spooned out

finally got the kit on the car 18G/b16a. Questions!

1. boost gauge, my gauge reads around 10-15 in vac at idle and when i let off the gas at cruising speed, normal?
2. When mashing on the gas the needle starts to rise towards the pressure side (boost?) but never passes 4psi.
3. car doesnt idle normal wondering if its vaccume lines since i used the wastegate actuator and bov and boost gauge all "T" off to the FPR, since thats about the only source of vaccume i'm aware of.
4. If the actuator needs pressure to push the flapper open how come everyone hooks it up to a vaccume source? wouldn't it have an opposite effect (closing) on the actuator?.

Need some imputs ASAP, driving it but not pushing untill i get more info.

Bspec18

1. Yes its Normal
2. You probably have a small leak on you Intercooler piping or your Wg Spring is opening to early.
3.what is the car idleing at? Did you retard your timing ? Tee the BOV from the brake booster and your WG from your compressor or FPR
4. When your boosting vaccum becomes boost (i think =P)

Sivik

1) Yes, it is normal for you to run vac at idle and cruising, hence the "vacuum line" you tapped. The only time it will read above 0 is when the turbo creates boost.

2) If it stops at 4 psi, then that is what your wastegate is set at. If its an internal wastegate, you need a boost controller to change the pressure. If its an external wastegate, you can adjust directly on the wastegate.

3) If you car seems to idle weird, you might have a vac leak. Check all your hoses to be sure. It might also have to do with your fuel management setup. My BOV, boost controller, and boost gauge are T'd off the FPR line. The wastegate should connect to the compressor housing. But it might be different on yours.

4) Think about what the turbo does... it builds pressure. When you floor the gas, your boost gauge goes into positive psi, not vacuum. That is what opens the wastegate. What the vacuum does is close it.

I think I answered these questions correctly, but anyone check me if I'm wrong. What I/we do need in order to help you is your complete setup.

spooned out

simple greddy 18G setup from 99-00 si.. hmmm custom spearco intercooler 3x6x25 give or take and apexi bov, FMC "blue box" RC 310's thats basically it and i can't hook up the actuator to the turbo since no holes are there for the 18G's, i can adjust the actuator to make the spring compress harder which would make it harder for the air to push the flapper once boost, i heard its not good to do it that way but isn't that what its for? And i was under the impression that the 18G greddy turbo spools up pretty quick (b16A) seems like mine takes awhile to get to boost after all its gotta get from 15vac too 0 first i'd say about 4500 rpm then it becomes "0"

RAWB

Your vacuum at IDLE is too low. Typically, you should be at 18-22in/HG(vacuum) Sounds like you either have a vacuum leak or have the lines routed incorrectly.
Also, your car should not take 4500 RPM to get past 0psi-especially with that 18G- clogged CAT???
Do a compression check to get an idea of the health of your engine- a tired engine will have low vacuum, as well.

spooned out

yeah i do the compression test, hmmmm clogged CAT could be the problem, any knoe where i can get an after market cat that won't cost me an arm/leg prefereably stock dimensions.....

Poop111444

You can some 2.5" pipe from your local parts store to replace that cat.

spooned out

hahhaah would be nice if we didnt have emissions test

RAWB

Test it by unbolting everything after the downpipe. This way you won't be wasting your money if your CAT is okay

spooned out

still not seeing boost till 4000rpm and at idle vac is at 16 how low is too low? i seen vac at 20 but not at idle, i think my cams (STR) are off could this be a problem with late boost? gonna try to take it to a tuner soon but wanna see if i can get some pointers before i do...

nigel

geeez thats some slow spool. try getting some soap in a squirt bottle. squirt your pipes. you might find a leak.

g2ls_turbo

my vacumm reads at 10/9 at idle and reads about 10/11at cruise. im sure its normal, you might just have a leak on your flange to head or manifold to turbo? but i dont think its the problem cause i got all kinds of leaks that my block is covered on black smoke, i still get full boost around 2700/3000k and its at 6/7 psi all the way to redline...

_Endless_

maybe your cam timing is off or your valve adjustment, these two can alter vacuum reading.

spooned out

ill try the soap spray on the tubing, how do you go about checking for leaks around the turbo/manifold thing gets too hot for comfort, is it okay to seal the rubber cupplings on the pippings with RTV or silicone?



Modified by spooned out at 5:15 PM 7/28/2003