If I can get a tire to hook.....running 27 vs 25 psi isn't going to matter to me.
My issue is that I can't get the boost low enough with the WG to have safe power levels with poor road conditions.
I might use one of my many dash switches to do a low power mode where the DBW limits boost for poor road conditions.
Or...I stack the DBW strategy (% by RPM and Gear) on top of the Boost control strategy, and use one switch to control it all. (9 position boost switch)
Suprised you dont have traction control setup with your ecu's.
https://www.extremepsi.com/store/pro...at=1626&page=1
Capital Driving Club Car # 102
How to turbo your car:
Step one. Install ecu and learn to tune and or have it tuned.
Step two. Install injectors and retune.
Step three. Install turbo parts and bits. get it running with out leaks. DO NOT DRIVE IT. Idling should be ok
Step four. Retune car
Step five enjoy
Thanks for the link.
Traction control is a very poorly named strategy. Once you exceed the slip rate of a tire on a given surface, you have to massively reduce torque to get tire rotation back under the threshold.
Ideally, you apply increments in power to get as close as possible to the peak slip rate (Correlate slip rate vs acceleration Gs), and then add an incremental timing retard above that slip rate to keep wheel speed in check.
When you apply torque multiplication through the transmission, you'll find that you might need 60% reduction in power to keep the slip rate close to target. Massive amounts of boost creep makes this impossible....
So while I do have traction control, I also have a light on my dash that tells me when it's cutting in. There's not much tuning you can do when you are constantly engaging either a slip or boost cut safety strategy....
Well said. People asked me all the time if my car had TC. And yes, it did, but it really doesnt help that much. It works great on a sticky tire that is on the limit of traction where the driver might not even know its spinning. But it wont be the end all of traction issues.
Ive had a few instances where ive seen the TC in the datalog and not even known it happened. Thats when it works the best.
328i Sedan Twin s366's, 6.0LS, TH400, MS3 Ultimate
9.20 at 150 on 22psi
Thought the ideal slip was closer to 3-5%.
Smoke occurs at 69%
Giggty
Btw forgot about this.
https://www.youtube.com/watch?time_c...&v=FembJNagxOE
https://www.diyautotune.com/news/tun...raction-world/
Last edited by euro2fast4u; 12-06-2017 at 04:23 PM.
Capital Driving Club Car # 102
How to turbo your car:
Step one. Install ecu and learn to tune and or have it tuned.
Step two. Install injectors and retune.
Step three. Install turbo parts and bits. get it running with out leaks. DO NOT DRIVE IT. Idling should be ok
Step four. Retune car
Step five enjoy
The slip management strategy with my (and most) Race Logic traction control systems is to cut one "injection" event on one cylinder when the onset of slip is detected and as the slip increases during that same event, it will cut another injection event on the same cylinder, or start cutting injection on additional cylinders to manage the slip to whatever level you have pre-set - zero to 25%.
As was mentioned before, if you don't know/feel it doing it it's working properly. Many times at autocross people have asked me why the car is misfiring and do I know how to correct it and I simply state that it's under control. During those times, I mostly don't feel it in the car other than knowing that the rear is not swinging out wildly while I'm mid-corner with my foot to the floor at 4,500-6,000rpm in 2nd gear with massive torque multiplication and 270whp-240ft/lbs on tap.
The only time it is REALLY felt is when it's set to wet mode in the rain. Then it sometimes feels like the car is severely lacking in power, but I still have my foot to the floor and the car is still accelerating as fast as the conditions/tires will allow. The DME gets pretty cranky though and after a full day of autocross in the rain I'll have a misfire code stored which is easily cleared with more driving.
*EDITED: I said spark instead of injection in my original post. The fuel is being cut. And no, we don't have to worry about a cylinder going lean. There is NO fuel for that combustion event. No possibility of a lean condition. The spark will fire into a combustion chamber with ONLY air!
Last edited by jakermac; 12-06-2017 at 10:05 PM.
Yea, fuel cut is way safer than a spark cut for the health of an engine. That fuel rich cylinder can detonate (cooling already expended on 'dead' cycle), or just rich misfire the next couple of cycles if you just cut the spark.
I did a test program ramping throttle position down, with 100% available up to 4000 RPM, then ramping down to the target by 5000 RPM
Road testing with the 10.5 PSI Spring:
65% Throttle = 12 PSI (Third gear)
70% Throttle = 13 PSI (Third gear)
75% Throttle = 14 PSI and holding (Third gear)
75% Throttle = 15 PSI and ramping up with RPM (Fourth gear)
80% Throttle = 15 PSI @ 5000 RPM ramping to 18 PSI at 5500 RPM (Fourth gear)
90% Throttle = 16 PSI @ 5000 RPM ramping to 21 PSI at 5500 RPM (Fourth gear)
Interestingly, my knock alarm went off a couple of times....and when I dug into the data, I found that cylinder #4 +3 degrees of trim applied to it, where everything else ranged from -1 to -3 degrees of trim. I think it was a finger error...and I'm glad I had the tools setup to catch it.
Exhaust backpressure at 21 PSI manifold pressure is 22 PSI in the exhaust manifold.....a massive improvement from the 42 PSI I saw with the GTX30 @ 19 PSI.
And here's the real shocker: I did this testing on 91 octane pump fuel, where I had to run a 102 octane race fuel mix to run the GTX30 over 15 PSI.....
Also, I was seeing 1700+ degrees exhaust temps with the GTX30, where with the GTX40 I'm now seeing between 1300 and 1400 under load....
idle to 4250 RPM = 100% throttle
Taper to 70% @ 4750 RPM
3rd gear:
12 PSI @ 4800 RPM
15 PSI @ 7600 RPM
Thats really cool. I'm jealous of the DBW throttle, I would love to be able to use that for traction control and idle.
- - - Updated - - -
Do you have any way to measure pre throttle pressure? I'm curious how much is being throttled off vs made.
It's official....I've maxed out my entire fuel system.
17 PSI @ 5900 RPM and my fuel pressure starts to drop, with IDC @ 91% in 3rd gear.
In 4th gear, I got to the same RPM with 18.5 PSI....and the pressure starts to drop. (From 5800 to 6800 it drops from 71 PSI down to 63 PSI) Injector duty cycle goes from 90% to 107%!!!!
- - - Updated - - -
I have a sensor for the turbo outlet pressure.....but I forgot to drill and tap the cover before installing the turbo/engine back in the car. So I've still got the sensor....it's just hooked up to nothing. I could probably run a boost line over to the pipe before the throttle to check......
There IS a difference to the exhaust back pressure when throttling like this though.....it goes up a bit. With 100% throttle, I'm at a pretty solid 1:1 EBP ratio....but when I run the throttle down to 70% it's closer to 1:1.2....
For those wondering about my fuel system:
Bosch 630cc injectors (Measured at 3 bar)
-6 AN lines
Stock fuel rail with -6 AN inlet and outlets
A1000 fuel pump with -10 AN feed
Surge tank semi pressurized under load to 3 PSI (Lift pump runs full time when WOT)
According to my airflow and fuel flow data, (From the ECU) I'm somewhere north of 700hp in 3rd gear at 7500 RPM. HP hasn't fallen off at that point.....but I'm not going to rev the engine any further without rods....
Did you upgrade the wiring to your fuel pump. I am curious what voltage you are at at 63psi
Capital Driving Club Car # 102
How to turbo your car:
Step one. Install ecu and learn to tune and or have it tuned.
Step two. Install injectors and retune.
Step three. Install turbo parts and bits. get it running with out leaks. DO NOT DRIVE IT. Idling should be ok
Step four. Retune car
Step five enjoy
May be too many amps going through that size wire and distance. Two pumps off the same wires, 15-20 amps each?
https://www.engineeringtoolbox.com/a...uge-d_730.html
Sorry late to the game.
Last edited by euro2fast4u; 12-07-2017 at 04:16 PM.
Capital Driving Club Car # 102
How to turbo your car:
Step one. Install ecu and learn to tune and or have it tuned.
Step two. Install injectors and retune.
Step three. Install turbo parts and bits. get it running with out leaks. DO NOT DRIVE IT. Idling should be ok
Step four. Retune car
Step five enjoy
Just one pump, but you might have a point.
I am measuring output voltage at the PDM, but I don't have a measure of what the voltage is at the pump. About 2 years ago I remember measuring this at idle, without much draw on the pump...but I can't remember the result. Ideally, I'd stick a volt meter across the terminals on the fuel pump under full load. (72 PSI line pressure) The thing is, I'm measuring line pressure at the end of the fuel system, so 72 PSI after the fuel rail, might be 80 PSI at the pump outlet. (Running through 20 feet of -6 AN line and multiple fittings, and a fuel filter)
There is a way to measure the voltage at the pump under load. I have 16 switch inputs on the PDM that can be triggered either high or low. Regardless of their function, you are able to log the pin voltage. I have a bundle of extra wires to the fuel pump area that was intended for additional pressure and temp sensors, so I could connected one of these wires to the pump + terminal, and log the pin input voltage.....
- - - Updated - - -
I have additional 12 AWG wires to run additional pumps in that area....so if need be....I could double or even triple them up....
ohms law should be able to help you with calculating the voltage drop at pump. My current guess is your seeing close to 11.8 volts at the pump at full load, taxing the injectors to 100+% duty cycle.
As for pressure drop from the pump output, there are two things, the suction side and supply side. Any restriction on either side will cause a lower fuel rail pressure.
I reviewed the O&M for the fuel pump. Few things.
https://www.aeromotiveinc.com/wp-con...0122-0revK.pdf
1. Maximum continuous operating pressure should not exceed 70 psi.
2. Wiring diagram for the pump has 10 AWG.
3. For long term driving applications where continuous run times exceed 30minutes and fuel capacity is less then 10 gallons, Aeromotive recommends theinstallation of a Fuel Pump Speed Controller to maintain lower fueltemperatures in the tank. See Aeromotive Fuel Pump Speed Controller 16306.
4. 30 AMP circuit breaker
5. If you choose not to install a reservoir sump, then you must install a high flowcapacity fuel tank pickup (9/16” to 5/8” inner tube diameter). Installing pickuptube instead of a reservoir sump may shorten the fuel pump life and causedrivability problems. When using a pickup, you should maintain at least ½ tankof fuel to avoid possible engine lean-out and/or fuel pump damage.
Over heated pump, over heated fuel, over heated wire can all cause a restriction and subperformance. Hope this helps
EDIT:
So i just reviewed the Motec PDM and it appears it can't handle more than 20amp continuous power. Id look into this as well.
Last edited by euro2fast4u; 12-08-2017 at 10:23 AM.
Capital Driving Club Car # 102
How to turbo your car:
Step one. Install ecu and learn to tune and or have it tuned.
Step two. Install injectors and retune.
Step three. Install turbo parts and bits. get it running with out leaks. DO NOT DRIVE IT. Idling should be ok
Step four. Retune car
Step five enjoy
I'd double up the 12 AWG to the pump and see how it performs. The mfg recommends 10 awg, which is probably where I'd be for a run of any length (longer than a foot or so). Dual 12 awg should eliminate wiring or the PDM current holding per connection as being a possible issue.
Capital Driving Club Car # 102
How to turbo your car:
Step one. Install ecu and learn to tune and or have it tuned.
Step two. Install injectors and retune.
Step three. Install turbo parts and bits. get it running with out leaks. DO NOT DRIVE IT. Idling should be ok
Step four. Retune car
Step five enjoy
Aye, there's that too.
Put some 1000-1300 cc inj on there so you can drop your base pressure ~10-15 psi and it should be handled.
Capital Driving Club Car # 102
How to turbo your car:
Step one. Install ecu and learn to tune and or have it tuned.
Step two. Install injectors and retune.
Step three. Install turbo parts and bits. get it running with out leaks. DO NOT DRIVE IT. Idling should be ok
Step four. Retune car
Step five enjoy
I've read this manual many times, and at one point (2013) had everything setup exactly as suggested. Things changed though....
The PDM outputs are rated continuous under worst operating conditions at 20amps. There is a section in the user manual that explains how to calculate load over time, which is how Motec sets up their limiting. In the software, you can set the limit at 25 amps, but there is an average load value that increments if you go over this until you hit 100% draw. At that point, the output shuts off until the average load value dips below 100%. On a single 20 amp output, I put my main radiator fan, and it would spike to 100amps draw when starting, then cycle down to 24-25 amps once running. I could run that fan for about 30 seconds before the output would turn off.....
The A1000 pump is fed from the bottom of a surge tank with a -10 AN line directly between the 2. The surge tank under WOT sees 3-4 PSI of positive pressure, so the A1000 isn't sucking as much as it's being fed from the tank.
I actually own the Aeromotive fuel pump controller, and had it in the car previously driving the A1000 Pump. When I put the Motec M150 ECU on the car, I switched to using a solid state relay to drive the A1000 with PWM. The control strategy from the M1 worked fine, but the Racegrade SSD did not. The instructions when I bought 2 of these devices showed that you could do 12V+ PWM pulsing....then a later revision to the instructions said that you couldn't. I wired the car to do 12V+ PWM.....then experienced intermittent fuel pressure issues when the SDD didn't do what it was told.....resulting in a blown head gasket and multiple valves being melted at the race track. I then hardwired the fuel pump directly to the PDM. Racegrade never admitted to their being an issue....but I still have both versions of the instructions as evidence...
So you see....I didn't just guess at what my current setup should be....it's been an evolution of goals and parts that either failed, or didn't meet the revised criteria. Prior to running the GTX40 turbo.....I never saw sustained current draw over 20 amps....and I was around 65% injector duty cycle max.
Just checked my wiring spreadsheets.....it's a 12 AWG wire. I built this harness when I was planning to run the smaller A750 fuel pump. (Which I did at one point) I seem to remember it pulling a maximum of 16 amps under load.....
- - - Updated - - -
Just saw the posts above:
I actually have ID 1050x injectors sitting on the shelf, (Had them for 6 months?) but I need to convert the connectors on my wiring harness which is a bit of job....so I've been holding off.
I suspect doubling up the wire gauge to the pump will help in the short term. The ground connection is pretty short, and 10 awg.
- - - Updated - - -
Thats the plan.
Been busy with all kinds of other family stuff though.....so it's been hard to fit in. The to do list:
Put new diff cover on the 210mm diff (I have a new cover with poly bushings)
Wiring to fuel pump
ID 1050x injectors
Im sure you followed the instructions to the tee. Looks like aero has updated the O&M of course there are no dates on it
Capital Driving Club Car # 102
How to turbo your car:
Step one. Install ecu and learn to tune and or have it tuned.
Step two. Install injectors and retune.
Step three. Install turbo parts and bits. get it running with out leaks. DO NOT DRIVE IT. Idling should be ok
Step four. Retune car
Step five enjoy
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