SKYPER

Between Haltec, PowerFC with price??? Vi-PEC ECU - http://www.vi-pec.com/ Link G4 ECU - http://www.linkecu.com/products/engine-man...-ecus/g4-xtreme Although after watching the Envy Imports R34GTR with Haltech ECU, kind of like the Haltech ECU -

Depends on what you want to do with engine. If you want a high reving engine for dragracing use (above 6400rpm) and need more rpm points (where ignition timing, amount of fuel injected changes) above 6400rpm, Haltech or PowerFC would be a better choice. If road / racetrack engine and not going to rev above 6400rpm, stock ECU will do the job. Also some aftermarket ECU's like Motec ECU for example is suited to competition use and can change troublesome sensors (CAS, etc) which can't be done with stock ECU, PowerFC ECU (have to run stock sensors, etc). Except for AFM that can be changed to Z32 AFM, etc. Also aftermarket ECU's have onboard boost control, launch control, etc. Just too many features to list. Usually more rpm points = rpm points closer together and result's in a smoother reving engine due to engine doesn't struggle to rev between rpm points, but takes longer to tune which cost's you $$$. Stock ECU with 6400rpm / 16 rpm points = rpm point every 400rpm. PowerFC with 6400rpm / 20 rpm points = rpm point every 320rpm. Haltech ECU with 6400rpm / 32 rpm points = rpm point every 200rpm Motec ECU with 6400rpm / 40 rpm points = rpm point every 160rpm. Can see why Motec ECU is popular on dragracing, racecar, etc engines. If engine is RB25DET, Haltech, Link or Vi-PEC ECU. Motec ECU if you have the $$$$.

Refresh with metal headgasket, etc, 370rwkw is possible - http://www.skylinesaustralia.com/forums/Tu...p;mode=threaded What that 370rwkw engine sounds like -

Check that cam cover screws aren't loose. It can happen on exhaust side of back of engine. Can hear lifters more and get a oil leak when that happens. Only proper solution to fix hydraulic lifter is pulling hydraulic lifter apart and cleaning the hydraulic lifter, as get gunk build up between 2 parts of hydraulic lifter that makes hydraulic lifter tick or seize (could be due to not servicing / changing oil often enough). Worse case you have to replace hydraulic lifter. It is said that you don't have to service hydraulic lifters, but I gather in reality you have to. Note: Always remove hydraulic lifter and put hydraulic lifter back in same spot with same parts (don't mix up with other hydraulic lifter parts). Why, because each hydraulic lifter is bed in with each lobe on factory cams x2 with RB25DET.

Knock??? If knock is detected or there's something on engine creating excessive noise (failing coilpack, wide sparkplug gap, loose mounting bracket, etc), knock sensor can make stock ECU switch to knock maps (some people know it as rich, retard, but the real name is knock maps). Knock ignition map on stock R33 ECU has O degrees of ignition timing when engine is on boost, foot to the floor, so that's probably why engine doesn't want to rev. I would suggest running higher octane gas, check for failing coilpack, check for wide sparkplug gap, check for anything loose on engine to see if it cures the problem. If above doesn't cure the problem, then Link G4 ECU with optional IAT (Inlet Air Temp) sensor. Link G4 ECU has onboard barometric compensation for altitude and VCT control - http://www.linkecu.com/products/engine-man...-ecus/g4-xtreme

If aftermarket BOV is recirculated with stock airbox, BOV release sound should be quieter. But with podfilter you should hear BOV release sound more (through podfilter). If you vent BOV to atmosphere / engine bay with a engine that has a AFM, then you'll have problems with engine running rich due to ECU can't compensate for loss of air inside intake piping behind AFM. If with aftermarket ECU + MAP sensor, IAT sensor, etc, shouldn't have any problems venting BOV to atmosphere because ECU can compensate via MAP sensor on intake manifold. Golden rule is to always recirculate BOV with engine that has a AFM, as recirculating air back through turbo retains the same amount of air inside intake piping and engine doesn't run rich. AFM is the reason behind why factory recirculates stock BOV. You'll need to retune ECU to take full advantage of BOV mod. A good BOV should make engine run leaner, as there's more air reaching engine and result's in more hp throughout powerband.

The flutter sound = form of compressor surge and is bad for turbo. It can mean BOV is not opening quick enough / properly. Usually the flutter sound is heard through podfilter. Check vacuum hose to top of stock BOV for leaks, as that can make stock BOV not open quick enough / properly. Or it happens after modifying stock BOV. This is what the worst form of compressor surge that you can encounter sounds like on a R33 25T and is related to turbo (can damage engine, turbo) - http://www.youtube.com/profile?user=synapt.../25/nCj6Spwl1CU I used to get flutter sound at low boost levels with modified stock BOV. My solution was a Synchronic BOV from USA, which is a piston type (no diaphram), pull type type (stock Skyline BOV is a push type, so get pushed open under boost) BOV which reacts faster due to having no diaphram and doesn't leak under boost due to being a pull type BOV. Synchronic BOV opens as low as 0.5psi on boost gauge on a Skyline, which gets addictive. Also get a noticeable increase in throttle response, transitional response from engine when Synchronic BOV is recirculated over modified recirculated stock BOV and engine feels better off boost. On a Skyline it sounds similar to this car in link below, but it's vented to atmosphere on that car (louder) - Alot of people say you don't get a increase in hp from changing a BOV. But you do if BOV is leaking, as shown on this 500rwhp+ turbocharged Corvette in link below - The A/F ratio plot for that Corvette shows a slightly leaner A/F ratio (I gather where the extra 24rwhp or so came from), so you know more boost is reaching engine. It also backs up what I have felt on my car. Synapse Engineering sell the Synchronic BOV - http://www.synapseengineering.com/

To be 100% sure they are aftermarket cams, pull camcovers off and measure the height of lobe and base circle diameter with vernier clamp. Aftermarket cams should increase mid to high hp, torque. Can create a bow look to dynograph at lower rpms when cams have enough duration, lift. Also aggressive enough cams should create a lumpy idle (or stock / Tomei cams that had camgears adjusted). Tomei Poncams probably would have a smooth idle and look similar to stock cams, unless you adjust the camgears to make idle lump. This dynograph shows what happens when intake, exhaust cams are adjusted on RB20DET (should be similar with RB25DET) - http://www.uniqueautosports.com/Dyno/yx32gtstdyno.gif But VVT plays a role with powerband, so I would be looking at VVT settings. Tomei has a section on their website ("Making a good use of VVT") that talks about how VVT affects powerband - http://www.tomei-p.co.jp/_2003web-catalogu...8_camshaft.html The first example under the heading (left side) where midrange is lost looks similar to your dynograph.

Can get custom forged pistons if you send your factory pistons to piston manufacturer. But most fit CP forged RB20DET pistons and haven't had any problems - http://www.spoolimports.com/content/CPPistons.asp Also H beam conrods for RB20DET - http://www.spoolimports.com/content/SPOOLRB20DETCONRODS.asp

Interesting. Aussie Rivalry - http://www.youtube.com/watch?v=pgAW2zaGkXU Aussie Rivalry 2 - http://www.youtube.com/watch?v=PXJYvS87q1c Aussie Rivalry 3 - http://www.youtube.com/watch?v=d_sWiWNMWKo

Interesting subject. Nismo didn't run stock BOV's on their 24hour R35GTR racecar (didn't hear about a turbo failure and can't hear any compressor surge) - http://www.viddler.com/explore/GTRBlog/videos/47/ Photo of Nismo 24hour R35GTR engine bay without stock BOV's - http://www.gtr-world.net/media/4/20080706-02-001.jpg But transmission seems to shift quickly on R35GTR, so probably keeps turbo's spooled up during gearchanges. Also I have read somewhere that the stock R35GTR turbo's are non ballbearing (non ballbearing turbo's can run without BOV's). Cefiro RB20DET engine didn't have a BOV, but had non ballbearing turbo, etc - http://www.flashoptions.com/i_prod/cefiro%20RB20%201.JPG R32 RB20DET had ballbearing turbo and BOV.

Who's R31Nismoid??? Only internal wastegate actuator that I know of, which would be around 10psi when tested on bench is a stock R32GTR internal wastegate actuator.

I don't think stock RB25 internal wastegate actuator is a problem at 10psi. With ECU retune, tuner probably still used the stock map scaling on GTS ECU that only goes to 6400rpm. Only GTR ECU maps that I know of go to 8000rpm and can add more ignition timing, more fuel above 6400rpm to keep boost, power rising with stock turbo's. After 6400rpm, stock GTS ECU uses the last settings at 6400rpm for fuel, ignition until rpm needle hits redline. My theory is more rpm = more air sucked in by pistons inside engine and air forced in by turbo + same amount of fuel injected by ECU at 6400rpm+ = leaner A/F ratio as revs rise and boost level drops. Also not enough ignition timing above 6400rpm, leaking stock BOV could be part of the problem. If a RB20DET internal wastegate actuator is tested on bench and arm moves at 10psi, then there's something wrong with the spring inside bulb part of internal wastegate actuator or is not a RB20DET internal wastegate actuator.

Do you mean 12psi R32 internal wastegate actuator??? I wouldn't expect power, boost to rise above 6400rpm with stock turbo, stock ECU tune, as it's running off the edge of fuel, ignition maps on stock ECU. So ECU tune probably would be the limiting area as far as power, boost goes, not stock internal wastegate actuator or stock turbo.

R33 RB25DET has 2x different internal wastegate actuators. Automatic R33 RB25DET internal wastegate actuator is around 4.8psi-5.6psi. But you'll probably find it's roughly 5.2psi when tested. Both auto, manual internal wastegate actuators on R32 RB20DET have the same psi. Not sure why they changed it on the R33??? Don't know about R34 RB25DET, but could be similar to R33 RB25DET. Manual internal wastegate actuator like where talking about above (he has a PowerFC which is manual ECU only) has a higher psi internal wastegate actuator. How to find internal wastegate actuator spring pressure - Remove internal wastegate actuator from turbo. Get a boost gauge or compound gauge with T fitting, 2x 6mm ID vacuum hoses and plumb boost gauge T fitting into middle of 2x 6mm ID vacuum hoses and plumb one of the 2x of 6mm ID vacuum hoses onto internal wastegate actuator bulb. Then slowly apply compressed air via a compressor to end of 6mm ID vacuum hose where nothing is plumbed in. Then see what psi on boost gauge that the internal wastegate actuator moves the arm. Then you'll have the spring pressure of the internal wastegate actuator. Factory BOV is a push type BOV and valve gets pushed open under boost, leaks. When factory BOV is modified it doesn't leak as bad as it did without the stock BOV mod, but you have blocked the quick release part of BOV, so flutter sound (form of compressor surge) can be heard at lower boost levels (bad for CHRA on stock turbo). The flutter sound you hear is the air reversing direction, hitting compressor wheel and slowing turbo down.