I've just fitted and Apexi power intake to my 1993 classic wrx (not out of choice but ?I have a FMIC and it wont fit with the stock airbox).

I took it for a spin and the car is now overvboosting. I have a esl chip fitted with 1.1 bar max boost, before I fitted the power intake it was rock solid at 1.1 bar max (as shown on boost gauge, which should prove it was/is reading correctly), now it looks like it spiked to about 1.2-1.3 on the boost gauge. Another factor which points to the boost gauge being spot on is that when I floored it it seemed to boost spike then lose power pointing to boost cut being hit.

I was going to fit a dawes device anyway which should remedy this problem, but why would fitting an IK lead to a boost spike?

It has also affected the sound coming from my HKS SSQV dump valve, its now less woosh and more chatter than it was before, is this normal? Can the DV be adjusted at all to give more woosh?

As ever all help much appreciated.

 

bump to the top for anyone who has an answer to this.

 

did you plumb the boost control hose from the bottom of the boost control solenoid back into the air intake. This normally goes into the bottom of the big black lunchbox/resonator thing.
Or did you throuh it way which normally happens when the air intake gets replaced.

There is a brass restrictor in this vacum hose that prevents boost spikes.

 

You have hit the nail on the head, the origional pipe did not stretch quit far enough so I replaced it with the one apexi provide. Luckily I have the old one on the garage floor so I'll be getting that back on somehow now. Thanks for the info, as ever much appreciated!
cheers
will

 

Cool....
Inside that pipe is a small brass restrictor. You can push is out with a long small screwdriver. If it fits tight in the new hose then just insert it into that.

 

Thanks scott, managed to get it out of the old pipe last night, will fit it into the new hose today.

Just a quick side point, If I were to bypass the boost solenoid with a dawes device, then what would be the implications for how quickly boost comes in and also how the ECU fuels accordingly for this? Its my understanding that the dawes would bring boost in as soon as possible and then relieve any extra pressure once the valve in it is activated. Surely this is different to how the stock ecu/solenoid would control boost and as such could result in incorrect fueling. Am I talking rubbish here or is there a danger a dawes could cause big engine damage, even if set to stock max boost settings?