What Have You Done To Your Stagea Lately?

[Sisbro666]

Wife

[rb26stagea]

So.... After 7 dyno sesions (of which only the run in tune didn't raise an issue/see a failure) , 2 engines, 6 turbos 2 fuel pumps, 3 blowoff valves, 2 sets of suspension, many$$, and a whole HEAP of frustration over the last 13 months, I took the car back to the dyno for its final power tune, having no fitted a recirculating BOV and a dirty great Walbro 460LPH fuel pump.

First run was impressive, and sounded great...

...Then it went pearshaped. again.

Engine started refusing to make power past 5700rpm.

Next run saw it struggle at all revs and start missing as soon as the throttle was pushed.

So we shut the car off and started diagnosis:

Long story short, we found that spark plugs in cyl 5 and 6 were looking pretty dirty (but not wet), which could possibly be explained by the fact that the car had done about 30km when I still had atmo BOVs last week, and it was running RICH off throttle.

So we swapeed the plugs around, and tried to run the engine. It was still "wrxing"...

We checked that the coils (splitfires) were functioning, and they all came back fine.

Checked timing and it was all good too.

Fearing something really nasty, given the ridiculous number of issues I've had during this build process, we checked the cylinder pressures: all ok at 107-110psi, so no issue there, thankfully!

After a whole heap of pressurising the inlet system, in different areas, we discovered that the blowoff valve was dropping all pressure at the flange, so the car has a major (complete) boost leak.

Confirmed this when we limped it off the dyno: boost set at 4psi, the car struggled to make any boost at all, coughing and missing as soon as the turbos started to spool.

So, yet again, I limped the car home (slowly, because it has a hissy fit at anything more than 10% throttle), and am now praying to the car gods that the BOV is the extent of the issues... The odd thing (to my imited knowledge) is that everything being monitored during the dyno runs looked fine: mixture, injector duty cycle, etc: it just didn't want to rev/make power. Instead, it would hit a wall, like hitting the rev limiter.

In hindsight, it did possibly feel a wee bit sluggish on the way to the dyno, but I've had so few opportunities to actually drive the old girl in the last year, I didn't really notice...

Either way, it goes in to get the BOV sorted, new plugs, and some very careful checking of all possibilities tomorrow: Spry is booked out for the next 2 weeks, so we have a little time up our sleeves to find and fix the issue(s).

8 Dyno sessions down, ??? to go....

Fingers crossed!!

[Sisbro666]

How many panels have you smashed with a spanner?

[scotty nm35]

You could have simply blocked the BOV with a cut out coke can to diagnose the issue?

[chef_stagea]

Bump

[Raysboostin]

Id say its time to change dyno tuner/ mechanic Micah. they should of at least had the tools to fix a leaky flange no problem. with the amount of stuff uve replaced it sounds to me like the car is not the problem. r u sure all is well with a comp test showing 110psi?? mine came back with 110psi and the head gasket is gone. I was told a healthy RB is up around 150psi.

[Commsman]

My blown VQ has ~140psi on all except the dropped cylinder (~100psi), but I don't think the actual figure is as important as the variation between cylinders as pressure gauges can read differently. Having said that, I don't know if seeing 110psi when 150psi is expected would be normal.

How could they all be that low? Very low compression build...? Head gasket not torqued down...? (but then would overheat).

I'm with you Ray - what's with Micah's tuner not trying to sort the BOV? After all the $ he's spent. P.I.T.S is off my list, lol.

[rb26stagea]

No "spanner panels" yet, but I came close!

We started blocking pipes at the top of the engine (easier), and worked our way down to the more inaccessible areas: I have the Greddy inlet kit (many pipes and joins) so the less PITA pipes were tested first.

The 110psi is acceptable due to the new pistons and the cams (Poncam type B: gotta love the lumpier idle!!).

The Mechanic and I have had some "discussion", and have reached an understanding: he picked the car up at 7am this morning, so I'm waiting to hear the prognosis.

As far as the tuner goes, he was brilliant: charging me nothing for all the diagnostic time we spent (a case of Coronas is heading his way!), and I've used him for years with absolutely no complaint.

Just desperate to get it back on the road: Once it's all sorted I'll organise a Gold Coast meet - I want to show it off with its new shiny bits, lower height, freshly painted brakes, powdercoated wheels (guess I'll have to change my profile pic!) and of course it's new level of performance!

Even running 18psi with around 430awhp, it felt healthy and STRONG... At 22 psi, without the hassles inherent in having atmo BOVs, it's going to be pure joy to drive!

Incidentally, I've taken a bit of a different tack with the tuning this time around: aiming at midrange over outright power, so peak power hits at around 7200rpm, as the cams are dialled back. In conjunction with the closer diffs, it's a whole different animal, and pulls like a train when boost and cams start playing together.

[rb26stagea]

I should add that that not one of the issues I've had on the dyno can be attributed to the tuner: I've had a particularly bad run of crappy luck, coupled with a few instances of shoddy workmanship/laziness.

To give you an idea, the first dyno booking revealed a blocked cat, causing around 9psi of back pressure (!!)

Second booking, the exhaust gasket on the rear turbo was leaking (due to lazy mechanic who hadn't machined the contact areas on the flanges of my 2nd hand exhaust manifolds)

Third booking, we popped the rear turbo (unknown age/km, as it was part of the original build, and bought used)

4th booking, melted 2 pistons (once again, the engine was internally stock and of unknown km)

6th booking part one: never actually made it onto the dyno due to bottom end knock: engine had spun a bearing 13km after rebuild

6th booking part two (rebuilt again): run-in tune

7th booking was for power tune, and tweaking a couple issues I had been having with cold start and the atmo BOVs. Decided to return to recirculating BOVs, and ran out of fuel pump capacity, having run a very lean 458awhp. boost was backed off to 17-18psi, bigger fuel pump ordered, and BOVs replaced with the current unit.

8th booking.... well, you now know how that one went!

Pitts (Matt) has been awesome through the entire process: patient, generous and fair! I can't recommend him strongly enough! Given the above, I can't find blame that can be attributed to him for any of the issues I've had so far...

time was an issue with the BOV: we were already an hour past the time he had to close, so I made the call and took the car home. Besides, I prefer to make it my mech's problem: His work, his product, his problem...

[Commsman]

^ fair enough Micah. Pits is back on the list (not that I have a list).

Maybe you'll have some good luck coming your way soon, if not keep persisting as it seems to be paying off.

[rb26stagea]

Welllllllll...... Pretty sure the three of us who did all the diagnosis need our eyes checked...

The BOV is an issue, so I'll order a new one today... I was thinking Trust Type R, unless anyone can suggest a better option? (assume they're all much of a muchness, as long as it's rated for my HP levels...?)

...But we kind of overlooked the disconnected throttle linkages to the rear 2 cylinders. FIXED!

Also, just to be neat, we have ordered a new, genuine wiring loom for the coils, as the existing one is starting to look pretty secondhand.

So, I now have a fortnight to get everything back together, and we'll give dyno booking number 9 a crack!

[pipster11]

stock gtr bovs?

They technically don't hold any pressure because both sides are presurised, its just the amount of air they can flow when open i guess

[R33huntme]

I'm running stock gtr bovs and I'm making 340atw kw haven't had a problem. Good luck with dyno no 9

[rb26stagea]

would look at the OEM valves, but since I'm insisting on buying brand new, I can pretty safely assume that aftermarket will be the cheaper way to go. Damn you, Nissan Australia for your parts prices! It will be interesting to see how hard they sting me for the bonnet liner when I get around to it: No aftermarket option for that part!

While I'm on my parts rant, here's a couple more examples:

Headlights for my Gloria: $900USD each was the cheapest I could find, but I ended up getting a used but mint pair off yahoo for $280.

Woodgrain trim piece around the gearstick (Gloria again), $900 from Nissan Australia, $32 delivered from yahoo

The only part that seems to be much the same cost (including freight from Japan) is the centre air vents for the Gloria: around $450.

Anyway, enough of my inane chitchat: carry on, Ladies and gents...

[pipster11]

Someone on the fb page said they got their bonnet liner from nissan for around $60!

Some things are actually decently priced

http://www.amayama.com/search/?q=1448305U00&cur=AUD

looks like $230 a piece from japan, plus shipping obviously

[rb26stagea]

Well that's more like it - will swing past later in the week and see what my local dealership wants for it: it's embarassing: shiny pipes, painted rocker covers etc, and manky old bonnet liner drooping over the whole thing...

[Sisbro666]

Correct me if I'm wrong but melting a piston is connected to running an engine too lean?

[GH05T]

after buying brand new decent tires for the 34 which is now going to be up for sale, i didnt want to waste the effort so i swapped the wheels.

black R34 gtt wheels look kinda good on the stag,

and yes....it will be much lower soon.

[rb26stagea]

Correct me if I'm wrong but melting a piston is connected to running an engine too lean?

Yeah, but with unknown km on the internally stock engine, coupled with the fact were pushing it pretty hard, it was suggested that carbon deposits on the pistons may have caused hot spots...? Either way, I've always considered the dyno a gamble on engines of unknown history, and I'd had a good run with that setup: 6 years of faultless motoring was a pretty good effort, I thought...

Doesn't matter now at any rate: it's all full of forged goodness.

[rb26stagea]

after buying brand new decent tires for the 34 which is now going to be up for sale, i didnt want to waste the effort so i swapped the wheels.

black R34 gtt wheels look kinda good on the stag,

and yes....it will be much lower soon.

Damn: that's similar to mine! Lol!

I thoroghly approve...