Stephen

That choking out observation was one the dyno operator mentioned too, but that it’s cause could be numerous.

I think a lot of the above highlights the issue. The ability to data collect with the stock ECU is really limited.

He said there was no point as it was plateaued, that if the power had dropped off there must be an issue as it should pull through the redline. He wasn’t comfortable pushing it past this apparently. Compared to other maps it seems I’ve looked at it seems that that plateau is pretty typical of stock turbo cars. It is on a series 1 PTU but it’s never caused a problem, especially not the stereotypical issue of hot misfire the issue I had was the opposite. It would misfire unless the engine was hot hot.

As it happens I was passing Horsham Developments so I popped in and had a long chat with Jez about the options they would recommend. I haven’t had anything back from SpecialityZ yet. I may just go Nistune and then the ability is there for future wether that’s me or someone else and the tube will be far better than any generic chip.

I’ve pinged them over an email and asked some questions. In all fairness, I drove the car last night and the mid range pull, especially since re-gapping the plugs is great, very smooth and responsive.

Like what though? The JWT ones and variants therein are all pretty poor. I could potentially get something from the US but I’d need to be careful about what fuel is mapped for etc. I have had a chat with Horseham Developments but I’d need to go Nistune.

There was one present at the time but it’s not on the print out. However there’s an old graph from a few years back, the car is in the same state as then having covered very few miles 1000 would be generous. The only difference really is the plug gap, decreased from 1.1mm to 0.85mm and a pair of Godspeed SMIC. So it’s pretty relevant data and what I saw on screen reflected the reading on this. I have done a boost leak test and didn’t find anything. It does run very rich as soon as it starts boosting. The chip is one that TurboNoz made as a generic.

A recent shot on the drive.

Higher figure is at 16psi, lower at 5psi

It’s all been done to death to be honest, I can’t really be bother to go over it. There’s so little experienced and skill on the tuning side of these cars and we go round in circles. Owning a Z is a different path, the different path is never the easy path. You have to be prepared to trail and error things and seek out specific people and have trust in them and even that isn’t constant as the go person is often like an annual bedding plant. Realistically to make a worthy gain from here I need a custom tune and that realistically means at the very least going Nistune. Of the limited amount of people prepared to do that for the board and map it’s a grand, which is a non insignificant amount for a gain of a 30-50hp and no real safety benefits. Nistune is so basic now compared to stand alone stuff which would not only offer greater power but greater safety for the engine. If you’re in for stand alone then running stock turbos and injectors is a waste of the ECU. I’ve been doing some thinking after the events and I felt pretty despondent, still do, being frank it’s a miracle I found enough motivation to reattempt the MOT this after after the first one being a cock up. That lack of motivation in the main Is due to personal things. Whilst for a while I thought my lack of ability to make a decision was down to not finding the right car, I think the real issue is I’m just not that interested in cars anymore.

Had the car on the Dyno today. Mix bag really. I found a fault, the boost controller was jamming so the first couple of rolls the car was pushing about 20-21psi, luckily all quite safely. With the controller disconnected a base line was set. First run we ran on wastegate pressure, about 5psi. So less than stock boost, safety boost basically, and she made a very healthy 286bhp more than it should. Then the boost was set to 16psi and we had a roll. Peak torque and hp arrived around 4500rpm at 320bhp. The car was running rich AFRs at this stage and no detonation but the car wouldn’t continue to pull progressively through the curve to produce more power into the 5k, 6k range. Why I’m not sure but if it had continued to build power at the same curve it would have produced about 350 maybe. So there lies the conundrum. There’s plenty of boost left, plenty of fueling left but we’re out of puff by 5k. On the positive a 35 year old car makes more power than new in virtually limp mode and there’s a very solid mid range performance. The question really is why doesn’t it make more power and what on earth will I do from here because the road to more is an expensive one, especially when my intention is to sell. Perhaps I should leave it as a solid car at near stock power and leave those questions to the next owner.

180 miles covered, €400 in tolls 😂

On the tax/insurance aspect the Vette is much cheaper. Tax is almost half, for almost twice the displacement:lol:

The series 1 I agree. The series 2 has the Recaro C1s or whatever they are called which I like a lot.

I have conflicting memories in my head. One part says for polys you are supposed to retain the outter ring. The other, that they sit in there. The top flange is supposed to push the frame away from the body. The rear subframe has lots of anti squat built in and this helps reduce this making the car easier to launch. For the record my car has solid ones.

I’d disconnect the MAF and see if it does it still. Check the TPS as well.

Something worth noting that. I think there’s two different tax brackets for the 370z depending on age, some cheaper than others.

Just to update this. Ive now mot’d the 32. I’ve been and looked at a couple of Z34s and driven one this week which had a remap and an exhaust. About 30k on the clocks and clean. I was quite surprised to find that essentially it just felt like my Z32, to the point that I felt confident very quickly. The driving position is slightly better. It did feel slower but maybe this was a lack of drama if you get me, being NA the power delivery is very different and linear where as my 32 the power comes in hard and fast. So basically yes I like it a lot, because it just feels like home, an updated and more forgiving home. I haven’t managed to drive a Corvette yet but did sit in one and the the LHD thing is a concern, changing gear with the wrong hand I can see being a problem when I use the car so rarely. The thought of trying the grab the door handle in a panic gives me fear. I have the car booked in on the 2nd for some tweaks to the map. Last time it was dynoed it was making 312whp from 4.5k onwards but running AFRs of 10:1. So there’s fuel left of the table. Hopefully get some cold engine drivability and get that boost up to 18psi or so. Once that’s complete I will I put it up and see if I can get what I’m after for it.

Any further knowledge on this topic?

Good find. I cannot believe that Nissan went through the expense and aggro of making a washer pump for these cars though. There must be a commonly available part that needs the plug splicing on.

Is it a Renault power train? Many are.

I know exactly what those two plugs are but il be damned if I can find the memory. One is for Air Idle valve, common delete and Nissan themselves removed them on later cars if I remember correctly. The second. I can’t remember but EGR rings a bell.

Yeah the Z4M is a cracking car and a future classic. The LHD thing does bother me but it’s a serious car, a super car in all but badge. I have considered things like TVRs and Caterhams as well but I don’t think it’s what I’m after.

If I had the space I’d just keep it but I’ve only got a smallish single garage, (5m long) and I don’t want to leave cars outside that are not in regular use. I have/had thought about getting a lock up which I could utilise for work and cars but the availability of anything like that in my area is both low and cost prohibitive.

Honestly that would be a serious list! The short runners for what I’d like to realistically own at the moment. C6 Corvette ZO6, Z4M Coupe, 370z Nismo. That’s the three that I’m mulling between really.