Chevy to Turbo 6, this is complicated!

[bossman]

OK guys, this may seem really basic but I've just had my '83 T for a little while and the learning curve is slow.
I've tried reading everthing I can on this site and my feelings range from "give me back my simple chevy 350" to "turbo 6's are COOL!".
My '83 is a real slug off the start but I CAN spin the tire(non posi) if I do a brake torque. If I just floor it the car may wait for 3 or 4 seconds before going or stall completely. The little plunger (TPS?) in front of the carb is not functional and I have no turbo gauge lights coming on in the dash.
Tha car is in great shape with 100,000 miles and looks to have been cared for. I just have to ask my friends for a 3 second head start before we go.
Any suggestions would be appreciated.

 

[b4black]

There is always going to be turbo lag that you will have to get used to, but 3 or 4 seconds is something else. I would bet the bad TPS is throwing the ECM off, cuasing the bog (hesitation). Another cause for bogging is vacuum leaks.

A SBC 350 is easy, but once it's in tune your done. With the Turbo V6, that's when it's time to turn up the boost.

This page should help with the lights:
http://home.flash.net/~rjgeorge/tplights.htm

And if you missed, read my Green Light Project thread:
http://www.turbobuick.com/forums/showthread.php?s=&threadid=51104

 

[bossman]

Good stuff.
I guess it's add a pound of boost then tune it in each time until you can't get it in so back off a bit. Lean is a really bad thimg.
Now, with mine being a carbed version where I'm not playing with injecters and fuel pressures, there must be a limit of boost that the carb can handle and then that's IT! Any idea what that limit might be as opposed to what my stock boost is?
Would I be correct in assuming that there is not a scan tool that I can use with this set up to monitor the rich/lean condition so that parts don't start spewing out?
I must say though. it's really neat to have a car that moves pretty fast and I've still gotten 26mpg on two tankfuls.

 

[b4black]

The Quadrajet isn't qoing to be your limiting factor. They put this same carb on big truck engines. It's a 750 cfm if the seconadies are fully opened. Even with the ECM, it's tunable. The ECM only controls the primaries. The seconadaries (for WOT) work off metering rods. I believe the stock turbo won't put out enough boost to overcome the Q-jet.

The EFI only type tools (like scanmaster) won't work on CCC cars. But there are other scan tools. An OTC Monitor 2000 (search this on ebay) is a good choice. All scan tools (except the EFI DirectScan) have a problem in that they only update too slow - 1 reading per 1.5 seconds (this is becuase of the ECM). For Air/Fuel, I'm going to read right off the sensor. A EGT gauge would be an even better choice.

The scan tool will also monitor knock. But I'm going to order a Casper's Knock Gauge (LED type) to have on at all times and it works before the ECM as well.

NOTE: Scan tools don't monitor boost. A boost guage is #1, then the scan tool.

 

[bossman]

Well, if I'm going to tune this thing right I'll need an A/F gauge, Boost gauge and knock gauge.
I read one of the postongs and they talked about the boost spike and how to modify the system to get more boost but that way was nothing like the adjustable wastegate actuator.
What's a boost spike and what does it do for performance?
Can both these modifications be done or is one better than the other?

 

[b4black]

The WG is supposed to hold the boost at 9 psi(or wherever it's set). Sometimes there is just too much exhaust flow for it to handle and boost will "creep" above the set point. When this occurs during a shift, boost will quickly "spike" a couple of psi, but come back down after the shift. This "spike" can cause some true knock (detonation). The engine's movement during shifts can cause some false knock as well (like if the downpipe is hitting the frame).


One way to get rid of boost creep/spike is too enlarge the WG hole a little. Unfortunately, this requires removeing the turbo. Something else that may work is a Relief Valve in line with the WG actuator.

Anybody have a link to TurboGus' page on Relief Valve's? My link's dead.