Manual boost controller

[Technohedge]

The Caldina has only been boosting to max 10psi (according to my boost gauge). Ive heard the factory setting is around 14psi?

Anyhoo, i picked up a cheap manual bleed valve (not a ball bearing and spring type) and chucked it on. Not after silly boost as I know its a big no no with these engines unless youre prepared to forge the insides etc.

Ive read a lot of info about these types of bleed valves (and how bad they are) but cant find any info on why they are bad. If Im using this to up the boost a couple of PSI only (to what should be factory spec PROVIDED MY BOOST GAUGE IS READING CORRECTLY) then is this a big risk?

Im not doing track time so its not being pushed hard, been keeping a very close eye on the gauge and it seems pretty consistent.

The other question would be why was it not reaching factory boost level in the first place? Can the TVSV block up or leak?

cheers

[Dell'Orto]

The main issue with them seemed to be consistency, often they would fail and seize up and let things freeboost.
Check your wastegate actuator is opening the flapper too, and not stuck partially open.

[Technohedge]

Its one of them bleed valves that dosent have a ball bearing, rather a screw type valve - no moving parts. I suppose it could always get blocked but i would have thought there was as much chance of that happening with the stock setup?

Is there a way to check the wastegate flapper without too much hassle?

cheers

[Ninja25t]

I ran manual needle style bleed valves for years without issue on both a skyline and starlet I used to own. Main problem with a bleed valve setup is that they don't cope with boost spikes very well so you end up having to set your boost lower than you might be able to achieve with a good automated controller, i.e. you might be sacrificing some power.

I never suffered any blockages but if it did block you would simply drop to factory boost level as the wastegate actuator would be receiving the actual pressure with the bleed not operating.

The chance of a decent quality needle value failing is minimal (a lot less than an automated controller), so as long as you are careful about ensuring all your connections are tight (and stay that way) you should be fine. Not sure about Caldina's but both the skyline and starlet had factory boost cuts so there was some additional protection if anything went wrong. Also recommend that you keep your bleed lines as short as possible.

Cheers,

[Technohedge]

Cool yea i thought that was going to be the case. I reckon i should shorten my bleed lines as the controller valve is in the glove box at the moment Had it there for easy adjustment. Now its pretty much where i want it ill put it in the engine bay.

In what situation would a boost spike occur with this sort of setup?

[iOnic]

Hate to be the devil's advocate but I would *STRONGLY* advise you to find out WHY the stock setup isn't reaching the preset boost level before you go adding a tap.

The 3SGTE boost control system is pretty robust and if boost is lowered it's usually because thats the failsafe reaction to another issue. If there's an engine I'd be overly cautious on its the Caldina 3SGTE