240z + 1JZ-GTE (manual)

johnymd

Club Member
Quick update.

The last rolling road session revealed a few issues. Firstly, I needed a better clutch, so fitted an Act extreme 6 puck paddle. Whilst the gearbox was out I replaced the gearbox input seal and the engine crank main bearing rear seal to fix an old oil leak. Unfortunately I may have screwed up the seal as I still had a leak. This morning I pulled the box again a put in another seal and another set of new flywheel bolts. I took better care of the seal this time and the leak now appears to be fixed.

The second issue was poor boost control ( I want to be able to select anything from N\A to full boost with the cal switch). To achieve this I've replaced the waste gate with a trial mvs and fitted dual control solenoid's. Then use a really soft Spring. While the manifold was off I've had it ceramic coated to try and control under hood temps a bit.

It's all back together now so nearly ready for Wednesday.
 

johnymd

Club Member
Yep, I was pretty happy with yesterday. Today didn't quite go as well although I got there in the end.

There's always stuff to do on the blue car but the less important things tend to get left so today I made a start on them. The heater fan has t worked for a few years now and it really starting to bug me. Especially when it's raining and the whole car mists up.

I started by checking the fuse behind the radio and then checked I had 12v to both the switch and the fan. All good there. The way a zed fan seams a bit odd to me but basically you have permanent live and switch the earth though different resistors to vary the speed. I checked the switch by testing in another car. I then bypassed the resistor pack and switch by connecting the black wire on the fan to earth and the fan ran ok. Checked the resistor pack and that appeared ok. Checked the wiring between the resistor pack and switch which also looked OK. Running out of ideas so started removing the loom around fusebox to find a black earth wire disconnected!!!!! And tucked under the fusebox. Ya, we have a winner. Now I just need to to put it all back together.
 

johnymd

Club Member
Unfortunately not Mark.

Anyway, I went back for another go yesterday and made some progress. The day wasn't without its problems but was much more successful than the first time.

The first issue was too much restriction in the waste gate dump pipe. Rather than run an open screamer pipe I fitted a Supertrapp muffler to the end of it. this was after a fair bit of research into what other people were doing, this seamed the best option. After the first run we found too much restriction in this pipe so had to remove the Supertrapp.

Second issue was controlling boost. The turbo wanted to make boost quickly and lots of it. I wanted to limit it and feed it in over a longer period of time. It took quite a long time to remove the boost oscillations at the start of boost control.

The third issue that was intermittent throughout the day was a misfire. It was only evident as we started to add boost but wasn't predictable. Frist thing we did was the obvious which was close the plug gaps up and that seamed to fix it for a little while. The next was increase the coil change time and that initially had an effect but then went back to misfiring. Then tried reducing the coil charge time which also initially fixed it. We now suspect its all down to the ignitor getting too hot. The ECU doesn't need the ignitor so I'll probably remove it and just fire the coils from the ECU.

At the end of the day, although we didn't get to do a top end power run, we did setup 4 low to medium power setting that I can switch between on the fly with a rotary switch. Starting with a low power, low boost, flat curve, 350hp setting, up to a 1.5bar 487hp 414ftlb setting I can have a bit of fun with. Also fixed a few other issues I had with starting and low rev pull aways. It was a long day and by 10:30 last night we had all had enough so the rest can be done another day.
 

jonbills

Membership Secretary
Site Administrator
sounds like good progress. I don't want to think about what a day that long costs :)
 

Mark N

Club Member
I’m not a fan of open screamer pipes either, do you have an option to plumb it back into the downpipe?
What are the multiple boost settings for? Track use?

I’m assuming that the coil packs are new seeing as they are not being considered as the cause of the misfire, are they standard or uprated?

Hope you get it sorted out soon!
 

johnymd

Club Member
Thanks Rob. Going to look at a bit of land Saturday so could be starting another build for something to do in my spare time :)

Peak numbers are not what I'm really into. On the low to no boost setting its a very linear curve with no real peaks. The others get close to full power from around 4k then rise slowly to the maximum at around 7k. This is from what I remember. I didn't get a chance to pick up any graphs but I'll get them to email some through to me.
 

johnymd

Club Member
Coil packs are the originals so, like the rest of the engine, only 25 years old. It could be one of them playing up. I'm not a lover of "uprated" stuff and prefer factory parts.
 

Mark N

Club Member
I'm not a lover of "uprated" stuff and prefer factory parts.

Like a GT3582R? :D

Coil packs are the originals so, like the rest of the engine, only 25 years old. It could be one of them playing up.

If they are anything like RB coils I would say there is a good chance that one or more of them have started breaking down.
What plugs are you using?

I have to say that those are good numbers for mid boost! :thumbs:
 

Ian

Club Member
490HP is a great power level for a Z, still very usable and crazy fast, you'll love it.
 

johnymd

Club Member
I know Mark. I have resisted change for a long time and still not sure I made the right move.

I've yet to try out the new power. Was going for a drive this afternoon but probably not wise as its p1$$ing down. Traction may be an issue in the rain :)
 

Mark N

Club Member
I know Mark. I have resisted change for a long time and still not sure I made the right move.

I've yet to try out the new power. Was going for a drive this afternoon but probably not wise as its p1$$ing down. Traction may be an issue in the rain :)

Worst case scenario, you down size your turbo to a smaller frame (a GT30 or similar) to have more usable power.
This was something I have always been prepared for when I bought my kit!
At the end of the day, there are plenty of hybrid S30s running more power than that and they can't all be wrong! ;)
 

tel240z

Club Member
I know Mark. I have resisted change for a long time and still not sure I made the right move.

I've yet to try out the new power. Was going for a drive this afternoon but probably not wise as its p1$$ing down. Traction may be an issue in the rain :)

You'l have your play on sunday at japfest and the sunah after :devil::devil:
 

johnymd

Club Member
Yep Tel. Need to do some rewiring to remove the igniter first and just ordered a spare set of coil pack just in case.

Looking forward to next Sunday. I guess your still a bit ahead of me on the power front with the supercharger?
 
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