i need some education on a 12a

[adookie02]

ok check it out i got an 87 quest with an 88-89 ecu 1st gen bov upgraded fuel pump aftermarket boost guage ( most of the basics needed) now other than that its stock so my question is how much boost can i push on my 12a.. i believe its a 12a iths the stock 87 turbo. now my by buddy said i can change the waste gate to an 88-89 waste gate and ill get 10 psi that way.. idk.. so im turnin to the club.. educate me please

[dstar88]

the 12a can boost as much as you want. but after 15lbs it will most likely start pushing hot air.

 

With that said. 15lbs is about the most i would push that little guy to. you could go more if you want. but the life of the turbo will start to decrease dramatically.

 

 

 

Daniel

[Indiana]

The hose that runs to the wastegate actuator, get a 1/16" vacuum "T" and put it in that line and leave the new branch open, in other words so it has that small leak. That will get you up to about 14psi or so. You do not change the wastegate, this is not a spring loaded external valve like an Audi, diesel truck or something like that has, it takes a boost reference hose from your intercooler to over come the spring pressure holding it back. If the hose pops off you'll get upwards of 30psi or so, not what you want to do. The shaft speed of the turbo will be so high to make that much pressure from a small turbo and being old after it would cool down it may be locked up.

[OPTIMUSPRIME]

If the hose pops off you'll get upwards of 30psi or so, not what you want to do.

 

 

HHHHHMMMMMM

OOOPS

[adookie02]

ok so i dont have to get a boost controller? just a 1/16 tee put it in the line and another line from that to the actuator and leave the other open end open?

[adookie02]

ok indiana.. i did what you said and im gettin 8lbs now was barely gettin 7 now 8 on the money... i dont know if i did something wrong but i doubt it i did what u said.. a hose from the ovcp to the tee then from the tee to the actuator and the other port left open

[Rexkrazy]

I use a ball valve w/ spring, + a needle valve to adjust vent pressure. Spools quick to 14 and sits on it.

 

I made mine, but you can buy them too. Most use a vent hole instead of a needle valve. The vent is there to relieve the pressure built up behind the ball valve connected to the wastegate actuator. w/o it the wastegate will hang open between shifts. Though if your ball doesn't seal perfectly (most don't or won't soon) you also need the vent to meter the flow to keep from building excess pressure causing a boost drop (this is why it's good to have a needle valve, so you can tune high rpm boost).

 

Anyway, you're just using a vent hole (boost leak) and it's not adjustable. Right now, if you want more boost you need to lower the pressure on the actuator line. Easiest way is to drill out the open port in the tee to vent more. BUT, you need to use a very accurate drill set and go up in the smallest increments possible.

 

Good luck

[Shelby]

going higher then 10 lbs on boost requires you to learn a few things and test a few more to make sure they are at 100%

 

one of the easiest and worst things to do with these cars is to get boost hook'd , sure you can boost till the parts start flying and a great many do then call the car a POS

 

the last thing you do is raise the boost level not the first , only after the entire fuel system has been gone over and it's 100% in all departments do you raise the boost

[Indiana]

Use a bigger T, you have to start somewhere no one size leak gives X amount of additional boost.

 

Save your money and get an EBC. Just get your car running well and its fuel system consistently working. Ignition system the same thing, it can be working one day then not the next. If the car won't run on stock boost don't push it until you get it fixed.