whitetrd

I installed my stage 0 kit about 3 weeks ago. I am running great except my autometer boost gauge is only getting up to about 4lbs maybe 5lbs but def not 6lbs of boost. Sean from zpi said this is probably just the gauge being off, but I am doubting this. I have checked everything and there do not appear to be any leaks anywhere...any suggestions?

toyota_scion_tc

Where did you tee the gauge into?

nebster

most likely is the boost gauge. additionally do you have any exhaust mods or anything else with the car.

whitetrd

Boostgauge is tied in to the vacume line attached to the throtle body along with my blow off valve and my wastegate. I have a zpi s-pipe, custom made test pipe, and ark full cat back exhaust (NO CAT).

nebster

your wastegate is directly tied to your bov?!?

sddykstr

Lol that's a whole problem in itself.

ScionTcZ

Only gain 4 lbs of boost ?

nebster

its because your wastegate is tied into your bov. your wastegate spring as set at 5.3 psi and so it will never show above that in fact it will show around 4 (which it does) because there is nowhere to create a proper vaccum. honestly i'm surprised your car still runs decent with it set like that

whitetrd

yes my wastegate has a vacume line tapped directly into the throtle body vacume line then my blow off valve and boost gauge come off of the wastegate vacume line. Is this a problem?

nebster

yes

whitetrd

so then where do I run the blow off valve and gauge from?

nebster

wastegate vac line should be going from the wastegate to the left back of the engine and nothing else

bov / boost gauge should tap into the throttle body vac line those are all fine

crzydesi

i made the same mistake on my setup but i'm still not hitting 6psi either... i dunno whats up with that. i also have the zpi stage 0 kit. i had a crack in my manifold and i thought that was the problem, but got it properly welded up and still isnt hitting 6psi.

nebster

boost gauges aren't precise. you wont hit a perfect 6 psi at wot all the time.

i hit 5 and sometimes it hits 6 but thats because of a lot of other things such as exhaust and FM.

GirlyTT

I don't know anything about this kit at all, but should this kit be holding 6psi? or does it spike at 6psi, and drop to around 4 or 5psi?

Also, does the boost gauges sit directly at 0 when the car is turned off? I had a Galant VR-4 a few years ago, and my boost gauge would sit at -1 when it was turned off, and would always be 1psi off. I'm not sure if this is your problem, or it's just something with the kit. Just my $.02

whitetrd

On zpiracing.net if you go into the kit and look at the picture the vacume line runs from the throtle body to the wastegate. So that seems to be the way that zpi does it.

nebster

its not

zpi installed my kit and thats not how it should be done.

crzydesi

yep i'd have to agree... the vac line does not go from the wastegate to the bov... but when i took it to the shop who specializes in turbos, he actually removed the line going into the bov from the TB... and now I have no vac lines connected to the BOV, and it actually works a little better.

Mr_Meaty

Wait, you have no vac line to your BOV? it's just sitting on your pipe with nothing else connected to it?
I thought the BOV used vacuum pressure to open up?
My BOV and Wastegate and both connected to the same vacuum block.

crzydesi

yep. no vac lines connected to the bov... i have one line going from the wastegate to the back of the engine block, and the other coming out of the TB to the sensor, with a T for the boost gauges... i thought it was odd myself, but he builds turbos here and he suggested it and the car actually idled a little better... the car is still getting worked on right now, so I'm not sure if he reattached it, but it works.