bco6 Posted December 3, 2008 Share Posted December 3, 2008 Hey Hybrid Z, I am a newbe to the 280zx turbo motor. I recently Purchased a 72 240z with an 83 zx turbo engine. I have spent the last few weeks searching threads. The car was originally set up to race so none of the lights were hooked up. After hooking up all the lights and driving on the road I noticed that it was fast as hell! , but the boost guage was showing 15 psi. I was warned at a local garage that this might be dangerous. It has all stock Turbo equipment, no intercooler, a very loud blowoff valve and to my knowledge stock injectors. Should i bring the boost down, and what is the best way to do so. My performance goals is 250 HP with reliability. I studied the Ultimate Turbo guide by Drax but am wondering where to start. I am not looking for a complete rebuild, just to modify the strong stock engine. Just purchased a 60mm TB, whats next.....intercooler? new ECU? Quote Link to comment Share on other sites More sharing options...
jc052685 Posted December 3, 2008 Share Posted December 3, 2008 First thing is go buy a quality wideband. If you dont know what it is google it. Then stay away from boost until it is installed on your car and you can then verify what is going on inside that time-bomb of yours. The factory ECU will not do more than factory boost level with any precision. Start searching the ecu section of the forum for a good staand alone ecu. There are a few other methods you can do. One is the z31 turbo harness and ecu swap. It is a mass air system and will tollerate slightly higher than stock boost far better than the L28et's computer. Also serch Nisstune. That will apply to the z31 ecu. Once you have established you have the Proper AFRs, that your timming is to factory spec AND you are not detonating. Then start getting back into the boost and keep a close eye on the wideband. You will know what to look for on the gauge because you will gave dome some of that "Tunning" resurch I spoke of earlier. This is not something to just jump into with out the knowledge of each system that controls the engine and what effect each has. I would alsso try your best to figure out why the boost is so far above the factory setting, and then fix it or remove it. At least until you have completed all of the above. Some will tell you you can ajust the AMF of yoour car to compensate for more boost or turn up the fuel pressure. I truely would steer clear of the factor L28 electronics if you are wanting to make any kind of power reliably. This is not to say some one is going to post how they are running 15psi on stock computer and no other mods and nothing has broke in the 5 years it has been like this. Believe me, this is not the norm and should not be taken as the gospel! Everything above is only an attempt to save you time, money and lots of headaches in the long run. Please use the search feacher of the forum as it will answer most if not all questions you may have. Quote Link to comment Share on other sites More sharing options...
jc052685 Posted December 3, 2008 Share Posted December 3, 2008 Oh, and I have a feeling that thee "loud blow off valve" is simply turbo surge. This is very bad for a stock turbo. Expext to be replacong it soon at those boost levels also Quote Link to comment Share on other sites More sharing options...
bco6 Posted December 8, 2008 Author Share Posted December 8, 2008 thanks jc052685! Ordered Wideband, we will see how the AFR is. will post results soon Quote Link to comment Share on other sites More sharing options...
jc052685 Posted December 8, 2008 Share Posted December 8, 2008 thanks jc052685! Ordered Wideband, we will see how the AFR is. will post results soon I will say this is very wise on your part. Hopefully there will more good things to come this car of yours. Post up anything you know about the car's setup for the rest to maybe be of some help also. Maybe post up some pics of the turbo. Tell us about the vacume routing from the wastegate actuator. You need to find out what injectors you have also. Is the exhaust stock also I wonder? Does the engine harness look to be in good shape or are there broken connectors and exposed wires? It is best to get all of the systems of your car in tip-top shap before trying to make it more powerful. I dont know how familiar you are with automobiles or turbo & fuel injection systems. To learn some of the basics without having to sift through many of the threads on here that are of no use, try Wikipedia.org. You will gain a general understanding of what makes you car function and what is needed to get what you want out of it. Just go on there aand start searcching all of those "key words" you have heard ie. blow off valve, intercooler, turbo, fuel injection. Good Luck!!! Keep us posted on your project. I am curious to see what you find out from the wideband. Quote Link to comment Share on other sites More sharing options...
whitechocolatelove Posted December 8, 2008 Share Posted December 8, 2008 i just did a turbo swap into my 240z and was told 10lbs of boost would be fine but i should swap out the ecu and all the fuel related stuff if i plan on anything above that which i believe is right around 250hp (accounting the 3 inch exhaust also) correct? Quote Link to comment Share on other sites More sharing options...
jc052685 Posted December 9, 2008 Share Posted December 9, 2008 i just did a turbo swap into my 240z and was told 10lbs of boost would be fine but i should swap out the ecu and all the fuel related stuff if i plan on anything above that which i believe is right around 250hp (accounting the 3 inch exhaust also) correct? Again, you can do anything you want. I would, BEFORE I do anything else, get a wideband sensor on the car. Then start turning up the boost if you want to. Please pay very close attention for detonation as you will be blowing tons of heat with no intercooler. If your AFRs are good then yes, I would say SLIGHTLY higher boost is ok. Quote Link to comment Share on other sites More sharing options...
bco6 Posted December 10, 2008 Author Share Posted December 10, 2008 Just got the car picked up from the electricial shop. here are some pictures of the engine......... I found a bottle cap jerry-rigged under the j tube......oh boy Quote Link to comment Share on other sites More sharing options...
bco6 Posted December 10, 2008 Author Share Posted December 10, 2008 Quote Link to comment Share on other sites More sharing options...
bco6 Posted December 10, 2008 Author Share Posted December 10, 2008 Also here some pics of the car Quote Link to comment Share on other sites More sharing options...
bco6 Posted December 11, 2008 Author Share Posted December 11, 2008 can any one tell me what type of injectors they are? or do i have to take them off and compare photos with the injector thread? Secondly i ordered a wideband and i will need to install the o2 sensor, can I pull out the existing o2 sensor and put in the new one? or will that mess up the ecu and cause the car not to run? Quote Link to comment Share on other sites More sharing options...
wigenOut-S30 Posted December 11, 2008 Share Posted December 11, 2008 I see a hint of brown on the injectors, They are most likely stock turbo injectors. As for the wideband. You will need to get to the muffler shop and have a 02 bung welded in at least 10"-12" away from the turbo. Too close to the turbo and you will burn that expencive wideband sensor up. The car looks great man!. Do you know what AFR's are good and what AFR's are bad for WOT? what you are looking for on 93 pump gas on a turbo car is around 11-7 to 11-8 AFR's. what kind of wideband did you go with? I would also suggest a nice front mount intercooler, much better flowing downpipe and 3" exhaust in your quest for more power. I noticed a huge difference when I was running stock electronics and 10psi of boost from when I added the Intercooler. Quote Link to comment Share on other sites More sharing options...
bco6 Posted December 11, 2008 Author Share Posted December 11, 2008 I see a hint of brown on the injectors, They are most likely stock turbo injectors. As for the wideband. You will need to get to the muffler shop and have a 02 bung welded in at least 10"-12" away from the turbo. Too close to the turbo and you will burn that expencive wideband sensor up. The car looks great man!. Do you know what AFR's are good and what AFR's are bad for WOT? what you are looking for on 93 pump gas on a turbo car is around 11-7 to 11-8 AFR's. what kind of wideband did you go with? I would also suggest a nice front mount intercooler, much better flowing downpipe and 3" exhaust in your quest for more power. I noticed a huge difference when I was running stock electronics and 10psi of boost from when I added the Intercooler. Thanks Wigenout! I went with a PLX wideband and bosh o2 sensor. should be coming soon.. I am currently trying to figure out this boost problem of mine then i will definitly get a intercooler over the winter. Where can i get a better flowing down pipe, should i install that when i install the o2 sensor? Quote Link to comment Share on other sites More sharing options...
wigenOut-S30 Posted December 11, 2008 Share Posted December 11, 2008 MSA used to have some.. but not sure if they are still selling them. Most of the time you just have to custom make one. thats what Im doing with my new setup. Quote Link to comment Share on other sites More sharing options...
510six Posted December 12, 2008 Share Posted December 12, 2008 I noticed a Mitsubishi Eclispe Blow off valve and flange welded to your intake piping. That is the sound you are hearing when letting off the throttle after boost, the BOV outlet really needs to be plumbed before the airflow sensor. http://en.wikipedia.org/wiki/Blowoff_valve http://www.atlanticz.ca/zclub/techtips/turbo/index.html Quote Link to comment Share on other sites More sharing options...
jc052685 Posted December 12, 2008 Share Posted December 12, 2008 I noticed a Mitsubishi Eclispe Blow off valve and flange welded to your intake piping. That is the sound you are hearing when letting off the throttle after boost, the BOV outlet really needs to be plumbed before the airflow sensor. http://en.wikipedia.org/wiki/Blowoff_valve http://www.atlanticz.ca/zclub/techtips/turbo/index.html you cant plumb it before the afm on this car. Only when the AFM is being boosted through can you do that. It is just goung to get a rich condition under shiftes. It will live. Yes, you definatly should do the intercooler, downpipe, wideband and exhaust before you start blasting the motor with all that heat from higher boost. Oh, and props on the PLX:mrgreen: Very nice car also, to bad the motor does not match. But hopefully it will soon!! Quote Link to comment Share on other sites More sharing options...
bco6 Posted December 14, 2008 Author Share Posted December 14, 2008 last week was finals week so i had some free time.. I read maximum boost and did a ton of research. and found my vacuum controlled manual boost controller tucked under the master vac. now which direction turns down the boost? screw it in or screw it out? Quote Link to comment Share on other sites More sharing options...
bco6 Posted December 14, 2008 Author Share Posted December 14, 2008 I did some more research and more bad news....my rings in cylinder 4 and 5 are probably gone...based upon the oil coming through around the spark plugs Quote Link to comment Share on other sites More sharing options...
wigenOut-S30 Posted December 15, 2008 Share Posted December 15, 2008 For now I would take the boost controller out of the mix and run strickly off the wastegate. (make sure you hook the vacuum lines back up to the wastegate) You might want to run a leak down test as well as a compression test on your engine. Quote Link to comment Share on other sites More sharing options...
jc052685 Posted December 16, 2008 Share Posted December 16, 2008 I would not suspect the rings on 4 and 5. I would suspect the spark plugs are not tight in the head. any readings on that wideband yet? I sencond the opinion to remove the boost controller all together for now. You need to run a dry then a wet compression test on all 6cyl to get a resonable idea of the condition of the motor. Quote Link to comment Share on other sites More sharing options...
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