Over Boosting

[mitchy_]

after fitting my 600x300x75 fmic, and boost controller... my car is hitting approx 15psi or more..

i used to have a 450x300x75 fmic, and no boost controller.. car used to hit 10psi, and the bov made a tad quieter than normal sound..

after fitting the 600x300x75 and boost controller (no adjustment made, tried it without it too), car got up to 0.5 bar as per normal, then it rocketed up to a bar, and the blow off valve makes a very loud noise on throttle release now...

edit: this isnt flat footing it either, this is 3/4 throttle up to about 5000RPM, then changing gears.

only thing i can think of is the hose from my boost controller/bleed valve is a smaller internal size than ther old hose, as it was too short.. is the smaller hose restricting flow to the wastegate, thus pushing boost up?

any ideas would be great, cheers!

Edited August 27, 2005 by mitchy_

[Steve]

Sorry mate, just re-read your post.

A boost controller will bring boost on much quicker than factory setup or even using a bleed. Add to that a cooler that may have a bit of pressure drop and you will have a world of difference.

Just remeber your stock boost pressure is around 9-10 psi, with a 2 stage boost control, where you get approx 2 psi less until you reach around 5000rpm.

Hoep that helps explain the difference

Edited August 28, 2005 by Steve

[mitchy_]

the wastegate was plumbed after the intercooler, and before the BOV, and the throttle.

edit: i dont think i have the normal 2 stage boost anymore, ive got a microtech lt12 so it used to hit high boost all the time.

old fmic was a ARC 450x300x60, but it ran the old piping, so maybe the 180 degree bend on the return side caused a bit of pressure drop?

Edited August 28, 2005 by mitchy_

[AD4M]

I would think a bend in a pipe wouldnt be causing any type off pressure drop but more likely a restrictive intercooler core....

But previously having an ARC cooler i wouldnt think such a thing, being one off the best coolers available on the market.

Maybe it might be a faulty actuator or a split in the line to it. And you have tried running it without the new boost controller aswell?

thats all i could think off

Cheers

Adam