Oil return hose + Smoking

[TGPRobNY]

My cars puffs an oil based smoke upon stopping and decided to remove the old oil return hose. The original (red liner 5/8")was in perfect condition. What should I look for now?  So I have a length of hydraulic hose availible for sale.. BTW..I use 87 octane and this car screams. Comments appreciated.

[florida_tgp]

on my small block chevy, it would blow smoke on deceleration, especially if i downshifted so engine was braking

[TGPilot]

Be very careful as to how much boost you run with only 87 Octane. The lower the Octane you run the risk of a "knock" and you will cook your motor. I accidentally put 87 in mine with 9-10lbs of boost running and it would knock hard as soon as it hit 4-5lbs of boost! If you have the line hooked up in the Waste Gate Actuator loop you will only run 4.5 lbs of boost anyway....all 89-90 TGP Waste Gate Actuators were set to 4.5 from the factory.  8)

[TGPRobNY]

Hi guys...I replaced the hose with a flexible oil/fuel type ($4 ft) and it runs fine now, even though the original looked fine, apparently when warm it collapsed internally. You will find that "hydraulic hose" is difficult to work with due to its stiffness and ability to slide over the ridges on the metal lines. Good luck everyone and thanks for your input!

[turbo90gp]

So what does that mean then?  The TGP only runs 4-5 lbs of boost?

[Tooky]

TGP owner's manual says maximum boost pressure is 7.5 PSI.  I'm sure the factory turbo boost gauge is woefully inaccurate, so has anyone ran a mechanical aftermarket boost gauge on their stock TGP to tell us what the boost really is?  I am waiting to do it myself but I need to find a solution to mount the gauge(s)...

[turby]

Can the loop be bypassed to get more boost or is it unchangeable?

[TGPilot]

OK...when I talked to Turbo-Engineering in Boulder Colorado about me making an adjustable waste gate, he told me that the adjustable arm would have to be set to the factory default for liability reasons because he didn't build the turbo. He said the factory waste gate actuator diaphram is set to 4.5lbs of boost. He also said I would not find anyone to build the adjustable arm for less than $200, he was right $225 was the cheapest.

Go here for how a turbo works  http://www.howstuffworks.com/turbo1.htm

Turbos need to have something to regulate the amount of boost it produces, this is done on our cars by using a waste gate. The waste gate has a spring loaded diaphram known as a Waste Gate Actuator (the little can with the rod coming out of it) attached to it which has the spring preload set internally. As the turbo produces boost, the little plastic "vacuum" line runs out of the turbo (pressure side), up to the sensor that is mounted just over the valve cover, through the sensor, then back over to the Waste Gate Actuator (this is the Waste Gate Actuator Loop that I refered to earlier). As boost is built up in the loop, the pressure pushes on the back of the Waste Gate Actuator Diaphram. When the boost pressure finally reaches 4.5lbs it opens the Waste Gate (with the actuator) not allowing the Turbo to produce any more boost than 4.5lbs. If the Actuator is set to 8lbs it will not open the waste gate until 8lbs...hense your turbo would produce 8lbs of boost. Our Turbos do not have an adjustable Actuator (I am in the process of making one though). From the Garrett factory the Wast Gate Actuator's are set to 4.5lbs.

On my car, and on Twalt's car, we have the line plugged where it would go into the Waste Gate Actuator. I can produce and sustain around 8-9lbs of boost. Now keep in mind that we are 6009 feet above sea level and the air compresses differently here. I do not suggest you just plug your line...but it is worth the try. For those of you who are running a lower octane...DON'T PLUG THE LINE UNTIL YOU PUT A FULL FRESH TANK OF HIGH OCTANE IN YOUR TANK. The higher boost rate is a higher compression ratio in your motor, and without high octane you will get a knock and DESTROY YOUR MOTOR!!!!

Hopefully this answers your questions... 8)

[Tooky]

I am not a turbo expert but I think your explanation had some inaccuracies.  The wastegate solenoid, the little metal box on the top front of the intake manifold that the wastegate vacuum hose runs through, has an important purpose.  Sure, the wastegate diaphragm spring may be set to 4.5 PSI but that doesn't mean that's the limit of the turbo OR the limit on a stock TGP.  It means if the pressure from the turbo was sent to the diaphragm all the time, it would make 4.5 PSI.  BUT, the pressure signal is not sent to the wastegate all the time, only part of the time.  The wastegate solenoid is sent an electrical pulse from the ECM.  I have watched this before on my GMC Syclone (turbo truck) which uses the same wastegate solenoid, using a test light.  When the boost raises, the test light hooked onto the wastegate solenoid circuit would flash.

Get where I'm going with this?  The ECM reads the boost pressure from the MAP sensor (black box at the top back of the intake manifold) and depending on how high the boost is, it sends the pulsing signal to the wastegate solenoid which blocks off the boost signal to the wastegate.  Since it is pulsing, the signal to the turbo is going "on off on off on off" which raises the boost over the base 4.5 PSI figure.  It can change the amount of "on" and "off" signals, perhaps it sends an "off off on off off" where it only is "on" 20% of the time.  That's the Wastegate Duty Cycle and it will show up as a percentage if you hook up a scan tool to your car's ECM.  It represents how much the ECM is trying to control boost.  Our cars have electronic boost control and I think it is a very nice feature to have.  If we had superchargers, the boost would change depending on air temps and humidity and there would be nothing you can do about it.  On an electronically controlled turbocharged engine, the electronics and sensors can read the changing conditions and adjust the wastegate in an attempt to keep the boost level at the same (Stock 7.5 PSI) no matter what the conditions are.  (Unless the RPMs get too high or the boost gets too high, then the stock chip will retard boost as a safety feature.)  

If the boost signal was blocked off completely by the solenoid and never sent to the wastegate, I would think the boost would be an engine-damaging amount.  You said it would be 9 PSI if I read that right.  I haven't tried so I can't say for sure but on my factory stock Syclone if you would block off the wastegate signal, the boost would go over 20 PSI without even giving full throttle.  It happened to me once when some wires got crossed and I let off so quick it was WAY before I hit full throttle.

In my opinion if you block off the wastegate solenoid's signal, you eliminate its ability to control boost and you WILL BLOW YOUR MOTOR, INEVITABLY and it's only a matter of time.  Remember this phrase, I have it burned into my memory - On a turbochanged motor, detonation is to be avoided at all costs!  If you ran high boost on pump gas (93 octane) you would be knocking (detonating) and burn a hole in your piston or shatter the engine internals in no time.  Especially with our relatively high 8.8:1 compression to begin with.  If you were experimenting with high boost, it would require high octane and when I say high I mean it.  100 octane unleaded would be a "medium" level of high octane.  110 octane leaded would be a high level of high octane.  116 octane leaded would be the highest I know of.

Just thought I would throw that out there, again I am still learning about my TGP but I think things work the same as on my Syclone.

[idbeast]

Josh, very well put :wink:  You are right on the mark with your explanation!!!
The wastegate actuator is controlled by the ECM and if you are running a stock chip, you will hit the overboost function and the car WILL sputter and surge at 7.5lbs of boost... with jeff's chip you will get 9 lbs of boost depending on conditions! I run external boost guages on all my TGP's so I know exactly what they are doing :mrgreen:
And for those of you who want to try disconnecting the wastegate solonoid keep in mind that I lost a motor opening day at the drag strip when a platnum shitfire caused engine knock on the first run and took out a piston :cry:

[TGPilot]

I am by no means a Turbo expert either (it obviously shows) but, running at 5000+ feet above sea level...my TGP runs a constant 8 or 9 lbs of boost with only the waste gate actuator line disconnected and I am not chipped...yet :wink: .

Like I said in my previous message...I do not suggest you just plug your line...but it is worth the try. If a person does not know how to listen for a knock, then they shouldn't be screwing around with the boost to begin with. This is not a Porsche 930 turbo that does 0-60 in 4.2 seconds out of the box. It is a 3400lbs lead sled that needs major tweeking to do 0-60 in 6 seconds. If you are not willing to take a chance blowing a motor, cooking a turbo, or spinning your transmission, then don't open the hood other than to fill your washer fluid! Oh...and make damn good and sure you leave the oil changes to Jiffy Lube.

[turbo90gp]

Tookycat-
I got the gaugepod off of RSM racing, and I think it was for a mustang or something, but it was under the GP section, I go to order it and its close, but needed some modding.  Took a heat gun and my, my pod, and my A-Pillar and very carefully softened the plastic to form to the A-Pillar, then let it cooled and painted it.   Worked great!

[TGPilot]

turbo90gp...please post the link or get us an address for the pod that worked for you. If you have any pictures of the finished product...please show those too. Many of us are very interested in aftermarket gauge pods... 8)

[GPChief]

For all of you "Non-believers & Neysayers"  TGPilot & I are not telling everyone to plug their wastegate actuators.   You all need to realize that we live in the rocky mountains at a vary high altitude with little air.  We can "boost" more here due to the differance in air.  
I plug my wastegate actuator sometimes (not allways) and on my 97 GTP I run a 3.1 pully with no problems at altitude, when guys at sea level need to do computer / FPR changes to run this combination.
Why do you all think that the Olympic training center is in Colorado?  Its because of the lack of oxygen in the air, this makes the athletes perform better at sea level.  I openly invite all of you to come to Colorado and climb one flight of stairs and tell me you are not winded.  I guarentee that at 35 yrs old I can out run (speed & distance) any 18 year old comming from sea level.  Once you are here 30 + days then your body is acclimated and all bets are off.
Once I move from Colorado I will not plug my wastegate actuator ever, promise :D Neither one of us wants to get anouther engine at this time.  And after Racing my STE a few days ago and talking to the Turbo guys ALL of them at this altitude plug the wastegate actuator.

[turbo90gp]

I dont have a picture cuz I am waiting to recieve a power cord for the scanner.  But anyways, RSM I guess doesnt sell the pod anymore for our GP's cuz I cant seem to find it anywhere on the site.  Feel free to email them if yad like.