B00STDZ Posted June 17, 2009 Share Posted June 17, 2009 Ran into what I think will produce a problem. I have the AEM tru boost controller gauge. Have been test driving it and set boost at 12 psi. Well even though the boost guage claims it is set at max boost of 12 psi, on WOT it pushes 15 psi. 15 psi on a stock engine and stock ecu/injectors/EVERYTHING. From reading some have said 12 is the max? How is this STOCK t3 turbo pushing 15 psi? The tru boost obviously isnt montoring it?... Quote Link to comment Share on other sites More sharing options...
skib Posted June 17, 2009 Share Posted June 17, 2009 stock turbo can push 15psi and above, its just not efficient psi, its just pretty much pushing hot air at that point. Quote Link to comment Share on other sites More sharing options...
B00STDZ Posted June 17, 2009 Author Share Posted June 17, 2009 So its pushing an "inefficient" 15 psi? Quote Link to comment Share on other sites More sharing options...
jc052685 Posted June 17, 2009 Share Posted June 17, 2009 I pushed 20psi on my stock turbo... Quote Link to comment Share on other sites More sharing options...
skib Posted June 17, 2009 Share Posted June 17, 2009 I wouldnt say that 15psi is inefficient, when you start getting past that your just blowing hot air on the stocker (in general). thats my opinion based on what Iv experienced anyway. Quote Link to comment Share on other sites More sharing options...
Challenger Posted June 17, 2009 Share Posted June 17, 2009 Is it spiking or just peaking and holding? Did you pay like $300+ for your controller? Quote Link to comment Share on other sites More sharing options...
B00STDZ Posted June 17, 2009 Author Share Posted June 17, 2009 Is it spiking or just peaking and holding? Did you pay like $300+ for your controller? It is peaking and holding at 14.4 psi usually, but has seen 15 psi once or twice. And yes, it is the expensive digital boost controller guage aem sells that im using... Quote Link to comment Share on other sites More sharing options...
B00STDZ Posted June 17, 2009 Author Share Posted June 17, 2009 I pushed 20psi on my stock turbo... On stock electronics?! The only thing I have added to a completely stock l28et is an intercooler and a BOV... Quote Link to comment Share on other sites More sharing options...
Challenger Posted June 17, 2009 Share Posted June 17, 2009 Yeah, I know a guy in town and he said he was at 18psi with alot of bandaid fixes, rrfpr, larger injectors, messing with the afm/head temp sensor, etc. He said it "♥♥♥♥♥♥♥ fast till it blew." Quote Link to comment Share on other sites More sharing options...
B00STDZ Posted June 17, 2009 Author Share Posted June 17, 2009 Thats the thing... I have stock injecters and the stock fuel rail... Quote Link to comment Share on other sites More sharing options...
DeleriousZ Posted June 17, 2009 Share Posted June 17, 2009 turbo's can push up to whatever boost pressure the engine can handle usually, it's rare to max a turbo's maximum pressure before blowing something in the engine. remember a turbocharged engine can act like a compounding air compressor. the more exhaust that comes out of the engine, the faster the turbo spins, the more air goes into the engine, rinse and repeat. Turbo's can only flow so much air in terms of cfm, the same goes for maximum pressure until something fails in the turbo. However by this point the engine has more than likely ran out of fuel to compensate for the extra airflow and/or combustion chamber pressure has become higher than the mechanical parts can handle. then, pop goes the weasel. Are you sure you have the controller hooked up right? Why is it set to 14.4 if people recommend 12? The stock wastegate is controlled by a preset spring pressure, not the ecu, unless I'm greatly mistaken. Every system on a mass production car I've personally experienced don't use the ecu to aid in regulating boost pressure. Assuming you're using the s130 gear, I imagine it couldn't be any more 'advanced' than the z31 stuff. Now then, it's far past my bedtime and I probably spewed a wad of text nobody can understand due to its incoherant mass of random words, lol. Quote Link to comment Share on other sites More sharing options...
wigenOut-S30 Posted June 17, 2009 Share Posted June 17, 2009 Yeah I used to run the stock T3 turbo at around 15-17psi. Although it killed the turbo and really doesnt do anything but move a bunch of hot air passed 15psi. (this was with MS&S, Front mount IC and 440CC injectors). It sounds like you either have something hooked up wrong on the boost controller or maybe your gain is up too high. I would double check the installation as well as go over all the settings. Do not run anything over 12psi on your stock ECU/injectors and fuel pump. Do you have a wideband on that gauge as well? If not.. I really suggest getting one so you know what your looking at there as far as A/F.. Quote Link to comment Share on other sites More sharing options...
B00STDZ Posted June 17, 2009 Author Share Posted June 17, 2009 I have an o2 sensor but not a wideband... So the turbo can push 15 psi, now I'm trying to figure out how it is doing it on stock electronics, because if I understand correctly, the stock ecu cant manage high boost (10+ psi), also how does the stock AFM meter 15 psi? Quote Link to comment Share on other sites More sharing options...
B00STDZ Posted June 17, 2009 Author Share Posted June 17, 2009 Are you sure you have the controller hooked up right? Why is it set to 14.4 if people recommend 12? Thats the thing... the controller is set at 12 but yet it still pushes 14.4. I have checked what the controller is set at numerous times and it still says 12, and if i set it back to 10 psi it still pushes 14.4. Quote Link to comment Share on other sites More sharing options...
wigenOut-S30 Posted June 17, 2009 Share Posted June 17, 2009 The stock electronics does not read boost at all. it is a very simple system.. It only sees the AFM wide open and just throws as much fuel down as it can.. I would not do ANY more pulls at that boost level unless you want to rebuild your motor. where are you getting your boost signal from going to your gauge? also .. I wouldnt even push 12psi without a wide band.. that should be first on your list...Turn the boost controller off until you get that wideband.. Once you get the wideband.. turn the controller all the way down as far as it will go and work your way up in boost from there.. EDIT.. to add I would start off here on the AEM site on if something is not working right with the controller. It sounds like either something is hooked up wrong or not working right.. http://forum.aempower.com/forum/index.php Quote Link to comment Share on other sites More sharing options...
drift_inertia Posted June 17, 2009 Share Posted June 17, 2009 (edited) I have an o2 sensor but not a wideband... So the turbo can push 15 psi, now I'm trying to figure out how it is doing it on stock electronics, because if I understand correctly, the stock ecu cant manage high boost (10+ psi), also how does the stock AFM meter 15 psi? "IF" I am understanding you right in this post, you are wondering how you stock ecu and electronics are registering and " putting out " 15 psi of boost. Your ecu and electronics dont "put out" any boost period, they just add more fuel, timing advance/retard, etc. Your boost should be regulated by your wastegate and boost controller, if you are using a mechanical boost controller ( simple turnable valve ) or an electronic boost control, it simply opens or closes a valve aloowing more or less vacuum to the turbo's wastegate diaphragm. the wastegate controls how much positive pressure (boost) is actually directed into the motor versus being sent into the exhaust stream. It sounds like your wastegate may be he issue. If it was me i would use a vacuum pump to check the wastegate and make sure it is functioning properly and isn't clogged and the seal is still good. that would cause a variation in what you SHOULD be boosting versus what you ARE boosting. Also as Skib pointed out, all turbo's have a certain effeciency range where the compresser and housing trim's and a/r 's will work best and produce clean boost (with highly dense charge air), compared to producing hot (less dense air) ineffeciant boost. clean boost ='s more tightly packed air molecules ='s more power at less boost and easier to compensate for. dirty boost ='s hot loose packed molecules, very minimal if any power gains, harder to compensatse for due to excess heat . this may have turned to rambling but i know there is some usefull info in it, hope it helps a little, Matt p.s. if you want to drive your car safely while you work out the problem just drop your boost with your controller 2 or 3 pounds and then the max you SHOULD hit would be ner your desired 12 pounds. Edited June 17, 2009 by drift_inertia added a p.s. Quote Link to comment Share on other sites More sharing options...
B00STDZ Posted June 17, 2009 Author Share Posted June 17, 2009 I realise the ecu doesnt control boost, have stock electronics though, wouldn't it cause the engine to run lean? I dont think stock 280zxt injectors are made to flow enough for 15 psi? That being said I do have supra injectors, polished n42 intake, JSK fuel rail, and a 60mm 240sx throttle body ready to be installed. Quote Link to comment Share on other sites More sharing options...
drift_inertia Posted June 17, 2009 Share Posted June 17, 2009 if you truly are boosting 15 psi, then yes your probably are running on the lean side, but being lean doesnt always mean you will detonate. timing, and heat come into play with detonation also. you may just be ( safely lean ) where you haven't started to ping yet. maybe you have really good octane gas in the car or just havent hit a real hot day where you live and you've lucked out to this point. do you know anyone with a spare boost gauge to hook up and see if yours is reading right? 15 psi of boost is hi for stock injectors and stock fpr, with an aftermaarket fpr you may be able to squeeze it out though? just my 2 cents Quote Link to comment Share on other sites More sharing options...
wigenOut-S30 Posted June 17, 2009 Share Posted June 17, 2009 I realise the ecu doesnt control boost, have stock electronics though, wouldn't it cause the engine to run lean? I dont think stock 280zxt injectors are made to flow enough for 15 psi? That being said I do have supra injectors, polished n42 intake, JSK fuel rail, and a 60mm 240sx throttle body ready to be installed. Yes you will be lean for sure. But since you do not have a wideband to monitor A/F you cant see just how lean you are running. Quote Link to comment Share on other sites More sharing options...
B00STDZ Posted June 17, 2009 Author Share Posted June 17, 2009 This is starting to make sense... In the past when I have been test driving it, after it had ran alittle while it kept getting hotter and hotter. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.