Wastegate routing?

[warmonger]

Looks more like tuning to me. Torque rises smoothly to about 320ft-lbs, then falls off jaggedly, then towards the end of the rpm range it jumps back up to where it "should" be. It looks like a spark issue, perhaps indicating too much timing being pulled while in the midrange rpm.
If you aren't getting any misfires I mean. If the power still feels smooth and no surging in the midrange, then I'd surely look to adjust my timing.

This also makes the assumption that you don't have too much timing because that would probably break a piston or rod. Therefore it looks like the timing is being pulled too drastically for some reason.
Perhaps by the tune due to a knock sensor, intake temps, or another reason. It doesn't make sense that it can just bump back up by 50ft-lbs of torque at precisely 6500rpm. It seems the PCM is getting a false indication or the tuner pulled too much automatically.
If the timing was being pulled for one of these reasons, since intake temps will still be rising then it wouldn't suddenly be able to safely jump up by that 50 ft-lbs. Now possibly it could with the knock sensor but that raises doubts in my mind.

If I recall, the knock sensor pulls timing in the low range from maybe 1500-5000 or so where sometime above there it is disabled automatically by the PCM. This is because there are too many false 'noises' in the engine that would falsely trigger it at higher rpms. It is really only useful and only used in the low rpm ranges. Might be you have a sensitive one, or the wrong one and when the RPMs climb the PCM is turning it off, which stops timing being pulled and the engine goes back up towards smoother performance. That would also explain the jagged nature of the curve. If it is giving you grief you can shut it off in the tune and go with experience on how much timing to run at those RPMs.

Anyway, that last little bump in the power tells me that it isn't a boost leak or a wastegate issue becuase that suddenly doesn't get better as the turbo is blowing max air at max rpm.

Oh, and I ate, breathed, and slept car stuff growing up so it just sort of stuck in there and I built upon it. lol

Thank you Tom, I meen damn dude where do you keep all that knowledge, do you have a storage shed in your mind:laugh:

But I think I may have the same problem that Brapple has as well. You tell me by my dyno chart Tom. This was with the old rfl that was leaking. I dont know what spring is in the wastegate.

 

[ryanblacksvt]

Looks more like tuning to me. Torque rises smoothly to about 320ft-lbs, then falls off jaggedly, then towards the end of the rpm range it jumps back up to where it "should" be. It looks like a spark issue, perhaps indicating too much timing being pulled while in the midrange rpm.
If you aren't getting any misfires I mean. If the power still feels smooth and no surging in the midrange, then I'd surely look to adjust my timing.

This also makes the assumption that you don't have too much timing because that would probably break a piston or rod. Therefore it looks like the timing is being pulled too drastically for some reason.
Perhaps by the tune due to a knock sensor, intake temps, or another reason. It doesn't make sense that it can just bump back up by 50ft-lbs of torque at precisely 6500rpm. It seems the PCM is getting a false indication or the tuner pulled too much automatically.
If the timing was being pulled for one of these reasons, since intake temps will still be rising then it wouldn't suddenly be able to safely jump up by that 50 ft-lbs. Now possibly it could with the knock sensor but that raises doubts in my mind.

If I recall, the knock sensor pulls timing in the low range from maybe 1500-5000 or so where sometime above there it is disabled automatically by the PCM. This is because there are too many false 'noises' in the engine that would falsely trigger it at higher rpms. It is really only useful and only used in the low rpm ranges. Might be you have a sensitive one, or the wrong one and when the RPMs climb the PCM is turning it off, which stops timing being pulled and the engine goes back up towards smoother performance. That would also explain the jagged nature of the curve. If it is giving you grief you can shut it off in the tune and go with experience on how much timing to run at those RPMs.

Anyway, that last little bump in the power tells me that it isn't a boost leak or a wastegate issue becuase that suddenly doesn't get better as the turbo is blowing max air at max rpm.

Oh, and I ate, breathed, and slept car stuff growing up so it just sort of stuck in there and I built upon it. lol

DAMN our the man Tom. I will be needing you to tweak it then for me when we can get the time.

 

[BrApple]

Yes, that looks like what mine was doing. I hit 350wHP on mine and that was with a 13psi spike at about 4000rpm then dropping down to 9-10psi as it pushed through 4800rpm or so and then stayed the same. So the more I cranked the manual controller the torque would rise in the 4000rpm range then always fall right back down to what 9psi would give me. Still good enough for 350 wheels though.

good to know, thanks. Just gives me more reason to get the 8 psi spring back in the wastegate instead of using the 3 psi spring and mbc to get to 8 psi.

 

[TRicker]

ryan's problem could also be too much timing and the pcm pulling timing on its own?

i'm not familliar with tuning at all just wondering

 

[Barge]

Pressure on the bottom opens the wastegate

Pressure on the top holds the wastegate closed

Just picture a valve with a little plate on the end with air pushing it one way or the other.

 

[ryanblacksvt]

Hey Tom here is something to look at, this is odd imo. This first one is at low boost 8psi and then the one below is same as posted earlier at 14psi. The power curve looks alot smoother at 8psi, I am wondering why it only drops down on the 14psi boost

8psi

14psi

 

[warmonger]

Hey Tom here is something to look at, this is odd imo. This first one is at low boost 8psi and then the one below is same as posted earlier at 14psi. The power curve looks alot smoother at 8psi, I am wondering why it only drops down on the 14psi boost

8psi


14psi

Well I think it is the same reason I listed before. That tune looks fine at 8 psi but when you crank the boost it is probably pulling timing. A lot of the timing is controlled by the load the engine sees, that is calculated off the MAF values. So that means at higher load it is pulling even more timing, disproportionately more than it needs. So either the load values are a bit off, or you are moving a lot of air and it just was never set up for that much of a load.

A lot of tuners only set up the tables for about 140% or so and don't continue to tune for higher levels. When you hit that level then the tune just defaults to max load levels and it will pull all the timing it thinks it needs to pull for 200% or so max load. That is probably why it is so drastic, like a switch as you crank up the boost.

 

[ryanblacksvt]

Well I think it is the same reason I listed before. That tune looks fine at 8 psi but when you crank the boost it is probably pulling timing. A lot of the timing is controlled by the load the engine sees, that is calculated off the MAF values. So that means at higher load it is pulling even more timing, disproportionately more than it needs. So either the load values are a bit off, or you are moving a lot of air and it just was never set up for that much of a load.

A lot of tuners only set up the tables for about 140% or so and don't continue to tune for higher levels. When you hit that level then the tune just defaults to max load levels and it will pull all the timing it thinks it needs to pull for 200% or so max load. That is probably why it is so drastic, like a switch as you crank up the boost.

Ohhhhh ok I didnt know that I am a young padawon learner:laugh: See thats why I need you to tune it Tom