OK, just finished putting the last bits of the slicktop back together, not convinced it's fixed, although is running very well, I've hardly any boost similar to when I first got it, I've replaced 90% of the hoses, and refitted the Intercooler, replaced all the missing gadgets on the engine,

 

I've tried to do a leak test using an old clutch cap ( actually a perfect fit) can't hear any leaks, although it seemed to be losing alot of air into the crankcase, particularly the dipstick tube, assuming the pcv valves have gone, hopefully someone can confirm, only used 10psi ( due to not having a compressor at home, used large tyres pressurised to 10psi as my source)

 

Now onto the boost issue my Profec has always been set high to produce around 13psi, it was only making 12 when put back together, so I've tried disconnecting the wastegates to see what their doing, only got 13psi, I was careful as I expected it to over boost, but it didn't, seemed a fairly consistent value too,does this mean my wastegates are weak? Wondering if this was the problem from day one.

Well I'm going to remove the pcv valves to replace them with sort off a spare plenum that look good, will order new ones when I'm back at work.

The PCV is bidirectional. The two hoses on the intake cams route to the accordion pipes, ie pre turbo. The circuit is reversed when you come on and off boost. Ie what your experiencing is normal, and is the reason why you should only apply 5psi as you "can" can... Pop seals, like cam seals by applying too much pressure from behind.

 

Pressurise the system the 5psi, then listen to hoses for hissing. If you cannot locate a pesky one, get some soapy water and a brush. Gently apply it so it doesn't bubble on application. You will soon get a bubble show on the leak.

 

Is everything routed correctly?

Oh I had read a thread on the leak tests saying to do it with about running boost, oops

 

I think everything is in the right place, although I did connect the boost source for the controller to the back of the plenum, should it be before the throttle bodies?

 

Tbh couldn't hear any leaks,

 

with the wastegates connected without a controller I get a constant and consistent 0.5 bar,

 

I'm off next week too so maybe I'll pull it again and recheck everything.

Yeah 0.5 bar is roughly 7psi ie, natural wastegate pressure aka safety boost. Sounds like the ebc is routed without restructors t the waste gates. Can't help on placement I'm afraid as I've not got an ebc so haven't learnt how to fit them. Your cars mapped for 14psi isn't it? If it's in safety boost it is going to feel slow.

Mapped for 14psi, John Dixon chip apparently, I'm leaving it in safety boost till I know what's wrong, can't help but think it's wastegates opening from exhuast pressure.

Mapped for 14psi, John Dixon chip apparently, I'm leaving it in safety boost till I know what's wrong, can't help but think it's wastegates opening from exhuast pressure.

 

You think the exhaust gasses are forcing the gate open? Surely if that was the case it would point to a worn wastegate actuator. It takes a fair amount of force to open one manually. You would assume that if this is the case the actuator would open early as well. It would sound like they are plumbed up without the restrictor. So if you applied air pressure to the line it will open at 7psi, if it's healthy. What leads you to that conclusion?

If you disconnect the wastegate actuators, there is no pressure boost applied to open the wastegates they should overbooked up to their maximum pressure, they opened at 12psi, far too low, would suggest they are worn imo

I

This would support why my greedy boost controller was set to 80% to achieve ~14 psi previously

If they are stock waste gates they open at 7 psi mate, tricked to 9 by the factory boost jets. If they don't open till 12 either there's further restrictions in circuit like boost jets or there not stock.

Unless you mean you disconnected them and instead of infinite boost you got 12psi?

You get 12psi with the vac line to the actuators disconnected? Are the actuator arms even connected? :wack:

That's what I mean worrying isn't it...

Is it incredibly laggy? When does it make positive boost?

There is a bit of lag, not alot really, starts boosting fairly quickly, it doesn't jump up either it's sort of gradual.

do you still have the standard recirculation valves in place ?

 

if so, one or both may be leaking internally and this won't show up in a boost leak test.

Nope, I don't have dump valves or recircs

Well there are two basic possibilities

 

Your turbos are worn/broken etc ie not capable of producing boost- this could include the waste gates or one turbo partially seized

The boost is leaking either internally or externally.

 

First off eliminate one of the above, the second would be the easier I would think

 

Leaking pcv valves could do this

Have you removed the stock recirculated valves then?

If you are not able to hold boost in a leak test I would continue searching out the leaks