Boost upgrade

[adzs12]

A simple boost increase can liven up your standard s12 with a bleed valve fitted between the turbo and its actuator as shown below:



Also an intercooler should be fitted as the s12 never came with a standard intercooler. Most popular option is the sierra cosworth and volvo although others have been used such as saab and wing mounted intercoolers which can be purchased for the 300zx, 200sx s13 and 200sx s14, and will fit the s12.

Next is to remove the safety valve found on the inlet manifold near the bulkhead and simply block it up with either a welded bolt or as i have used a cap from a plumbing store which does the job perfectly.

Colder plugs NGK BCPR7ES should replace the standard NGK BCPR6ES.

The gapping should be set to .9mm using a feeler gauge.

The timing may need adjusting to prevent detonation.You may even be able to advance the ignition timing to upto 17.5 degs if you use super octane petrol. A rolling road run is always a good idea after any boost increase or serious modification

Once all this is completed a boost gauge should be installed so a safe boost can be set using your newly installed bleed valve.

A standard T2 will be stretched at 14psi and most opt for a safe 10-12psi as this is proved to be a reliable and safe setting

[s12Rob]

or you could buy a evc, boost controller which will prevent spiking and holds the boost v.nice

[PukkaSilvia]

There are many options. Ball and spring manual controllers are the prefered after the electric solenoid ones like you have. Depends what people have lying around or easily available to use.

Good useful thread to a new s12 owner :-)

Also fit an aftermarket boost guage before trying to set up your boost pressure increase. Try getting one in psi showing 1psi increments as this will be the most clear to read and setup in my opinion.

[s12Rob]

thanks for that pukka, was just getting to that exact point, lmao

[bigtim]

link to info
some old info on boost controlling

[alundra]

You can add a better exhaust system and a sport filter in box .

[alundra]

I've seen many pics for how fit a MBC:



In this pic, the hose which go to the intake, is the intake manifoild or turbo manifoild?

I'll fit a dump valve single piston.

In some pic, i've seen only the MBC between the actuator and the tubo manifoild:



Can you explain the difference, please.

[datdrift]

so am i better off paying around £10 for a bleed valve, or getting a mbc of ebay for around £25

[turbomike]

the bren device mbc is good,goes for around £10-£30 secondhand or about £43 new from apex