What Next?

[Tangles]

Ok, had my last tune done a few weeks back. Automatic, hiflow Slide turbo, usual mods etc, 183kw.

Boost seems to be dropping off..... car ramps up on the street to 105kmph so perfectly, then there is the boost drop and you can see that has a stranglehold on peak power.

Tune curve looks good for an automatic, 4th gear, with 2x piggyback controllers (Sitc / SafcII). If the boost held better I have no doubt a bit more (10kw+) power ultimately could be found in the top-end. Torque is fairly impressive, and on road 0-100km is very nice indeed for a family wagon.

But - what to do about the boost drop. Get a HKS adjustable turbo actuator, and set to 1bar, so that it holds peak boost for longer?

Power is down tho, lat tune 189kw this tune 183kw. Feels more responsive on the street tho. Had the group-buy Aerospeed adjustable cam gear wheel installed, wonder if it was set correctly (ie retarted 4degrees and not advanced 4degrees!); plus had to have the water pump replaced too.

Other than that, its all good. This was my 30k project over the past 2yrs (incl car price + mods + labour/tunes), and now its all done. Just figure tho that it isnt quite right, feels great but the graph shows the boost loss and a cple kws down on what it should have. What to do about it?

* might save up for a DrDrift ecu remap (1300 hundred! I think) and 500cc injectors, then retune still using the SAFC/SITC combo *

Any hints tips comments appreciated.

tangles

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Dayz special edition series 1 Stagea RS V Four,

94000kms, automatic, RB25DET engine, Attessa 4wd

1997 model silky snow pearl, lives in southern Adelaide

Clarion stereo tape unit with 6-stack cd player

Clarion amp

Clarion 10inch subwoofer

Pioneer 260w 4-way front door speakers

Eclipse 80w 2-way rear door speakers

Black Widow 10000 car alarm

New Oxygen sensor

New 400amp battery

New fuel filter

New oil filter, fresh Motul 10/40w Turbolite engine oil

Fresh fluid throughout, 100,000km service done (new water pump, belts, all fluids, exhaust studs etc)

Davies Craig automatic transmission oil cooler upgrade kit

MV Automatic shift kit & service kit

Whiteline front and rear adjustable swaybars

Dayz adjustable engine swaybar

Whiteline front castor kit

Whiteline rear subframe alignment kit

Maltech stainless steel braided brake lines, front and rear

DBA slotted front brake discs

Benidx Advance front and Heavy Duty rear brake pads

R34 GTT 17inch rims with Hankook K104 Vetus tyres, 235/45/17

Bilstein front and rear suspension shocks, with ‘lowering’ circlips, using standard springs

Bosch 040 fuel pump with direct battery feed at 13.8volts

Volt stabiliser kit

Aerospeed adjustable exhaust cam gear pulley wheel

Greddy remote oil filter relocation kit

Sump plug drain valve

Nismo adjustable fuel pressure regulator

Nissan Z32 Air Flow Meter

3inch JustJap stainless steel single dump pipe system

3inch Catco high flow catalytic converter

3inch cat-back exhaust system with GTR Kakimoto racing free flow muffler

K&N pod filter

Cold Air Induction aluminium box w/ lid setup, using standard snorkel air feed

Hybrid dual stage Electronic Boost Controller, set to 1bar

Apexi 'hybrid' front mount intercooler with custom return air feed pipe kit using stock holes

Apexi boost gauge

Apexi SAFC Super Air Fuel Computer

Apexi SITC Super Ignition Timing Computer

Sliding Performance water/oil cooled bush bearing HiFlow Turbocharger

183kw @1bar in 4th gear

[Cubes]

Hey Tangles,

Head down to bill at ATS and pick up a 14psi garrett actuator. Form memory they are around $120-150 ish

The std actuator is only rated to 7-8psi or so. 1bar is a big ask especially as turbine pressure rises and attempts to push open the wastegate.

How is the cat? Maybe thats not too healthy.

The slight difference in power 'may' be simply a different day, different tie down.

Or you could be right.. lol

Either way if mid range is up then thats the affect the cam gears have made.

[Tangles]

whats the better option - HKS Heavy Duty Actuator for $135 delivered for Nissan Stagea from Nengun, or a Garrett version.

Id like my engine to be able to hold the boost for longer...........

[Cubes]

HKS from nengun. All though its a wait from nengun its bolt on where as the Garrett requires a bit of messing around.

Obviously becarefull until its retuned.

[Abo Bob]

It's probably the actuator but check that your bov isn't leaking first.

[Tangles]

it does sound quite 'airy' at high boost.

might look for a GTR bov, what year would I need for a '97 rb25?

If I need to replace the stnd bov I would definately be after a plumb back unit that wont leak at 1bar; Turbosmart I guess.

ordered from Nengun a HKS Heavy Duty actuator and a nice 1.3kp radiator cap.

[Cubes]

Rip your std bov off and block its bleed hole off. OR do the coke can block the bov off trick to see if it helps it hold boost.

Saves you wasting $$ on a problem that may not be related to the bov.

[Tangles]

well, I found a cheap GFB Stealth FX skyline atmo (or) plumback bov.

off for a drive across adelaide and will be picking it up shortly.

Id imagine that when set to 100% plumback mode it should run alright on the rb25det.

if I installed it straight away would I require a retune or would it be safe to drive? car seems to be running slightly rich at the moment.

or is it safer to wait till next tune to install it - along with the heavy duty actuator with a quick 1hr dyno session to retune the top end (probably around new years time)

cheers