Author Topic: Blair Patrick thanks for my Tunnelport for my 69 Torino Cobra project  (Read 69060 times)

0 Members and 1 Guest are viewing this topic.

fe66comet

  • Guest
Re: Blair Patrick thanks for my Tunnelport for my 69 Torino Cobra project
« Reply #30 on: February 19, 2013, 11:13:43 AM »
I am wiring my system from scratch as I always do. Kits are limited on options and if a circuit fails on a intergraded circuit it costs a huge bundle over a analog circuit. As far as data logging buy what you need in separate components rather than one board that has way more than you will ever use and the cost exceeds an engine or trans.

69Cobra

  • Jr. Member
  • **
  • Posts: 40
  • A goal without a plan is just a wish
    • View Profile
Re: Blair Patrick thanks for my Tunnelport for my 69 Torino Cobra project
« Reply #31 on: February 19, 2013, 11:47:12 AM »
Thanks for the advice Jon but I think RacePak has proven themselves over and over and over again. The only thing that will limit the ability of a Smartwire is the person programing it. As far as the data logging its self nobody make individual devices that log individual sensors by themselves and if they did the weight and clutter that would accompany it would be ridiculous compared to one dash that will display it all and one small box that weight about 1.lb. I can program the Smartwire to shut off the ignition and fuel system if oil pressure falls below x amount. If it catches that and save you an engine one time its paid for its self. Racing and running FE's to 7400 rpm's going on 20 years I've blown up a couple of them and I can tell you they aren't any cheaper to rebuild the second time around. What's a little extra insurance worth to you?
Kris Rachford
69 Cobra 428 CJ Jerico 4 speed
NHRA C/Stock Eliminator 3032

Chad D

  • Full Member
  • ***
  • Posts: 113
    • View Profile
Re: Blair Patrick thanks for my Tunnelport for my 69 Torino Cobra project
« Reply #32 on: February 19, 2013, 04:38:58 PM »
The real limit to the Racepak stuff is that it uses (used to use?) a CANbus (http://en.wikipedia.org/wiki/CAN_bus) variant, which is pretty limited for sensor resolution (it is a function of time slots at bus frequency).  All sensors are 'smart' and share the bus, the more sensors, the faster your resolution per sensor drops off, as contention limits the amount of data that can be transmitted.  In order to get the resolution back, you need to run a multiple bus setup.  This is pretty old tech, in place for a long time on big rigs and many European cars to make maintenance and repair regimens more cost effective.  Works very well for low data rate streams or very simple controllers.

For most peeps, CANbus works just peachy, but if you're needing analog to digital analysis at high resolution (bit 'depth' of resolution) and high frequency (Kilo or Mega Hertz) to uncover transitory events, you're pretty much out of luck with Racepak.  For example, seeing clutch chatter by comparing crank sensor speed to trans input speed is pretty much impossible with the two magnet collar setup, but moving to the eight magnet setup, it's possible, if you have enough bus time to sample fast enough.  A vibrating broken or loose sensor wire (or other intermittent connection) can be diagnosed with high frequency sampling, you can see the value shift quickly from a valid number to zero, and back.  Insufficient frequency will often just show a wandering low average, as the sample often is not at zero but transiting between zero and a real value, which can cause you to chase a phantom tune.  Wideband O2 sensors also sample much faster than is generally acknowledged (individual cylinder events can be distinguished), but the rise and fall of sensor values (response curves) are only visible with high frequency and high resolution sampling.  For appropriate sampling choices, consider reading a bit on the Nyquist-Shannon sampling theorem:  http://en.wikipedia.org/wiki/Nyquist%E2%80%93Shannon_sampling_theorem

As far as data acquisition and analysis technology is concerned, Racepak's best stuff is kinda old tech.  It does offer a nice one stop shopping package, though, and may be quite appropriate for your application.

69Cobra

  • Jr. Member
  • **
  • Posts: 40
  • A goal without a plan is just a wish
    • View Profile
Re: Blair Patrick thanks for my Tunnelport for my 69 Torino Cobra project
« Reply #33 on: February 19, 2013, 11:51:18 PM »
Sample Rates:
V-Net: up to 100 per second
Analog: up to 1000 per second
Digital: RPM and switch contacts up to 100 per second
Digital: Timing intervals within 1/1000th of a second


Can you show me something that is better for an automotive application?
What I've used in the past was 100 per second sample rate on my driveshaft speed sensor and it was just a two magnet. With the RacePak I'll be using an eight magnet collars for better resolution. But if there is something better out there I'm all ears.
« Last Edit: February 20, 2013, 01:54:06 AM by 69Cobra »
Kris Rachford
69 Cobra 428 CJ Jerico 4 speed
NHRA C/Stock Eliminator 3032

jayb

  • Administrator
  • Hero Member
  • *****
  • Posts: 7577
    • View Profile
    • FE Power
Re: Blair Patrick thanks for my Tunnelport for my 69 Torino Cobra project
« Reply #34 on: February 20, 2013, 01:17:44 AM »
Hmmmmm, this is an interesting subject.  Just thinking out loud here.  Let's take an example of an engine that redlines at 7000 RPM, with a 2.32 first gear in the trans, a 30" tall tire and 4.56 gears.  First let's calculate driveshaft rotations per second in first gear.  7000 RPM is the same as 116.6 rotations per second for the engine, and with the 2.32 first gear the driveshaft will be rotating at 50.28 rotations per second.

Now think about the magnets on the driveshaft ring, and the spacing between the magnets.  There is a magnetic sensor mounted on a bracket near the driveshaft, that will detect the position of those magnets.  There is some angle of the driveshaft movement where the sensor will detect the magnet.  Let's say for the sake of an example that this is 20 degrees of driveshaft rotation.  This is 20/360 of the total driveshaft rotation, or 5.55% of each rotation.  The 50.28 driveshaft revolutions per second means that each revolution will take 1/50.28, or .01988 seconds.  5.55% of .01988 seconds is 0.0011 seconds that the sensor has to pick up each magnet as it goes by.  The sensor is easily capable of doing that; magnetic sensors are fast.  But the Racepak setup can only transfer the data at .001 second intervals if I'm reading your specs correctly.  So that means that it will barely have enough time to pick up the signal from the magnetic sensor as the magnet goes by.

In addition, Chad mentioned the Nyquist sampling criteria, which states that for a reliable signal you should have at least two samples for each signal that you are trying to measure.  So that means you would need almost 2000 samples per second to guarantee an accurate measurement.

Of course, you are probably not gathering the data at 50 driveshaft revolutions per second.  Your car is running from a standing start, and your driveshaft does not instantaneously accelerate to full speed.  When you dump the clutch the RPM will drop somewhat, and clutch slip will also be a factor.  So at the launch, which is probably where you are primarily interested in the data, the driveshaft will be going much slower than in the example I gave above.  In that case I would guess that the Racepak setup will have plenty of resolution.

So, Kris, you will have to let us know how it all works 8)
Jay Brown
- 1969 Mach 1, Drag Week 2005 Winner NA/BB, 511" FE (10.60s @ 129); Drag Week 2007 Runner-Up PA/BB, 490" Supercharged FE (9.35 @ 151)
- 1964 Ford Galaxie, Drag Week 2009 Winner Modified NA (9.50s @ 143), 585" SOHC
- 1969 Shelby Clone, Drag Week 2015 Winner Modified NA (Average 8.98 @ 149), 585" SOHC

   

69Cobra

  • Jr. Member
  • **
  • Posts: 40
  • A goal without a plan is just a wish
    • View Profile
Re: Blair Patrick thanks for my Tunnelport for my 69 Torino Cobra project
« Reply #35 on: February 20, 2013, 02:17:40 AM »
Hey Chad,
 Here's a link to Autometer's new Data loggers and their best system "Pro System" is only 500hz which is half of what the RacePak is and they are also using the CAN bus system.
http://autometer.com/datasystems.aspx

I'm replacing this http://autometer.com/cat_data_tachdetail.aspx?pid=10 with the RacePak system and I've used it for about 10 years with a two magnetic collar and its only 100hz so I think the RacePak with a 1000Hz and an 8 mag collar should be a whole lot better.

Like Jay mentioned. 90% of what I'm looking at is in the first second of the run and the rest is at the gear changes which all take place in the first half of the track. After that the clutch is locked up and we're just on cruise control from that point on.
Kris Rachford
69 Cobra 428 CJ Jerico 4 speed
NHRA C/Stock Eliminator 3032

Chad D

  • Full Member
  • ***
  • Posts: 113
    • View Profile
Re: Blair Patrick thanks for my Tunnelport for my 69 Torino Cobra project
« Reply #36 on: February 20, 2013, 12:39:49 PM »
Hey Chad,
 Here's a link to Autometer's new Data loggers and their best system "Pro System" is only 500hz which is half of what the RacePak is and they are also using the CAN bus system.
http://autometer.com/datasystems.aspx

I'm replacing this http://autometer.com/cat_data_tachdetail.aspx?pid=10 with the RacePak system and I've used it for about 10 years with a two magnetic collar and its only 100hz so I think the RacePak with a 1000Hz and an 8 mag collar should be a whole lot better.

Like Jay mentioned. 90% of what I'm looking at is in the first second of the run and the rest is at the gear changes which all take place in the first half of the track. After that the clutch is locked up and we're just on cruise control from that point on.

If the Racepak or whatever satisfies your requirements and is at an acceptable price, then by all means use it.  I was just trying to explain how you could be limited.  Certainly my own bias was revealed, my apologies if you were insulted.  I think you might have missed where I said 'It does offer a nice one stop shopping package, though, and may be quite appropriate for your application.'

Racepak may work fine... or Autometer, or any other brand.  My main gripe with Racepak is how they are advertised as being the latestgreatestomfgdatawhutsit when they are not, and that the price tag is quite shocking for what you get.  Personally if the price tag is going to be that high, I'd start with Pi http://www.veracitydata.com/NewFiles/PiProductLine.html, but the packaging and setup may not be in line with what you expect.  Perhaps piece your own together from parts at http://www.mccdaq.com/, but I'm guessing you want a packaged solution.  Innovate also offers excellent products.  Many product similarities exist between brands, simply because they're often rebranded reference designs at extremely different price points, just like many other electronic products.

Personally, I find the resolution of Racepak to be wanting, but I'm pretty damned picky, and accustomed to doing data analysis in the >=12 bit range, and 10KHz/channel and higher sampling rate.  Seeing the rise and fall (and rate of change) of sensor values from nominal to maximum is useful to me.  Knowing the event period and scale is an important part of deciding how to measure.  High resolution does make data storage and transmission path considerations a part of the package, some el cheapo off the shelf stuff simply doesn't play along.  The principle I live by is that you can always mathematically smooth or compress a data set, but you can't just 'imagine' where dips, spikes, or frequency changes may exist; you must measure them.

For example, my cousin and I are trying to sort the clutch on his 9000 RPM bracket car.  The eight magnet driveshaft collar wasn't enough, so we're changing the sensor to a 60 tooth trigger wheel and moving it to the input shaft, to give us a better picture of the relationship between the flywheel and the input shaft when the clutch is released at the line.  His 'box' (a used Pi Indycar piece from Menard) is quite capable of handling the data stream, where a Racepak would not.  It's overkill, but the parts were on hand and offered the necessary resolution.

69Cobra

  • Jr. Member
  • **
  • Posts: 40
  • A goal without a plan is just a wish
    • View Profile
Re: Blair Patrick thanks for my Tunnelport for my 69 Torino Cobra project
« Reply #37 on: February 20, 2013, 01:14:12 PM »
Chad,
 No worries here. Its going to take a whole lot more than that to insult me. lol I'm all ears. I've never heard of PI but looking at the links you posted I still don't see anything that's more than 1000hz unless I missed it.

What are the issues with your friends clutch? What clutch is he running?
Kris Rachford
69 Cobra 428 CJ Jerico 4 speed
NHRA C/Stock Eliminator 3032

Chad D

  • Full Member
  • ***
  • Posts: 113
    • View Profile
Re: Blair Patrick thanks for my Tunnelport for my 69 Torino Cobra project
« Reply #38 on: February 20, 2013, 04:03:22 PM »
Chad,
 No worries here. Its going to take a whole lot more than that to insult me. lol I'm all ears. I've never heard of PI but looking at the links you posted I still don't see anything that's more than 1000hz unless I missed it.

What are the issues with your friends clutch? What clutch is he running?

Pi Research is now Cosworth, news to me!  Here's one that I thought was on that page... obviously I wasn't paying attention:

http://www.cosworth.com/products/motorsport/data-loggers/sigma-lightweight-systems/

Cousin has this ECU, modded a bit by Menard Racing:

http://www.cosworth.com/products/motorsport/control-systems/engine-control-units/pectel-sq6m/

There's also an external data logger of provenance unknown to me (guessing Pi also) that interfaces with the ECU.

The clutch is a 'hybrid' to put it politely.  Car is a tube framed Opel, engine is a General Mayhem Ecoblecch, with a lightened aluminum SBC flywheel, Ram 8 inch billet clutch, DNE 5 speed, Dana 60 (5.13/spool) rear.  I'll probably burn in hell for mentioning all that on this board... apologies for the hijack, folks.

fe66comet

  • Guest
Re: Blair Patrick thanks for my Tunnelport for my 69 Torino Cobra project
« Reply #39 on: February 20, 2013, 06:01:09 PM »
MSD makes individual components and how much info do you need with a carbureted car with a non computer controlled trans. If you have a injection system then that is all built in anyhow. Nitrous staging, boost retard and A/F can all be controlled and recorded though a good ignition control. I honestly do not see adding all the extra weight and electrical load helping at all. My philosophy is keep it simple, keep it light and keep it dependable. Putting a desktop computer and a football field of circuits is not going to make the car faster, proper design and tuning does that.

69Cobra

  • Jr. Member
  • **
  • Posts: 40
  • A goal without a plan is just a wish
    • View Profile
Re: Blair Patrick thanks for my Tunnelport for my 69 Torino Cobra project
« Reply #40 on: February 20, 2013, 11:13:58 PM »
Chad,
 Below I copied their description of what looks to be their top of the line data logger and I still see 1khz sample rate and CAN technology being used here. Not to mention that phone number at the bottom lol where is that?

Data Loggers
01L-301000-L2
Omega L2
The Omega L2 Plus, Pro and Ultra range of upgradeable loggers are the latest addition to the Omega logger family, building on the success of the L2 platform in Formula Renault 2.0, World Series by Renault, TTA and as the specified FIA / ACO WEC scrutineering logger.
The Omega platform is exceptionally simple to use, and offers the user full configurability and control of analogue & digital inputs, logging table, alarms and qualifying mode for driver comparison. Configuration is via Cosworth's latest configuration software, Toolset, and all data is offloaded in Cosworth's market leading Toolbox analysis software.
Headline specifications include;
- Up to 16x 0-5V Analogue Inputs and 6x Digital Inputs
- Up to 2GB of logging memory, with fast offload via the onboard 100 BaseT Ethernet connection.
- Logging rates up to 1KHz
- Fully configurable "box-maths" - advanced on-board math capability with users able to configure channels to run on the box to calculate statistics and other calculations. For example;
o Calculation of accurate statistics - time in gear x, time on throttle, number of over revs etc.
o Brake Balance, Minimum Corner Speed and Maximum Straight Line Speed
o Complex alarms to minimise false occurrences - i.e. only flag a Low Pressure alarm after a number of instances and / or when any number of other conditions are true.
- Expandable - CAN nodes can be added for expanded I/O in test environments.
- Built-in accelerometers for track mapping & acceleration measurements and internal diagnostic channels for battery voltage and box temperature.
The L2 has reverse battery, over-voltage and load dump protection built in as standard, and sensor supply and signal ground pins are also protected against shorts to battery positive and negative. The enclosure for the unit is robust, offers Deutsch Autosport connectors and is environmentally rated to IP67.
Contact a representative if you are interested in purchasing this product.
> Request more information
> Call Us on +44 1954 253600
Kris Rachford
69 Cobra 428 CJ Jerico 4 speed
NHRA C/Stock Eliminator 3032

jayb

  • Administrator
  • Hero Member
  • *****
  • Posts: 7577
    • View Profile
    • FE Power
Re: Blair Patrick thanks for my Tunnelport for my 69 Torino Cobra project
« Reply #41 on: February 20, 2013, 11:18:25 PM »
The +44 is the country code for England.  Makes sense if it is Cosworth...
Jay Brown
- 1969 Mach 1, Drag Week 2005 Winner NA/BB, 511" FE (10.60s @ 129); Drag Week 2007 Runner-Up PA/BB, 490" Supercharged FE (9.35 @ 151)
- 1964 Ford Galaxie, Drag Week 2009 Winner Modified NA (9.50s @ 143), 585" SOHC
- 1969 Shelby Clone, Drag Week 2015 Winner Modified NA (Average 8.98 @ 149), 585" SOHC

   

69Cobra

  • Jr. Member
  • **
  • Posts: 40
  • A goal without a plan is just a wish
    • View Profile
Re: Blair Patrick thanks for my Tunnelport for my 69 Torino Cobra project
« Reply #42 on: February 20, 2013, 11:21:52 PM »
Yeah I was thinking the UK somewhere but didn't know for sure. Now all I can picture is the host off of Top Gear bashing all our cars.
Kris Rachford
69 Cobra 428 CJ Jerico 4 speed
NHRA C/Stock Eliminator 3032

69Cobra

  • Jr. Member
  • **
  • Posts: 40
  • A goal without a plan is just a wish
    • View Profile
Re: Blair Patrick thanks for my Tunnelport for my 69 Torino Cobra project
« Reply #43 on: February 20, 2013, 11:47:09 PM »
MSD makes individual components and how much info do you need with a carbureted car with a non computer controlled trans. If you have a injection system then that is all built in anyhow. Nitrous staging, boost retard and A/F can all be controlled and recorded though a good ignition control. I honestly do not see adding all the extra weight and electrical load helping at all. My philosophy is keep it simple, keep it light and keep it dependable. Putting a desktop computer and a football field of circuits is not going to make the car faster, proper design and tuning does that.

MSD will not log a clutch or driveshaft speed input, oil pressure, oil temp, water temp, shock travel, crank case vacuum, multiple 02's etc... There will not be extra weight as it will be lighter than having individual gauges for each item. The V300SD data logger weight 10 ounces and the Dash that is going to replace all the gauges including the tach weights about 1.lb. I don't know how much experience you have at racing but the more you can learn from each pass the better you are going to be in the end. Its all about knowledge and staying on top of your program. Proper design and tuning without actual data will not get you as far as proper design and tuning with accurate data. Hence the reason we use dyno's.
Kris Rachford
69 Cobra 428 CJ Jerico 4 speed
NHRA C/Stock Eliminator 3032

chris_r

  • Jr. Member
  • **
  • Posts: 82
    • View Profile
Re: Blair Patrick thanks for my Tunnelport for my 69 Torino Cobra project
« Reply #44 on: February 21, 2013, 12:54:10 AM »
Kris keep us in the loop on how the smartwire works out for you. Sounds like what i need myself.