Help tuner says mechanical problems and engine builder says nothing is wrong
10-16-2018, 01:01 AM
#41
Those springs are pretty terrible vs newer stuff. esp the heavier locks. Add an aggressive lobe and its first train to out of control city.
If you need any components to freshen up your build after youve diagnosed it, keep us in mind. hate to see builds go bad snd then tossed in the corner because you lose interest or motivation.
If you need any components to freshen up your build after youve diagnosed it, keep us in mind. hate to see builds go bad snd then tossed in the corner because you lose interest or motivation.
10-16-2018, 02:36 AM
#42
So far things went okay until 9psi was made getting on the highway to go to the test spot. I kept blowing a pipe off so i am going to have to get that issue solved before I test 12psi. Rolled into and it pulled up until that moment. Battery and fuse box voltage was between 14-16 volts didn't get the alternator voltage as i derped and let the engine get hot before hooking up the leads. The meth kit light came on but I didn't get a change to record the process.
10-16-2018, 09:57 AM
#43
Your graphs still don't show A/F ratios so I have no idea what it was reporting, but those graphs you posted are text book valve float especially on a turbo setup. I don't care if the valve springs have 2 miles on them, shim them up towards the safety margin of their rated coil bind or use better valve springs. I've found most rear mount turbo setups are even worse since they typically use a smaller turbo to compensate for their lag and therefore induce more hotside back pressure which tends to hang the valves without adequate seat pressure, etc. Reading your signature you have a 6.0L engine, a relatively large cam with somewhat aggressive unforgiving lobes, a small TC78 rear mount and those usually have an F1-68 turbine wheel, needless to say it's very restrictive and is going to produce a ton of hotside back pressure.
10-19-2018, 01:44 AM
#45
Your graphs still don't show A/F ratios so I have no idea what it was reporting, but those graphs you posted are text book valve float especially on a turbo setup. I don't care if the valve springs have 2 miles on them, shim them up towards the safety margin of their rated coil bind or use better valve springs. I've found most rear mount turbo setups are even worse since they typically use a smaller turbo to compensate for their lag and therefore induce more hotside back pressure which tends to hang the valves without adequate seat pressure, etc. Reading your signature you have a 6.0L engine, a relatively large cam with somewhat aggressive unforgiving lobes, a small TC78 rear mount and those usually have an F1-68 turbine wheel, needless to say it's very restrictive and is going to produce a ton of hotside back pressure.
tell me about it. The car at most sees more warm up time than driving.
10-19-2018, 11:00 AM
#47
stair stepping power not attributable to anything like spinning/bouncing the tires on the roller
also the AFR will go rich as unburnt hydrocarbon displaces oxygen in the exhaust
if you go again to the dyno, don't leave until you can get and AFR trace sync'd with the power numbers. the power output only tells half the story.
also the AFR will go rich as unburnt hydrocarbon displaces oxygen in the exhaust
if you go again to the dyno, don't leave until you can get and AFR trace sync'd with the power numbers. the power output only tells half the story.
10-25-2018, 12:43 AM
#48
stair stepping power not attributable to anything like spinning/bouncing the tires on the roller
also the AFR will go rich as unburnt hydrocarbon displaces oxygen in the exhaust
if you go again to the dyno, don't leave until you can get and AFR trace sync'd with the power numbers. the power output only tells half the story.
also the AFR will go rich as unburnt hydrocarbon displaces oxygen in the exhaust
if you go again to the dyno, don't leave until you can get and AFR trace sync'd with the power numbers. the power output only tells half the story.
Could small fluctuations in boost make the dyno wavy also? I was given that as a possible reason.
Also when pulling the valve springs can I do like the intake bolts and put rubber bands or magnets on the valves to hold them up while I go to another cylinder (going to be holding them up with air)?
Right now just trying to find all things wrong before I start spending money because if I have to pull it apart I would like to upgrade more things in there as I go along.
10-25-2018, 09:07 AM
#49
so the only notice I have seen with valve float is just a change in sound. the car just lays down even as the revs increase. no misfiring or jerkyness.
why is the wideband pre turbo? widebands do not like boost pressure at all.
and 10.0 afr is like a coughing, barely running too rich. target should be at least 11.0
why is the wideband pre turbo? widebands do not like boost pressure at all.
and 10.0 afr is like a coughing, barely running too rich. target should be at least 11.0
10-25-2018, 11:08 AM
#50
so the only notice I have seen with valve float is just a change in sound. the car just lays down even as the revs increase. no misfiring or jerkyness.
why is the wideband pre turbo? widebands do not like boost pressure at all.
and 10.0 afr is like a coughing, barely running too rich. target should be at least 11.0
why is the wideband pre turbo? widebands do not like boost pressure at all.
and 10.0 afr is like a coughing, barely running too rich. target should be at least 11.0
for future references. At the time when I was getting the pipes, engine and trans done I left it to the mechanics and didn't know myself. I just bought it and learned my lesson on other things so I don't do that anymore.
I think he was trying to change the afr to see if there was any changes but with the injector tables being the way they are I am not sure what exact target they were hitting.
10-28-2018, 01:24 AM
#52
so the only notice I have seen with valve float is just a change in sound. the car just lays down even as the revs increase. no misfiring or jerkyness.
why is the wideband pre turbo? widebands do not like boost pressure at all.
and 10.0 afr is like a coughing, barely running too rich. target should be at least 11.0
why is the wideband pre turbo? widebands do not like boost pressure at all.
and 10.0 afr is like a coughing, barely running too rich. target should be at least 11.0
10-29-2018, 10:51 AM
#53
Yes pressure skews the reading but you can calculate by how much if you know what the actual measured hot side back pressure is and the sensor type since it's manufacturer published information. Doesn't mean you should have it in the pressure side, just that you can figure it out. The one thing that is known though is that it will cause the sensor to read farther from 14.7 in either direction, meaning as the pressure rises rich values get richer and lean readings get leaner. If it's down into the 10s under boost it's actually probably up in the 11s with a lot of hot side back pressure.
10-29-2018, 10:54 AM
#54
I appreciate the info you are putting out and the suggestions as I have been searching around with no concrete info before this thread. BTW what makes the graphs text book valve float? Are there other conditions that mimic valve float on a dyno graph? As of right now the car is parked and waiting for parts and tools to come in so i can check the springs.
10-29-2018, 07:40 PM
#55
Check the springs, shim the springs to within the acceptable limit of coil bind, throw it back on the dyno and see if there is any change. It's the easiest and cheapest thing you can do to try to fix it and that's probably all it needs. Continuing to guess on the internet isn't going to fix it any sooner.
10-30-2018, 10:21 AM
#56
I wasn't just putting possibilities out there for future reference and if anyone else is trying to diagnose funny stuff going on with their cars or if they don't have a dyno sheet to know if they have valve float. Shoot I noticed in the clips my fuel pressure getting kinda high and coupled with some problem spots with the tune had me guessing if there could be more going on. Shoot I was even told that the small fluctuations in the boost was the cause. The earliest time I can get it on the dyno is Dec because of football and travelling so I have a bit of time to get rid of all what ifs.
10-30-2018, 03:51 PM
#57
I'm just saying, somebody said you've been having problems for 8 years and one of the first things I would have done would have been to check and shim the valve springs to get their seat pressure up simply knowing how restrictive that turbo is on the exhaust side. I've seen this more times than I can count on very restrictive turbo setups with weak valve springs, etc and any competent shop would take a couple of hours and make sure the seat pressure is up there as well as one of the very first troubleshooting steps with the way that graph looks. Of course there could still be a problem elsewhere but there isn't much that can cause the issues you are having besides a spark issue or valve float and those happen to be the two easiest and quickest things to change.
Last edited by The Fugitive; 10-30-2018 at 03:56 PM. Reason: making the ar clear that it has been on and not laying around
11-22-2018, 09:33 PM
#58
So a quick update before checking the springs. Had the WBO2 moved to post turbo and found that the car was super lean @5000rpm the afr was at 13 and climbing. Tuner added fuel so now it is down to a 11.3 afr car was smooth and still felt strong.