Barnesy

Has anyone got a 'numpties' guide to fitting a 3 port boost solenoid to an STI8
Cheers

New_scooby_04

iTrader: (4)

Hi mate,

Can't help you with the guide I'm afriad, but you do know the car will need mapping straight after installation don't you? Many get it done by their mappers immediately before the car is mapped.

Ns04

WR1 Ant

Cant see why it will need maping it does the same job but just has more accurate control of the boost.

People get it done before mapping because it becomes more neccessary to have a 3 port after mapping as more accurate control of the boost is required.

Barnesy

Will be trying to fit just before having it mapped.

The Trooper 1815

iTrader: (31)

Few extra bucks and get them to do it.

cw42

iTrader: (1)

come look at mine stuart, if your at the g/f's I'll pop over to you tea time if you like

New_scooby_04

iTrader: (4)

My understanding is that, yes, it does the same job better, but you need it mapped straight away as the ECU is expecting a certain signal from the 2 port and gets a different signal from the 3 port. I didn't ask my mapper what would have happened if I had tried to run the car after installing the 3 port without the mapping, but I'm guessing that my boost control would have been all over the shop.

Also, if I understand it correctly, not everyone needs a 3 port after mapping, especially when they're sticking with the same turbo, or staying below a certain level of boost.

I'm far from an expert though, I'm sure a mapper or someone more knowledgable will contribute.

Ns04

KenS55STI

If you fit a 3 port in interupt mode (without restrictor using all 3 ports) then it will cause the car to overboost,ie produce more boost than the targets in the map. This is why they are normally fitted at the time of mapping. How much it overboosts will vary from car to car depending on spec etc. This may cause drivability issues and possible detonation.

You can fit it in place of the 2 port using the original pipework with the restrictor still in place using only 2 of the ports and it should work the same as the 2 port, but that kind of defeats the object unless you want to just get it installed and are having it mapped later.

I know this because I have one fitted to my sti 7.

If you don't have any issues with boost control using the 2 port and aren'tplanning on having it remapped then youmight as well stick with the 2 port.

Scott.T

iTrader: (2)

3-ports only worth fitting when you get up around 1.3bar.
It will need a remap, as described above, due to it's slightly different configuration.

It doesn't send any signals back to the ECU, the ECU just drives it at the duty cycle determined by the map.

If it's setup with no restrictor valve in the hoses (which is how it should be), the duty cycle will be bleeding alot more air away from the actuator, so it will overboost.

You may be able to work around this mechanically by fitting different size restrictors in the return hose (the very bottom hose from the solenoid).