boost question

[TURBOELKY]

i finally got the car to build boost, and it runs sweet!!! me and a buddy were out replacing a valve cover, decided to pop off the waste gate housing, and noticed a bolt was put in there and it bent the puck lever to where it stayed open! bent it back, replaced the too long bolt for a shorter one, replaced a few gaskets and BAM!! put on a boost gauge, its at about 5-6 psi, but where should it be???? what was the factory setting? and whats the limit on pump gas or what ever? anyways, i'm very excited about it pulling like it should, and can say since the turbo has not worked for at least or maybe 10 years, more than likely, the engine should be in good condition it was drived its whole life by an old lady, and i'm sure she did'nt floor it! so what should the boost be at? thanks guys!!

 

[Ttype83]

9 PSI is stock for most. Glad to see you are making progress

 

[b4black]

INCREASING BOOST - ADJUSTABLE WASTEGATE ACTUATOR - Adjusting maximum boost may be accomplished by changing the rod length of the actuator. For all years, except the 1981 model, shortening the rod will increase boost. The factory boost level is 8-9 psi. Increase the boost as much as possible without causing the engine to knock. Use high octane fuel to prevent knocking (read about the ESC). If your turbocharger or actuator has ever been replaced, it should already be adjustable. If it is not, this tech page from the the Turbo Regal Web Site has directions for converting a non-adjustable rod to adjustable. Turbo Regal Web Site Adjustable Wastegate


LOW BOOST? - I have found that the most common source of low boost is the Quadrajet's secondaries failing to open. When then don't open, boost is limited to about 6 psi. Check the NA notes page for a procedure for checking the secondaries in the carb section titled "Secondaries Not Opening?"

TURBO POWER SWITCH - The "Turbo Power" switch controls the yellow and orange indicator lights. The yellow light turns on at about 3.5 psi and the orange at 6 psi. They can be adjusted by turning the screws. The switch is located on the left inner fender or fire wall. The 1978-'79 Buicks use two switches GM part number 1259745 and 1262154, which have been discontinued. The '80-'83 pressure switch is the same switch that is used on '84-'87 Turbo Regals with the digital dash (RPO U52) option. It is still available from GM (part# 25503871). The original switch is green, but replacements are black For non-operating lights, see TURBO POWER LIGHTS DIAGNOSIS.

AFTERMARKET BOOST GAUGE - The stock boost ("Turbo Power") gauge only uses two lights and is unreliable. An aftermarket boost gauge is very useful for tuning the Turbo V6. Changes in maximum boost can be the result of various things (plugged converter, cracked manifold, bad actuator, etc.). "Seat of the pants" won't always tell you when you've lost a few psi. Stock set-ups run about 9 psi and an easy way to up performance is to increase the maximum boost (see "adjustable waste gate actuator"). I recommend an Auto Meter Ultra-Lite 4301. It measures 30 In. Hg Vacuum and 20 psi Boost. (It is unlikely that you will run more than 20 psi of boost, so don't lose scale with a 30 psi gauge.) It also matches the Turbo Regal's stock gauges well. See the LINKS page for Auto Meter.

1981 WASTEGATE ACTUATOR - For 1981, Buick changed the wastegate actuator from a normally closed design, to a normally open design. It was an attempt to improve fuel economy that was quickly abandoned in 1982 in favor of increased performance. (The NC design has more precise boost control.) The 1981 unit can be identified by the use of only one vacuum hose (instead of two). To accommodate this change, the wastegate lever on the elbow was rotated 180 degrees. A conversion is as simple replacing '81's actuator and elbow with '82/'83 units. If the turbocharger has been replace, this may have already been done.

 

[TURBOELKY]

thanks guys. And yup, its around 6 psi right now. It does have an adjustable wastegate actuator rod, but its still the 81 housing. I've posted before looking for an 82 or 83 set up, no luck yet! I figured people would throw that stuff away practically I found my carb is missing the peice that holds the primary air foil plate thingy open, so I had to zip tie it open so it does'nt flood out, and run like crap but that made it run even better The car shifts hard, runs very very smooth, but is still lacking a little power i'm sure. I'm going to work on the carb. on my next day off, adjust the throttle cable to see if the secondaries open up under wot. I know the map sensor is unplugged, when I put the vac. line to it, it would light up the check engine light. But that was with the vaccume line hooked up to the wrong spot on the turbo that would not let it spool, so i'll try again. Thanks guys for the info again, i;ll keep you posted.