Gt35 Overboost Problem, Not Normal Creap,

[Rezlo]

Just fitted a GT3582R .82 with Tial 44mm gate in place of my previous GT3076R .82 with tial 38mm.

The 3076R ran mint, zero problems keeping boost at .8 to .9bar with zero EBC bleed off,

With the 3582R .82 w/ 44mm gate it is perfect till 5800rpm, doesnt even flinch, stays spot on .8bar, but as it hits 5800rpm it climbs like a btch to 1.8 1.9bar in a flash,

Ive checked all the boost controler hoses, all is fine, also turned it off, still same thing, checked my mapping, no massive changes in timing or fuel anywhere, particualy around that RPM,

Just wondering is anyone has has a problem like this, im wondering if maybe the new tial 44mm gate is not retracting all the way, displaying symptoms not common with regular wg being to small or manifold not flowing right where its a gradual increase, my problem feels more like a lightswitch effect,

as FYI this is on a RB25 S1 run with R33GTR D-jetro PFC, full built motor with 256 poncams, still the same mani and exhaust setup as the 3076R used without a problem,

Any hints would be fantastic,

[GeeTR]

Going from calaisturbo.com experience, one would have to ponder the m.fold / gate setup

[Rezlo]

I would have also said that, but its the exact same setup that the only minutely smaller GT3076R used, I increased the WG to 44mm (from 38mm) and increased the WG pipe size to try accomodate the slightly larger turbo, cant see it causing such a huge boost rise and not just a general over boost

[Ceffy]

G'day Rezlo.

I was just wondering if you were able to fix the problem with the overboost and what you actually did to fix it? as im experiencing the a similar problem to you. I have upgraded my turbo to a GT3062 and having the boost climb to high levels like your car.

[jay1]

bump

[Rezlo]

Yeah, The 44mm tial gate had a pinched diafram from the factory... Not the first time I have seen this now, had a 38mm two weeks ago also with a pinched diaframe.

[Ceffy]

  Rezlo said:

Yeah, The 44mm tial gate had a pinched diafram from the factory... Not the first time I have seen this now, had a 38mm two weeks ago also with a pinched diaframe.

ok, so did u just change the diaphram or the whole actuator?

[NYTSKY]

GT35R suffer from this more than other GT turbos.

Either get a new manifold built or tap your wastegate into the rear turbo housing.

What manifold do you have now?

[Rezlo]

Ive seen a few guys doing gates off the turbine housing, looks odd but works well. Just make sure its welded by a pro that knows about the materials hes using so it doesnt quench the housing.

[mico]

yes, would be good 2 know what manifold u are using.

[NYTSKY]

  Rezlo said:

Ive seen a few guys doing gates off the turbine housing, looks odd but works well. Just make sure its welded by a pro that knows about the materials hes using so it doesnt quench the housing.

My GT3076 is getting done as week speak. My mates GTK1000 has been done too.

Will never have any boost control problems ever again.

[Rezlo]

  NYTSKY said:

My GT3076 is getting done as week speak. My mates GTK1000 has been done too.

Will never have any boost control problems ever again.

Nope, never will, most effective place to have it,,,

[Ceffy]

Im using a stock hi flowed manifold with the GT30xx, im actually not entirely sure wat the exact specs of the turbo as the rear housing is a custom item which is smaller then wat u can actually buy, ive been told its something like a GT3062. When i fitted it to the RB the wastegate wasnt completely opening and fouling on a weld in the custom dump pipe, but after that was fixed it still wants to continually boost, even with the boost controller all the way down. my mircotech has an ignition cut at 16 psi to prevent from overboosting. so could the problem be with the actuator itself?