boost controll problems.
 

Hi Guys. just another one with boost probs. (have searched archives.)
to cut a long story short. when i bought the car my only complaint was that it was slow upon installing an autometer vac and boost gauge i found that i could only get about 3psi of boost. total. thanks to the auto sport race tech turbo troubleshooting i got the boost up the 3" pipe from the bottom of the intercooler was split so now with a 98 model pipe on there im boosting. so then i installed a turbo smart dual boost controller with rocket switch on the dash so i can alternate between high and low boost. for driving conditions( i also have bypassed the boost control solenoids). and road tested with a boost of round 16psi in low gears and 20psi plus if im driving at 100kmh in 4th or 5th gear and put my foot down. not too good. i have then replaced the turbo smart unit thinking that it was faulty but same again. i have then installed 2 x gfb manual boost controllers 1 in the line between the compressor housing and the pre control actuator and the other in the wastgate line. i can not wind down the boost at all. during road testing i have found that in 3rd gear under load and at bout 4500 to 5000 rpm the car makes a horrid loud noise and i loose all power. have spent ages taking manifold off air box out checking vac hoses and cable tieing as many as i could. could not find anything wrong.

Are you saying part of your problem is that you cannot get wasegate control? If that is so, then you need to make sure that actuator rod ihas not disconnected and the actuator is not faulty.

hey thanks i have checked the acuator. had car up on a hoist and checked from underneth that when i boosted at wot to 6500 rpm the acuator arm moved in and out. that is the bottom acuator. the wastgate i think.

Did you cap off the lower line on the wastegate when you installed the boost controller? Also, what kind of setup are you running? 20psi on stock twins with no fuel mods? If you hear air rushing when under boost, most likely a boost leak.
Art

The "bottom" actuator to the right of the oil pan is the turbo-control actuator. That should actuate around 4500 RPM to open exhaust flow to the second turbo. the WG actuator is located at the RF corner of the engine, just above and to the right of the pre-spool-control actuator.

Hey. i havnt capped off the lower line on the waste gate. didnt realise i had to. is that the line that runs from the bottom of the actuator to the waste gate? and does it need to be capped off?

And the engin has been rebuitl with 3mm seals. i have also just installed an air fuel ratio gauge. but no fuel mods as of yet am tryin to get boost down to 14 or 15psi. cant hear any air rushing. but am going to do a air leak test with the tennis balls as described by someone else on the forum.

Cheers mark

thanks dave have now located the wasegate acuator and no which is wich is which now. so will check operation of that today and let you know how i get on.

altough i did run a diagonistics check and it was telling us that the wg was 95% closed on idle and apparently that was functioning properly.

Cheers mark

the lower nipple out of the wg actuator needs to be capped off with a manual or electronic BC. If it isn't the wastegate has no reference and just stays shut!
Art

Thanks Art i will try that 2day. fingers crossed

Mark

Thanks heaps Art i have capped off the nipple and i am now able to control my boost with the manual boost controllers. not yet the duel stage one but will work on that one. at least now i can keep my boost down to a respectable level of round 14 12 14 which i am happy with. next thing is ecu up grade and any needed fuel mods. no where in any of the destructions that i read did it say anything bout blocking that nipple off. so am greatfull for your knowledge. otherwise i would still be playing with pipes. he he

thanks Mark :)

Glad to see you are able to controle boost now! But I strongly urge you to take it back down to stock levels until after you get your ecu & fuel upgrades. you are extremely luck your motor has lasted this long, but i wouldn't suggest pushing your luck any further.

All sorted and back down to stantdard 10 8 10. for the ecu and fuel mods i was thinking a apexi power fc or a microtech ( which im told does not support sequential turbos. and as for fuel i have no idea. any recomendations.

Thanks mark.

No problem
The PFC and commander is an excellent choice. just make sure there is somene in your area that can tune it for you .(this goes for any upgraded ECU) .as for fuel. this link may help... http://www.newwave.net/~flanham/wlan.../850pri.html#5 .TT supra fuel pumps are a popular upgrade, and a fuel pressure regulator would be a good idea.

There are ample threads on this forum that have a lot more info.
Good luck

Cyan

Cheers Cyan will check that link out later 2day.
Thanks mark

95%? That is not diagnostic test to tell if the WG is properly opening. That only told you that the ecu was signaling to the WG solenoid. It would tell you the same thing if the solenoid were dead, a line were off, or actuator were bad..etc. Sounds like you are on the right track. I could not tell if your "air fuel meter" was a wideband unit. I HAS to be or its useless.

The iar fuel meter is branded as an autometer how do i tell if it is a wideband or not.

it is wired into the oxygen sensor and has a series of led lights in a range from lean through stoich and then to rich. as far as i am concerned it workes of the voltage that the o2 sensor puts out as it varies. the led's go to rich under boost which i am told is a good thing.
Thanks mark

Spend 15 minutes here:
http://www.innovatemotorsports.com/resources.php