Shockster0429

You never can be sure no. However the power it made on the first pull was ballpark where it should have been based on others setups the motor pushed out a bit of coolant. Then the limiter was raised 500 rpms higher and every pull after that the power dropped off as the engine pissed more coolant. Until finally the HG let go. This is over I believe it was 4 total passes. I guess a better way to state it is. "This damage was only evident over the course of a few pulls."

1. Idea I've considered it, however its the same exact gas station I run in my WRX. Which is tuned for 93 octane (US) the WRX has no issues. Ideas on testing the octane level? I could siphon some out and give it a try I suppose. I just have no idea where to take it. 2. Raised compression? You mean 9:1 which is what a stock RB25 is anyway? That is not raised that is factory level. People have made high HP on pump gas with a factory bottom end with stock compression. 3. Fuel system: Look in the background of this picture. You see the blue 90 degree fitting? This is coming off an inline filter, below the filter is the Y for the dual pump setup. There is about 2 feet of fuel line before the rail where its just one line. Look at the top view and you can see the line running behind my coil packs. The end of the fuel rail has the stock line welded shut, and a -6 steel fitting welded to the end of the rail. This setup is less restrictive than factory. Its not the problem with my issues, period. 4. This is not looking like a knocking issue, this a looking like a pre-ignition issue. Lets take your example - Okay you use those det-cans. Whose to say there was enough time to even distinguish between regular engine noise and knock (if there was any) before destruction? This damaged happened over a matter of a few pulls.

Thanks for looking it over Guilt-Toy whats exactly how both my tuner and myself felt about the tune. It sucks however having conflicting reasons for this. Where as I'm on the side that this is microtech/cas related issue. Where on the microtech forum they are disagreeing, posting an rb26/30 vid reving to 9500 with a big single with no issues running a Nissan CAS. The guy blamed my wiring, I posted up how I wired it, then he says its correct, and if it wasn't the engine wouldn't have ran at all... contradiction much? Then he goes back to blaming the tune. I wish I could back track two weeks here, and physically free rev the engine through the entire band with a timing light on the balancer and compare physically timing at the crank to what the microtech is actually reading. That is no longer possible however... If I do redo this for the 3rd time I will look into another standalone. The vipec system is something new to me I'll have to read more about it. I'd like to stay on a standalone side for sure since my factory harness is gone. Any more suggestions of what works with NO issues? As for the injectors if I do what I want to do, they will be gone, and precision top feeds will be in place, along with a dual feed rail to get rid of the dreaded "Y"....

No their not, they power quite a few high HP cars, they have been proven time and time again. Sorry for your buddies luck. Here is the timing map, mines on the bottom, above it is a PFC map we were comparing it too.

Maybe I should rephrase this. "From more research this afternoon this is looking like a CAS/trigger wheel issue with my aftermarket EMS" Does your trigger wheel have varying window openings? Or are they all the same? The believed issue is the windows changing their opening size. Did you go through and read any of the information links I posted?

is this 8 degrees ontop of the static 15 degrees therefore 23 degrees? What turbo, power ect are you making? You match the engine timing with a light to that of what the microtech is reading on the laptop by manually adjusting the CAS.

Thats not to case, EGT's were slightly ignorance, I do not have an EGT gauge, at the time it was driving tuners thought it was loosing power due to head issues, valve float. Not due to the fact my exhaust cam gear was clocked completel retarded. Its not easy to see this at a glance due to the CAS covering the gear. Turns out that might have not even been then issue, that's just speculation to a possibility to the engine dieing. Tuner is VERY careful I just gave you all the maps, and a/f's in which the engine was running. You make is sound like we were just beating on this engine like a bunch of apes with no care that is totally not what was happening. There is so much mismatch/incomplete information out there. I search this site for Microtech issues and all I see is majority of people just bashing it giving no solid explanation to reasons they do not like it. When no one really addresses CAS issues with other EMS's. I know AEM had to make their own trigger wheel to fix the issues they had with the nissan OEM CAS. People have had problems getting their Haltechs to work properly with the OEM CAS. From more research this afternoon this is looking like a CAS/trigger wheel issue. Do please read the last page or so of this thread. Also read the following link as well to a modification to the RB CAS with a Z31 wheel. http://forums.nicoclub.com/zerothread?id=325824&page=9 http://forums.hybridz.org/showthread.php?t...p;highlight=cas It seems that the stock CAS for aftermarket ECU's can cause timing issues, some cases are more severe than others. But from this information it seems that the varying windows on the trigger wheel at high RPM cause issues for the ECU to read properly causing improper timing that go unseen while logging/monitoring. Food for thought but I'm starting to feel with a proper trigger wheel, with a non varying trigger wheel opening might solve this problem.

Interesting info, the first time. (last year when this same issue occured) The CR was 8.5:1 since the deck required a good deal of shaving to clean up my quench wells I went with a 1.5mm gasket to allow it to be at 9.0:1 compression. Last year when the car did the same thing the timing was the same as it was now. 15-16 degrees@ full boost which includes peak torque. Question would be now last years destruction be caused from running on a maxed retarded exhaust cam gear for a few hundred miles with crazy high EGT's or was it caused after I fixed the cam gear back to the zero position? At this time the compression was 8.5:1.

I'll try to answer you again. 1. Manifold is a CPC Plenum from Ariel Banco. Stock flange/runners, new plenum, stacks and Q45 TB. 2. Injectors are 740cc's from Deautchwerks (factory modified injectors, all flow tested and spray tested, I have these results from them, these injectors have power high 800-900 hp cars, obviously with a different CC but same setup) 3. a. fuel pressure is 45 psi static vac off, ramping up one PSI per lb of boost. So was maxing at 57-58 psi. b. no the pumps havent been tested independently. The 044 is 1200-1300 miles new, the walbro 255 is about 12,000 miles old. This fuel system is not in series, its in parallel the pumps have separate lines and filters until right before the fuel rail. I wanted to run a dual feed rail with a middle return however to my knowledge there isn't one made to support factory style side feed injectors that I run. When using this setup above with the nismo reg and not the A1000 reg, the nismo unit was not allowing the FP to rise properly and the fuel was off the map (engine was heading lean), it might been a faulty unit or it might not have been able to handle the flow of both pumps. The A1000 was put into place for the unit and that was the END of my fuel pressure problems. This was done last year while on tuning on the dyno. 4. There is no knock device on the ECU, Microtechs have never run them since they have been in existence. People have pumped out big power with this ECU w/o knock detection. From what I understand with aftermarket knock detectors half of them do not even work since they are detecting valve train noise, regular engine noise, injectors, open wastegate w/e it might be and not providing accurate knock detection. This motor sounded completely normal and healthy, there was no audible sound coming from it to draw any type of alarm. The owner of the shop we are at builds 1000 hp high compression n/a v8's, he even stated how well the car sounded and how he heard no knocking. We pulled plugs and they looked okay. There was really no sign of detonation them them at all. I can post pics if you need me too. Is there a reason for this? On our rb25 motors do the intake side quench wells on the head absorb all this energy and hide plug readings? If that is the case it makes a lot more sense to why the plugs werent showing a significantly bad problem. The head was the same as last years, just fixed and decked properly. The block was re-honed from last time for it wasnt damaged. This time I will need a new head for sure, and possible a new block. As stated below our 93 octane is equivalent to your 98ron Why do you suggest redoing the line into just one? To simply eliminate a possible issue? Cant go back to the nismo if I did this it would be with the A1000 which is a proven fuel pressure regulator. I have the complete UK 7XX page manual for the R33 engines, I use it EVERY time I'm working on a anything engine. Items are torqued to specs noted in the manual for everything. Thanks for the luck, I have no plans to rebuild until I've pinpointed the issue. Modified because the 255 pump will be on its max for the HP we were looking to get. They are only safely good for low 400's on their own. Sure people have gotten over 500whp with a single 255 pump with a rewire and 14-14.5 volts, but theres no need to take that risk. The 240sx has very limited options with fuel, the 044 is simply easier to mount outside the car instead of trying to jam into the factory tank. So I ran them in parallel and with a larger return this setup and a dual feed rail this should be good for 700 plus HP. My pumps have been rewired as well and are seeing 14.0 volts. +-.2 thank you for stating that for me. Any ideas on the Mircotech unit itself displaying false readings? Or receiving the right signal from the CAS but executing the wrong timing for the engine? The ECU is throwing no codes, and seems to be working properly. Just another thought on the issue... thank you everyone for replying and trying to help locate the exact case.

CPC intake with 90mm Q45TB Damage was done over the course of 4-5 pulls, it was steady state tuned till in 500-1000 rpm increments to 5000 rpms before this however. Compression is 9:1 due to my head having to be shave quite a bit to clear up my old damage quench wells. I have quad-dropple checked this. Listen to the video you hear nothing out of the ordinary, granted the car is very loud, there's no breaking up, no audible detonation. No one does RB's anywhere near my location. Local engine builder builds V8's mainly, I do not think this is a mechanical issue. Tuner firs time working with an RB, he has tuned plenty of v8's and 4g63's, very knowledgeable guy. Injectors have been flow tested I have the charts somewhere in my room, they are all within 2% of another. Factory regulator wouldn't handle the flow of the new setup, How does it look like an abortion? I wanted to be safe for fuel on the dyno and not max my walbro out if the car made what it should have made. It was a safety thing. Using an Aeromotive 1000 reg, all steel braided lines, welded a -6an fitting to my stock rail to eliminate hoses. Running a dry FP gage for accurate readings. Static pressure was set to 45 psi, reg was working properly. Last time the engine did this it was attributed to super high EGT's when my exhaust cam gear was rotated completely clockwise and driven on for a few weeks before discovering where my HP was going. (very embarrassing to say the least, however it was missed by over a dozen mechanics/car knowledgeable car enthusiasts, two of which were my old tuners) Fresh build the bears were all changed out, although the old ones were still okay. People make high 500 hp through 2.0 liters on our 93 octane, 2jz's have made over 600 on 93 ocatane, a few RB's have made over 500 on 93. I don't see how how an build RB cannot if this is the case. Also the microtech static timing is 15 degrees, now are you suggesting this value be changed to say 10 degrees or even 5 degrees so that we can retard to such a state? 15-16 degrees full boost at 13 psi just seems very conservative for a fat bore very short stroke motor. You could be right though, maybe it is on pump gas? Last destruction was all cylinders the first one looked the best. But I have 6 melted 700 mile JE pistons from the first time. We checked plenty mechanically, new tuner this time as well. What else would you have checked? Please enlighten me. The car was ran over for any leaks, everything was torqued properly, cams were at factory 0 degree setting base, ring gaps were not aligned, head was completely redone as far as valve seals and proper flatness/roughness, as well as the block. New bearings, new head gasket, new steel braided fuel lines. Engine pic. Peak torque was around 290 ish ftlbs at 6000 rpms. So timing at this point was 16 degrees. Does anyone have a similar octane map with a decently large turbo on an RB motor? I'd really like too look at one. I have a few details on a states rb20 build with a 30r, hes running 20-21 degrees advanced at 21-22 psi through it making 400whp on pump 93 American octane without issues. I appreciate the responses thus far. Anymore insight on the standard Nissan CAS? I saw the above post, I know it reads the #1 cylinders location, however its still sending a voltage/resistance signal (not sure of how Nissan has it setup internally) to the ECU, its not a mechanical signal...

I'm going to really need some ideas on this post here guys. This issue has completely bewildered both myself and my tuner. I cannot for the life of me figure out this problem. My engine has repeated its almost same exact destruction as it did last year. Melted pistons on intake side, melted quench wells on my head past the fire ring, this time with a blown HG as well as very scored cylinder walls. This is bad VERY bad. Old threads on the issue http://www.skylinesaustralia.com/forums/Me...-S-t232311.html http://www.skylinesaustralia.com/forums/Blow-By-t222021.html Here is the worst. I have pictures of the damage as well as of my maps. Main Setup Rb25 with 26 crank, rods, 87mm wiesco pistons. 9:1 compression. 67mm Precision Turbo, .68 a/r exhaust. 740cc injectors, Dual pumps one 255 walbro and one 044 bosch. Running into a Y right before my fuel rail. ECU microtech lt12s Rotella T 15w40 oil used BCPR7ES plugs gapped to .8mm Dyno runs. 2 seperate widebands hooked up to my car. Both within .1 -.2 of another. a/f's 11.2-11.6 from 1-2 psi to full boost. boost pressure at 13 psi pump gas 93 octane timing set at 15 base ramping up to 22 max then backing down to 16 degrees fullboost. (13psi) engine made no physical signs of issues besides starting to push coolant out, and slowly raising coolant temps. Car made 380hp@6500 13psi boost first pull, then slowly HP started to fall off and engine began pushing out coolant. Engine had about 500 miles on it Dyno Vid of the pull These values are SO damn conservative it isn't even funny. But yet I a destroyed block for the second time now. Both times the damage is pointing to a lean condition/advanced timing issue. However with the values I have listed everything at this engine isnt even flexing its muscles. Thoughts on this? I was just on the phone with my tuner for an hour. We are both engineers, he is an Aerospace Engineer, but also does cylinder head development and has tuned some crazy fast DSMs. We have talked and came to no solid solution or explanation for this event to have occurred. Possible thoughts I have. Bad CAS - from what I have read in the past a bad CAS generally just doesn't work, and if it does work the car runs like a POS, I have never come across an instance where a nissan one was bad, but still allowed the engine to run, and run pretty damn well. Is there ANY reason for my CAS to be occasionally sending wrong voltage/resistance outputs to my ECU telling it the engine is at a time that it really is not? So instead of being at 20 degrees its telling my ECU to be at like 30 or 40 degrees? -boiling my fuel? (not sure if this could case this issue) The 255 pump uses standard feed, the 044 uses 3/8" line, the both Y together before the rail through a -6an line, then out into a -6an line into my FPR, then back into my stock return line to tank. Maybe this extra fuel temperature is enough for it to pre-ignite? If this is even a possible reason.... -thoughts/input on this id like to hear or see a situation where this has happened. I cannot see how it would be my fueling since we have 2 separate widebands spitting out basically the same identical values. This whole situation sucks big time, this final blow has been the worst by far. Here are pictures and my ECU maps. -thanks ahead of time for any input.

Here are some pics of the damage this is the #6 cylinder piston and it is the worst. All 6 of them were damaged. Also a few close ups of 3 spark plugs, as far as I can tell they show no signs of pre-det from what I can tell. Just carbon/oil marks from being rich and well burning oil due to serious blow by. As you can see in the pic the damage is ONLY on 50% of the piston all on the intake side. The exhaust side of the piston is as smooth as they day I bought them... Timing was 16 degrees WOT @ 16-17 psi through the 67mm. 2.7 liter 8.5 to 1 compression. Super super conservative. 93 octane A/f's were 11.0's WOT till 7250rpm were I was letting out. Intake temps around 30-32 C, coolant 88-92 C. I didn't appear to be having EGT issues during this time. It was before when my exhaust adjustable cam gear was super retarded w/o me knowing (finally found the issue) and I was missing 50% of my power when my manifold/turbine housing would be glowing as red as a stop sign after a pull or two. Question comes down to what does a knowledgeable person on reading pistons feel would make it only melt on the intake side?

Its looking like thats what I will be doing... Well, got some awesome results from the latest compression test. I let the motor warm up to operating temp while idling... here is the run down!!! 1 - 132psi 2- 132 psi 3- 132 psi 4- 118 psi 5 -118 psi 6- 72 psi (ouch)... So hmm bad of course, lets put about a table spoon of oil in each cylinder and try again. (testing to see whats causing the leak) 1- 180psi 2-175 psi 3- 155 psi 4-188 psi 5-170 psi 6- 157 psi Yeah my rings are definitely not seating/scuffed/****ed all of the above? Heres some pics of what I was talking about. Poping off hose Mess its making on my hood when it does. 150 mile old Rotella T 15w40 diesel oil .. nice and black Plugs burning equally, have a bit of fuel on them from the cold start. (motor leans out to 14.5's once warm at idle) The rest on the threads seems to be nasty oil **** #6 cylinder (72psi one)spark plug showing no signs of pre-det Nasty goo on the tops of my pistons I scraped off with a magnet So yeah, rings are looking like they are at a point of no return since the comp test has gone down since the one ~ 2 weeks ago.... Most likely will be pulling the head this weekend to get a closer inspection.. I'll be calling my builder tomorrow to let him know whats up. These are JE pro-seal rings and pistons as well, opinions on them anyone?

The ticking is most likely the Hydro lifters filling back up with oil from the long sit with no pressure. Change your oil/filter if thats the tick it should go away after a few drives.

holy torque curve. That thing must come on like a monster at 3.5k-4k. Nice setup!