Jump to content
SAU Community

Recommended Posts

Hi, I have a problem with my car overboosting and causing it to knock

here is my set up

GCG HF/BB

555 HKS injectors

Pro spec B2 B/C

FMIC

it was set to 15psi high boost and 10psi low boost on the dyno

on the road high boost climbs to 17.7 psi and low to 12.2psi low

my boost controller on high is set at

gain 15%

set gain at 50

the over boost cause to knock after 6000rpm

any ideas why

cheers

joe

Link to comment
https://www.sau.com.au/forums/topic/192179-overboosting-knocking/
Share on other sites

when my m8s car was on high boost it started knocking at high revs... then at most revs... then at all revs... the knocking getting worse and worse... turned out he had done a big end bearing. probly nothing this major in your car just a thought thats all

running power FC

had a knock reading of 94

on the dyno it showed a nice straight line at 15psi at peak getting 252rwkw

Take it to your tuner and get him to adjust the tune - it's not a matter of adjusting the boost controller, esp considering on a freezing night you'd be likely to get a spike again anyway... rather you should try to ensure the tune is better...

So speak to your tuner :ninja:

Take it to your tuner and get him to adjust the tune - it's not a matter of adjusting the boost controller, esp considering on a freezing night you'd be likely to get a spike again anyway... rather you should try to ensure the tune is better...

So speak to your tuner :ninja:

this is been an ongoing problem on dyno its sweet on the road in spikes even with the boost contoller of it boosts to 12psi

even with a perfect EBC it'll still spike a bit - I'm surprised your tune is so close to the limit that a tad more boost causes knocking. Why not richen up the tune (or take out a tad of timing) a little so at least you can drive the thing properly whilst identifying your issue :ninja:

Edited by TommO

Thanks everyone, its really fustraiting me I had the spike problem with it before, i was informed that the OP6 housing will fix it. but im back to square 1

I'm to the tuner 2moro

if i get them to tune

13psi high boost do on the road i should get 15psi

8 psi low road 10psi

maybe that will work

why don't you just have one tune at one set boost, and control the power with your foot?

I have one tune running 300rwkw and 18psi of boost.

When I want half power, I use half throttle?

Edited by The Mafia
why don't you just have one tune at one set boost, and control the power with your foot?

I have one tune running 300rwkw and 18psi of boost.

When I want half power, I use half throttle?

how do you do that when its on man.. all you wanna do full throttle and punch the gears,

how do you get 300 stock engine no knock

how do you do that when its on man.. all you wanna do full throttle and punch the gears,

how do you get 300 stock engine no knock

a decent tune.

I ran 370rwkw, no spike, no knock.

Its a combination of things.

Plus your running a PFC - so you cant have two maps unless your running a datalogit and change it everytime you change boost setting.

Power/boost is controlled by the right foot. I ran 24psi daily without issue

a decent tune.

I ran 370rwkw, no spike, no knock.

Its a combination of things.

Plus your running a PFC - so you cant have two maps unless your running a datalogit and change it everytime you change boost setting.

Power/boost is controlled by the right foot. I ran 24psi daily without issue

370rwkw with the RB25?

Sounds like a handful lol

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • No. The ECU's hose is for a connetcion between the plenum (assuming single throttle body, not ITBs) and the ECU's internal MAP sensor. This is the primary load measurement of the ECU - so you need to get this one right. This has NOTHING to do with the boost contol. The wastegate also needs to see a boost signal - but it is actually far better for it NOT TO COME FROM THE PLENUM (again, assuming single TB, and not ITBs). This should come from the turbo's compressor housing (assuming there is a nipple on there, which there might well not be), or on the boost pipe somewhere between the turbo and the TB. On the pipe from the turbo to the intercooler is usually most convenient. The boost controller is then located between that boost source and the wastegate, ACCORDING TO THE CORRECT PLUMBING DRAWING FOR THAT BOOST CONTROLLER. There is no general diagram or instruction that will be correct for every case. Then the other ports on the plenum are for purposes such as Duncan described. If the boost controller has an internal MAP sensor, for a boost display, etc, then it will want to be hooked up there, alongside the ECU and the FPR.
    • Ok gotcha, so one post to fpr  another to bov  and I have the mishimoto boost controller and a link g4+ so I’d just have the tuner set it up properly. For the last two from plenum post throttle to  ecu/ boost controller, I know that I have a hose coming from the ecu that I was confused about so I assume that’s what connect to the boost controller from the ecu? And then the last is just from plenum to boost controller then to wastegate?
    • From there, it was just a quick electrical check, prime the oil and start her up Which, is not what happened. 1. Bloody seppo Aeropro battery holder. Not only was it too tall for the battery (which I'll forgive them for, I have another battery the same nominal size that is taller than Neil's one, but the bracket is a fixed height so the battery was spaced up) But the thing that really shits me is the hardware to hold it on requires a 7/32 Hex key. WTF. No-one will ever be able to remove or install the damn thing without a hex key they don't own 2. Kill switch no longer worked once the console was installed. Neil mentioned above he had to adjust the length but it no longer cleared the console once installed. Sorted. 3. Suspiciously, the brake light holders were hanging in the boot with no globes. Sure enough the stopper on the brake pedal was missing so they are always on unless the kill switch is activated. Will pick one up tomorrow (turns out 32 and 33 don't use the same stopper) 4. All that sorted, I turned on the kill switch, turned the key to ACC. Nothing. Turned it to IGN. Nothing. Checked some fuses and found the main IGN in the boot was missing which improved things once it was replaced. Now ECU and dash lights turn on with IGN but still no fuel pump. 5. Turned it to Start....ECU on, no fuel pump, no starter. Plus the voltage dropped straight to 9v.  I suspect the starter is f**ked but am going to have to work through it all and see what is happening, really looks like more than one issue. Does anyone have the R33 fuse box key with the circuit it sources from (eg BAT, ACC, IGN, SRT etc) and supplies? I can find a translated list showing Amps and circuit without supply circuit, and I can find supply circuit without Amps and target circuit.
    • 3rd time lucky, the AAC is now all plumbed up after getting some final fittings All set up under the plenum of maximum access
×
×
  • Create New...