Turbo Flutter

[gmac90]

After I have rebuilt my engine (Rev 1 tubby) about 4 months ago I finally took it down the road to the spray booth.

I was taking it easy all the way just in case, but I noticed that I had really loud flutter between gears. ( I have standard BOV)

Also as it was a country road I was trying to get to 60mph, and the car fluttered and then jerked really badly like I lost all power, but if I kept the revs down it drove ok. Would that be due to over boosting and the fuel cut kicking it or something a bit more serious?

[chrismit]

Hi

Is the vacuum on the BOV hooked up?

Do you know the factory BOV you are using is working and you have it plumbed back into the intake?

I never had any flutter whatsoever with the factory setup

[gmac90]

Yeah the vaccum is hooked up coz I replaced all the hoses...I cant say if the BOV was working before... Yeah its plumbed back into the intake pipe.

Think ill need to look for a second hand BOV

[gmac90]

Heres a pic of it setup ...

[chrismit]

Looks right!

Only reason you would be hearing any flutter is if the factory BOV was not opening to recirc the air and it was going back around the compressor.

If you want to cover the postage charge i could probably send you one that i know is working to rule that out

[jimGTS]

Where's the vtv valve on the bov? I don't see!

[gmac90]

Whats the VTV valve? Only came with the t-piece for the smaller bore pipe connecting to the larger bore pipe .

[Ryan S]

Whats the VTV valve? Only came with the t-piece for the smaller bore pipe connecting to the larger bore pipe .

It's a small plastic valve that sits in the bracket on the factory bov. It's not quite a one way valve but resistance is greater one way than the other.

[gmac90]

Would this then cause the air to flow the right way through the BOV?

[androo007]

No

[Ryan S]

Would this then cause the air to flow the right way through the BOV?

I'm not 100% sure what it does but when I put one on the wrong way many moons ago I do remember the valve not opening correctly and having some turbo flutter. Realistically it shouldn't affect operation if it's not there as the valve is a pull type so the vacuum should open it.

[chrismit]

Not having that valve would not create turbo flutter

[gmac90]

Not having that valve would not create turbo flutter

So it is more than likey a faulty BOV?

My stock boost gauge dosent even move either would the BOV contribute to that aswell?

[Ryan S]

Not having that valve would not create turbo flutter

So it is more than likey a faulty BOV?

My stock boost gauge dosent even move either would the BOV contribute to that aswell?

Sounds like the valve could be staying open slightly. Swap it for a known working one and see how you get on.

[gmac90]

Cheers lads Ill take Chris on his offer see if that aorts it... Last thing I want ro do is wreck my engine I have just built

[2mad]

What if the coil is braking down and missing up high (revs) .. the turbo flutter would just be a by product of this ?

And yes fuel cut wiill do this if activated

[parker455]

Your breather isn't hooked up on top of the cam cover either!

[jimGTS]

Your breather isn't hooked up on top of the cam cover either!

whilst thats true, the other end is blocked on the intake pipe.
so shouldnt cause any running issues.

aside from spraying oil mist over the turbo/intake.

obviously good idea to get a filter on there, catch can, or route it back into the intake.

[gmac90]

Yeah Im going to get a mini filter for that was meant to measure the size of the pipe.. unless anyone knows what it is?

[2barGee]

Yeah Im going to get a mini filter for that was meant to measure the size of the pipe.. unless anyone knows what it is?

18mm i just bought one yesterday.