YBJ

iTrader: (3)

What maximum boost should a standard T3 turbo for a cossie give at say 6000-6500 rpm?

I run a 330bhp chip from MSD. Boost is set to peak and hold 22 psi but tails off from 5000 backwards to only 15 psi at 6000 rpm. How can this boost fall back be reduced, anyone who knows?

Jim Galbally

std turbo, 2WD or 4WD?

pa_sjo

I doubt MSD would sell a "330bhp" chip for a T3........

Twellsie

iTrader: (1)

mine hits 25psi than tails of to 21psi, but its a 4x4 turbo, which I believe can run a little higher

YBJ

iTrader: (3)

Yes, its just a standard turbo for a 4x4 cossie.

Is that 21psi at 6000 rpm??

Twellsie

iTrader: (1)

I would have to check with Karl or a boost gauge, but yeah, I believe so

YBJ

iTrader: (3)

Do you use an open airfilter? Maybe this can make such a difference. I have a JR panelfilter in a standard airbox.

Twellsie

iTrader: (1)

I do run a cone filter yes, but it will be the chip in the ECU that is managing the amount of boost you run

cozmeister

iTrader: (1)

25 is about the limit of a T3. They will make more, briefly, but they'll most likely need rebuilding afterwards

Your chip will determine how much boost you get, and at what engine speed the boost will be cut.

Jim Galbally

cozmeister, no it wont determin that at all on a std T3 trying to push out 300+bhp

cozmeister

iTrader: (1)

Eh? Won't determine what?

Jim Galbally

the software on the chip.

the laws of physics will determine the boost level well before the amal valve will

GUZZLER

iTrader: (3)

is the actuator ok?

mechanic28

iTrader: (5)

amel valve jetted?

YBJ

iTrader: (3)

Yes, the amalvalve is jetted like MSD described and a 31- actuator is fitted.

I get the feeling it does has something to do what Jim wrote:

When I disconnect the plug on the amalvalve the boost is 19psi so the ecu cant reduce the boost anymore electronically IMHO. But the boost still goes further down to 15psi at 6000rpm
Therefor I was thinking of trying to reduce the inlet resistant by placing an escort BT airbox and bigger inlet hose. Dont know if this really make sense though.

Twellsie

iTrader: (1)

speak to Stu, ask him what the boost should be set at for the chip you have

daviddunlop83

iTrader: (7)

I got a chip from motorsport developments for a standard 2wd cossy with standard intercooler and exhaust running dark greens, -31, 3 bar map sensor and stu said it will make a genuine 320bhp peaking about 25psi and holding about 22 or 23.

Only just got it sorted as it wouldnt boost cause of the jet in the amel valve which i removed last night but was too wet to try it out properly

YBJ

iTrader: (3)

I know it should be set at 25psi max. This was the instruction that came with the chip. But it's the big reduction at higher rpm that I am woundering.

Twellsie

iTrader: (1)

sounds like the actuator to me

Jim Galbally

i would be looking for airleaks actually

YBJ

iTrader: (3)

How can an airleak give such a reduction at higher revs than and not at lower rpm?

pa_sjo

Because the engine is consuming more.. eventually the turbo simply wont be able to meet demand.

YBJ

iTrader: (3)

Ok, that make sense. Just fitting new RVS boost clamps from AS at the moment, so maybe these give a difference. Although the new clamp for the outlet of the turbo is all the way screwed tight and the hose still can be turned a little bit. Find that strange for a fully kit that they have available for a T3 turbo.