HeavyIron Posted September 28, 2009 Report Share Posted September 28, 2009 I can't put into words how happy I was to pass the 1000 mile mark and push the throttle down only to have nasty misfires spil the fun above 16psi. My plugs were gapped right, but after a quick call to my personal Angel (you know who you are) I discovered that NGK R 6E plugs are too hot to run with high boost. So, I got a set of OEm Volvos and problem solved. Now on to the next issue. I got an MTE tune that is supposed to let my 19t run to 25psi, but I seem to have diffuculty holding anything over 19psi and have only spiked to 22psi once. AFR's are real solid at WOT ruuning between 10-11. Idle and part throttle are running 13.5 - 15. Could the boost fade be due to the stock actuator? Here is what I am running 19t, green injectors, walbro fuel pump, ipd intercooler, ipd HD tcv, MTE 25psi tune, new engine, etc... Link to comment Share on other sites More sharing options...
Chilled man Posted September 28, 2009 Report Share Posted September 28, 2009 LOL duh :lol: Link to comment Share on other sites More sharing options...
Dave 54 Posted September 28, 2009 Report Share Posted September 28, 2009 Most likely the stock actuator is the source of your issue. Has anyone hogged out the wastegate opening in these a bit.? I know when I was on the DSM scene(flame away) we would hog open the WG opening just enough that the flap would seal, think it was like a dime size hole hogged open to almot a nickel sized opeing, this really helped alot once I started running anything over 18psi with fade and creep. Link to comment Share on other sites More sharing options...
lookforjoe Posted September 28, 2009 Report Share Posted September 28, 2009 What RPM range are you hitting the highest boost? When I had the 19T in the following dyno run, I still had the stock CBV attached. you can see the trend... boost drops off as RPM/torque peaks, pretty normal (that tune was also not meant for a 19T) Are you using a BOV or did you put a CBV back on? What base pressure did you set the actuator rod for - it should be around 5psi before it begins to push.. Link to comment Share on other sites More sharing options...
Fake-R Posted September 28, 2009 Report Share Posted September 28, 2009 Check what was said. The stock actuator is not good for that PSI, and the CBV is most likely long gone at that high boost as well. Link to comment Share on other sites More sharing options...
HeavyIron Posted September 28, 2009 Author Report Share Posted September 28, 2009 Check what was said. The stock actuator is not good for that PSI, and the CBV is most likely long gone at that high boost as well. Running a beta test on IPD's new CBV diaphragm and it seems to be alot stronger than stock. Also I hear the wastegate closing between 4-5psi and looking at Husseins graph that pretty much mimicks my car except I cannot hold 20+ psi from 2700 - 4800rpm Link to comment Share on other sites More sharing options...
lookforjoe Posted September 28, 2009 Report Share Posted September 28, 2009 Running a beta test on IPD's new CBV diaphragm and it seems to be alot stronger than stock. Also I hear the wastegate closing between 4-5psi and looking at Husseins graph that pretty much mimicks my car except I cannot hold 20+ psi from 2700 - 4800rpm To check whether the actuator can hold 20+, temporarily install an MBC; that will eliminate the TCV & allow you to judge whether it will hold. Maybe you just need a better TCV (IPD or AC Delco, perhaps). It is true that you are moving to the extreme end of the actuator's range at that point. A 10psi actuator would make more sense. For my 20g, I went with a 15psi actuator, so that is the least pressure I can run, it just won't open below that. Link to comment Share on other sites More sharing options...
EricF Posted September 28, 2009 Report Share Posted September 28, 2009 The more preload you need to use to get your desired boost level, the more issues you will have with boost fade. Try what Hussein says, get a higher pressure wastegate actuator. I think a shorter travel actuator for a Garrett turbo could be a good idea too. I had some issues at those boost levels with my 19T as well, the bottom line is that they are just flat out difficult to control. In my blue car, I have the wastegate flapper wired shut and it's spiking 25 psi and fading to 19 or so. Not really sure I should ever mention that car in a thread trying to explain something though as it only serves to confuse Try a higher pressure actuator with lower travel, see where that takes you. Link to comment Share on other sites More sharing options...
dublin14 Posted September 29, 2009 Report Share Posted September 29, 2009 Running a beta test on IPD's new CBV diaphragm and it seems to be alot stronger than stock. Also I hear the wastegate closing between 4-5psi and looking at Husseins graph that pretty much mimicks my car except I cannot hold 20+ psi from 2700 - 4800rpm For what its worth, i bought a 14psi CBV spring from Lucky at IPD. The stock spring is 8psi. Noticed a difference straight away. I think he had a bunch custom made? Link to comment Share on other sites More sharing options...
Black Betty Posted September 29, 2009 Report Share Posted September 29, 2009 Not to thread jack but huessin, do you have beefed internals? If not I thought even a few pounds of boost at the low rpms put the stock rods in jeopordy? Link to comment Share on other sites More sharing options...
HeavyIron Posted September 29, 2009 Author Report Share Posted September 29, 2009 Not to thread jack but huessin, do you have beefed internals? If not I thought even a few pounds of boost at the low rpms put the stock rods in jeopordy? True that is why both of us have forged rods, and he has forged pistons too To check whether the actuator can hold 20+, temporarily install an MBC; that will eliminate the TCV & allow you to judge whether it will hold. Maybe you just need a better TCV (IPD or AC Delco, perhaps). It is true that you are moving to the extreme end of the actuator's range at that point. A 10psi actuator would make more sense. For my 20g, I went with a 15psi actuator, so that is the least pressure I can run, it just won't open below that. I already have the IPD TCV, but I do have a queestion about the higher pressure actuators. How does it affect drivability if they do not open until 10 or 15psi? For what its worth, i bought a 14psi CBV spring from Lucky at IPD. The stock spring is 8psi. Noticed a difference straight away. I think he had a bunch custom made? I will have to call Lucky after he gets back from Vacation. Link to comment Share on other sites More sharing options...
lookforjoe Posted September 29, 2009 Report Share Posted September 29, 2009 True that is why both of us have forged rods, and he has forged pistons too I already have the IPD TCV, but I do have a queestion about the higher pressure actuators. How does it affect drivability if they do not open until 10 or 15psi? Just H-Beam rods, not forged. The pistons are Mahle OS1, nothing special/custom. Having a higher pressure actuator makes no difference to drivability until you get on the fast pedal It won't affect normal driving in any way shape or form; it simply prevents boost fade due to the actuator failing to hold your preset boost. Link to comment Share on other sites More sharing options...
EricF Posted September 29, 2009 Report Share Posted September 29, 2009 If not I thought even a few pounds of boost at the low rpms put the stock rods in jeopordy? This is not correct... The rapid onset of boost at low RPM levels is dangerous, just because it happens so quickly and a lean spot or too much timing at or just before the torque peak is very dangerous. A few pounds of boost at low RPMs is normal and pretty much required for an acceptable level of part throttle performance. Link to comment Share on other sites More sharing options...
Black Betty Posted September 29, 2009 Report Share Posted September 29, 2009 This is not correct... The rapid onset of boost at low RPM levels is dangerous, just because it happens so quickly and a lean spot or too much timing at or just before the torque peak is very dangerous. A few pounds of boost at low RPMs is normal and pretty much required for an acceptable level of part throttle performance. hmm well that still means I need a pyrometer. Link to comment Share on other sites More sharing options...
850 LongBeach Posted September 29, 2009 Report Share Posted September 29, 2009 This is not correct... The rapid onset of boost at low RPM levels is dangerous, just because it happens so quickly and a lean spot or too much timing at or just before the torque peak is very dangerous. A few pounds of boost at low RPMs is normal and pretty much required for an acceptable level of part throttle performance. pretty much keep it under 1 bar (15psi) before 3k RPM's if you want to save your rods Im on stock rods, stock injectors, 19t with an EBC I hit 19psi at 3200rpm's and it drops to 17 psi with 1-2 psi spikes within shifts AF/R's are in 10-11.5 There are many determining factors as well in bending rods, but the number 1 cause is to high of boost at Low rpms.. please dont exaggerate it 850 whiteblocks are actually pretty beefy Keep your motor in good maintenance and proper stage zero, you should be able to hit 19-20 psi on a 18t-19t turbo without problems as long as you watch your gauges ;D Link to comment Share on other sites More sharing options...
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