well now im really scratching my head, its just sprung another MASSIVE exhaust leak worse than ever before when i went for a cain in the hills, hit limiter in 2nd round a hairpin and BANG. Its too dark to see were its coming from but ill find out tommorrow. Im hoping they did actually get the exhaust manifold flat, either that or them damn ezyfit gaskets are total crap, coated both sides in good quality heat proof silicone too. Stupid non crossflow engines theres just no room

ca ca ca ca18det

My first thought looking at your plenum is too much flat surface.

Between the heating/cooling going on between vacuum and boost plus the vacuum/boost pressure transitions I think the top of the plenum is flexing and broke the sheet metal next to the welds.

Have you had the car on a dyno where you could watch the top of the plenum to see if it is flexing up and down while transitioning from vacuum to boost?

It used to flex but once i welded on those braces its been fine. I went out and started it this morning and put my hand down to feel were the leak was coming from, too my horror it was coming from between the block and cylinder head. On closer inspection there was a gap and a bit of gasket blown out, it looked like this




I removed the manifolds and the manifold gasket wasnt blown which im happy about, then whipped off the head and indeed it had spat another gasket in the same spot as before, no.1 right side.







This has got me thinking that maybe the head has a low spot there so im getting it machined flat. Also thinking maybe it is pinging on the limiter? Although its too loud to hear and the piston/chamber looks fine. Ive heard a few times how #### these ezyfit gaskets are maybe they just cant handle the extra pressures, might have to buy a genuine nissan gasket or if they make good quality aftermarket then one of them, are copper gaskets any good?
As far as a ca goes ive just already spent way too much, too late to turn back now, and as much as problems suck its good that im learning. I think once the reliability of gaskets is sorted and i get a good tune/boost 150rwkw should be near doable, oh and did i mention how good it sounds

my car does about 100rpm idel

just spoke to datsport, really top bloke, told me that a lot has to do with the technique/method of instllation. With the l series especially boosted its critical that these steps be taken.

1:Head/block have to be totally clean, eg shiny metal. Tap all bolt holes and blow out, clean bolt threads and lubricate, dunk head/washer in oil.
2:Torque the head up in stages, 20,40,60ft/lb using correct sequense
3:Back all the bolts off untill loose using correct undo sequense.
4:Again 20,40,60ft/lb
5:With no water/coolant start and run until you can touch around no.2cyl on head with wet finger and get slight sizzle.
6:Let cool down and one by one undo each bolt till loose and then tighten it down in one smooth action to 60ft/lb.
7:Fill with coolant and your laughing

Haha different to ezyfit instructions, tourque down to 30 then 60ft/lb- done. The ####ty $20 ezyfit etc gaskets are made of graphite, the genuine nissan headgaskets at $70 are muuuuch better. Then theres good quality aftermarket ones at $90 and $170, but apparently you get what you pay for!
Looks like ive left it too late today and will have to do it all tommorrow! Hope it works. Oh yea and NO sealants at all to be used

that picture of the gasket looks pretty funked! its not only blown out a section, its warped the whole circle shape!

hope you get it sorted quickly.

otherwise ive got one and a half words for you.
A-series.