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Trent made a suggestion that the boost drop maybe due to the stock BOV on the GTT not up to task? But were not 100% yet until I do the coilpacks and go back in for a retune.

Anyone know what the power limit on the stock BOV is before you need to be concerned?

He said to get a GTR one if it is the case.

No such thing as a power limit for a BOV when you understand exactly how they work. There'd only be a possible boost limit the seal inside it could withstand, though I quite doubt you've reached it. Plus plenty before you have done fine with it.

It usually means an intake restriction more than anything.

Consider:

If your boost was going up but power wasnt, and it wasnt massively DET prone, it would likely be an intake restriction.

If boost was going up, power not increasing by much, is detonating easily AND not making the right power then its probably an exhaust restriction.

If boost is going up, already nearly at the right power, and not making extra then the turbo is probably close to its limit and your motor as a whole (package) is why its not meeting expectation.

Hmmm. I don't think it's an intake restriction since I have a 4" aluminium intake as others do.

If your "cold side" of your intercooler piping is quite warm (hot side is burning hot) during dyno runs does that generally point to cooler also? Or is it not unusual to have warm IC piping during power runs? I've put my hand on it after going for a drive before and it's been cool, but that's not really the same as flogging it on the dyno.

Edited by copycutter

Hmmm. I don't think it's an intake restriction since I have a 4" aluminium intake as others do.

If your "cold side" of your intercooler piping is quite warm (hot side is burning hot) during dyno runs does that generally point to cooler also? Or is it not unusual to have warm IC piping during power runs? I've put my hand on it after going for a drive before and it's been cool, but that's not really the same as flogging it on the dyno.

"Intake" is generally defined as everything before the combustion chamber.

Yes I'm currently overseas and due back in couple of weeks time. But my workshop is still operating so carrying out jobs as usual, if I'm not answering the phone please send in an email. I will usually reply within 24 hours.

yeah the dyno guy said that for some reason some nissans do that weird shit with the rpm... he said it wouldnt affect anything but.

The power graph really supprised me because it feels nothing like that...it actually has nothing for ages then all of a sudden kicks in massively and frys tyres but that graph makes it look very linear.... very strange

I believe this behavior has some thing to do with short runners inlet manifold, put your stock inlet back on and that should smooth the power curve out. Also was it dynoed in 4th gear? It looks like as if it has wheel span off the rollers as the no. for KM/H is too short for the gear, if that is the case then the reading won't be true.

With the boost drop best is to get a boost reading pre the cooler. If that is also dropping then have a play with the actuator preload, try a stronger actuator or the twin actuator setup. That generally lowers it to about 2.5psi. Needs to play with it a little to set it up. Or come pass once I get back I should be able to twick it to the right level driving it around in 3rd gear with a boost gauge.

Where's Stao these days? I want some Turbo.news :)

:action-smiley-069: I've done two more drawnings relating to newer generation of FNT turbine housings so hopefully be ready for trail when I get back. The new housing is a little bit more "for giving" that allows more circulation of exhaust gas in the exhaust housing, which should lower heat and increase turbine side efficiency. In theory would work well in abit restrictive eviroment.

2ndly as we all know split pipe creates boost creep. The 2nd drawning allows an adjustable "bank" inside the turbine housing making the creep controlable. That should combate boost drop behavior in upper rev range. I might need to re-engineer a special actuator that allows more travel for it to work. Will post results and photos once they are made.

Stao my SS1PU held up all weekend at SAU Nats!

Over 800m I Managed a 0:21.893

Running Street Federal 595's with my daily R33

On a rough rocky airport surface and it was my first time having a crack at drag racing.

Cant wait to get out again and see what it can do with some more practice

:action-smiley-069: I've done two more drawnings relating to newer generation of FNT turbine housings so hopefully be ready for trail when I get back. The new housing is a little bit more "for giving" that allows more circulation of exhaust gas in the exhaust housing, which should lower heat and increase turbine side efficiency. In theory would work well in abit restrictive eviroment.

2ndly as we all know split pipe creates boost creep. The 2nd drawning allows an adjustable "bank" inside the turbine housing making the creep controlable. That should combate boost drop behavior in upper rev range. I might need to re-engineer a special actuator that allows more travel for it to work. Will post results and photos once they are made.

New parts are always good :)

Keep me posted

:action-smiley-069: I've done two more drawnings relating to newer generation of FNT turbine housings so hopefully be ready for trail when I get back. The new housing is a little bit more "for giving" that allows more circulation of exhaust gas in the exhaust housing, which should lower heat and increase turbine side efficiency. In theory would work well in abit restrictive eviroment.

2ndly as we all know split pipe creates boost creep. The 2nd drawning allows an adjustable "bank" inside the turbine housing making the creep controlable. That should combate boost drop behavior in upper rev range. I might need to re-engineer a special actuator that allows more travel for it to work. Will post results and photos once they are made.

Sounds good Stao :thumbsup:

Just got my tune done today and ive currently got a highflow version , it made 270rwkw on 18psi, is this a safe/good level to be on for this turbo?

Mods i have are :

Hdi ebc

Apexi 3inch power intake with pod

Haltech plug pro

S15 injectors

Sard Fuel pressure reg

Pretty much all mods that can be done without doing the internals.

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