nickz32

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

This!

Small update i borrowed a UJ off a good friend of mine so that my car stays mobile in time for this weekend (BIG milestone coming!) I removed mine and found it was utterly goosed, both notchy and stiff to move in all directions. JoelyP also pointed me in the direction of a recent FB post that identifies 350Z steering UJ’s as identical and half the price of 300zx ones! Nissan U.K. haven’t got any at the moment max but I’ve got one coming from European stocks that will arrive in plenty of time for my road trip in September

Good to see you back on here buddy!

Well on further inspection, I found I’d made a mistake when I reinstalled the rack when replacing the bushes. It appears that I’ve misaligned the column in the UJ, which has thrown the lower UJ out of phase with the upper…. While I’m not 100% sure it’s the cause of my stiff steering, it’s deffo worn out the lower UJ. I removed it today and found it to be free moving but very notchy. hopefully I can source a used replacement in the next day or so and I’ll look at getting a new unit when funds allow (theyre £240 for an OEM replacement!)

Ah nice! Let us know how you get on with them!

Turning left of centre the steering gets heavy and feels like it’s binding (I can feel it through the floor aswell as the wheel). At the moment everything mechanical checks out (column, UJ, wheels, hubs etc) so I’m going on the assumption it’s something hydraulic.

I’ve got a trip up to Snowdon at the end of Sept planned with my two closest mates in their cars (Gen 1 Legacy turbo and a 944) which I’m really looking forward to. ive still got a steering issue that I’ve got to figure out. I think im probably going to strip rebuild the rack as im running out of ideas as to what the problem is

Not yet, but completely agree. its going to be hard keeping it this clean with the amount of driving I want to do in it (let’s face it… I’ve got years of pent up z driving) but it’ll be a fun challenge!

Over the last few months, a friend of mine and I have been undertaking the most thorough detailing work I’ve ever undertaken. Just over 70 hours of work have gone into my car, from 2500 and 3000grit wet and dry, compounding, polishing, refining and ceramic coating. My back is utterly destroyed, so the pics aren’t as good as they could be, but I’m super proud of the results. I’d say I’ve achieved 99% correction (a couple of scratches couldn’t be removed), but she’s as good as I could ever hope to achieve #nofilterneeded