nickz32

For anyone wondering who Nick Johnson is….. it’s me!

Thanks bud. If I can ask people to comment on the YouTube vid and share it so I can play the “algorithm game” and get maximum exposure, that would be massively appreciated!

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Yes, our 99 is the same as their 93. personally, the amount the dual MAF setup costs, you’re 80% there to a Haltech Platinum Pro standalone that absolutely snots a stock ecu and “dual” MAF setup in every measurable way possible…. I know what I’d do out of those two options! This is where I feel whoever did the dyno last time could have spent an extra few minutes to help diagnose. Really, they should have dropped the boost to see if the issue persisted or changed or disappeared. Maybe that was a lack of knowledge of the car on the tuner part and has taken the “engine wants what it wants” a bit too literally. I wouldn’t be using him again. Again, if it were me, I’d have tried incremental increases from wastegate to 16 psi to establish where the loss of ability to reach full RPM disappeared (Stock 9psi, 12psi, 14psi). That would have shown if it was an airflow problem or something else. I’d suggest it would probably be worth an hours dyno time at Horsham etc just to do some runs on different boost levels, monitor the AFR’s and see what the engine does and where the problem arises. I wouldn’t do it on your own with just boost level changes as you don’t know what the fuelling has been set up like above where the tuner was terminating the dyno runs Dont give up on the car yet. A bit like my situation, it’s not the cars fault that it’s not running right….. after all it’s an inanimate object! It just needs setting up properly! On a proper tune at 16psi, it should be in the low 400’s and a very very different car to drive.

Just for clarity, when you raised the boost, did you got from wastegate pressure straight to 16psi, or was it raised incrementally?

Honestly, for you spec, I wouldn’t bother with the selin. Any gains would be marginable. I ran single intake up to 590hp with no problems.

I mean there’s nothing screaming out as a glaring issue. 2.25” exhaust is small and will be causing back pressure issues. That will be a contributing factor…. Be worth checking that none of your silencers/resonators have collapsed internally. what brand air filter is it?

I’ve gone back to 2017 and can’t see a spec sheet of your build bud, mind writing one out?

That’s exactly why I went to Haltech so long ago! When my car was virtually stock (Stillen filter and kakimoto cat back) it made peak power at 6850 before tailing off to Rev limit….. and it stock boost made 339bhp at SRR. I’ll see if I can find the dyno print Something I hadn’t noticed before is the fact you low boost makes peak power and revs out cleanly to red line yet your high boost doesn’t is also unusual! I’ll go back through your thread and see if there’s anything I spot that could be a cause, because at lower boost your engine is flowing enough air to breath all the way to red line, yet when you up the boost it appears to choke out

Somethings deffo not adding up here, there no mechanical reason why it shouldn’t be revving up to the factory 7200rpm rev limiter. It has to be electronic systems based issue. But for the sake of being thorough, I’d do a compression and leak down test to eliminate any potential issues in the combustion chamber (I’m not suspecting any, but better to be safe than sorry and know for sure!) the fact the dyno sheets don’t show what happens after 6200 rpm doesn’t really help with being able diagnose the issue. Did the tuner give a reason as to why he didn’t Rev it all the way out to the limiter? I don’t think the issue is VTC as I originally thought. The engine would still Rev out but it’s peak power would be made at around 5000 rpm and the torque curve would drop off more dramatically than that. spark gap shouldn’t have made the slightest bit of difference at 16psi of boost, even at 24psi I ran NGK supplied gaps with no issue at all. Which makes me think ignition system based issue producing a weak spark Is it still on a S1 PTU? Any sign of any misfire no matter how minor?

Can you post a photo of the dyno graph so I can see what it’s doing at the top end… gut instinct says VTC isn’t disengaging and it’s stuck with too much valve overlap

Hey all. well I’m happy to say my engine saga is now pretty much behind me and I’m free to move on with my car! So, what does the future hold…. Well I’ve pretty much got to start again. I’m yet to finalise what is salvageable and what isn’t, hopefully I’ll get a definitive answer on that in the not to distant future. However, I know the crank and turbo chargers are goosed and will need replacing. I’ve already sourced a replacement crank and block should I need to replace that…. Turbos are by far my biggest future expense, so will have to take some time to consider my options. I do know I won’t be staying on GT525’s, I simply can’t make full use of my build specs on these turbos. Even with all supporting mods, I’ve hit the limit of what they can safely produce without E85. im also going to do some chassis mods while the engine is out. This will mainly be refreshing bushings and arms with a bit of powder and zinc coating thrown in for good measure. looking forward to getting started and being active again in the Z community….. I’ve really missed it!

Hey all. just a quick post to say I’m still around. However, I can’t really talk about my car at the moment due to the issues I’ve mentioned above… I’m sure you can read between the lines as to what that involves. im hoping to have a resolution at some point in the next 12 months, but it may be longer depending on time lines out of my control. Whether I’m able to talk about things depends on the resolution. It’s a rough period in my Z ownership, and it’s killing me not being able to do anything with the car….. hence why I’m not on here much anymore. But, I remain optimistic that my Z ownership journey can pick up again in the relative near future. I’ve already pencilled in some trips for when the Z is running again, future improvements and fail safes to help prevent such devastating damage again. A positive note to end on, I’ve just renewed my insurance for the year and after submitting the required pics and paperwork, I’ve secured a £48,000 agreed value with no quibbles!(I’ll ask for higher next year ?)

Cheers chaps

A bit of an update the long and short is the engine is goosed and will require a significant amount of work to sort it out, none of which is covered under warranty. The “why” of the failure is a bit of a sore topic. I have my beliefs on the cause, EPR have theirs. However, the end result is the same, the block requires a significant amount machine work to get everything straight and how it should be, the crank needs either a regrind or replacing and I need to replace both turbos as debris has damaged the CHRA’s to the point the compressor wheel touches the housings, aswell as replacing two of my pistons. the engine is not going back to EPR again, and I’ll be sorting it out myself. There may be an opportunity to upgrade a few bits, but machining costs will dictate if it’s affordable.

Was hoping to volunteer, but my engine has suffered significant damage and it looks like it’ll be off the road for the forseeable. gutted to say the least

I’ve come to expect the worst when it comes to my luck with this car, and my luck didn’t disappoint. I pulled the engine yesterday, and removed the sump, where I found… I’m pretty confident that is bearing delamination. There is virtually zero shimmer to the oil, which means that it hasn’t been instigated by bearing to journal contact. what makes things worse is that it appears the issue has taken my turbos with it

Mechanical or body resto?

It’s bearing material…. Which bearing is unknown at the moment

So yet again, it looks like I’m going to have to strip the engine down and figure out what’s gone wrong and try and deduce why. the oil analysis will tell me if the rich base map has diluted the oil, but due to the time frames and lack of fuel smell from the oil, I’d be very surprised. Highly gutting, but I refuse to let an inanimate object beat me!

Fairly major update the Z went to Abbey motorsport last week for mapping. with fuelling 80% done and boost levels decided upon (1.5 bar) she made 524hp and 519 lb ft at the hubs, which equates to 602hp and 591lbs ft at the crank. Considering that no changes to the base map ignition timing were made, she’s on track to make well over 600hp/lbs ft. however…. We stopped play when the VTC developed a rattle and a slight drop in oil pressure was noticed. We decided to inspect the oil filter and send an oil sample off for analysis to make sure everything was ok unfortunately, I got some bad news today.

Happy birthday chap

Will see what next year brings mate!

I haven’t seen it referred to as a z34 in any of the Nissan literature. it’s not even called a 400Z…. It’s model name is simply Z