leecharlton

hi iv just fitted a boost gauge to my 2001 bug eye impreza its a uk car the chap i brought it from told me he had someone adjust his actuator so it runs more boost but when i installed the boost gauge in second gear the boost pressure go's upto 20 psi and then drops to about 13 psi in full boost think this is called boost spike has any one got any ideas how to get my boost pressure running smooth think it can have it upto about 16psi at a safe limit i was going to buy a manual boost controller to control levels but not sure if this will get rid of the boost spike

scoobiewrx555

Your impreza already has 3D boost mapping so doesn't require an external controller. I assume you've got a TD04 Turbo therefore you need to re-adjust the wastegate actuator arm but to normal length to get your boost back down to where it should be.

Remove the wastegate actuator arm from the wastegate lever, loosen the locking nut, turn the adjuster on the end anti-clockwise half a turn making the arm longer, put it all back and check. If it's still not right do the whole thing again by another half turn.

Other things you can do is replace the standard 2 port electronic boost controller with a Perrin or Prodrive 3 port electronic boost control solenoid for better boost control, and replace the standard vacuum pipes going from the old solenoid (including the T-piece with restrictor pill because you won't need it) with 3mm internal diameter silicone hose. That should help a fair bit.

If you still get boost spiking the only other way to is to have the wastegate ported. TD04's are prone to spiking so there's no super cure for it but you can reduce it down to levels that won't affect the running much at all.

Once you've done all that get your ECU mapped.

leecharlton

ok will try that and let you no how i get on thanks for all the info