boosting issues

[Limbo]

Hi guys
Just wanna see if anyone can give me some ideas with my car.
Currently its boosting but only around 6PSI, it spikes at 7PSI but drops to 6PSI.

Was working fine before, i changed the intercooler.
I've changed to a smaller cooler for better airflow around the car.

I've chcked for air leaks but found none, changed the BOV just in case.
checked the eboost lines, but nothing coming up with anything.

Anyone with any ideas?

Was working fine before i changed intercoolers.

[mugen_ctr]

did u get a larger cooler? usually this is why it happens, larger volume of air, requiring more air to fill it to get it above positive air pressure....

1psi spike is nothing, if ur spiking to 12psi than id b worried! since the set limit was on 6psi

If u got money to blow, electronic boost controller ftw! they can hold the boost at 6psi much better than any bleed valve through the whole RPM's

[Limbo]

i changed to a smaller cooler & i'm running eboost2

[mooshie]

How much of a size difference are we talking and what boost have you got it set to?

[DLO01]

And where is E boost plumbed in to? Before intercooler or after? I'd say you have it before interecooler?

What was the boost with the old intercooler?

[Limbo]

plumbed into intake manifold for reading
boost on older cooler was 10PSI.
Can feel the difference when i drive it also, doesn't have the punch it use to after 4.5krpm

[B16]

Have you checked the wastegate? There could be a problem there, stuck or something similar. If you have no leaks and the boost source point is at the IM, it would not be different from the previous setup.

I had a fubar wastegate that was leaking and causing boost creep, could be a similar problem but reversed.

[TODA AU]

Your problem is simple, easily explained & rectified with what you already have.
Steady 10psi - no problem,
Your real problem is that you probably can't do this yourself & deep down, you know you're going to have to pay someone to sort it out for you. Lol...
You can try do it yourself...
But at your own peril... lol

Your issue in a nutshell...
You have an increased pressure drop across the cooler core.
You have not compensated for this in your ebc settings.
Dropping the gate pressure will solve the perceived spike.
Increasing the rate will up the boost.

[Slaz]

lol at some of the posts, but Adrian has pointed out the problem.

[B16]

Please explain. I don't understand how that can be correct. If the eboost is measuring and regulating pressure at the intake manifold, it doesn't matter two hoots what the pressure drop across the intercooler is as the EBC should just keep the wastegate closed longer untill the pre determined pressure is reached at the measuring/regulating point, in this case the intake manifold....

[DLO01]

^^^ thats how I understand too Matty. Its measuring boost for wastegate at intake manifold.

[Limbo]

Please explain. I don't understand how that can be correct. If the eboost is measuring and regulating pressure at the intake manifold, it doesn't matter two hoots what the pressure drop across the intercooler is as the EBC should just keep the wastegate closed longer untill the pre determined pressure is reached at the measuring/regulating point, in this case the intake manifold....

yeah that's what i thought too. By decreasing the cooler size i would have thought the boost would increase. it actually boosts up quicker. Eboost is set to 12PSI, the max readin i've been getting is only 7.4 PSI.
Will be changing some of the vacumm hoses first and see if that solves it

i just don't have the ability to drop the car off at the moment.
Will get it sorted when it goes in for its water-to-air additional cooling