dylanh Posted January 12, 2013 Share Posted January 12, 2013 (edited) I bought randy77zt's car last year and here was the dyno. It was on 12psi and the water/meth was turned off. mod list here http://forums.hybridz.org/topic/108767-77-turbo-z-in-southwest-louisiana/ dyno graph here--> http://s52.beta.photobucket.com/user/wolfboy708/media/IMAG0475.jpg.html Edited January 12, 2013 by dylanh Quote Link to comment Share on other sites More sharing options...
dylanh Posted January 18, 2013 Author Share Posted January 18, 2013 Did a boost leak test today because after reading several threads I realized my car was spooling VERY slowly, and found I have a huge boost leak out of the coupler directly attached to the turbo. Hopefully thats why the numbers look pretty disappointing. Quote Link to comment Share on other sites More sharing options...
Gollum Posted January 19, 2013 Share Posted January 19, 2013 262 isn't terrible for 12psi with no water/meth on pump fuel. What intercooler setup does that car have again? That car has certainly made some decent power in the past, hopefully you can only improve on it. Quote Link to comment Share on other sites More sharing options...
dylanh Posted January 23, 2013 Author Share Posted January 23, 2013 Its a large ebay intercooler for a 240sx flipped upside down. boost is coming on really slow and I found a large boost leak after this dyno. boost is still coming on slow thinking it has something to do with either the wastegate or possibly the bov is releasing some pressure. Quote Link to comment Share on other sites More sharing options...
dylanh Posted January 23, 2013 Author Share Posted January 23, 2013 I can hear my bov let off pressure when I let off at about 1-2psi so perhaps it needs to be tightened. Quote Link to comment Share on other sites More sharing options...
letitsnow Posted January 23, 2013 Share Posted January 23, 2013 Check it for leaks first, you want it as loose as possible without leaking. Quote Link to comment Share on other sites More sharing options...
Xnke Posted January 24, 2013 Share Posted January 24, 2013 (edited) Your BOV SHOULD let off boost at 1-2PSI when you drop throttle. It should open nearly any time that the manifold pressure is somewhat lower than the compressor outlet pressure. Edited January 24, 2013 by Xnke Quote Link to comment Share on other sites More sharing options...
Tony D Posted January 24, 2013 Share Posted January 24, 2013 If you lift your throttle, the BOV should direct overboard the excess boost in proportion that your throttle plate is restricting... In effect, 1-2psi is high, and is slowing the compressor wheel as its flow-loading is higher than turbine input power at that point. You see this on a turbo tachometer. This is why manifold waste gate control is so nice---you lift throttle, that vacuum applies to the diaphragm and slams that waste gate closed NOW! Keeping maximum flow through the turbine. In extreme cases you can see on the TT the wheel speed spike upwards on drop throttle. "Bad Control" but good for on-throttle response! If boost is coming on slow, outside of leaks (the BOV should have manifold boost plus spring pressure on it, preventing leaks) the waste gate is he culprit. A BOV leaking limited boost during initial onset may not be a bad thing... Generally boost is exponential, as rpms rise Oostende is produced far easier off the compressor wheel... IF the waste gate is properly fully closed until set point is reached. (Another reason for manifold referencing of the waste gate signal! ) Quote Link to comment Share on other sites More sharing options...
Lazeum Posted January 24, 2013 Share Posted January 24, 2013 (edited) If you have a boost leak, you should check your system by pressuring it. This is what I was doing on my Evo before. I had built with rubber adapter found on hardware & a tire valve a tool that could be installed on my intake system before the compressor. You then need to apply pressure to it. If you do not have a compressor like I did (how come I could have worked on my car without one!?! ) you could purchase for around $20 a bottle to hold some air at high pressure you can fill up at a gas station & use in your garage. With your system pressurized, you can take your time to find the problem with soapy water & you ears. Edited January 24, 2013 by Lazeum Quote Link to comment Share on other sites More sharing options...
dylanh Posted January 27, 2013 Author Share Posted January 27, 2013 (edited) That is a good point about the BOV I suppose I never really thought about it. According to this thread http://forums.hybridz.org/topic/28001-t3t4-boost-lag-4k/?hl=stage+turbine&do=findComment&comment=216635 my spool actually is just about right considering its a t3/t4 .60 trim with a stage 5 wheel and .86 ar. I fixed my main boost leak all that is left is two small pinhole leaks in some welds. Can't wait for income tax to come in to get her dyno tuned at around 20psi! Edited January 27, 2013 by dylanh Quote Link to comment Share on other sites More sharing options...
TimZ Posted January 28, 2013 Share Posted January 28, 2013 Generally boost is exponential, as rpms rise Oostende is produced far easier off the compressor wheel... ...So either you have a Flemish spellchecker, or this type of BOV only works in Belgium. Quote Link to comment Share on other sites More sharing options...
Tony D Posted January 28, 2013 Share Posted January 28, 2013 ENG (UK) / Soumi / Vali.... Quote Link to comment Share on other sites More sharing options...
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