My engine came pretty bare. No knock sensor or PEVR valve. I installed the MSD Boost regulator and it helped but is not enough. I would like to go back to stock and see if performance is better. I lag bigtime at the start and knock at 10Lbs. boost. I know you guys have been through all this before I just can't find the right threads. I found this http-::www.turbobuicks.com:forums:before-black:24315-solenoid-power-valve-control.html and it might be an option for the PEVR, but I'm having difficulty finding a knock sensor. Any insight. Thanks
Anti Knock PEVR
- Thread starter 51 Turbo
- Start date
MNcarbturbo
What's Fuel Injection?
- Joined
- Mar 9, 2009
I saw guys that run megasquirt EFI have built knock sensors. Basically a knock sensor creates a slight voltage so you can take a small listening device and solder a connector from the knock sensor to the listening device. Total cost of like $30. That way you can find exactly when it is knocking. You then turn the MSD BTM dial to where it doesnt knock. The factory knock retard setup is junk. Using a BTM, 91 and alky should be able to get to 13+ PSI or so. I can run to 11 on 91 without alky. Never heard it knock on alky with the BTM actually.
PEVR is a big problem. I dont have one and manage to pull down 21 MPG with a 350 and 2.41 gears. It has that same laggy situation as you do. Not sure if if its laggy because of the tight converter and 2.41's or a rich mixture. Ive got 3.42's and a 2004R with a good converter going in so I will find out that soon enough. Gotta purchase a wideband o2 also and if niether is bad its the turbo.
PEVR is a big problem. I dont have one and manage to pull down 21 MPG with a 350 and 2.41 gears. It has that same laggy situation as you do. Not sure if if its laggy because of the tight converter and 2.41's or a rich mixture. Ive got 3.42's and a 2004R with a good converter going in so I will find out that soon enough. Gotta purchase a wideband o2 also and if niether is bad its the turbo.
Well reading that 9 lbs. is stock I think I can't complain knocking at 10. At first I had a side pipe on the car. Thrush Packs 4" OD 3" ID and the boost was off the charts. I really had to pay attention and keep the tunes down. The dual exhaust has stymied the boost. I have the MSD cranked to the max and I always run 91. It's the lag that buggs me the most. Sometimes it rocks off the line, other times I am feathering the gas waiting for the sweet spot. Thanks for the info. All these years my kids have called me "retarded" now I wish my car was.
dr_frankenstein
Mad Scientist
- Joined
- Mar 17, 2008
we need to look and see what turbo housing you have. I bet its the early 82 A/R unit and thats causing alot of the lag. we need to tighten that up!
Alky injection will let you push that boost level much higher...
an ESC is not that far out of reach... I think i have a total of 7 repaired and rebuilt units that are ready to go... but the small parts like the knock sensor will kick your butt.
Alky injection will let you push that boost level much higher...
an ESC is not that far out of reach... I think i have a total of 7 repaired and rebuilt units that are ready to go... but the small parts like the knock sensor will kick your butt.
b4black
Well-Known Member
- Joined
- May 24, 2001
Are you referring to the early 1978/80 setup, or all setup's through 1987?
b4black
Well-Known Member
- Joined
- May 24, 2001
Are you talkig about an MSD BTM? All they way to 3° per psi? I found ½" per psi was too much for my car. I try to run at almost zero - if doing it again, I'd pass on the BTM. I'll take more timing/less boost over less timing/more boost.
MNcarbturbo
What's Fuel Injection?
- Joined
- Mar 9, 2009
Im only speaking about the 78/80 setups. I shouldnt say flat out junk, just that there is better things out there. A wristwatch probably has more computing power than those boxes.
I usually run my BTM around 1.25 degrees on 87 or 89 when im putting serious miles on the car since 91 is 25 cents more than 87/89 around here. On 91 I can turn it to .5 degree or less and it wont detonate until it really starts boosting. Mine was stock boosted to 7PSI and I turned the wastegate to 8 just to see if it would change witch it did. Problem is with my 82 AR and 83-85 GN tubular manifolds, ported heads, bigger cam, opened up secondary air flap, ported plenum ect it boosts to 14. It only knocks when its hot too, if I ran pure methanol on a cool day with a non hot lap engine on 91 I am almost thinking I could run 16 without knock. Problem is I gotta open my wastegate hole up since it doesnt boost up that high except when the motor is really spinning right before gear changes. I doubt that porting the wastegate hole is even going to help that enough. 6 PSI of boost creep is a lot to take care of just opening the hole up. I cant imagine how bad it would be on one of the early housings or once I get my 87 wheel in the cold side.
I usually run my BTM around 1.25 degrees on 87 or 89 when im putting serious miles on the car since 91 is 25 cents more than 87/89 around here. On 91 I can turn it to .5 degree or less and it wont detonate until it really starts boosting. Mine was stock boosted to 7PSI and I turned the wastegate to 8 just to see if it would change witch it did. Problem is with my 82 AR and 83-85 GN tubular manifolds, ported heads, bigger cam, opened up secondary air flap, ported plenum ect it boosts to 14. It only knocks when its hot too, if I ran pure methanol on a cool day with a non hot lap engine on 91 I am almost thinking I could run 16 without knock. Problem is I gotta open my wastegate hole up since it doesnt boost up that high except when the motor is really spinning right before gear changes. I doubt that porting the wastegate hole is even going to help that enough. 6 PSI of boost creep is a lot to take care of just opening the hole up. I cant imagine how bad it would be on one of the early housings or once I get my 87 wheel in the cold side.
b4black
Well-Known Member
- Joined
- May 24, 2001
I have never used the 1978/80 set up, so I can't speak from experiance, but one thing I don't like is that you cannot connect a scan tool or gauge to see what they are doing. I suspect they early setup way over compensates, like the later set ups. If my '83 knocks more than a few times, it falls on it's face since so much timing is pulled out (and it takes long to recover). The goal is to not knock at all, and use the ESC as a safety net.
Modern cars knock often. The ESC pulls just enough timing and recovers quickly. They run "off the knock sensor" so to speak. They are designed to run past the edge of knock and then let the ESC pull them back.
1978, there was no such thing as unleaded premium. Unleaded premium came around 1981-1983.
If I were building a 1978-80 motor, I would consider dropping the Turbo Control Center and installing a 1983/87 knock sensor and ESC module. Then connect a Casper's knock gauge and audible alarm.
Modern cars knock often. The ESC pulls just enough timing and recovers quickly. They run "off the knock sensor" so to speak. They are designed to run past the edge of knock and then let the ESC pull them back.
1978, there was no such thing as unleaded premium. Unleaded premium came around 1981-1983.
If I were building a 1978-80 motor, I would consider dropping the Turbo Control Center and installing a 1983/87 knock sensor and ESC module. Then connect a Casper's knock gauge and audible alarm.
So help me with knock sensors. The one for us B4Bs is just not available, but the ones used on the GN's are @$35. My logic dictates this is a "Sensor" sending info to a computer. It's the computer (ESC) that does all the thinking. Has anyone used the GN sensor with the ESC?
The only markings on the turbo is " Airesearch M3" Mean anything to you? There is also a plate on the carb side that says "rebuilt for General Motors" Also on the plate are serial #s that are too small for my old eyes. And tell me this Doc, could I be loosing significant oil pressure through the turbo? After the car warms up my oil pressure drops to almost nothing at idle. The engine is new and I don't think the issue is there and it just occured to me it might be the turbo oiler. I am fearful to block it off and run the car to check that lead. Any thoughts?
dr_frankenstein
Mad Scientist
- Joined
- Mar 17, 2008
Well as far as the turbo we need to look the the turbine housing, it should display a marking the says " .63 A/R" or ".82 A/R" the 63 housing being the desirable one. Its possible to maybe have a oil leak at the turbo, but i would doubt it unless your seeing huge clouds of smoke when it runs. What weight of oil are you running? What oil filter do you run? All of these variables can effect the hot idle pressure.
As for the knock sensor, they are available. Is the original ESC definitly something you would want? A package could be assembled for you.
As for the knock sensor, they are available. Is the original ESC definitly something you would want? A package could be assembled for you.
I really don't see any stampings. Are they on the carb side or exhaust. Hope the images will help. What is recommended filter and oil? Seeing the pressure go so low I have been using 20W40, and I'm due for a change. And just who's design was the baffle in the valve cover? That guy should be shot! Let me know how much the package would be. Mostly I'm curious what difference there is between the MSD and stock. I would also purchase the $30 knock sensor to see if it works the same as stock.
b4black
Well-Known Member
- Joined
- May 24, 2001
Pictures help a lot. You have a 1981 turbo. The wastegate on your turbo is normally open (NO). It's a one year setup that was for better fuel economy. They went back to normally closed in 1982 for better performance. To ID a NC wastegate, the lever arm on the turbine should point forward, your's points towards the firewall.
Your wastegate actuator rod is original. Replacement actuator are adjsutable in length, which then adjusts boost levels.
You have the .82 housing. Look at the top bolt on the wastegate elbow. The bump where it screws into the turbine housing is rounded. On .63 housings, this bump is very square looking. .63 housings were used in 1982 and '83.
The NO wastegate is probably responsible for the majority of your lag. You need an elbow and actuator from any year turbo but an '81. They can be changed without removing the turbo from the engine.
Your wastegate actuator rod is original. Replacement actuator are adjsutable in length, which then adjusts boost levels.
You have the .82 housing. Look at the top bolt on the wastegate elbow. The bump where it screws into the turbine housing is rounded. On .63 housings, this bump is very square looking. .63 housings were used in 1982 and '83.
The NO wastegate is probably responsible for the majority of your lag. You need an elbow and actuator from any year turbo but an '81. They can be changed without removing the turbo from the engine.
dr_frankenstein
Mad Scientist
- Joined
- Mar 17, 2008
well cheap and these engines rarely go together well.....
b4black
Well-Known Member
- Joined
- May 24, 2001
I dunno, I found my parts at junkyards, swap meets and ebay. Finding them is tricky, but they usually are cheap when you do. If you can locate a used 1982 or 1983 turbo (even if needing rebuild), you would get everything is on shot. I do think there are places that sell the actuators new. That would be worthwhile because many used actuators have ruptured diaphragms.
