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Increase of Stock Boost on 89


Guest Kenmarrow
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Guest Kenmarrow
Hey gurus... I know I have seen it here, but cannot find it today.. Some one had a diagram on how to change the hoses to increase boost from 7 to 10+ on a stock system on that diaphram thing-mi-bob, with 3 hoses. Thanks Ken
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I don't know about re-routing the vacuum lines to do that.

But I do know how to do it with the WG actuator DIY mod, and re-port the vacuum trigger to the manifold for more accuracy.

 

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Hey gurus... I know I have seen it here, but cannot find it today.. Some one had a diagram on how to change the hoses to increase boost from 7 to 10+ on a stock system on that diaphram thing-mi-bob, with 3 hoses. Thanks Ken

 

The front drivers side port is the 10 psi one. Hook your OVC directly to that one leave the rear one open and plug the third one.

 

A 16G is nice but remember in stock form the fuel system is only capable of about 260 HP. If you want more than that you need a different fuel controller/ecu to do it properly. 3' exhaust is a waste on the stock system. 2.5" mandrel bent exhaust works better untill you start passing the 300HP mark. You will loose a little bottom end power from using 3" on a stock setup. Trust me I worked in an exhaust shop and tried it.

 

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Guest Kenmarrow
I don't know about re-routing the vacuum lines to do that.

But I do know how to do it with the WG actuator DIY mod, and re-port the vacuum trigger to the manifold for more accuracy.

 

Yes this is what I was thinking of.. It is on the WG the three hoses. One was moved to front one left open and one plugged I think.. I just cannot find it again... thanks

 

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http://216.77.188.54/coDataImages/p/Groups/125/125361/folders/106218/783467MVC-004S.JPG

 

 

Is that what you're thinking of?

 

 

 

There is no routing of hoses that will increase boost, unless you leave the vac line open altogether. lol

 

Are you thinking of the ignitor mod that lets you have the full 10.5psi under 4K rpms like the auto tranny cars?

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Hey gurus... I know I have seen it here, but cannot find it today.. Some one had a diagram on how to change the hoses to increase boost from 7 to 10+ on a stock system on that diaphram thing-mi-bob, with 3 hoses. Thanks Ken

 

Install a Manual Boost Controller. You will only get 10 psi by changing the hoses. Appox. 14.7 psi boost on a 12a with the MBC. Do I recommend doing it?....... NO. Have I done it ?.....YES.

 

CALIBER 308

Edited by Caliber308
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The port that is by itself, leave it open.

 

The half that has two, you use one of those and cap the other.

 

The two are common to the same chamber so if one is left open that's a leak and the hose connected would do nothing

 

The single one if that was capped you'd have trapped air and then when the back chamber moves that air would compress and you'd not want that, and I doubt it would matter if anything it would result in a slightly HIGHER boost level, so leave it open.

 

10psi is nothing

 

15psi is nothing

 

20psi is nothing for a tiny 12a but I'd suggest you have a working distributor and vacuum advance unit, two fresh cleaned injectors, premium fuel and a 1G MAS and let the dogs that claim that is bad start barking now.

 

 

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Guest Kenmarrow
The port that is by itself, leave it open.

 

The half that has two, you use one of those and cap the other.

 

The two are common to the same chamber so if one is left open that's a leak and the hose connected would do nothing

 

The single one if that was capped you'd have trapped air and then when the back chamber moves that air would compress and you'd not want that, and I doubt it would matter if anything it would result in a slightly HIGHER boost level, so leave it open.

 

10psi is nothing

 

15psi is nothing

 

20psi is nothing for a tiny 12a but I'd suggest you have a working distributor and vacuum advance unit, two fresh cleaned injectors, premium fuel and a 1G MAS and let the dogs that claim that is bad start barking now.

 

OK now this is what I was thinking about... it sounds bad.. bark bark... thanx

 

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Guest Kenmarrow
Thanks to all that responded.. I did remember someone putting that pic up before Thanks Just paus.. I am not wanting to do too much to this engine,it is stock and I want to keep it that way, I just thought a lil more boost might be nice as long as it does not hurt anything.. If I am getting 7.5 lbs now and can get 10 psi by this mod, thats a 25% increase.. I like it.. So where and what Manual boost controller do you all recommend. Because once bitten by the HP monster.. Thanks Peace Ken
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Ken,

 

I don't remember if you have a 5 speed, but if you do here is a OLD Starquestclub.com xshootfaq from 6/14/02. I did a search for it but I could not find it. But I printed out a hard copy off of my printer back then and have saved it cuz it may be something I'd consider in the future.

 

You don't have to pull the actuator hoses.

 

Original post below is by norats

 

From below on I'm typing verbatum:

 

Ignitor Box Mod on 6/14/02

 

"WARNING 1988-1989 only!

Step by step:

 

1) With the engine off, key out of the ignition, unplug the battery.

 

2) Locate the 2 millimeter thick black and yellow wire (black wire with yellow strip) at the ignitor module near the ignition coil. Cut the wire at the connector-on the ignitor side of the connector.

 

3) Connect the cut wire from the ignitor (NOT the stub remaining on the wiring harness side) to the 1.25 millimeter thick red wire on the ignitor connector.

 

4)Tape off the stub wire from the black +yellow wire in the connector since this wire continues to the ECU.

 

5) reconnect the battery and go for a test drive.

 

The boost should build to 10.5 psi or so at all RPMs now. If not, there is something wrong with the ignitor module, solenoid, knock sensor, or turbo waste gate. The boost will drop to 7 psi when knock is detected.

 

One extra bit to this post. ...the wires may change colors as they go through the connectors....on some88/89 ignitors the black+ yellow wire turns into a lime green wire between the ignitor box and the connector. This lime green wire is the wire to cut.The end coming from the ignitor is then spliced into the other wire. The end poking out of the connector is taped."

 

Mike C further on in the post goes on to say:

 

"The ignitor boxes are all the same for the 88-later cars, regardless of the tranny installed; my mod cheats this wire on the stick shift cars to make the ignitor think the car is an automatic tranny which removes the 4000RPM on the stick shift 88-later cars........"

 

Further on the post Mike goes on to say, "As I stated in a previous post...the ignitors (and ECU) are identical between 5-speed and automatic tranny cars for the 88-89 years. The wiring harness is different depending on the tranny type and it's the harness that "selects" the mode of the ignitor and ECU. Swapping your ignitor with one from a automatic won't do a thing. My ignitor box mod modifies the harness at the ignitor box to trick the ignitor into thinking the car is an automatic. The ECU still sees the stick shift though...."

 

I'm not going to type this whole post thread out but they bring up some excellent facts about ... "the 88-later ECU's having much smarter software tables/equations that do NOT get confused until much higher boost levels - anywhere from 17 psi to beyond 23 psi depending which iteration you get......"

 

My Whole point of this is why don't you just mod the ignitor harness as Mike suggests rather that opening and plugging nupples on the actuator.

 

Much simpler and cleaner. ;)

 

For What It's Worth.

 

KEN

 

Any spelling errors above are my own.

Edited by Starfighterpilot
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OK now this is what I was thinking about... it sounds bad.. bark bark... thanx

 

Double bark from me.....2O psi on a 12a with no fuel mods or a A/F Gauge to monitor the A/F ratios????? Sounds like a disaster in the making.

 

CALIBER 308

Edited by Caliber308
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So where and what Manual boost controller do you all recommend.

 

Turbo X/S makes a manual boost controller that is affordable (appox. $80.00) and works great. Try here: http://racetep.com

 

 

CALIBER 308

Edited by Caliber308
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KenMarrow, if you car is an auto, leave the ignitor as is. If it is a 5spd. do the ignitor mod. It is simple and only takes a few minutes to do. Get a turbo xs manual boost controller and an aftermarket boost gauge. Run up to 15 psi on the 12a if your motor is tight and running right.

 

Just my .02

 

jimmy

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Double bark from me.....2O psi on a 12a with no fuel mods????? Sounds like a disaster in the making.

 

CALIBER 308

 

The OEM fuel system, if it is right, will support this. I run a bastardized 19c at 20 psi on a new oem fuel pump. 3.5" gm maf and translator and run pig rich. i need to back off my wot setting but the fuel delivery is there.

Jimmy

 

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The OEM fuel system, if it is right, will support this. I run a bastardized 19c at 20 psi on a new oem fuel pump. 3.5" gm maf and translator and run pig rich. i need to back off my wot setting but the fuel delivery is there.

Jimmy

 

On a 1st gen set up there is no way to adjust the Air/Fuel ratios??? So how can you say that the stock fuel system will support 20 psi. Were not talking about your set up, we are talking about advice given from another. Also, I never saw anything about using a A/F Gauge to see if the motor is going to turn to toast at 20 psi. I have run a 12a with a 89 ecu, Walbro, MSD-2222 and a MBC to 15 psi and it started to cut out at 16. It was and is bad advice to boost a 12a to 20 psi. Besides that, the TDO512A s efficiency range is 7 to 15 psi, not 20. Even the old t-racing.com turbo tech page states: 12A 320CFM 7 to 15 psi efficiency range. Fuel mods: no fuel mods required. That's to 15 psi not 20. Anything over 15 psi and the turbo won't last long!!!! Great advice to run it to 20 psi.... Especially, if your in the market for a new turbo.

 

CALIBER 308

Edited by Caliber308
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Guys,

 

I did not post this stuff to start a controversy over the 12A turbo. I believe Mike was saying that SOME of the later 88 & 89 ECU's were smarter than others and the fuel maps could support the increased boost using whatever turbo you are using to get to 17 to 23 lbs. boost. I'd sure like to know what the MITSU part no. is for those ECUs.

 

BTW where is Mike C? I have not seen a post from him in a long while.

 

For What It's Worth.

 

KEN

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Guest Kenmarrow
Whoa guys take it easy... I am not going to put 20 psi into anything I got...and will most likey leave it at the 10 with the WG mod. I do appreciate everyones input here, and I understand some of your concerns. This car in an Auto so the ignitor stuff is ok. All I am trying to do with this car is to make it right so I can sell it, so I am not gonna put a lot of $ mods into it.. It is an unmolested sunroof figi, a sweet ride, Thanks
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Whoa guys take it easy... I am not going to put 20 psi into anything I got...and will most likey leave it at the 10 with the WG mod. I do appreciate everyones input here, and I understand some of your concerns. This car in an Auto so the ignitor stuff is ok. All I am trying to do with this car is to make it right so I can sell it, so I am not gonna put a lot of $ mods into it.. It is an unmolested sunroof figi, a sweet ride, Thanks

 

You're going to turn it to 15psi. The temptation is too great.

 

Especially when you can play tag with a modified Subaru WRX STi that has about $3000 worth of work done under hood/ecu wise and you can catch him in 2nd gear, pace him and wave, laugh like a maniac and shift, and pull away.

 

That guy was pissssseedddd.

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The front drivers side port is the 10 psi one. Hook your OVC directly to that one leave the rear one open and plug the third one.

 

A 16G is nice but remember in stock form the fuel system is only capable of about 260 HP. If you want more than that you need a different fuel controller/ecu to do it properly. 3' exhaust is a waste on the stock system. 2.5" mandrel bent exhaust works better untill you start passing the 300HP mark. You will loose a little bottom end power from using 3" on a stock setup. Trust me I worked in an exhaust shop and tried it.

 

a 16g compressor wheel and 16g turbo are different in most cases but mostly cost. Being able to keep the boost at 7.5 or 10, he will not be at that 260 mark....but higher than stock so he wont have to worry about fuel issues...nor would you need a fuel controller or ecu at that boost level. Now sense he has a 16g COMPRESSOR WHEEL, a 3" exhaust is needed, and is better than a 2.5 also in everyway! Read our forums more and find the dynos ;) On a stock system a 3" exhaust is better than a 2.5 also if im not mistaken...point was evan the stock turbo at 15 psi is nothing..so dont waste your time or money to turn the boost up! Spend 700$ and ahve the 16g compressor wheel and 3" on the 10psi nipple and youd be much happier :)

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Guest Kenmarrow
You're going to turn it to 15psi. The temptation is too great.

 

Especially when you can play tag with a modified Subaru WRX STi that has about $3000 worth of work done under hood/ecu wise and you can catch him in 2nd gear, pace him and wave, laugh like a maniac and shift, and pull away.

 

That guy was pissssseedddd.

 

Never happen here where I live, no two lane roads, no WRX's just old pick up trucks with tobacco spitting old women sitting in back of truck with broken windshield and plastic on side windows, while her drunken son drives under the speed limit headed to Wal-mart. the 10 psi will be ok for now and there's always the bottle !! hehehaha

 

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a 16g compressor wheel and 16g turbo are different in most cases but mostly cost. Being able to keep the boost at 7.5 or 10, he will not be at that 260 mark....but higher than stock so he wont have to worry about fuel issues...nor would you need a fuel controller or ecu at that boost level. Now sense he has a 16g COMPRESSOR WHEEL, a 3" exhaust is needed, and is better than a 2.5 also in everyway! Read our forums more and find the dynos ;) On a stock system a 3" exhaust is better than a 2.5 also if im not mistaken...point was evan the stock turbo at 15 psi is nothing..so dont waste your time or money to turn the boost up! Spend 700$ and ahve the 16g compressor wheel and 3" on the 10psi nipple and youd be much happier :)

 

Sure you can get a little more top end power with 3" vs 2.5" but on a stock system you loose some bottom end power. With my 2.5" my 12a comes on boost almost instantly. With 3" it created a little lag. I'm not saying you wont get more power with 3" I'm saying around town driveability will suffer slightly when using 3" on a stock system.

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Ken, your car should do 10+ stock. My '88 auto does. Do you

still have the stock aircan? If so, two of those lines from the

wastegate actuator should go over to an electric vacumn

switch mounted on it. If the system isn't sensing a "knock"

it routes vacumn to the front of the actuator which lets the turbo hold

more boost. Try reversing the two lines, if they've accidentally

reversed that's your problem. If vacumn is being routed to the

rear of the actuator it's closing the wastegate way too soon.

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Guest Kenmarrow
Ken, your car should do 10+ stock. My '88 auto does. Do you

still have the stock aircan? If so, two of those lines from the

wastegate actuator should go over to an electric vacumn

switch mounted on it. If the system isn't sensing a "knock"

it routes vacumn to the front of the actuator which lets the turbo hold

more boost. Try reversing the two lines, if they've accidentally

reversed that's your problem. If vacumn is being routed to the

rear of the actuator it's closing the wastegate way too soon.

 

OK I will check that. Thanks

 

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