[Davey]

As per my other post we have replaced all of the boost solenoid hoses with silicone items and peak boost has jumped to 1.5bar..

Its a MY94 WRX, my question is how does the restrictor effect the boost levels, I would assume a smaller hole woud make the actuator open later and hold higher boost?? Or is it merely because the silicone hose has some stretch to it??

The car is pulling lke a train at 1.5bar (obviously) but is this safe? I know for a fact it over fuels so leaning off shouldnt be a problem.

Is it wise to make up a new restrictor, and if I did what sort of ID should I use?

Jolly Green Monster

iTrader: (4)

remove the restrictor from the original pipe work..

very much doubt it is safe at 1.5bar.. the standard map sensor will top out at 1.23bar and so the ecu has no idea it is running such high boost. Also the injectors will be maxxed out at about 1.3bar. The difference between rich at 0.9bar and fuelling at 1.5bar is huge especially as the ecu will only see 1.23bar or less if you have masked it.

I assume you have a fuel cut defender on it?

It is not all about fuelling either.

The silicone hoses which are soft are unreliable as they balloon under high boost hindering boost control.. but they look pretty.

Simon

[Davey]

Thanks for the reply, I have no idea if the car has a FCD, there is nothing on the car that looks after market, where abouts would it be installed?

Do you think we'll get away with the silicone hose if I make up a restrictor, the original hose that went to the actuator is rather knackered, it feels like its about to break up.

Jolly Green Monster

iTrader: (4)

if running nearer standard boost then yes the silicone hosing will probably be fine.

that is not the restrictor that is to allow large pipe to small pipe connection.

The restrictor is in the pipe from the vent on the three port to the air intake and is within the pipe.

Simon

scoobykevuk

what happens if this pipe breaks off the air intake like mine has????

sifly

Do different models have different size restrictors that can be swapped to change the boost setting?

Scott.T

iTrader: (2)

Not alot. You;ll just be drawing in a very small amount of un-metered air.
Alot of them break off as people don't realise it's attached until it's too late.

Scott.T

iTrader: (2)

There are different sizes depending on the turbo and MY.
Swapping them around will not achieve much as the turbo knows what boost it's supposed to be achieving. So will either fuel-cut if very high or spike and pull back to standard pressure if slightly higher then expected.

You can play with the sizes if swapping turbo's and you want to achieve the same level of boost. I had to do this when I swpped to a VF28 by using the slightly larger TD04 restrictor. This prevent over-boost/fuelcut until it was remapped propper.