cam/VCT read -17 roughly at idle vacuum, now I’m seeing about -3.7 at idle.. we think this is causing brake performance issues. We have no clue where to start. We found this today. All of these issues.

Car would not hook. We finally got it hook up a little, cutting a 1.56. Sure I could use some better front suspension. Maybe a little more tuning on the Viking rears. Running crusader double adjustable. The last pass we hit a 1.56 60, but still spun through 1st. Launching at 7k off two step. Compression 10 rebound 14 was the last pass we did and it seemed to be drastically better than previous testing. But man, we’re getting close to maxing it out. Could shocks be bad? Or do I truly need to max them out? I know more goes into the 60 than the shocks, but hell I figured id hop on here and pick yalls brain for some stick 60ft advice. BMR drag springs also.

This is the worst part. When I shift into 4th, the car falls flat on its face. 2nd is nasty. 3rd feels fast. 4th feels like a Honda civic. And not a laptop civic! Lol. Buddies and I are leaning towards valve float.. we have no data to back it yet. I’ve spoken to others that have locked cams and do not have the same issue. I may have been misinformed slightly when I was told my stock springs would be fine with custom locked cams… so that’s where we’re leaning. Just sucks at this point since the cam jobs already done and now I’m looking at replacing springs. RIP.

Sorry this is a lot. I’m sure I’m missing some critical info. If you took the time to read through this essay, I appreciate it. Thank you all for any info that can help me solve these issues.

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[RNM]

Who is your tuner?

 

[BreckinHardin]

Wengerd Performance. Pretty confident it’s nothing tune related

 

[Wolfys11]

Wengerd Performance. Pretty confident it’s nothing tune related

Valve float wouldnt explain the brake issues, its possible your vacuum lines could be not hooked up correctly/ have a leak? If you have new lines to clean up the oem lines, make sure you have the right setup for “vacuum only” and “vacuum/boost” lines

im not too familiar with swapped cams nor locked cams, however my buddy is running a 95mm pully stock cams and doesnt have any high rpm (8000) issues with valve float, car runs perfectly fine. However its entirely possible the cams change that

 

[gcadorette13]

Valve float wouldnt explain the brake issues, its possible your vacuum lines could be not hooked up correctly/ have a leak? If you have new lines to clean up the oem lines, make sure you have the right setup for “vacuum only” and “vacuum/boost” lines

im not too familiar with swapped cams nor locked cams, however my buddy is running a 95mm pully stock cams and doesnt have any high rpm (8000) issues with valve float, car runs perfectly fine. However its entirely possible the cams change that

He has a dedicated vacuum block and the brake booster sees vacuum directly from the manifold not the block. If this thing had VCT I don't think we'd be struggling with most of these issues.

It seems that these cams are too aggressive for the stock springs even tho the guy that spec'd them out swears stock springs are fine.

 

[K4fxd]

If the valves are floating they will float in every gear and almost always at the top of the RPM band. Being boosted could throw a monkey wrench into this. Try reducing boost and see if it runs better in 4th.

 

[gcadorette13]

If the valves are floating they will float in every gear and almost always at the top of the RPM band. Being boosted could throw a monkey wrench into this. Try reducing boost and see if it runs better in 4th.

We'll give that a shot a see if it helps at all.

 

[robvas]

Is it just the RPM drop going from 3rd to 4th?

 

[gcadorette13]

Is it just the RPM drop going from 3rd to 4th?

The 3-4 RPM drop is a lot but even after the shift at 5800-5900RPM he said the car looses all power pretty much. Looking at logs, everything tune related seems to be fine. Timing is good and the boost is there as well. Based off of some dragy hits the car is significantly slow after that 3-4 shift.

 

[80FoxCoupe]

Racing a stick shift car is complex. Just have to tackle one issue at a time and don't get overwhelmed trying to solve multiple issues at once. Why lockout the cams? I don't see the need for it with what you listed. On your rpm drop into 4th, what kind of power does the car make at the recovery rpm? Post dyno graph.

 

[gcadorette13]

Racing a stick shift car is complex. Just have to tackle one issue at a time and don't get overwhelmed trying to solve multiple issues at once. Why lockout the cams? I don't see the need for it with what you listed. On your rpm drop into 4th, what kind of power does the car make at the recovery rpm? Post dyno graph.

The car should be getting dyno'd on Thursday. He spent prob $10K+ in diagnosing a P0340 code and pretty much gave up and locked the cams out to take the phasers out of the equation.

 

[engineermike]

Trying to help diagnose this, been going back and forth by e-mail and exchanging information with OP. At first I thought it was just a poorly matched combo of a wide-ratio MT82, aggressive cams, and a centrif blower that doesn't make much low/mid rpm boost. However, while that all may be partly true, I've learned there are some real issues.

- I'm nearly certain the issue isn't due to valve float. Nothing in the data logs points to that, he's not spinning past 8000 rpm, and while the cam duration is long, the lift isn't that high.
- The cams are 240/250 deg at .050 which are quite aggressive. They are set to "5/30", which is a high rpm setting for the intake cam plus they are locked there. I believe it could gain some low/mid rpm torque if the intake cam were advanced as much as possible, but this will exacerbate the vacuum situation. Anyway, the combination of the high duration, late intake cam timing, and centrif boost curve results in an engine load that doesn't exceed 1.0 until 4200 rpm and takes until 6200 rpm to reach 1.8 load. After shifts, the load is dropping below 1.4.
- The injector pulsewidth is my biggest concern on this car. For reasons not currently understood, there is a massive spread in the pulsewidths for the various injectors. Math says that cyl 4 is running at 1.6 lambda while 1, 2, and 5 are at 0.6 lambda. This explains some earlier mis-fire codes logged on #4. The problem doesn't really show up until about 5400 rpm. The cursor in the attached graph is at 6350 rpm and you can see a >10:1 ipw discrepancy. You don't typically see more than 10% difference from one cylinder to the next so there is definitely an issue here.

The good news is we've found a smoking gun. The bad news is, this is a very unique issue that few seems to have answers for.

Personally, I'd go after this injector PW issue first. Once resolved, if VCT is to remain disabled I would install a set of stock cams and set them around 0/15 or possibly 10/15. This will help with idle and mid-range torque, vacuum, plus we know they work with the stock valvesprings. The car will scream once this is done.

 

[K4fxd]

First thing I'd do is pull the injectors and send them out to get tested. Looks like a few are not able to shut fuel off at high duty cycles.

I think Banish still tests injectors.

 

[BreckinHardin]

First thing I'd do is pull the injectors and send them out to get tested. Looks like a few are not able to shut fuel off at high duty cycles.

I think Banish still tests injectors.

injectors are brandddddd new but ofc I know it’s possible to be bad out of the box.

 

[engineermike]

I’m just not seeing how a bad injector(s) could cause this. The pcm would have to sense something is wrong and change the commanded ipw as a response. I just don’t know how the pcm would sense individual bad injectors. I know it can sense individual cylinder knock and misfires but not individual bad injectors, unless it’s somehow sensing differences in impedance and adjusting for that, but I’ve not seen anything in gen3 diagnostic info that would indicate it’s doing that. I’ll look a little more into this later.

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