Boost restrictor pill Removal

[Scubasteve]

Just wondering has anyone removed this boost restrictor pill and what changes good or bad have been experienced? I have a 3" Aftermarket System Fubi and HKS Drift filter but no aftermarket ECU. Any help thanks guys.

[Kitty's VR4]

I've done it....

Definitely notice the difference, not great gains but it is noticable, if your light on the throttle - no real difference to economy. If moderate (bit of spirited and normal driving), lost about 50k's per tank...... during track day got 175km from 45litres...... so thirsty as hell if your into it.....

In the above pic the restrictor valve appears to be plastic, mine was a brass valve.... additionally great care should be taken removing the valve from the solenoid body, with under-bonnet heat the plastic of the boost solenoid body can become a little brittle, I had no problems removing mine carefully, but I know of a few members that have snapped the vacumn hose tube off, so use kid gloves........

I used a small crochet hook to get mine out...

[Scubasteve]

Thanks Kitty, u can't get away from Q's LOL

[Kitty's VR4]

I dont have a boost guage fitted so I don't know what difference it made to psi reading, have also fitted series 2 -2002 ECU since then... kitty feels to be 10-20% up on power..... a seat of your pants reading...... i'll get a better idea at the next dyno day

[pu-11-me]

Just get a $30 MBC off ebay lol..... SOOOOOOOOO much easier

If you want regulated and controllable boost, get an EBC

[The Vee]

Surprised to hear of power gains - in my understanding all it does is restrict the the amount of rapid change therefore smoothing changes in boost not actually altering the final amount. I have got mine completely bypassed and I do find that when accelerating, if you come off throttle quickly it will produce a jolt as I think the rapid change to off boost confuses things slightly!

[Turbo_Steve]

That's also possibly caused by your dumpvalve "overdumping". That's what happens on the Evos.

[peter thomson]

Surprised to hear of power gains - in my understanding all it does is restrict the the amount of rapid change therefore smoothing changes in boost not actually altering the final amount. I have got mine completely bypassed and I do find that when accelerating, if you come off throttle quickly it will produce a jolt as I think the rapid change to off boost confuses things slightly!

I also get that jolt with my VR4

[Kitty's VR4]

Ummm, I haven't experienced the Jolt yet..... jolt... sounds violent..... my thinking was it reduced the boost spike, for example it smoothed the boost to an even 7psi, with the restrictor removed boost would spike out to 9ish psi, thats how it read in some of the japanese tuner forums.......

I think its time to buy a boost guage to see exactly whats happening, do some boost readings with the restrictor in and then again with it out......

Certainly felt like it made a difference...... was it the placebo effect???????

[MPBVr4]

That's also possibly caused by your dumpvalve "overdumping". That's what happens on the Evos.

Yep I get it now with a GFB Hybrid BOV fitted when half open to Atmosphere.
Close it for recirc only and no jolt.

[White Lightning]

That's also possibly caused by your dumpvalve "overdumping". That's what happens on the Evos.

I remember the JD used to do that when I drove it for a while ... that had an HKS SSQV fitted (and the Blitz EBC) and I thought it was probably caused by that.

Just one of the reasons I have decided not to fit a VTA dump valve to mine to date.

[MPBVr4]

The Hybrid one is OK if it's only open a bit (not half way) It's still enough to make small kids and cat's run for cover
I will grow up one day

[Turbo_Steve]

It's all down to the spring rate, and how big the holes in the dumpvalve are.

[Scubasteve]

Ok i'll test it with my boost gauge, but..... where the hell is it. I can't find anything that looks like that or even know where to begin please point a noob in the right direction

[matchtheclown]

Follow the red tipped hose that is connected to the intake pipe which is on the end of your throttle body.

You will need to remove the intake pipe from the throttle body and bend it back out of the way because it is underneath it.

[wintertidenz]

Here's some pics, excuse the weird piping - someone put my car back together the wrong way before I bought it.

You can see a pipe looped back in the top right corner, this is where the red tipped pipe starts:
http://i100.photobucket.com/albums/m..._0097small.jpg

Clearer here:
http://i100.photobucket.com/albums/m..._0233small.jpg

That pipe goes to two solenoids down here:
http://i100.photobucket.com/albums/m..._0230small.jpg

The one with the WHITE connector is the boost solenoid.

[Scubasteve]

Cheers guys where would VR4 Noobs be without u's. Probably driving Nissans or even worse Honda's lol

[MarkSanne]

Did this myself after reading somewhere on here about these restrictors and thought I'd post up a few pics in the forums instead of links (I hate those linked-pics as they seem to stop working after some time, right at the time one needs them).

So here it goes:

Remove the air intake pipes for some clearance as much as you want. If you're used to fiddling around tight spaces and/or have small hands you might not need to remove this much (I removed the MAF too as I did that mod too).

WARNING: I read the plastic parts of these solenoid casings can get brittle so I removed the bracket (2 bolts) where 2 solenoids are mounted on first, then turned the bracket around and unbolted the 'white' one (white connector).

One hose didn't want to let go, so I used a very small screwdriver and pried/lifted the rubber hose. Carefully again! Then it came of without a problem.

Alright, here we go. Pics!







I first used a small size paperclip that I bent slighty, but it wouldn't let go so I put the solenoid in a drill-clamp and on to the pillar type drilling machine with a very small drill. Ever so carefully applied pressure on it and within seconds without hardly any drilling done, the restrictor moved down a bit. Now it ws just a matter of using the paperclip method again to wiggle it out. All done within 5 minutes.

[AlanDITD]

im confused, thats two differnt parts of the car compared with what the firstpost in this thread is talking about.

[MarkSanne]

That's why I like to take actual photo's and post them.