Stock boost solenoid modification

[Airzone]

Hi guys,

Just looking to modify my boost solenoid on my stock r33 gtst.

I went out to the car with the trusty ol' multimeter and disconnected the plug to the boost solenoid. I measured the voltages and although one of the lines was 13.5 volts, bridging the 2 connections showed nothing on the multimeter. My guess is that the ECU has a negative trigger that controls this (i.e. takes the negative line and shorts it to ground when it wants the solenoid open).

Just to test, I left it disconnected and went for a fang - and no trademark boost increase (was expecting that anyway).

Anyway, I figure that if I were to have the solenoid always open, the midrange power should increase because there's going to be 7psi of boost instead of 5. Then when the engine revs above 4,700 rpm, it should be exactly the same as before ('cause that's when the solenoid is opened by the ecu). Obviously it'll also have no effect while the turbo's not boosting.

So, I'm going to modify the solenoid so that it's always powered either by running my own lines into the beast, or joining the ecu's negative trigger to a real ground (won't affect the ecu anyway) which should also keep the thing always open.

Won't increase performance much, but should give me an edge over other stock r33's

[kjb_r33]

yep, solenoid only dumps some pressure back to the low pressure side when its powered...

[Airzone]

Heh, it works Cost me all of about $0.30 for my first performance mod.

Here's what I did...

Got a length of wire about 5cm long and stripped both ends. On one side went a small fork crimp and the other side had the smallest spade crimp I could get (about 2mm). Got another length of wire about 20cm long, and put a similar spade crimp on one end and a crimp with a 13mm hole on the other end..

The big wire went on the LEFT connector in the solenoid and was bolted to one of the bolts that held on the power steering bracket. The small wire went from the RIGHT connector of the solenoid and I cut one of the forks off. The remaining fork was shoved in the RIGHT connector of the original sire to the solenoid.. Electrical tape holds it in tight.

No pics sorry, but it gave a little extra boost between 2.5k rpm and 4.7k rpm and you don't get that extra boost level at 4.7k rpm anymore.

Now all I need to do is find a purely stock skyline to test it out (not while it's raining though )