boost gauge query

[Nozila]

today i have just installed my boost gauge thanks to tutorial i used from here but came across a problem when i took it for a drive. The thing is it only boosts to 5 psi but i have a cat back and a pod filter so shouldnt it be at least 7 psi. Another thing, when i start the engine the needle goes to 20 ngm, is this right or should it be on 0. I have a speco gauge. any help would be much appreciated. thanks

[knore]

should be on -20 when on idle

standard boost is 5psi till 5500-6000rpm then it goes to 7psi for a little bit

see my gallery, ive got a dyno graph when i was running standard boost, u can see it stay on 5 then spike to 7

[Nozila]

So the gauge is working perfectly fine. What about my boost pressure, i would have though it would be at 7 or 8 psi with a cat back and pod. I's also mention that havent fiddled with increasing the boost before either.

[croat]

Nozila when you complete the exhaust you should see an increase. Mine with a full 3" ran 8 psi non-stop with no bleed valve. If you just install a bleed in the boost and set the boost to the levelo you want you will hold and hit the desired amount of boost a lot better.

[Nozila]

cheers croat. I will get my hands on a bleed and see how the gauge responds.

[Messiah]

was that my guide???

to explain yr set up. if you tapped yr hose into the intake manifold (as u should) yr gauge will read a vacuum while idling as the manifold holds a both a vacuum or boost depending on yr throttle position. now if tapped in before yr throttle body, thats a boost only source, and as such yr boost gauge would read all sorts of wonderful spacko figures as it would be reading a greater and 0 reading at all times (theoretically). This would give you a high point when idling ( as the air enters in intake pipe before the throttle body but doesnt escape through it) and a second high point when the throttle body is open and the boost is at full... what readings you'd get in between is anyones guess.

As for the boost yr getting. thats normal, remember that yr exhaust and intake will only vary your cars intake capacity, it will be easier to suck and to blow, but you havnt really changed the way the bov turb and waste gate function, so you wont see any great boost increase.

as above a 33gtst will boost to 5psi at low revs then up to 7 later... or the other way round i cant remember,

[fresh]

mine boosts to 5 till about 5500 then hits 7, u can fell the jolt, this is normal rightb???

[Nozila]

yes i think it was messaih, cheers mate.

boost gauge shows an idle reading of 20 ng/h. I tapped the aftermarket vaccum line in the factory one. btw can someone tell me how to get the vaccum hose from the engine bay into the dash im having problems after searching around the firewall near the peddles.

[Messiah]

u wont find one near the pedals.

look in the engine bay... just to the right of the plennum (when viewed form the front).

you should see a hole there

[paulr33]

check here if you want to change the stock r33 boost

http://www.skylinesaustralia.com/forums/sh...ead.php?t=42895

[Nozila]

cheers paul