boost problems single turbo

[n boost]

Hello guys

 

I recently changed my ex manifold gasket as it was blowing. I was boosting at 1.35 bar when i had the leak.

When i went for a drive it started boosting to 1.45 bar which was due to the boost leak which had been sorted.

I adjusted my wastegate down to 1.2 bar so that is the spring pressure.

If i try to raise the boost using ebc it won't go up regardless of how much duty i dial in. It peaks at 1.28 bar using ebc and if i run of wastegate spring it peaks at 1.23 bar.

I checked for boost leaks and found a slight leak from my greddy bov which i sorted. I also checked all hoses, ebc connections but still can not get desired boost pressure.

 

Any ideas guys will be much appreciated

Thanks in advance

[Ian C]

Check your boost controller is a) plumbed in correctly and b) set to external wastegate and not integral.

 

-Ian

[Chris Wilson]

Send a drawing of how the wastegate's plumbed, as Ian says, probably it's wrong.

[n boost]

Hello guys,

 

The boost cont was working fine before changing the gasket. I have a t coming of the compressor housing with one side going to the ref port ( the one near the middle) of my wastegate and the other going to the IN on my solenoid. I have the OUT from the solenoid going to the top of my wastegate and the controller is set to wastegate.

If i connect my wastegate direct the spring runs at 1.25 bar and when it runs through the b-cont it hits 1.29 bar. I have a blitz sbc and can see the valve working on the screen.

I have changed my bov recently, prior to doing the gasket and was thinking could that be leaking. Also if i adjust my wastegate to near 3/4 turns the spring pressure only increases to about 1.38 bar from the 1.25 bar.

I had a greddy rs which i changed to another greddy item as they both had the same flanges. Today i also realised that if i unwind the screw on my bov the boost pressure drops so the more i wind it in the higher it goe's. I have it as far down as it will go so there is no more room for adjustment and am only reaching 1.3 bar max in 4th gear.

[Homer]

The BC sounds like it's plumbed in properly.

 

Has the car ever run below 1.25 bar and do you know what WG spring is in there? Even with the BC turned off? What manifold do you have?

[n boost]

The BC sounds like it's plumbed in properly.

 

Has the car ever run below 1.25 bar and do you know what WG spring is in there? Even with the BC turned off? What manifold do you have?

 

The spring is 1.2 bar and runs this when connected straight to wastegate.

The manifold is fine as i modded it being a xs one. Also i have been driving the car for 2 mths with low boost set at 1.1 bar and high at 1.35 bar and achieved this consistently.

I think i was getting 1.1 bar as boost was leaking from the manifold gasket, but as soon as gasket sealed leak the boost went up to 1.2 bar.

I played around with the greddy bov today, and tried loosening the screw and the boost dropped to 1.23 bar from 1.28 bar.

I then tightened the screw as far as it could go and achieved a max of 1.32 bar.

1,Has any of u guys had any problems with ur bov on single turbos?

2, What bov are u using at what boost pressure?

 

I was thinking hks racing 2 but think it might not work properly at my boost as the spring might be too stiff.

[Chris Wilson]

Just test it it with no BOV (block the three pipes off) I never run a BOV at all, on any modded turbo engine.

[n boost]

Just test it it with no BOV (block the three pipes off) I never run a BOV at all, on any modded turbo engine.

 

I will try blocking the bov tonight and see what happens. Just need a plate or something to block off the flange.

[n boost]

All sorted.

 

The bov was leaking, changed to another one from mate's car and am boosting as normal.

[rob wild]

Just test it it with no BOV (block the three pipes off) I never run a BOV at all, on any modded turbo engine.

 

Just out of interest why?

[Chris Wilson]

The recirculating BOV was first introduced at about the same time on turbo engines by Saab, Cosworth and Porsche, using the then new fangled Bosch recirculation valve. It's purpose was to stop the noise of the turbo when under boost and the throttle suddenly closed. The noise was expected to be unwelcome and misunderstood by the majority of customers. It has little, if any, effect on reducing lag, is potentially troublesome, weighs a finite amount and I am happy to accept the noise, so I either don't fit them, or remove them, the same with PCV systems, except on race engines with big enough dry sump scavenge pumps to run the crankcase in vacuum at full revs, to aid ring sealing (helps stop ring flutter). I am talking performance engines here, I don't bother removing the PCV system on my Daewoo Matiz, or the BOV on a bone stock Volvo turbo engine

 

I would run neither on (say) a single turbo 2JZ-GTE, and most certainly would NOT run any aftermarket BOV, as the OEM ones are seemingly ALWAYS more reliable, IMO.