Car boostin at 14psi

[silnv]

I got to drive my car around some today and I have a boost controler inline but it isnt hooked up. Watching my boost guage I was hittin 14psi consistant. So I powered up my controler and turned the boost levels all the way down and it is still going at 14psi. Any ideas why?

Car info.

89 hatch with sr20 stock t25 turbo stock internal wastegate

[S13CRAVE]

what brand boost gauge do you have? that could make a big difference. some autometer boost gauges are notorious for giving ****ty readings. where is the sensor for the boost gauge located? placement could also change the reading.

~Ian

[silnv]

Autometer-- I have it spliced in with my boost controler vaccum hose

[AceInHole]

the only autometer gauges notorious for "crappy" readings are the electronic ones. it's hard to screw up a mechanical gauge.

boost controllers are used to turn boost up. they don't do anything to turn boost down, unless of course you have a solenoid actuated wastegate, but then... you wouldn't have wanted to run with it not hooked up.

to turn boost down, you'll have to get at the wastegate itself. are you using an internal or external wastegate?

[silnv]

I have the stock t25 on an sr with the stock internal wastegate that is supposed to be set at 7psi. Thats why I dont know why it is going to 14psi.

[DuffMan]

Maybe the previous owner of the SR put a modifed wastegate in.

[silnv]

I started to wonder that when it had iridum plugs and a fried clutch.

[DuffMan]

Since the SR20DET was so popular modified wastegates were available cheaply and cost a lot less than a boost controller.

[silnv]

I am gonna completely bypass the boost controller tomorrow and see what it does when it would have a factory vaccum routing if it still does it I have my answer.

[Robthechef]

you have a vacuum leak in your wastegate line, or your wastegate is frozen shut, either way it's a ten minute repair. Make sure the door opens and closses, if it does, great!!. then replace the vacuum line from the compressor to the wastegate accuator. if that doesn't work the wastegate accuator diaphram might be dead in which case you need a new accuator, but I have yet to see one just up and die

[silnv]

Thanks for the info I will give it a check tomorrow.

[SRKperformance]

if i were you i would damn happy it holds 14psi consistanly out of the box, most sotck internal wastgetes never hold boost consistantly. Just dont push it on pump gas untill you get a afc and some better injectors and you should be fine, unless you really want ot lower the boost! i woudnt know why tho! enjoy it! does it pull hard? have you ever been in a stock 7 psi sr powered car, if its 14 psi youd be ****ting your pants if your not used to 13sec car. how does it pull? Try taking the bc all the way off of the vacum system and splicing the boost gauge vacum line off closer to the intake manfiold, then come back. Is it a mechanical boost gauge???

[silnv]

Well some more testin today and now its boostin higher.


I completley removed the boost controller and ran all direct lines.
Checked the accuator and it does move freely doesnt act frozen.
Took it for a lap around the block and got into it it got to about 15 so i let completley off and parked it. I am completley lost not.

other notes. Checked all intercooler piping, vaccum hoses and cant find any leaks.

My gauge is a Autometer comp lite mechanical

is it possible that my bov could be messing with the pressure.

any ideas?

[uiuc240]

what part of the piping did you tap into for the wastegate pressure line?

Eric

[silnv]

One of the lines from my bov

[uiuc240]

Well, there's your problem, it's not seeing a signal until you let off the throttle.

You need to tap directly into either the hot or cold pipe...closer to the turbo outlet is better. If you're using the stock SMIC piping, there is a nipple on the cold pipe nearest the turbo to accomplish this task.

Eric

[silnv]

I have a GReddy hot pipe. So how would I go about do it with that?

Does anyone here have a Greddy typ s bov? if so how did you hook the vaccum lines up to it?

[burgy240]

where in ohio are you? You could bring it to the shop if your near Cleveland. I'll be there tomorrow cause I got a small oil leak in my SR. :mad

[silnv]

I am just about 4hrs south of cleveland. If I didnt have to work i would consider bringing it up i am sooo ****ed with it right now.

[uiuc240]

Originally posted by silnv
I have a GReddy hot pipe. So how would I go about do it with that?

Does anyone here have a Greddy typ s bov? if so how did you hook the vaccum lines up to it?

The hot pipe didn't come with a nipple? If not, go to the hardware store and buy a brass nipple. On one side will be threads, the other will be a hose nipple. Drill and tap the pipe (careful where the shavings go) as near to the turbo outlet as you feel appropriate. Then connect a hose from that to the signal nipple on your wastegate. Voila. Boost control.



Eric

[silnv]

My type s bov has two fittings on it. I know what the back one is but what is the other smaller one for?

[uiuc240]

From a DSM board (Google had your answer in 5 seconds)

The small hose you removed from the stock BOV must be connected to the larger nipple on the anodized cap (closest to the adjustment screw.)
(Note: This connects to the intake after the throttle butterfly and will pull vacuum when the throttle is closed)

The smaller nipple on the cast aluminum body of the BOV may be spliced into the turbo outlet pipe or into the line between the turbo and wastgate actuator. Use the T-connector supplied. This connects to pressure even when the other line has vacuum. This will activate the BOV faster by applying pressure under the valve seat.

The smaller nipple may also be left unconnected. The BOV will operate slower and more quietly. I did not test this mode.

_____________________

Now, remember, you need to attach a signal hose from the hot pipe to your WASTEGATE...not your BOV. The BOV line comes from the vacuum nipple at the throttle body (so it gets vacuum when you close the throttle and the BOV releases pressure...)

OK?

Eric

[silnv]

Thank you I will give it a shot tomorrow if I can get some time.

[nrcooled]

I was going to say that you would know if your car was running 14lbs. When I first turned it up to 14 lbs the difference was amazing. Like, put you back in your seat and make you dump throttle, different.

-Then you get used to it and want more power

FMIC here I come