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Discussion Starter #1
Hi Gang,

I just wanted to see if anyone had some input on my Profec B problems or if there is something I am overlooking.

For reference, I can uncap the nipple on the front of my wastegate and boost at around 21psi. I dont want to use my gas pedal as a boost controller though, hence the Profec B.

The Profec B is installed, I believe correctly ( unit vaccuum hose is T'd to the boost gauge, Servo IN vaccuum hose to the #1 turbo pressure port, Servo OUT vaccuum hose to top of wastegate).

Following all the setup directions, and with the dip switches set to actuator type, I have my low boost knob all the way down and get 12psi min, and my high boost knob all the way up and get 16psi max. The balance knob really doesnt seem to be doing jack. There is a noticeable albeit small difference between lo and hi boost settings, but I really am hoping to get 18psi from the high setting.

If anyone has run into these probs and have a fix please drop a post, or if I may be overlooking something please set me straight. I also am wondering if i should play around with the dip switches and set them to external wastegate just for kicks.

Thanks in Advance,

Bob


P.S. Im new to the forum, nice to meet everyone. Ive been reading it for about 4 months, never really posted because I just got my 93.5 MKIV about 3 weeks ago. I have previously owned 3 MK2 supras and can probably build one blindfolded, but I figured it was time to step up to the big leagues, and oh what a step it was :D
 

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Check out this link http://www.mkiv.com/techarticles/blitz_dsbc/index.html
I install my profec B exactally this way and it works great. The low boost know maxes out around 15psi for me, and I can hit over 20psi with the hi boost knob if I want to.
Sounds like you have the unit installed correctly, but I'm not sure if you capped off the wastegate VSV and the wastegate actuator.

Let me know if you need more help.
 

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Discussion Starter #3
Thanks Josh,

I actually referenced that site a few times to make sure I had it all done correctly. All my connections are spot on. And I have 4 caps on the system. One on the wastegate front nipple, 2 on the wastegate VSV, and One on the vacuum hardpipe up top that originally went down to the VSV. All it takes for me to go from my limited 16psi with Profec B to 21psi is to pull the cap on the wastegate.

I even cut my vacuum hoses from the servo to the shortest length possible yesterday.

Bob
 

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Discussion Starter #5
Yup, set to "actuator type", just like you said. Im going to go play around with the dip switches later today and see if maybe the "external wastegate" setting may trick it into boosing more. Im hinging on the unit, or maybe even to servo's being the culprit, but maybe someone has experienced this before and has a magic fix, heh

Bob
 

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Are you hooking the boost controller up to the front actuator only? Cause when that's done the boost doesn't always act correctly and one turbo works harder than the other. It is recommended to T the line coming out of the servo, one going to the front turbo and the other going to the back one. And the second nipple on both actuators should be capped. It may take some work getting to your back turbo.
 

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Actually you should never T off that boost controller to the back turbo. There is no need to do that, and you'll probably just screw something up doing that (I know for a fact it happened to a friend of mine who had one hooked up wrong like this at some hack shop)
There's only one actuator it should be hooked to, the front one, and it seems like you've done this already...
 

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DO NOT hook to 2nd turbo or pressure tank!!!
No need, plus causes loss of pre-spool on 2nd turbo...and is PIA and adds no performance gain..just premature turbo failure.

Hook to front only .
Remove hose that runs from the front turbo nipple to top of wastegate.
Remove the hose that runs from the bottom of wastegate to right side of vsv.....then put 2 vacuum caps over these nipples. Can leave the left side vsv hose hooked up as stock.
Then run Profec B to nipple and top of actuator.

Then make sure dp switches 1 and 3 are on , and 2 and 4 off

Then if all other hose routings and back pf profec b is correct then thats it!!

To set Profec B as follows:

Put BALANCE knob at 12 o clock.pushed in.
Then pop out both HIGH and LOW knobs and turn them to MIN.
Then push in the LOW knob in all the way at MIN. (This will run as low as boost as you can)
Then switch over to HIGH....and turn the knob to about 2-3 oclock
and push knob in. ( this should give you around 17-20 psi and should notice alot more power)

Leave BALANCE knob at 12 o clock.......i have found it to do nothing on stock twins. But for reference anytime you turn the balance knob right or left....you must resest high and low boost settings as stated above again.

Thats it......Very easy and should work perfectly
Hope this helped
 

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Discussion Starter #9
Thanks for the replies gang,

Im still working on this. Seems after all the posts im hooked up fine. Im teetering towards maybe a bad Greddy servo box. Beyond that I have more pressing Supra issues now:

The nice people at the local car wash decided that I needed to go Wingless Doh!

I watched that pos giant drying machine through the customer viewing area window work its way across my car and once it got across my roof, it made a bee line to my wing and ripped it clean off the deck lid. Fiberglass hanging and all.

Can you just imagine how I felt when I saw this? The looks on the car wash peoples faces were that of horror too.

Needless to say, They were very prepared for these problems and sent me directly to their body shop which their insurance uses. The final balance is $1300 to fix it. The factory wing alone from Toyota is $800. The rest of the cash goes to priming, painting, and fixing the creases left in my deck lid.

Sooo, Ill not be letting others wash my car anymore. Ive never had bad luck with this before, but my car being in the body shop for a few days because of it changed my thinking on the automated washing places.

Hose and Bucket
Bob
 

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I have question about my Profec B:

Has anyone ever noticed a ticking noise coming from the stepping motor during low boost or spool up? Say around .2-.5 bar or 4-6psi of boost. The ticking only starts while boosting in any gear and not at idle or cruising. I have no idea what it could be..

SH
T78
 
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HoustonSC300 said:
I have question about my Profec B:

Has anyone ever noticed a ticking noise coming from the stepping motor during low boost or spool up? Say around .2-.5 bar or 4-6psi of boost. The ticking only starts while boosting in any gear and not at idle or cruising. I have no idea what it could be..

SH
T78
Thats the stepping motor working. Normal operation.....at higher boost there is too much road and engine noise for you to hear it, but it still keeps ticking.
 

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MONSTER said:


Thats the stepping motor working. Normal operation.....at higher boost there is too much road and engine noise for you to hear it, but it still keeps ticking.
Monster,

On the contrary, I've noticed that sound but at other times it is not there. On my buddy's 93 auto (he has a Profec B), it just sometimes does it....other times it doesn't. It sounded to me like a popping relay or someone holding a Twizzler in the fan. :)

He has a fairly quiet exhaust and the tick is very noticeable (when it does it). Are you with me? :) :)
 
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