Weird Sounds When On Boost.....

[GTS R33]

Past few weeks ive noticed car making popping sounds (machine gun like/powerdrill sound when u cant drill any further) when on about 11-13psi throughout the rev range. So i turned boost controller right down and it is still doing it, but in higher rev range. Also with turned down it just spools slower but is still 10-12psi????

anyone have any ideas.....

[StealthX]

missfire?

check your plugs and coils.

gap your plugs down cos it seems your boost is blowing out your spark.

or it could be detonation you're experiencing, what fuel are you using?

p.s. might help to list the mods your car has mate lol. then weve got some sorta idea what your engine is dealing with...

[GTS R33]

3" cat back, pod filter, hybrid intercooler, el cheapo manual boost controller go fast bits.

i only run bp ultimate fuel.

gts-t r33 series 1

it is worse when its colder temperature outside .... e.g. night and early morning

[51NNA]

gap your plugs to 0.8 and go from there

[Bunta]

I beleive you have found richen and retard airflow point in your stock (?) ecu, once the computer senses a certain airflow it will richen the mixture and retard timing. The reason this could be happening now when it wasnt before could be due to the colder weather, colder denser air = more total air into the engine at the same boost. Try turning the boost down to stock and see what happens!

[.:: GimpS-R34 ::.]

also out of curiosity.. have you washed your engine bay down at all?

[GTS R33]

washed engine bay like 6months ago, i did clean MAF sensor a 2weeks ago... i tried winding boost down, i will try other way in case i opened it up, but as per instructions it is down as it seems to stay under 15...... holds on 10psi then higher revs when spiking over 10psi it hits the noises.

[Bunta]

washed engine bay like 6months ago, i did clean MAF sensor a 2weeks ago... i tried winding boost down, i will try other way in case i opened it up, but as per instructions it is down as it seems to stay under 15...... holds on 10psi then higher revs when spiking over 10psi it hits the noises.

R&R for sure

[GTS R33]

how do i overcome this

[Jdfnq]

I beleive you have found richen and retard airflow point in your stock (?) ecu, once the computer senses a certain airflow it will richen the mixture and retard timing. The reason this could be happening now when it wasnt before could be due to the colder weather, colder denser air = more total air into the engine at the same boost. Try turning the boost down to stock and see what happens!

^^^ What he said

how do i overcome this

Wind back the boost..... 10psi is sometimes enough for the ecu to R&R....

Your could also try re-setting the ecu and see how that goes.... If it hasn't been done for a while, it is well worth doing.....

[GTS R33]

ok dumb question, but where is ecu and how do i reset.

i am thinking of upgrading ecu system, would this also overcome this problem if it can be adjusted

[Bunta]

to reset the ecu just unhook the battery and leave it for a while, when you hook the battery up again it will reset itself. A new ecu will solve the R&R problem as this is a feature only the stock ecu has!

[GTS R33]

ecu prices???? whats good??? im still quite new to turbo cars and what can be done, and what needs to be done at a time......

[mad082]

z32 ecu + nistune = a lot cheaper than a pfc and pretty much just as good

[Bunta]

yeah i would investigate a nistue, depending on future plans of course

[defari]

if it helps, i got a sII with similar mods.. mine was making the same noise when i first bought it.. turned the boost down to stock (had to do a bit of trial an error with the manual boost controller and the boost gauge) running 7-8psi no missfire/popping noise when foot is flat on the gas.. I tried turning the boost back up a few weeks ago up to 11-12psi, which made it missfire slightly again.

stock turbo / ecu doesn't like anything above 12psi

[externaled]

sounds like an engine misfire to me, check plugs and coil packs first, igniton will mostly break down under load, more load the worse the misfire. This sounds like what you are experiencing