Supercharger/ignition timing questions
08-27-2013, 04:39 AM
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just my $0.02....
I've got a supercharged 6.0 liter engine here. Are you sure it is a 6L? Has a Vortech Supercharger What model Vortech SC? What is the model number, and what is the pulley ratio between the SC pulley and the Crank Pulley? With this information, you can get a compressor map and know what exactly you have in front of you with a call to Vortech, or downloand a map from the web.with a Vortech water to air intercooler. What size IC? What size pump.? and how big is the reservoir? Is it the washer fluid bottle? Apparently makes about 19 pounds of boost....I have no idea....I'm literally afraid to go out and drive it...much less step on it. Good idea to not drive it until you can confirm the components and baseline first...
The engine has S4 intake with S3 computers. Appears that the S3 wiring loom was used and modified to fit to the S4 intake. Has a "great big blue" fuel pressure regulator. Is it an S3 motor? with just an S4 intake, or S3 bottom end with S4 heads and cams? Block serial number and a degree wheel on the cam and crank and #1 cylinder will certify that.. How can you be sure it has 944Turbo pistons for a 2V head which would require some funky valve pockets (Who knows what would have been done in the piston modification...), and not 944S2 dished pistons which would have come from Mahle, or JE pistons made for a 4v head with a dish to lower the compression?
Has 30 pound injectors with an Autothority performance chips. Did the injector model # confirm this? or just customer say so?
It would literally barely idle when I first got it.....it had virtually no vacuum to the fuel pressure regulator. All of the vacuum diaphragms that were designed to see only vacuum were blown, apparently from boost. Got all of that fixed and now it idles...but obviously very rich.
Uses fuel like a 747 on takeoff from LAX.
The very first thing I did was change the oil.....stunk of fuel.
The car seems to run (at cruise) under 210 degrees. If you shut it off....after about 5 minutes it starts puking out coolant, from the overflow tank....but the radiator has a leaky tank and I assume that the pressure drops and the fluid boils. I would be curious if it were so rich that the exhaust is so hot from residual heat of the rich mixture that the coolant in the heads boil after from that, or it also has steam pockets and that sends the coolant to the expansion tank with lots of heat and pressure... With no cap, it would surely overflow/puke..
Or are the head gaskets already screwed up? Is coolant in the oil?
Got all my "Sharktuner 1", with the ability to tune the '85/'86 brains and finally got my computer to recognize the system.....that took several days. Great start to diagnostics..
First obvious problem is that the Sharktuner system did not recognize what "map" was being used. There were cursors in both the full throttle map and the cruise map.
Turns out that the throttle switch is hooked up to the idle stabilizer leads (at the brain) and the idle stabilizer leads are hooked up to the idle switch leads (at the brain).
Obvious questions:
How the hell did this thing drive here?
What is it going to take to fix it? Some diagnostics, reset to baseline, then add the compressor back based on capacity of the engine to handle more load..
I'm smart enough to know the only reason there is a head gaskets (if they are still "alive") and pistons still in this engine is because there is lots of fuel "covering up" the obscene amounts of ignition timing.
Obviously, I can redo the stupid wiring problem....and get an idle, cruise, and full throttle map working. However.....there is still not going to be any boost ignition timing retard capacity and it would seem, to me, that as soon as I start removing some of the huge volumes of fuel being delivered, this is going to be an issue.....
Apparently, John Speake makes an EZK box with a map sensor, so that the brain can detect boost and then make changes in timing, when under boost.
Is this what people are using....or are they (you) just running stock timing, at boost.......and praying?
The engine has S4 intake with S3 computers. Appears that the S3 wiring loom was used and modified to fit to the S4 intake. Has a "great big blue" fuel pressure regulator. Is it an S3 motor? with just an S4 intake, or S3 bottom end with S4 heads and cams? Block serial number and a degree wheel on the cam and crank and #1 cylinder will certify that.. How can you be sure it has 944Turbo pistons for a 2V head which would require some funky valve pockets (Who knows what would have been done in the piston modification...), and not 944S2 dished pistons which would have come from Mahle, or JE pistons made for a 4v head with a dish to lower the compression?
Has 30 pound injectors with an Autothority performance chips. Did the injector model # confirm this? or just customer say so?
It would literally barely idle when I first got it.....it had virtually no vacuum to the fuel pressure regulator. All of the vacuum diaphragms that were designed to see only vacuum were blown, apparently from boost. Got all of that fixed and now it idles...but obviously very rich.
Uses fuel like a 747 on takeoff from LAX.
The very first thing I did was change the oil.....stunk of fuel.
The car seems to run (at cruise) under 210 degrees. If you shut it off....after about 5 minutes it starts puking out coolant, from the overflow tank....but the radiator has a leaky tank and I assume that the pressure drops and the fluid boils. I would be curious if it were so rich that the exhaust is so hot from residual heat of the rich mixture that the coolant in the heads boil after from that, or it also has steam pockets and that sends the coolant to the expansion tank with lots of heat and pressure... With no cap, it would surely overflow/puke..
Or are the head gaskets already screwed up? Is coolant in the oil?
Got all my "Sharktuner 1", with the ability to tune the '85/'86 brains and finally got my computer to recognize the system.....that took several days. Great start to diagnostics..
First obvious problem is that the Sharktuner system did not recognize what "map" was being used. There were cursors in both the full throttle map and the cruise map.
Turns out that the throttle switch is hooked up to the idle stabilizer leads (at the brain) and the idle stabilizer leads are hooked up to the idle switch leads (at the brain).
Obvious questions:
How the hell did this thing drive here?
What is it going to take to fix it? Some diagnostics, reset to baseline, then add the compressor back based on capacity of the engine to handle more load..
I'm smart enough to know the only reason there is a head gaskets (if they are still "alive") and pistons still in this engine is because there is lots of fuel "covering up" the obscene amounts of ignition timing.
Obviously, I can redo the stupid wiring problem....and get an idle, cruise, and full throttle map working. However.....there is still not going to be any boost ignition timing retard capacity and it would seem, to me, that as soon as I start removing some of the huge volumes of fuel being delivered, this is going to be an issue.....
Apparently, John Speake makes an EZK box with a map sensor, so that the brain can detect boost and then make changes in timing, when under boost.
Is this what people are using....or are they (you) just running stock timing, at boost.......and praying?
If the engine is now running and the wiring is solved, maybe you can validate the baseline maps with the ST and validate the intake & exhaust cam timing so you know what you really have on your hand.
In NA mode, with SC belt disconnected, the car can then be driven with the STuner to datalog what is happening across the rpm band in varying load situations and datalogged for that specific engine. Of course, a wideband would also be attached with a professional grade controller like a Horiba, ECM, PLM etc. and fed to the ST so these values can be logged as well with all the other values in the ST logging.
Once you get the Vortech parts validated, you can then build your own LH map based on the airflow of the compressor mapped to the engine load/VE.
If you don't have a pressure gauge on it from inside the manifold, after the TB, one could be installed and datalogged as well. The ST will log the air temp in the manifold, so you will be able to use pressure and temperature to figure out the density the engine is actually seeing. This with the wideband will tell you where to set the fuel, and you can adjust spark from stock to a better map, but the stock spark map may be good enough for a conservative 91 octane setting depending of course on the fueling and charge temp, and if you need to add fuel to compensate for the heated charge because the IC can't...
The customer should invest in a J&S Safeguard as Ed mentioned, they are excellent units, and allow more timing with leaner mixtures and the ability if individual cylinder timing/knock control as well as a boost rerefenced circuit to retard for pressure as well as knock. (Actually, with a simple setup of just the SC, probably don't need the boost retard as it is linear, while the spark is based on knock threshold which is not linear and more effective.) It would be quite simple to screw in one or two knock sensors to the block, connect the J&S, and tweak the timing as needed. $600 very well spent.
Once you figure out what you can run on paper with the motor by looking at the datalogging, you can then upgrade the injectors, get rid of the Vortech FMU/FPR, and calibrate the LH to use the upgraded injectors instead. You can calculate the BSFC that the stock pump can provide fuel for and get injectors for that limit if the customer does not want to get an 044 pump. Of course, the pulley of the SC can be changed to lower the output of the compressor so that the SC stays in line with the stock fuel system limits as well.. However, unless you know what you have, it's all a guessing game as you know..
Tim mentioned he could help with a calibration, and if the parts of the kit such as the SC and intercooler are from his setup, then you can obviously use one of his known calibrations and tweak for a 6 Liter engine with XYZ cam timing.
If it was purchased from Chris Clouser (Delta P), or is some sort of hybrid, then you may have to do a little more detective work. If the customer can't afford to fix it properly, then maybe they should get it running stock for the moment, and fix the SC bit once they have saved some more $$$ to do it properly..? Not my budget, nor my car, so I can't comment on priority.
Also, I don't trust much unless I can validate to my satisfaction what I have in front of me. Maybe I am paranoid, or just crazy, or both....!
I can live with that though..
Hope the $0.02 was helpful...
